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FOOD  INSPECTION  AND  ANALYSIS. 


FOR  THE  USE  OF  PUBLIC  ANALYSTS,  HEALTH 

OFFICERS,  SANITARY  CHEMISTS, 

AND  FOOD  ECONOMISTS. 


ALBERT   E.  LEACH,  S.B., 

Late  Chief  of  the  Denver  Food  and  Drug  Inspection  Laboratory,  Bureau  of  Chemistry, 

U.  S.  Department  of  Agriculture;    Late  Chief  Analyst  of  the  Massachusetts 

State  Board  of  Health. 

\ 

REVISED   AND   ENLARGED    BY 

ANDREW   L.  WINTON,  Ph.D., 

Chief  of  the  Chicago  Food  and  Drug  Inspection  Laboratory,  Bureau  of  Chemistry', 
U.  S.  Department  of  Agriculture. 


THIRD  EDITION,  FIRST   THOUSAND. 
TOTAL  ISSUE,   FIVE  THOUSAND. 


f 


NEW    YORK: 
JOHN   VVn.EY  &  SONS. 
London:  CHAPMAN  &  H^ALL,  Limited. 
1913. 


Copyright,  1904,  1909. 

BY 

ALBERT  E.  LEACH. 


First  Edition  Entered  at  Stationers'  Hall. 


Copyright,  1913. 

BY 

Mrs.  MARTHA   T.  LEACH. 


THE   SCIINTIFIC   PRESS 

IKMCRT   DnuMMOND  AND    COMPANV 

BHOOKLVN,    N.   V. 


L4tf 

1313 


Affectionately  Dedicated  to  the  Memory  of 
FORMER  Analyst  of  the  Massachusetts  State  Board  of  Health, 

WHOSE  lovable  PERSONALITY  AND  STERLING  INTEGRITY  WERE 

A  CONSTANT  INSPIRATION   DURING  MANY  YEARS 

OF  CLOSE  COMPANIONSHIP  TO 

THE  AUTHOR. 


PREFACE  TO  THIRD   EDITION. 


The  period  since  the  appearance  of  the  second  edition  has  been,  in 
America,  one  of  steady  progress  in  food  science  as  compared  with  the 
period  of  special  activity,  stimulated  by  federal  legislation,  immediately 
preceding  and  the  pioneer  period,  in  which  the  author  was  a  prominent 
figure,  that  led  to  the  publication  of  the  first  edition. 

Without  changing  the  general  plan  of  the  work,  which  ought  ever  to 
remain  as  a  monument  to  the  author's  remarkable  grasp  of  the  subject, 
new  matter  equivalent  to  about  80  pages,  not  including  some  40  pages 
changed  in  the  last  thousand  of  the  second  edition,  and  12  new  cuts,  have 
been  added.  The  size  of  the  work,  however,  has  been  increased  but  47 
pages,  as  much  anticjuated  matter  has  been  replaced  by  new,  thus  per- 
forming a  double  service  to  the  reader. 

Among  the  new  features  are  improved  general  methods  and  apparatus 
for  the  determination  of  moisture,  ash,  and  arsenic,  modem  apparatus  for 
the  Babcock  test,  processes  for  the  detection  of  foreign  fat  in  dairy  prod- 
ucts, methods  for  the  determination  of  ammonia  and  acidity  in  meat, 
and  of  sugars  in  cereal  products,  correction  of  Munson  and  Walker's  sugar 
table,  new  methods  for  vinegar  analysis  (including  glycerine  determina- 
tion), schemes  for  the  separation  of  food  colors,  a  subchapter  on  formic 
acid  (recently  introduced  as  a  preservative),  methods  for  the  analysis  of 
lemon  and  orange  oils,  a  summary  of  analyses  of  authentic  samples  of 
vanilla  extract,  and  a  complete  revision  of  the  final  chapter  on  fruit  and 
vegetable  products  with  new  sections  on  tomato  ketchup,  dried  fruits,  pre- 
serves (including  maraschino  cherries),  fruit  juices,  and  non-alcoholic  car- 
bonated beverages.  In  the  final  chapter  are  included  descriptions  of 
recent  methods  for  the  determination  of  tin,  vegetable  acids,  and  habit- 
forming  drugs,  and  for  the  detection  of  saponin,  also  microscopical 
methods  for  the  detection  of  spoilage. 

The  text  of  the  Federal  Pure  Food  Law,  as  amended  during  the 
present  year,  and  of  the  Meat  Inspection  Law,  are  added  for  ready 
reference  as  an  Appendix. 


Yi  PREFACE. 

The  substantial  work  of  Dr.  T.  B.  Osborne  In  the  subchapter  on 
proteins  and  of  Dr.  W.  D.  Bigelow  in  the  chapter  on  meats,  both  intro- 
duced in  the  second  edition,  appear  unchanged  in  the  present  edition,  and 
grateful  acknowledgment,  previously  expressed  by  the  author,  is  here 
repeated. 

The  revision  has  been  carried  out  with  the  generous  assistance  of  Dr. 
Kate  Barber  Winton  and  of  a  number  of  chemists  whose  methods,  duly 
credited,  appear  in  tlie  text. 

A.  L.  W. 
Chicago,  III.,  November,  191 2. 


PREFACE   TO   FIRST   EDITION. 


In  the  preparation  of  the  present  work,  the  requirements  of  the  public 
analyst  are  mainly  kept  in  view,  as  well  as  of  such  officials  as  naturally 
cooperate  with  him  in  carrying  out  the  provisions  of  the  laws  dealing 
with  the  suppression  of  food  adulteration  in  states  and  municipalities. 
To  this  end  special  prominence  is  given  to  the  nature  and  extent  of  adul- 
teration in  the  various  foods,  to  methods  of  analysis  for  the  detection  of 
adulterants,  and  to  some  extent  also  to  the  machinery  of  inspection. 

While  the  analyst  may  not  in  all  cases  have  directly  to  deal  with  the 
minutlcB  of  food  inspection,  his  work  is  so  closely  allied  therewith  that 
this  branch  of  the  subject  is  of  vital  interest  and  importance  to  him. 
Indeed,  in  many  smaller  cities  one  official  often  has  charge  of  the  entire 
work,  combining  the  duties  of  both  inspector  and  analyst. 

Endeavor  has  been  made,  furthermore,  to  deal  with  the  general  com- 
position of  foods,  and  to  give  such  analytical  processes  as  are  likely  to 
be  needed  by  the  sanitary  chemist,  or  by  the  student  who  wishes  to 
determine  the  proximate  components  of  food  materials. 

It  has  been  thought  best  to  include  brief  synopses  of  processes  of 
manufacture  or  preparation  of  certain  foods  and  food  materials,  in  cases 
where  impurities  might  be  suggested  incidental  to  their  preparation. 

In  view  of  the  fact  that  Massachusetts  was  the  pioneer  state  to  adopt, 
over  twenty  years  ago,  a  practical  system  of  food  and  drug  inspection, 
and  for  many  years  was  the  only  state  to  enjoy  such  a  system,  no  apology 
is  perhaps  needed  for  more  frequent  mention  of  Massachusetts  methods 
and  customs  than  those  of  many  other  states,  in  which  the  food  laws 
are  now  being  enforced  with  equal  zeal  and  efficiency. 

Considerable  attention  has  been  paid  in  the  following  pages  to  the 
use  of  the  microscope  in  food  analysis.     Of  the  figures  in  the  text  illus- 


Viu  PREFACE. 

trating  the  microscopical  structure  of  powdered  tea,  coffee,  cocoa,  and 
the  spices,  fifteen  have  been  reproduced  from  the  admirable  drawings 
of  Dr.  Josef  MocUer,  of  the  University  of  Graz,  Austria.  Acknowledg- 
ment is  gratefully  given  Dr.  ISIoeller  for  his  kind  consent  to  their  use. 

The  photomicrographs  in  half-tone,  forming  the  set  of  plates  at  the 
end  of  the  volume,  were  all  made  in  the  author's  laboratory,  and  may 
be  divided  into  three  classes:  ist,  illustrations  of  powdered  pure  foods 
and  food  products,  as  well  as  of  powdered  adulterants;  2d,  types  of 
adulterated  foods,  chosen  from  samples  collected  from  time  to  time  in 
the  routine  course  of  inspection;  and  3d,  photographs  of  permanently 
mounted  sections  of  foods  and  adulterants. 

While  recent  works  covering  the  whole  field  of  general  food  analysis 
are  comparatively  few,  the  number  of  treatises,  monographs,  government 
bulletins,  and  articles  scattered  through  the  journals,  dealing  with  special 
subjects  relative  to  food  and  its  inspection,  is  surprisingly  large,  and  from 
a  painstaking  review  of  these  much  information  has  been  culled,  for  which 
it  has  been  the  author's  intention  at  all  times  to  give  credit. 

Special  mention  should  here  be  made  of  the  valuable  publications  of 
the  U.  S.  Department  of  Agricuhure,  r3oth  the  bulletins  issued  from 
Washington,  and  those  from  the  various  experiment  stations,  an  ever- 
increasing  number  of  which  are  becoming  engaged  in  human  food 
work.  The  author  has  freely  drawn  from  these  sources,  and  especially 
from  the  data  and  material  furnished  by  his  coworkers  in  the  recent 
and  still  pending  labor  of  preparing  food  methods  for  the  Association  of 
Ofiicial  AgricuUural  Chemists,  and  he  wishes  to  extend  his  thanks  to 
all  of  them  for  their  assistance.  Appreciation  is  also  expressed  for  the 
care  and  discrimination  shown  by  Mr.  L.  L.  Poates  in  the  preparation  of 
the  cuts.  Thanks  are  especially  due  to  Mr.  Hermann  C.  Lythgoe, 
Assistant  Analyst  of  the  Massachusetts  State  Board  of  HeaUh,  for  his 
invaluable  cooperation,  and  to  Dr.  Thomas  M.  Drown  for  helpful  hints 
and  suggestions. 

BosTo.v,  M/\ss.,  July  i,  1904. 


TABLE    OF   CONTENTS. 


CHAPTER  I. 

PAGE 

Food  Analysis  and  Official  Control 1-13 

Introductory,  i.  Food  Analysis  from  the  Dietetic  Standpoint,  2.  Systematic 
Food  Inspection;  Functions  of  tlie  State  Analyst;  Standards  of  Purity;  Na- 
ture of  Analytical  Methods,  3-5.  Adulteration  of  Food,  5.  Misbranding,  6. 
A  Typical  System  of  Food  Inspection,  6-9.  Practical  Enforcement  of  the  Food 
Laws;  Publication;  Notification;  Prosecution,  10. 

References  on  Food  Inspection  and  Official  Control,  11. 

CHAPTER  II. 

The  Laboratory  and  its  Equipment 14-38 

Location,  14.  Floor;  Lighting;  Benches,  15.  Hoods,  16.  Sinks  and 
Drains,  17.  Steam  and  Electricity;  Suction  and  Blast,  19.  Apparatus,  20- 
25.  Reagents,  26-35.  Equivalents  of  Standard  Solutions;  36^37.  Indica- 
tors, 38. 

References  on  Laboratory  Equipment,  Reagents,  etc.,  58. 

CHAPTER  III. 

Food,  its  Functions,  Proximate  Components,  and  Nutritive  Value 39-52 

Nature  and  General  Composition  of  Food;  Fats,  39.  Protein,  and 
Classification  of  Nitrogenous  Bodies,  40.  Proteins,  their  Subdivisions,  Occur- 
rence, and  Characterstic  Tests,  40-45.  Amino  Acids,  etc.,  45.  Alkaloids; 
Nitrates;  Ammonia;  Lecithin;  Carbohydrates  and  their  Cla.ssification,  46. 
Organic  Acids;  Mineral  or  Inorganic  Materials;  Fuel  Value  of  Food; 
Bomb  Calorimeter,  47-48. 

References  on  Dietetics  and  Economy  of  Food,  49. 

CHAPTER  IV. 

General  Analytical  Methods .S3-80 

E.xpression  of  Results,  53-54.  Preparation  of  Sample,  55.  Specific  Gravity; 
Methods  and  Apparatus,  55-60.  Determination  of  Moisture,  61.  Deter- 
mination of  Ash,  62-63.  Continuous  E.xtraction  with  Volatile  .Solvents,  63-68. 
Separation  with  Immiscible  Solvents,  68.     Determination  of  Nitrogen,  69-73. 


X  TABLE   OF  CONTENTS. 

PAGE 

Determination   of  Free   .\mmonia;  Determination   of    Amido  Nitrogen,    74. 
Determination  of   Carbohydrates,   74.     Poisoned  Foods,   74.     Detection  and 
Determination  of  Arsenic,  74-77.      Colorometric  Analysis,  77.     Tintometer, 
78. 
References  on  General  Food  Analysis,  79. 

CHAPTER  V. 

The  Microscope  in  Food  Analysis 81-99 

Microscopical  vs.  Chemical  Analysis,  81.  Technique  of  Food  Microscopy, 
82.  Apparatus  and  Accessories,  82-84.  Preparation  of  \'egetable  Foods  for 
Microscopical  Examination,  85.  Miscroscopical  Diagnosis,  86.  Vegetable 
Tissues  and  Cell  Contents,  under  the  Microscope,  87-90.  ^licroscopical 
Reagents,  90-93.  Microchemical  Reactions,  90-93.  Photomicrography; 
Appurtenances  and  Methods,  93-98. 

References  on  the  Microscope  in  Food  Analysis,  98. 


CHAPTER  VI. 

The  Refr.actometer 100-123 

Butyro-refractometer,  loi.  Refractometer  Heater,  102.  Manipulation, 
102-104.  Equivalents  of  Refractive  Indices  and  Butyro-refractometer  Read- 
ings, 105-106.  Temperature  Correction,  107.  Abbe  Refractometer,  108. 
Construction;  Manipulation,  109-111.  Immersion  Refractometer,  111-112. 
Manipulation,  113-115.  Equivalents  of  Refractive  Indices  and  Immersion 
Refractometer  Readings,  116-119.  Strength  of  Solutions  by  Refractometer 
120.  Temperature  Corrections,  121. 
References  on  the  Refractometer,  122. 


CHAPTER  VII. 

Milk  and  Milk  Products 124-210 

Composition  and  Characteristics  of  Milk,  124.  Milk  Sugar;  Milk  Proteins, 
and  other  Nitrogenous  Bodies,  125.  Milk  Fat;  Citric  Acid;  Composition  of 
the  Ash,  126-127.  Fore  Milk  and  Strippings,  128.  Colostrum;  Frozen  Milk; 
Fermentations  of  Milk,  129.  Analysis  of  Milk,  130.  Specific  Gravity,  131-133. 
Total  S<^)lids,  132.  Ash,  134.  Fat,  by  Extraction,  by  Centrifugal,  and  by  Re- 
fractometric  Methods,  134-144.  Proteins;  Casein,  145.  Albumin;  Other 
Nitrogenous  Bodies,  146.  Milk  Sugar,  by  Optical  Methods,  147-149,  by 
Fehling's  Solution,  149-151.  Relation  Vjetween  the  Various  Milk  Constituents; 
Calculation  by  Formula?,  151-153.  Acidity,  153.  Boiled  Milk,  155.  Modi- 
fied Milk  and  its  Preparation,  155-157.  Prepared  Milk  Foods,  Milk  Powders, 
and  Artificial  Albuminous  Foods,  157-159.     Koumis,  158.     Kephir,  159. 

Milk  Adulteration  and  Inspection;  Milk  Standards,  159-161.  Forms  of 
Adulteration,  and  \'ariation  in  Standard,  161-162.  Rapid  Approximate 
Methods  of  Examination,  163-164.  I^xamination  of  Milk  Serum;  Constants, 
164-168.  Systematic  Routine  Examination,  168.  Analytical  Methods  for 
Solids,  Pat,  and  .Ash,  170-173.  Added  Foreign  Ingredients,  173.  Coloring 
Matters  and  their  Detection,  174-177.     Preservatives,  their  Relative  Efficiency 


TABLE  OF  CONTENTS.  xi 

PACE 

and   their   Detection,    177-185.     Added   Cane   Sugar,   and   Starch,    185.     Added 
Condensed  Milk;  Analysis  of  Sour  Milk,  186. 

Condensed  Milk;    Composition,  Standards,  Adulteration,  186-188.     Methods  of 
Analysis,  188-1QI.     Calculation  of  Fat  in  Original  Milk,  ig2. 

Cream;    Composition,  Standards,  .Adulterants,  Foreign  Fat,  iQ3-ig5.     Analyt- 
ical Methods,  195-1Q8. 

Ice  Cream;  Standard,  Fillers,  198-199.     Analytical  Methods,  199-201. 
Cheese;    Composition,  Varieties,  202.     Standards;    Adulteration,  203-204. 
Analytical  Methods,  204,  205.     Separation  and  Determination  of  Nitrogenous 
Bodies,  206,  207.     Lactic  Acid;   Milk  Sugar;   Foreign  Fat,  207. 
References  on  Milk  and  its  Products,  208. 


CHAPTER  VIII. 

Flesh  Foods 21 1-260 

Meat;  Structure  and  Composition,  211.  Proximate  Components  of  the 
Common  Meats,  212-217.  Meat  Inspection,  217.  Standards,  218.  Meat 
Preservatives,  218.  Curing,  219.  Use  of  Antiseptics;  Eflect  of  Cooking,  220. 
Canned  Meats,  221.  Sausages,  223-224.  Analytical  Methods,  225.  Fats 
of  Meats,  226-227.  Classification,  Separation,  and  Determination  of  Nitrog- 
enous Bodies,  226-231.  Determination  of  Gelatin,  231.  Determination  of 
Nitrates,  232.  Preservatives  and  their  Detection,  232.  Starch  in  Sausages, 
233.  Horseflesh  in  Sausages,  and  its  Detection,  234-238.  Muscle  Sugar,  238. 
Coloring  Matters  and  their  Detection,  238-239.     Detection  of  Frozen  Meat, 

Meat  Extracts;  Character  and  Standards,  240-241.  Composition,  242-244. 
Meat  Juices,  245.  Miscellaneous  Meat  Preparations,  246.  Methods  of 
Analysis,  246-249.  Separation  of  Nitrogenous  Compounds,  249-253.  Acidity, 
253.     Preservatives;  Glycerol,  254. 

Fish;  Structure,  Composition,  and  Methods  of  Analysis,  254-255.  Crus- 
taceans and  Mollusks,  256.  Floating  of  Shellfish;  Preservatives  in  Fish  and 
Oysters;  Colors,  257. 

Concentrated  Foods  for  Armies  and  Campers,  257. 

References  on  Flesh  Foods,  258. 


CHAPTER  IX. 

Eggs 261-270 

Nature  and  Composition,  261.  The  Egg  White  and  its  Nitrogenous  Com- 
pounds, 262.  Preparation  of  Albumin;  The  Egg  Yolk  and  its  Composition, 
263.  Composition  of  the  Ash,  264.  Analytical  Methods;  Determination  of 
Lecithin,  265.  Preservation  of  Eggs,  266.  Cold  Storage  Eggs,  267.  Physical 
Methods  of  Examination,  267.  Opened  Eggs;  Desiccated  Eggs,  268.  Egg 
Substitutes,  269.  Custard  Powders,  270. 
References  on  Eggs,  270. 


XI 1  TABLE  OF  CONTENTS. 

CHAPTER  X. 

PAGE 

Cereals  and  their  Prodi'cts,  Legumes,  Vegetables,  and  Fruits 271-364 

Composition  of  Cereals,  Vegetables,  Fruits,  and  Nuts,  271-276.  Methods 
of  Proximate  Analysis,  276-279.  Carbohydrates  of  Cereals,  279.  Starch; 
Detection,  \'arieties.  Classification,  Microscopical  Examination,  279-283. 
Starch  Determination,  by  Direct  Acid  Conversion  and  by  Diastase  Methods, 
283- JS4.  Sugars,  2S4-285.  Cellulose;  Crude  Fiber,  285.  Pentosans  and  their 
Determination,  285-204.  Separation  and  Determination  of  the  Carbohydrates  of 
Cereals,  205-206.  Proteins  of  Cereals  and  Vegetables;  Separation  and  Methods 
of  .\nalysis,  2o()-2o8.  Proteins  of  Wheat,  their  Separation  and  Determination, 
2oS-,^oo.  Proteins  of  Other  Cereals  and  Vegetables,  ,^00-301.  Ash  of  Cereals  and 
Vegetables;  Scheme  for  .\sh  .\nalysis,  301-305.  Sulphur;  Chlorine,  305.  Micros- 
copy of  Cereal  Products,  306-311. 

Flour;  Milling,  311.  Composition,  312.  Damaged  Flour;  Ergot,  313. 
Adulteration,  314.  Alum;  Bleaching,  315.  Inspection  and  Analysis;  Fine- 
ness, 316.  Color,  Absorption,  and  Dough  Tests,  317.  Expansion  of  Dough. 
318.  Baking  Tests,  317-319.  Proximate  Constituents;  Ash,  319.  Gluten; 
Protein;  Acidity,  320.  Detection  of  Bleaching;  Nitrites,  321.  Bamihl 
Gluten  Test,  322. 

Bread;  Composition;  Varieties,  323-325.  Methods  of  Kxaminilion,  325- 
326.     .\dulteration  of  Bread;  Alum,  326.     Cake,  327. 

Leavening  Materials;  Veast,  327.  Compressed  Veast;  Dry  Veast,  328. 
Com{K)sition  and  Microscopical  Examination,  329.  Yeast  Testing;  Available 
Carbon  Dioxide,  330.     Starch  in  Compressed  Yeast,  331. 

Chemical  Leavening  Materials;  Baking  Powders,  their  Classification  and 
Composition,  332-^^4.  Adulteration,  334.  Cream  of  Tartar  and  its  Adultera- 
tion, 335.  Analysis  of  Baking  Chemicals,  336.  Carbon  Dioxide,  336-339. 
Tartaric  .\cid,  339-343.  Starch,  343.  Aluminum  Salts,  344.  IJme;  Potash; 
So<la.  345.     Phosphoric  Acid;  Sul[)huric  .Vcid;   Ammonia;   Arsenic,  346. 

Semolina,  Macaroni,  and  Kdible  Pastes;  Noodles,  347-348.  Adulteration,- 
Analytical  Methods;  Lecithin-Phosphoric  .Vcid,  349.  Colors,  349-352.  Shredded 
Wheat,  352. 

Prepared  Cereal  Breakfast  Foods;  Nature  and  Composition,  352-354.  Analyt- 
ical Methods.  354. 

Infants'  and  Invalids'  Foods,  354.  Classification,  355.  Composition,  356. 
Diabetic  Foods,  357-358.     Analytical  Methods,  359-360. 

Rcf'-'renccs  on  Cereals,  Vegetables,  etc.,  361. 

References  on  Leavening  Materials,  364. 


CHAPTER    XL 

Tka,  Coffke,  and  Cocoa 365-407 

Tea;  Varieties,  Method  of  Manufacture,  Compositions,  365-36S.  .Analytical 
Methods,  368.  Kxtract;  Tannin.  370-372.  Thein,  or  Caffeine,  372-374.  Adul- 
teration and  Detection  of  .Adulterants;  Facing,  374.  Spent  Leaves,  375.  Foreign 
I^eavcs;  Stems  and  Fragments,  376.  Added  Aslringcnts;  Tea  Tablets,  377. 
Microscopical  Structure.  37S. 

Coffee;  .Nature.  Composition,  Kfifect  of  Roasting,  379-381.  Substitutes 
and     Adulterants,     382.     .Analytical     Methods;      Caffetanic     Acid,     382-383. 


TABLE   OF  CONTENTS.  xiu 


PACE 


Caffeine,  384.  Adulteration;  Imitation  Coffee;  Coloring,  384.  Glazing; 
Methods,  385.  Microscopical  Plxamination,  386.  Chicory;  its  Microscopical 
Structure,  386-388.  Composition  of  Chicory,  and  its  Determination  in  Coffee, 
389.     Date  Stones;   Hygienic  Coffee;   Substitutes,  390-392. 

Cocoa  and  Cocoa  Products;  Composition,  Methods  of  Manufacture,  392- 
395.  Theobromine  and  Nitrogenous  Substances,  396.  Milk  Chocolate;  Com- 
pounds, 397.  Analytical  Methods,  398.  Starch;  Sucrose;  Lactose,  399. 
Theobromine  and  Caffeine,  400-401.  Adulteration,  and  Standards  of  Purity, 
402.  Addition  of  Alkali,  Microscopical  Structure,  403-404.  Cocoa  Shells; 
Added  Starch,  Sugar,  Fat  and  Colors,  405. 

References  on  Tea,  Coffee,  and  Cocoa,  406. 


CHAPTER  XII. 

Spices 408-470 

Methods  of  Proximate  Analysis  Common  to  all  the  Spices,  408.  Moisture; 
Ash;  Ether,  and  Alcohol  Extract;  Nitrogen;  Starch;  Crude  Fiber;  Volatile 
0115,409-411.     Microscopical  Examination,  412.     Spice  Adulterants,  412-413. 

Cloves;  Composition,  412-415.  Tannin,  415.  Microscopical  Examination, 
416.  Clove  Stems,  417.  Adulteration  and  Standard  of  Purity;  Exhausted 
Cloves,  418.     Cocoanut  Shells,  419. 

Allspice;  Composition,  420.  Tannin  Equivalent,  421.  Microscopical 
Structure,  422-423.     Adulteration  and  Standard  of  Purity,  424. 

Cassia  and  Cinnamon;  Composition,  424-425.  Microscopical  Structure, 
426-427.     Adulterants;  Standard,  428.     Foreign  Bark,  428. 

Pepper;  Composition,  428-432.  Nitrogen  Determination,  432.  Piperin, 
433.  Microscopical  Examination,  433-434.  Adulteration  and  Standards,  435. 
Pepper  Shells  and  Dust,  435.  Olive  Stones,  436.  Buckwheat,  437.  Eong 
Pepper,  438. 

Red  Pepper;  (Cayenne,  Paprika,  etc.).  Nature;  Varieties:  Composition, 
439-441;  Microscopical  Structure,  441-443.  Adulteration,  443-445.  Added 
Oil  in  Paprika,  445. 

Ginger;  Composition,  445-446.  E.xhausted  Ginger,  and  its  Detection,  447- 
448.     Microscopical  Structure,  449.     Adulteration  and  Standard,  450. 

Turmeric;  Composition,    450.     Microscopical    Structure,    451.     Detection, 

443- 

Mustard;  Composition,  Preparation,  453-456.  Mustard  Oil  Determina- 
tion, 457.  Microscopical  Structure,  458.  Adulteration  and  Standards;  Charlock, 
459-460.  Coloring  Matter,  460.  Prepared  Mustard;  Composition,  Adulteration, 
460.     Analytical  Methods,  461. 

Nutmeg  and  Mace;  Composition  of  Nutmeg.  462-463.  Microscopical  Struc- 
ture of  Nutmeg;  Adulteration;  Standard  of  Purity,  464.  Composition  of  Mace, 
465.  Microscopical  Structure;  Adulteration;  Standard,  466.  Bombay  or  Wild 
Mace  and  its  Detection,  467.     Macassar  Mace,  468. 

References  on  Spices,  468. 


xiv  T/tBLE  OF  CONTENTS. 

CHAPTER  XIII. 

PAGB 

Edible  Oils  and  Fats 471-564 

Nature  and  Properties,  471.  Fatty  Acids,  471-472.  Saponification,  472. 
Analysis;  Rancidity;  Judgment  as  to  Purity;  Filtering,  Weighing,  and 
Measuring  Fats,  473.  Specific  Gravity,  474-476.  \'iscosity,  477.  Melting- 
point,  4S0.  Reichert-Meissl  Process  for  Volatile  Fatty  Acids,  481-482.  Po- 
lenske  Number,  483.  Soluble  and  Insoluble  Fatty  Acids,  484-486.  Saponifica- 
tion Number,  486.  Iodine  Absorption  Number;  Hiibl's  Method,  487-490. 
Hanus's  Method,  491.  Wijs's  Method,  492.  Bromine  Apsorption  Number, 
492-493.  Thermal  Tests,  493.  Maumene  Test,  494.  Bromination  Test, 494- 
497.  The  Acetyl  \'alue,  497-498.  The  Valenta  and  Klaidin  Tests,  499. 
Free  Fatty  Acids,  500.  Titer  Test,  500-501.  Unsaponifiable  Matter,  501. 
Cholesterol  and  Phytosterol,  502.  Separation  and  Crystallization,  503-506. 
Burner's  Phytosterol  Acetate  Test,  507.  Constants  of  Edible  Oils  and  Fats, 
508-509.  Parraffin;  Microscopical  E.xaminaltion  of  Oils  and  Fats,  510. 
Olive  Oil,  511.  Composition  and  Adulteration,  512.  Standards,  513.  Tests 
for  Adulteration,  513-515.  Cottonseed  Oil,  516.  Bechi's  Test,  517.  Hal- 
phen's  Test,  518.  Sesame  Oil,  518.  Adulterants  and  Tests,  519.  Rape  Oil, 
520.  Tests,  521.  Corn  Oil,  521.  Sitosterol,  522.  Peanut  Oil,  522.  Adul- 
terants; Renard's  Method,  523.  Bellier's  Method,  524.  Mustard  Oil,  525. 
Poppyseed  Oil,  526.  Sunflower  Oil,  526.  Rosin  Oil,  527.  Cocoanut  Oil,  528. 
Cocoa  Butter;  Tallow,  529. 

Butter,  529.  Composition,  530.  Effects  of  Feeding,  531.  Analytical 
Methods,  531.  Water,  531-533.  Fat,  533.  Ash;  Casein;  Milk  Sugar; 
Lactic  Acid;  Salt,  534.  Standard  Butter  Fat,  535.  Adulteration,  535. 
Colors,  535-537.  Preservatives,  538-539.  Renovated  or  Process  Butter,  540. 
Oleomargarine;  Manufacture,  541.  Coloring;  Detection  of  Palm  Oil,  542. 
Adulterants;  Healthfulness,  543.  Distinction  from  Butter,  544.  Distin- 
guishing Tests  for  Butter,  Process  Butter,  and  Oleomargarine,  546.  Butyro- 
refractometer,  546-548.  Reichert-Meissl  Number;  Specific  Gravity;  P'oam 
Test,  549.  Milk  Test,  550.  Curd  Tests,  551.  Microscopical  Examination, 
552-553-     Foreign  Oils,  554. 

Lard,  554.  Composition;  Lard  Oil,  555.  Compound  Lard;  Standards; 
Adulteration,  556.  Foreign  Oils,  557.  Microscopical  E.xamination,  557-558. 
Analysis  of  Lard  and  Lard  Substitutes,  559.     Effects  of  Feeding,  560. 

References  on  Edible  Oils  and  Fats,  561.  References  on  Butter,  562.  Refer- 
ences on  Lard,  563. 


CHAPTER  XIV. 

Sugar  and  SArrnARisE  Products 565-652 

Nature  and  Cla.ssification,  565.  Cane  Sugar;  Standard,  566.  Sugar  Cane; 
Manufacture  of  Cane  Sugar,  567.  Compxisition  of  Cane  Sugar  Products,  568. 
Sugar  Beet;  Manufacture  of  Beet  Sugar,  569.  Refining  Sugar;  Maple  Pro- 
ducts, 750.  Compositions,  Standards,  and  Adulteration  of  Maple  Products, 
571-572.  Sorghum,  573.  Grape  Sugar,  573.  Levulose;  Malt  Sugar,  574. 
Dextrin;  Commercial  Glucose,  575.  Standards  and  Healthfulness  of  Glucose, 
576.     Milk  Sugar;  RafTinose,  577. 


TABLE   OF  CONTENTS. 


The  Polariscope  and  Saccharimetry.  578-583.  Comparison  of  Scales  and 
Normal  Weights,  583.     Specific  Rotary  Power;  Birotation,  584. 

Analysis  of  Cane  Sugar  and  its  Products;  Tests  for  Sucrose,  585.  Moisture; 
Ash;  Non-sugars;  Sucrose  Determination  by  Polariscope,  586-587.  Inversion; 
Clerget's  Formula,  588.  Detection  and  Determination  of  Invert  Sugar,  589. 
Ultramarine  in  Sugar;  Copper  Reduction,  590.  Volumetric  Fehling  Process, 
591-592.  Gravimetric  Fehling  Methods,  593.  Defren-O'Sullivan  Method, 
594-597.  Munson  and  Walker  Method,  598-607.  Allihn  Method;  Elec- 
trolytic Apparatus  608-612.     Sucrose  Determination  by  Fehling  Solution,  612. 

Analysis  of  Molasses  and  Syrups,  613.  Solids;  Ash;  Polarization,  613- 
620.  Double  Dilution  Method  of  Polarizing;  Rafimose  Determination,  620. 
Adulteration  of  Molasses  and  Standards,  621.  Glucose  Determination,  621- 
624.     Ashing  Saccharine  Products,  624.     Tin  Determination,  625. 

Separation  and  Determination  of  Various  Sugars,  625-626. 

Analysis  of  Maple  Products,  627.  Moisture;  Ash;  Malic  Acid  Value,  627, 
Lead  Number,  628.     Hortvet  Number,  628-630.     Sy's  Method,  630. 

Analysis  of  Glucose;  Polarization  Formulae,  630-631.  Dextrin;  Ash;  Sulphurous 
Acid,  632.     Arsenic,  633. 

Honey;  European,  633.  Canadian;  American;  Hawaiian,  634-635. 
Adulteration,  636-638. 

Analysis  of  Honey;  Moisture;  Ash;  Polarization,  639.  Reducing  Sugars; 
Levulose;  Dextrose;  Sucrose;  Dextrin,  640.  Acids;  Glucose,  641.  Invert 
Sugar;  Distinction  of  Honeydew  from  Glucose,  642. 

Confectionery;  Standard;  Adulteration;  Colors,  645.  Analysis  of  Con- 
fectionery; Mineral  Adulterants,  646.  Ether  E.xtract;  Paraffine,  647. 
Starch;  Polarization,  648.     Alcohol;  Colors;  Arsenic,  649. 

References  on  Sugars,  650. 


CHAPTER  XV. 

Alcoholic  Beverages 653-758 

Alcoholic  Fermentation,  653.  Alcoholic  Liquors  and  State  Control,  654. 
Liquor  Inspection,  655-656.  Analytical  Methods  common  to  all  Liquors; 
Specific  Gravity,  657.  Detection  and  Determination  of  Alcohol,  657-660. 
Alcohol  Tables,  661-674.  The  Ebulioscope,  675-676.  Extract;  Ash;  Arti- 
ficial Sweeteners,  677. 

Fermented  Liquors;  Cider,  678.  Manufacture  and  Composition,  678-681. 
Adulteration,  682.  Perry,  683.  Wine,  684.  Classification  of  Wines,  685. 
Composition  and  Varieties,  686-689.  Standards,  689-691.  Adulteration, 
691-695.  Analytical  Methods  for  Wine;  Extract;  Acidity,  696.  Extract 
Table,  697-699.  Tartaric  Acid,  701.  Malic  Acid,  702.  Sugars;  Glycerin, 
703.     Tannin,    704.     Foreign  Colors,    704-706. 

Malt  Liquors;  Beer,  707.  Varieties  of  Beer  and  .-Me,  708.  Composition, 
709.  Malt  and  Hop  Substitutes,  710.  Adulteration  and  Standards,  711. 
Malted  vs.  Non-malted  Liquors,  712.  Preser\'atives;  Arsenic,  713.  Tem- 
perance Beers,  714.  .Analytical  Methods,  714.  .Alcohol,  715.  Extract,  715- 
722.  Original  Gravity,  722-724.  Sugars;  Dextrin;  Glycerine;  .Acids,  724. 
Protein;  Phosphoric  Acid,  725.  Carbon  Dioxide,  726.  Bitter  Principles,  726- 
727.     Arsenic,  728.     Malt  Extract,  729. 


X\-i  T.-4BLE  OF  CONTENTS. 

PAGE 

Distilled  Liquors;  Standards  for  Spirits,  730.  Fusel  Oil,  731.  Whiskey,  731. 
Manufacture.  731-732.  Standards,  733-734-  Composition,  734-737-  Adultera- 
tion. 73S.  Brandy;  Manufacture;  Composition.  739.  Standards,  740.  Adul- 
teration. 741.  Rum;  Composition,  742.  Standards.  742-743.  Gin;  Composi- 
tion, 744.  Analytical  Methods  for  Distilled  Liquors;  Extract;  Acids;  Esters; 
Aldehydes,  745.  Furfural.  746.  Fusel  Oil,  746-749.  IMethyl  Alcohol,  749-752. 
Caramel,  752-753.     Opalescence  Test,  753. 

Liqueurs  and  Cordials.  754.     Analysis  of  Liqueurs,  755. 

References  on  Alcoholic  Beverages;  on  Beer,  756. 

References  on  Cider  and  Wine,  757;  on  Distilled  Liquors,  758. 


CHAPTER   XVL 

VlNEG.\R 759-781 

.Acetic  Fermentation;  \'arieties  of  Vinegar,  759.  Manufacture  and  Compo- 
sition, 760-761.  Cider  Vinegar,  760.  Wine  Vinegar,  761.  Malt  Vinegar,  762. 
Spirit.  Glucose,  and  Molasses  Vinegars,  763.  Wood  Vinegar,  764.  Analytical 
Methods;  Density;  Extract;  Ash;  Phosphoric  Acid,  764.  Nitrogen;  Acidity, 
765.  .\lcohol;  Mineral  Acids,  766.  Malic  Acid,  767.  Lead  Precipitate,  768. 
Potassium  Tartrate;  Sugars,  769.     Pentosans,  770.     Glycerine,  770-772. 

.Adulteration  of  \'inegar;    Standards,   772-773.     Artificial  Cider  Vinegar,   774. 
Character  of  Residue  and  .Ash,  774-775.     Character  of  Sugars,  776.     Tests,  777. 
Composition  of  Artificial  Cider  Vinegars,   778.     Detection  of  .Adulterants,  and 
Mineral  Impurities,  779-780. 
References  on  Vinegar,  780, 

CHAPTER  XVn.  ^^. 

Artifici.^l  Food  Colors 782-820 

Extent  of  Use;  Objectionable  Features,  782.  Toxic  Efifects,  783.  Harmful 
Mineral  Colors,  784.  Harmful  Organic  Colors,  785.  Harmless  Mineral  Colors; 
Harmless  Organic  Colors,  786-788.     Use  of  Colors  in  Confectionery,  788. 

A'egetable  Colors,  789-791.  Special  Tests;  Orchil;  Logwood;  Turmeric,  791. 
Caramel;   Indigo,  792.     Cochineal,  792. 

Mineral  Pigments;   Prussian  Blue,  792.     Ultramarine;   Lead  Chromate,  793. 

Coal-tar  Colors,  793.  Allowed  Colors,  794.  Detection  in  Food;  Basic  and 
Acid  Dyes;  Wool  Dyeing,  795.  Double  Dyeing  Method,  796.  Vegetable  Colors 
on  Wool;  Extraction  of  Colors  by  Immiscible  Solvents,  797.  Separation  with 
Ether.  798.  Special  Tests,  799.  Classification  and  Identification  of  Coal-tar  Dyes; 
Rota's  Scheme,  799-804.  Direct  Identification  of  Colors,  805.  Table  of  Reactions 
for  Colors  on  the  Fiber,  806-813.  Reagents,  814.  Separation  and  Identification  of 
Allowed  and  -Acid  Colors,  814.  Price's  Scheme,  815.  Mathewson's  Tables,  816-818. 
Analysis  of  Colors,  818.     Solubility  Tables,  818. 

References  on  Colors,  819. 

CII.VPTER   XVIII. 

Food  Preservatives 821-849 

PrcscfN'ation  of  Food,  821.  Regulation  of  Antiseptics,  822.  Commercial  Food 
Preservatives,  823.  Formaldehyde,  824.  Determination  in  Preservatives,  825. 
Detection   in    Food,   826.     Determination,   827.     Boric   Acid;     Determination   in 


TABLE   OF  CONTENTS.  XVU 


Preservatives,  827.  Detection  in  Foods,  828.  Determination,  829-830.  Salicylic 
Acid;.  Detection,  831.  Determination,  832.  Benzoic  Acid,  833.  Detection,  834- 
835.  Determination,  835-839.  Sulphurous  -Acid,  839.  Detection;  Determina- 
tion, 840.  Formic  Acid;  Detection,  841.  Determination,  842.  Fluorides,  Fluo- 
silicates,  Fluoborates,  843-844.  Beta-Napthhol;  Detection,  845.  Asaprol  or 
Abrastol,  845.     Detection,  846. 

References  on  Preservatives  and  their  Use  in  Food,  846. 


CHAPTER  XIX. 

Artificial  Sweeteners 850-856 

E.xtent  of  Use;    Saccharin,  850.     Detection  of  Saccharin,  851.     Determination, 
852. 

Dulcin;  Detection,  853.     Determination  of  Dulcin,  854.     Glucin,  855. 
References  on  Artificial  Sweeteners,  855. 


CHAPTER  XX. 

Flavoring  Extracts  and  their  Substitutes 857-899 

Vanilla  Extract,  857.  Vanilla  Bean,  857.  Composition,  858.  Vanillin; 
Exhausted  Vanilla  Bean,  859.  Composition  of  Vanilla  Extract,  859-861.  Tonka 
Bean,  860.  Coumarin;  Standards;  Adulteration  of  Vanilla  Extract,  862.  Arti- 
ficial Extracts,  863.  Detection  of  Artificial  Extracts,  864.  Determination  of 
Vanillin  and  Coumarin,  865-867.  Tests  for  Coumarin;  Vanillin  and  Coumarin 
under  the  Microscope;  Normal  Lead  Number,  867.  Acetanilide,  868.  Glycerin; 
Alcohol;  Caramel,  869.     Limits;  Colors,  870. 

Lemon  Extract,  870.  Standards,  870.  Adulteration,  871.  Analytical  Methods; 
Determination  of  Lemon  Oil,  872-875.  Alcohol;  Total  Aldehydes,  875.  Citral, 
877.  Methyl  Alcohol;  Colors,  878.  Solids;  Ash;  Glycerin;  Examination  of 
Lemon  Oil,  879.  Constants  of  Lemon  and  other  Oils,  880.  Citral,  Citronellal, 
and  other  Adulterants,  88r.  Lemon  Oil;  .Analytical  Methods;  Density;  Refrac- 
tion; Rotation;  Citral,  882.  Aldehydes;  Physical  Constants;  Pinene;  Alcohol, 
883. 

Orange  Extract,  884.  Almond  Extract,  884.  Benzaldehyde;  Standard,  885. 
Adulteration;  Analytical  Methods;  Determination  of  Benzaldehyde,  886.  Nitro- 
benzol,  887.  Distinction  and  Separation  from  Benzaldehyde;  Artificial  Benzal- 
dehyde; Alcohol;  Hydrocyanic  Acid,  888.  Wintergreen  Extract;  Standards,  889. 
Adulteration;  Determination  of  Wintergreen  Oil;  Peppermint  Extract;  Pepper- 
mint Oil,  890.  Standards;  Analytical  Methods;  Spearmint  Extract,  891.  Spice 
Extracts;  Standards,  892.  Analytical  Methods,  893-894.  Rose  Extract;  Stand- 
ards; Determination  of  Rose  Oil,  895.  Imitation  Fruit  Flavors,  895-897.  Deter- 
mination of  Esters,  898. 

References  on  Flavoring  Extracts,  898. 


CHAPTER   XXI. 

Vegetable  and  Fruit  Products 900-964 

Canned  Vegetables  and  Fruits;    Method  of  Canning,  900-901.     Composition, 
902.  Decomposition   and   Detection   of   Spoiled    Cans,   902.     Gases   from    Spoiled        ^ 


X\'iii  TABLE  OF  CONTENTS. 


Cans,  oo,^  Metallic  Impurities,  904.  Action  of  Fruit  Acids  on  Tin  Plate,  905- 
90S.  Salts  of  Lead.  ooS.  Salts  of  Zinc  and  Copper,  909-pio.  Salts  of  Nickel; 
Toxic  EtTects  of  Metallic  Salts,  911.  Preservatives;  Soaked  Goods,  912.  Analyt- 
ical Methods;  Proximate  Analysis;  Lead  in  Tin  Alloy,  913.  Tin,  Copper,  Lead, 
Zinc,  and  Nickel.  914-019. 

Ketchup,  910.  Standards;  Process  of  Manufacture,  919.  Composition; 
Decayed  >L-itcrial;  Refuse,  920.  Foreign  Pulp;  Preservatives;  Colors;  Analytical 
Methods;  Solids,  921.  Sand;  Sugars,  922.  Citric  and  Lactic  Acids,  923.  Micro- 
scopic Examination,  924-925. 

Pickles,  925-926.    Adulteration,  926.     Horseradish,  927. 

Preser\-es,  927.  Fruit  Butter;  Mince  Meat,  927-928.  Pie  Filling;  Maraschino 
Cherries,  92S-929. 

Jams  and  Jellies,  930.  Composition;  .Adulteration,  931-934.  Compounds; 
Imitations,  936.  Analytical  Methods;  Solids,  936.  Ash;  Acidity;  Protein,  937. 
Sugars.  938-940.  Glucose;  Dextrin,  940.  Alcohol  Precipitate;  Organic  Acids,  941. 
Citric  Acid;  Colors;  Preservatives;  Sweeteners,  942.  Starch;  Gelatin;  Agar-agar; 
Apple  Pulp,  943.     Fruit  Tissues,  944. 

Dried  Fruits,  944.  Lye  Treatment;  Sulphuring;  Moisture;  Spoilage,  945. 
Zinc;  Analytical  Methods,  946. 

Fruit  Juices,  946-947.  Grape  Juice,  947.  Sweet  Cider;  Lime  Juice,  948. 
Analytical  Methods;  Acidity;  Tartaric  and  Malic  Acids,  949-950.  Citric  Acid, 
951.     Fruit  Syrups,  052. 

Non-Alcoholic  Carbonated  Beverages,  952.  Soda  Water,  952-953.  Syrups,  953. 
Bottled  Beverages;  Sweeteners,  954.  Acids;  Preservatives;  Colors;  Foam  Pro- 
ducers; Habit-forming  Drugs,  955.  Analytical  Methods;  Solids;  Ash;  Acids; 
Sugars;  Flavors;  Colors;  Preservatives;  Sweeteners;  Alcohol,  956.  Saponin, 
956-958.     Caffein;  Cocaine,  958-961. 

References  on  Vegetable  and  Fruit  Products,  961. 


APPENDIX. 

The  Food  and  Drugs  Act,  965.    The  Meat  Inspection  Law,  969. 


TABLE  OF   CONTENTS.:/  XIX 

PLATES  I-XL. 
Photomicrographs  of  Pure  and  Adulterated  Foods  and  of  Adulterants. 

Cereals:  Barley,  I.  Buckwheat,  II,  III.  Corn,  III,  IV.  Oat,  IV,  V.  Rice,  V, 
VI.     Rye,  VI,  VII.     Wheat,  VIII. 

Legumes:  Bean,  IX.     Lentil,  IX,  X.     Pea,  X,  XL 

Miscellaneous  Starches:  Potato;  Arrowroot;  Tapioca,  XII.  Turmeric;  Sago,  XIIL 
Cofifee,  XIV,  XV.     Chicory,  XV,  XVL     Cocoa,  XVI,  XVII.     Tea,  XVIII. 

Spices:  Allspice,  XVIII,  XIX.  Cassia,  Cinnamon,  XX-XXII.  Cayenne,  XXII- 
XXIV.  Cloves;  Clove  Stems,  XXIV-XXVII.  Ginger,  XXVII-XXIX.  Mace,  XXIX. 
Nutmeg,  XXX.     Mustard,  XXXI-XXXIII.     Pepper,  XXXIII-XXXVI. 

Spice  Adulterants:  Olive  Stones;  Cocoanut  Shells,  XXXVI.  Elm  Bark;  Sawdust; 
Pine  Wood,  XXXVII. 

Edible  Fals:  Pure  Butter;  Renovated  Butter;  Oleomargarine,  XXXVIII.  Lard 
Stearin,  XXXIX.     Beef  Stearin,  XL. 


FOOD   INSPECTION  AND  ANALYSIS. 


CHAPTER  I. 
FOOD  ANALYSIS  AND   OFFICIAL  CONTROL. 

INTRODUCTORY. 

The  general  subject  of  food  analysis,  in  so  far  as  the  public  health  is 
concerned,  is  to  be  considered  from  two  somewhat  different  standpoints: 
first,  from  the  outlook  of  the  government,  state,  or  municipal  analyst,  whose 
mission  it  is  to  ascertain  whether  or  not  the  food  may  properly  be  con- 
sidered pure  or  free  from  adulteration ;  and  second,  from  the  point  of  view 
of  the  food  economist,  whose  aim  is  to  determine  its  actual  composition 
and  nutritive  value.  The  one  protects  against  fraud  and  injury,  the 
other  furnishes  data  for  the  arrangement  of  dietaries  and  for  an  intelligent 
conception  of  the  role  which  the  various  nutrients  play  in  the  metabolism 
of  matter  and  energy  in  the  body.  The  two  fields  are  as  a  rule  distinct  each 
from  the  other,  often  involving,  in  the  examination  of  the  food,  diflferent 
methods  of  procedure. 

Official  Control  of  Food. — In  view  of  the  importance  of  the  consideration 
of  food  with  reference  to  its  purity,  an  ever-increasing  number  of  states 
have  realized  the  necessity  of  protecting  their  citizens  from  the  unscrupu- 
lous manufacturers  who  in  various  lines  arc  seeking  to  produce  cheaper 
or  inferior  articles  of  food  in  close  imitation  of  pure  goods.  IMany  of 
the  states  have  laws  in  accordance  with  which  the  sale  of  such  impure- 
or  adulterated  foods  is  made  a  criminal  ofifense,  and  some,  but  not  all! 
of  these,  are  provided  with  public  analysts  and  other  officers  to  enforce 
these  laws  and  punish  the  offenders.  Numerous  communities  are  awake 
to  the  importance  of  municipal  control  of  such  commonly  used  articles 
of  food  as  milk,  butter,  and  vinegar,  and  in  many  cases  have  machinery 
of  their  own  for  regulating  the  sale  of  these  foods. 


2  FOOD   INSPECTION   AND  ANALYSIS. 

Since  January  i,  1907,  the  federal  government  has  been  actively  en- 
gaged in  the  enforcement  of  the  national  food  law  of  June  30,  igo6,  through 
the  Bureau  of  Chemistry  of  the  U.  S.  Department  of  Agriculture.  In 
addition  to  the  central  laboratories  of  this  Bureau  at  Washington,  upwards 
of  20  branch  laboratories  have  been  established  in  the  principal  cities  of 
the  United  States  to  enforce  the  provisions  of  the  national  law  which  regu- 
lates interstate  commerce  in  foods,  as  well  as  their  manufacture  and  sale 
in  the  territories  and  the  District  of  Columbia,  and  their  importation  from 
foreign  countries. 

Food  Analysis  from  the  Dietetic  Standpoint. — The  study  of  the  prin- 
ciples of  diclclics  has  been  given  increased  attention  during  the  last  decade 
in  the  curricula  of  many  of  the  technical  schools  and  colleges.  Much 
has  been  accomphshed  by  certain  of  the  state  experiment  stations  working 
as  a  rule  in  connection  with  the  United  States  Department  of  Agriculture 
along  this  Une.  Investigations  of  this  character  are  especially  valuable, 
and  are  indeed  rendered  necessar)'  by  the  general  tendency  of  the  modern 
physician  to  regard  the  hygienic  treatment  of  disease,  especially  with 
reference  to  the  matter  of  diet,  as  often  of  far  greater  importance  than 
the  mere  administering  of  drugs. 

The  food  economist  studies  the  \'arying  conditions  of  age,  sex,  occupa- 
tion, environment,  and  health  among  his  fellow  men,  with  a  view  to  show- 
ing what  f(;ods  are  best  adaj)ted  to  supply  the  sj)ecial  requirements  of 
various  classes.  The  (juantity  and  ])r()])()rtion  of  protein,  fat  and  carbo- 
hydrates, or  of  fuel  value  best  suited  for  the  daily  consumption  of  a  given 
class  or  individual  having  been  determined,  dietaries  are  made  up  from 
various  food  materials  to  supply  the  need  with  reference  as  far  as  possible 
to  the  taste  and  means  of  the  consumer. 

Exj)criments  are  made  on  families,  clubs,  or  individuals,  representing 
various  typical  conditions  of  life,  and  extending  over  a  given  period,  dur- 
ing which  records  are  kept  of  the  available  food  materials  on  hand  and 
received  during  the  term  of  the  experiment,  as  well  as  of  those  remaining 
at  the  end.  In  the  case  of  individuals,  additional  records  may  be  kept 
of  the  amount  and  composition  of  the  urine  and  feces.  From  such  data 
the  physiological  chemist  calculates  the  amount  of  nutrients  utilized, 
and  studies  the  metabolism  of  material  in  the  human  body. 

Up  to  this  point  no  ver)'  extensive  apparatus  is  required,  but  if  in 
addition  the  income  and  outgo  of  heat  and  energy  are  to  be  studied,  which 
are  impfjrtant  to  a  complete  investigation  of  the  economy  of  food  in  the 
bofly,  the  student  will  require  a  respiration  calorimeter  and  its  appurte- 


FOOD  ANALYSIS    AND  OFFICIAL   CONTROL.  3 

nances.  The  calorimeter  is  so  constructed  that  an  individual  may  be 
confined  therein  for  a  term  of  days  under  close  observation  and  with 
carefully  regulated  conditions.  Such  an  equipment  involves  a  large 
expenditure  and  is  to  be  found  in  but  few  laboratories. 

It  is  not  the  ])urpose  of  the  present  work  to  go  beyond  the  strictly 
chemical  or  physical  processes  involved  in  making  the  analyses  by  which 
the  proximate  components  of  the  foods  arc  determined.  For  more  com- 
plete information  in  the  field  of  dietary  studies  and  the  metabolism  of 
matter  and  energy  in  the  body,  the  student  is  referred  especially  to  the 
investigations  of  Atwater  and  his  coworkers,  as  published  in  the  annual 
reports  of  the  Storrs  Experiment  Station  at  Middletown,  and  in  the  bulle- 
tins of  the  U.  S.  Department  of  Agriculture,  Office  of  Experiment  Stations, 
a  list  of  which  is  given  at  the  end  of  Chapter  III. 

Commercial  Food  Analysis. — The  proper  preparation  of  food  products 
has  long  ceased  to  be  carried  on  by  the  hap-hazard  rule-of-thumb  methods 
that  formerly  prevailed.  Now  in  the  manufacture  of  many  prepared  foods 
and  condiments,  especially  on  a  large  scale,  it  has  become  a  necessity  to 
use  scientific  processes,  rendered  possible  only  by  the  employment  of 
skilled  chemists.  In  fact  it  is  coming  to  be  more  and  more  common  for 
food  manufacturers  to  establish  chemical  laboratories  in  connection  with 
their  works,  in  the  interests  both  of  economy  and  of  improved  production. 

Frequently  disputed  points  arise  in  the  enforcement  of  the  food  laws 
that  render  the  services  of  the  private  food  analyst  of  great  importance 
both  to  manufacturer  and  dealer.  Thus  a  wide  tield  is  open  to  the  analyst 
of  foods  outside  the  domain  of  the  government  or  state  laboratory,  either 
in  connection  with  the  large  food  manufacturing  plants  directly,  or  m 
private  laboratories  for  experimental  research,  or  for  analytical  control 
work. 

SYSTEMATIC   FOOD   INSPECTION. 

Functions  of  the  Official  Analyst. — The  public  analyst  is  employed  by 
city,  state,  or  government  to  pass  judgment  on  various  articles  of  food 
taken  from  the  open  market  by  purchase  or  seizure,  either  by  himself  or 
by  duly  authorized  collectors  employed  for  the  purpose.  The  sole  object 
of  his  examination  is  to  ascertain  whether  or  not  such  articles  of  food  con- 
form to  certain  standards  of  purity  fixed  in  some  cases  by  special  law^,  and 
in  others  by  common  usage  or  acceptance.  Such  a  public  analyst  need  not 
concern  himself  with  the  dietetic  value  of  the  food  or  whether  it  is  of  high 
or  low  grade.     It  is  for  him  to  determine  simply  whether  it  is  genuine  or 


4  FOOD  INSPECTION  AND  ANALYSIS. 

adulterated  ^vilhin  the  meaning  of  the  law,  and,  if  adulterated,  how  %,nd 
to  what  extent.  Asiile  from  his  skill  as  a  chemist,  it  is  often  necessary  for 
him  to  possess  other  no  less  important  qualifications,  chief  among  ^Vllich 
arc  his  ability  to  testify  clearly  and  concisely  in  the  courts,  and  to  mcTat 
any  time  the  most  rigid  kind  of  cross-examination,  it  being  of  the  ui'^'^Gst 
importance  that  he  understand  thoroughly  the  nature  of  evidence. 

Standards  of  Purity  for  Food  Products.* — Under  an  act  of  Congress 
approved  March  3.  1903,  standards  of  purity  for  certain  articles  of  food 
have  been  established  as  official  standards  for  the  United  States  by  the 
Secretary  of  Agriculture,  The  earlier  of  these  standards  were  formulated 
under  the  Secretary's  direction  by  a  committee  of  the  Association  of  Official 
Agricultural  Chemists.  Later,  however,  a  joint  committee  of  that  asso- 
ciation and  of  the  Association  of  State  and  National  Food  and  Dairy 
Departments  has  had  charge  of  this  work.  Standards  have  been  and 
art  being  thus  adopted,  covering  the  entire  range  of  food  products. 
'■''  Nature  of  the  Analytical  Methods  Employed. — Usually  but  a  small 
percentage  of  the  samples  submitted  for  examination  are  actually  adulter- 
ated. The  analyst  should,  therefore,  adopt  for  economy  in  time  the 
quickest  possible  rehable  processes  for  separating  the  pure  from  the 
impure,  so  that  most  of  his  attention  may  be  devoted  to  the  latter. 
The  nature  of  the  processes  by  which  this  is  done  varies  with  the  foods. 
Experience  soon  enables  one  to  judge  much  by  even  the  characteristics  of 
taste,  appearance,  and  odor,  though  such  superficial  indications  should  be 
used  with  discretion.  One  or  two  simple  chemical  or  physical  tests  may 
often  suffice  to  establish  beyond  a  doubt  the  purity  of  the  sample,  after 
which  no  further  attention  need  be  paid  to  it. 

A  sample  failing  to  conform  to  the  tests  of  a  genuine  food  must  be 
carefully  examined  in  detail  for  impurities  or  adulterants.  While  in 
most  cases  usage  or  experience  suggests  the  forms  of  adulteration  peculiar 
to  various  foods,  the  analyst  should  be  on  the  alert  to  meet  new  conditions 
constantly  arising.  His  methods  are  largely  qualitative,  since  technically 
he  need  only  show  in  most  cases  the  mere  presence  of  a  forbidden 
ingredient,  though  for  the  analyst's  own  satisfaction  he  had  best  deter- 
mine the  amount,  at  least  approximately. 

In  reporting  approximate  quantitative  results  in  court,  especially 
when  they  are  calculated  from  assumed  or  variable  factors,  or  when  they 
are  the  result  of  judgment  based  on  the  appearance  of  the  food  under 

*  U.  S.  Dept.  of  Agrir.,  Off.  of  Sec,  Circ.  19. 


FOOD   ANALYSIS   AND    OFFICIAL    CONTROL.  5 

microscope,  the  analyst  should  always  be  conscn^ative  in  his  figures 

expressing  the  lowest  or  minimum  amount  of  the  adulterant,  so  as 
to  ^Ive  the  defendant  the  benefit  of  any  doubt.     When  exact  standards 

fixed  by  law,  as  in  the  case  of  total  solids  or  fat  in  milk,  for  example, 
vi  is  of  course  great  necessity  for  preciseness  in  cjuantitative  work. 

A  full  analysis  of  an  adulterated  food  beyond  establishing  the  nature 
and  amount  of  the  adulteration  is  entirely  unnecessary,  and  in  most 
instances  adds  nothing  to  the  strength  of  a  contested  case,  as  twenty 
years'  experience  in  the  enforcement  of  the  food  laws  in  Massachusetts 
has  shown. 

The  responsibility  resting  upon  the  analyst  is  not  to  be  lightly  con- 
sidered, when  it  is  realized  that  his  judgment  and  findings  constitute  the 
basis  on  which  court  complaints  are  made,  and  the  payment  of  a  fine 
or  even  the  imprisonment  of  the  defendant  may  be  the  result  of  his  report. 
Therefore  he  should  be  sure  of  his  ground,  knowing  that  his  results  are 
open  to  question  by  the  defendant.  Where  court  procedure  is  apt  to  be 
involved,  a  safe  nde  is  for  the  analyst  to  consider  himself  the  hardest 
person  to  convince  that  his  tests  are  unquestionable,  making  every  possible 
confirmatory  test  to  strengthen  his  position  and  consulting  all  available 
authorities  before  expressing  his  opinion;  and  finally,  after  being  fully 
convinced  that  a  sample  is  adulterated,  and  having  so  alleged,  let  him 
adhere  to  his  statements  and  not  waver  in  spite  of  the  most  rigid  cross- 
examination  to  which  he  may  be  subjected. 

While  each  state  or  municipality  has  its  own  peculiar  code  of  regula- 
tions and  restrictions  concerning  the  duties  of  the  analyst  and  other  officials, 
these  rules  are  in  the  main  very  similar.  For  instance,  it  is  usually  neces- 
sary, excepting  in  the  case  of  such  a  perishable  food  as  milk,  for  the  analyst 
to  reserve  a  portion  of  a  sample  before  beginning  the  analysis,  which 
sample,  in  the  event  of  proving  to  be  adulterated,  shall  be  sealed,  so  that 
in  case  a  complaint  is  made  against  the  vendor,  the  sealed  sample  may, 
on  application,  be  delivered  to  the  defendant  or  his  attorney. 

Adulteration  of  Food. — Except  in  special  cases  a  food  in  general  is 
deemed  to  be  adulterated  if  anything  has  been  mixed  with  it  to  reduce 
or  lower  its  quality  or  strength;  or  if  anything  inferior  or  cheaper  has 
been  substituted  wholly  or  in  part  therefor;  or  if  any  valuable  constituent 
has  been  abstracted  wholly  or  in  part  from  it;  or  if  it  consists  wholly  or 
in  part  of  a  diseased,  decomposed,  or  putrid  animal  or  vegetable  sub- 
stance; or  if  by  coloring,  coating,  or  otherwise  it  is  made  to  appear  of 
greater  value  than   it    really  is;    or  if   it   contains  any  added  poisonous 


6  FOOD   INSPECTION  AND   ANALYSIS. 

ingredient.  These  provisions  briefly  expressed  are  typical  of  the  general 
food  laws  adopted  by  most  states  and  by  the  government,  though  the 
verbiage  mav  dilTer.  Laws  covering  compound  foods  and  special  foods 
var^•  widelv  with  the  locality.  As  to  the  character  of  adulteration,  nine 
out  of  ten  adulterated  foods  are  so  classed  by  reason  of  the  addition  of 
cheaper  though  harmless  ingredients  added  for  commercial  profit,  rather 
than  bv  the  addition  of  actually  poisonous  or  injurious  substances,  though 
occasional  instances  of  the  latter  are  found. 

Authentic  instances  of  actual  danger  to  health  from  the  presence  of 
iniurious  ingredients  are  extremely  rare,  so  that  the  question  of  food 
adulteration  should  logically  be  met  largely  on  the  ground  of  its  fraudu- 
lent character.  Indeed  the  commoner  forms  of  adulteration  are  restricted 
to  a  comparatively  small  number  of  food  products,  the  most  staple  articles 
of  our  food  supply,  such  as  sugar  and  the  cereals,  eggs,  fresh  meat,  fresh 
vegetables  and  fruit  being  rarely  subject  to  adulteration. 

Misbranding. — Under  the  federal  food  law  and  the  laws  of  many  of 
the  states  misbranding  constitutes  an  offense  as  well  as  adulteration.  By 
misbranding  is  meant  any  untrue  or  deceptive  statement  or  design  on  the 
label  of  a  food  package,  either  regarding  the  nature  of  the  contents,  or  of 
the  jjlacc  of  manufacture  or  name  of  manufacturer.  One  of  the  com- 
monest forms  of  misbranding  consists  in  the  incorrect  statement  of  weight 
or  measure.  Extravagant  and  untrue  claims  as  to  nutritive  value  have 
hitherto  constituted  a  frequent  form  of  misbranding. 

A  Typical  System  of  Food  Inspection. — The  efficiency  of  a  system  of 
public  food  inspection  is  greatly  enhanced  if  the  business  part  of  the 
work,  including  the  bookkeeping  and  attending  to  the  outside  public, 
be  done  wholly  through  some  person  other  than  the  analyst,  as,  for  example, 
a  health  officer,  to  whom  the  collectors  of  samples  and  the  analyst 
may  report  independently  as  to  the  results  of  their  work,  and  whose 
duty  it  is  to  determine  what  shall  be  done  in  cases  of  adulteration. 
In  this  way  the  analyst  knows  nothing  of  the  data  of  collection 
nor  the  name  of  the  person  from  wiiom  the  sample  was  purchased, 
so  that  he  can  truthfully  state  in  court  that  his  analysis  was  un- 
bia.sed. 

Suppose,  for  example,  that  three  collectors  are  employed  to  purchase 
samples  of  food  for  analysis,  their  duties  being  to  visit  at  irregular  intervals 
different  j>ortions  of  a  state  or  municipality.  Each  collector  keeps  a  book 
in  which   he  enters  all  data  as  to  the  collection  of  the  sample,  includ- 


FOOD  ANALYSIS  AND    OFFICIAL  CONTROL. 


Fig.  I. — Inspectors'  Lockers.  Insuring  safe  legal  delivery  of  samples  collected  by  tnreo 
inspectors.  Each  locker  has  a  door  in  the  rear  accessible,  from  an  anteroom,  to  the  ini 
spector  holding  key  to  that  locker  only. 


FOOD    ISSPECTION  yIND  ANALYSIS. 


Fig.  2. — Inspectors'  Lockers.  Front  View.  The  lockers  are  accessible  to  the  analyst  in  the 
Iabf)ratr)r\'  hy  a  single  sliding-sash  front,  provided  with  a  spring  lork.  The  removable 
sliding-racks  arc  convenient  for  returning  clean  sample  Vjottlcs. 


FOOD  ANALYSIS  AND   OFFICIAL    CONTROL  9 

ing  the  name  of  the  vendor,  assigning  a  number  to  each  sample,  which 
number  is  the  only  distinguishing  mark  for  the  analyst.  One  collector 
may  use  for  this  purpose  the  odd  numbers  in  succession  from  i  to  9999, 
the  second  the  even  numbers  from  2  to  10,000,  vi^hile  the  third  may  use 
the  numbers  from  10,000  up.  Each  of  the  two  former  would  begin  with  a 
lettered  series,  as,  for  instance,  A,  numbering  his  samples  lA,  3A,  5A,  7A, 
etc.,  or  2A,  4A,  6A,  etc.,  till  he  reached  10,000,  then  beginning  on  series 
B  and  so  on.  If  the  analyst  is  to  be  kept  in  ignorance  of  the  brand  or 
manufacturer  in  the  case  of  package  goods,  the  collector  must  remove 
from  the  original  package  sufficient  of  the  sample  for  the  needs  of  the 
analyst,  and  deliver  it  to  the  latter  in  a  plain  package,  bearing  simply  the 
name  under  which  the  article  was  sold  and  the  number.  Such  precau- 
tions are,  however,  not  always  practicable  and  depend  largely  on  local 
regulations.  The  analyst  reports  the  result  of  the  analysis  of  each  sample 
with  the  number  thereof  on  a  librar}'  card,  with  appropriate  blanks  both, 
for  data  of  analysis  and  for  data  of  collection,  the  latter  to  be  filled  by 
the  collector  from  his  book  after  the  analyst  has  handed  in  the  card  with 
the  data  of  analysis.  This  system  of  recording  and  reporting  analyses 
has  been  successfully  used  for  years  by  the  Department  of  Food  and 
Drug  Inspection  of  the  Massachusetts  State  Board  of  Health. 

Legal  Precautions. — The  laboratory'  of  the  public  analyst  should 
preferably  be  provided  with  a  locker  for  each  collector,  to  which  access 
may  be  had  only  by  that  collector  and  the  analyst,  so  that  in  the  absence 
of  the  latter,  or  when  circumstances  are  such  that  the  samples  cannot  be 
delivered  to  him  personally,  there  may  be  such  safeguards  with  respect 
to  lock  and  key  as  to  leave  no  question  in  the  courts  as  to  safe  delivery 
and  freedom  from  accidental  tampering.  With  such  a  system  it  is  un- 
necessary for  the  collector  to  place  under  seal  the  various  samples  sub- 
mitted for  analysis.  Unless  such  lockers  or  their  equivalent  are  employed, 
it  is  best  to  carefully  seal  all  samples. 

Such  a  system  of  lockers  for  use  with  three  collectors  is  shown  in 
Figs.  I  and  2.  The  same  careful  attention  should  afterwards  be  given  to 
keep  the  specimens  in  a  secure  place  both  before  and  during  the  process 
of  analysis,  and  to  label  with  care  all  precipitates,  filtrates,  and  solutions 
having  tr  do  with  the  samples,  especially  when  several  processes  are 
being  simultaneously  conducted,  in  order  that  there  may  be  no  doubt 
whatever  as  to  their  identity.  The  importance  of  precautions  of  this 
kind  in  connection  with  court  work  can  hardly  be  too  strongly  emphasized. 


lo  hXlOD    ISSPhCTION   .-IND    ^N.-i LYSIS. 

Practical  Enforcement  cf  the  Food  Law. — In  the  case  of  foods  actually 
found  adulterated,  there  arc  three  practical  methods  of  suppressing  their 
further  sale,  viz.,  by  pubhcation,  by  notification,  and  by  prosecution.  These 
mav  be  separately  employed  or  used  in  connection  with  each  other,  accord- 
ing to  the  powers  conferred  by  law  on  the  commission,  board,  or  official 
having  in  charge  the  enforcement  of  the  law,  and  according  to  the  dis- 
cretion of  such  olTicial. 

Publication. — Under  the  laws  of  some  states,  the  only  means  of  pro- 
tecting the  people  Hes  in  publishing  lists  of  adulterated  foods  with  their 
brands  and  manufacturers'  names  and  addresses  in  periodical  bulletins 
or  reports.  Sometimes  it  is  considered  best  to  publish  for  the  informa- 
tion of  the  public  lists  of  unadulterated  brands  as  well,  and,  again,  it  is 
held  that  only  the  offenders  should  thus  be  advertised. 

Such  pubhcation,  by  keeping  the  trade  informed  of  the  blackUsted 
brands  and  manufacturers,  certainly  has  a  decidedly  beneficial  effect 
in  reducing  adulteration,  and  involves  less  trouble  and  expense  than 
anv  other  method.  It  is  obviously  an  advantage,  however,  in  addition 
to  this  to  be  able  in  certain  extreme  cases  to  use  more  stringent  methods 
when  necessar}'. 

Notification  and  Prosecution. — The  adulteration  of  food  is  best  held 
in  check  in  locahties  where  under  the  law  cases  may  be  brought  in  court 
and  are  occasionally  so  brought.  The  mere  power  to  prosecute  is  in 
itself  a  safeguard,  even  though  that  power  is  not  frequently  exercised. 
Under  a  conservative  enforcement  of  the  law,  actual  prosecution  should 
be  made  as  a  last  resort.  Neither  the  number  of  court  cases  brought 
bv  a  food  commission  nor  the  large  ratio  of  court  cases  to  samples  found 
adulterated  are  criteria  of  its  good  work.  Except  in  extreme  cases, 
it  is  frequently  found  far  more  effective  to  notify  a  violator  of  the  law, 
csfK-cially  if  it  is  a  first  offense,  giving  warning  that  subsequent  infraction 
will  Ix;  followed  by  prosecution.  Such  a  notification  frequently  serves 
lo  stop  all  further  trouble  at  once  and  with  the  minimum  of  expense. 
Instances  arc  frequent  in  Massachusetts  where,  by  such  simple  notifica- 
tion, widely  distributed  brands  of  adulterated  foods  have  been  immediately 
withdrawn  from  sale. 

Massachusetts  was  the  first  of  all  the  states  to  enact  pure-food  legisla- 
tion, and  since  the  year  1883  has  had  a  well-established  system  of 
inspection,  [prosecuting  cases  under  its  laws  through  the  Food  and  Drug 
Department  of  the  State  Board  of  Health.  Cases  are  brought  in  court 
with  practically  no  expense  for  legal  services.     Complaints  are  entered  by 


FOOD  /IN  A  LYSIS   AND  OFFICIAL    CONTROL.  ii 

the  collector,  or,  as  he  is  termed,  inspector,  who  makes  complaint  not  in 
his  official  capacity,  but  as  a  citizen  who  under  the  law  has  Vjeen  sold  a 
food  found  to  be  adulterated,  and  who  is  entitled  to  conduct  his  own 
case,  which  he  does  with  the  aid  of  the  analyst  and  such  other  witnesses 
as  he  may  see  fit  to  employ.  Experience  is  readily  acquired  by  the  inspector 
in  conducting  such  cases  in  the  lower  police  or  municipal  courts,  where 
they  are  first  tried,  and  years  ago  the  services  of  legal  counsel  in  Alassa 
chusetts  were  dispensed  with  as  superfluous.* 

Statistics  in  the  annual  re])orts  of  the  Massachusetts  Board  show  with 
what  uniform  success  these  trials  have  been  conducted.  While  more 
often  settled  in  the  lower  courts,  occasional  appeal  cases  are  carried  tc 
the  superior  courts,  where  the  services  of  the  regular  district  ai^torney  are 
of  course  availed  of  in  prosecuting  the  case. 

Such  a  system  as  the  above,  while  admirable  for  a  state  or  city  after 
long  experience  in  the  enforcement  of  food  laws  in  the  courts,  is  obviously 
impracticable  with  newly  established  systems  of  state  food  inspection. 

REFERENCES    ON    FOOD    INSPECTION    AND    OFFICIAL    CONTROL. 

Abbott,  S.  W.  Food  and  Drug  Inspection.  Article  in  Reference  Handbook  of  the 
Medical  Sciences,  Vol.  3,  pp.  162-180.     N.  Y.,  1902. 

Andrews,  O.  W.  Public  Health  Laboratory  Work  and  Food  Inspection.  London, 
1901. 

BiGELOW,  W.  D.  Foods  and  Food  Control.  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui. 
69,  rev. 

Food  Legislation  for  the  Year  Ending  June  30,  1907.     Ibid.,  Bui.  112. 

Pure  Food  Laws  of  European  Countries.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem., 

Bui.  61. 

BUCHKA,  K.  VON.  Die  Nahrungsmittelgesetzgebung  im  Deutschen  Reiche.  Berlin, 
1901. 

Chapin,  C.  V.     Municipal  Sanitation  in  the  United  States.     Providence. 

ELenwood,  H.  R.     Public  Health  Laboratory  Work.     London,  1904. 

Leach,  A.  E.  Character  and  Extent  of  Food  and  Drug  Adulteration  in  Massachu- 
setts and  the  System  of  Inspection  of  the  State  Board  of  Health.  Tech.  Quar- 
terly, March,  1900. 

Moor,  C.  D.     Suggested  Standards  of  Purity  for  Foods  and  Drugs.     London,  1902. 

Nexjfeldt,  C.  a.     Der  Nahrungsmittelchemiker  als  Sachverstandiger.      Berlin,  1907. 

*  Where  such  a  practice  is  in  vogue  an  intelligent  inspector  must   of  course  be  chosen 

with  reference  to  his  ability  to  do  this  court  work.     The  food  laws  are  few  and  simple,  as 

are  also  the  court  decisions  rendered  under  them,  so  that  it  is  no  great  task  for  the  inspector 

to  become  much  more  familiar  with  them  than  the  average  general  lawyer  whom  he  meets 

[  in  court  and  who  not  infrequently  consults  the  inspector  for  information  regarding  these  laws. 


12  FOOD  INSPECTION   AND   ANALYSIS. 

PouN  ET  L.\BiT.     Examcn  dcs  Aliments  suspects.     Paris,  1892. 

TrCKER,  W.  G.     Food  Adulteration:    Its  Nature  and  Extent  and  How  to  Deal  with 

It.     Med.  Rev.  of  Rev's,  Oct.,  1903. 
Vachkr.  F.     The  Food  Inspector's  Handbook.     London,  1893. 
Wedderbi'RN,  a.  J.     Reports  on  Extent  and  Character  of  Food  and  Drug  Adulteration 

in  the  United  States.     U.  S.  Dept.  of  Agriculture,  Div.  of  Chem.,  Bulletins  25, 

32,  and  41. 
Wiley.  H.  \V.     Foods  and  Their  Adulteration.     Philadelphia,  1907. 
WrRZBVRC.    A.     Die    Xahrungsmittelgesetzgebung    im    Deutschen    Reiche.     Leipzig, 

1903. 
The  British  Food  Journal,  London,  1899  et  seq. 

Food  and  Sanitation,  London,  1892-1900  (discontinued  August,  1900). 
Journal  of  the  Sanitan.-  Institute,  1892  et  seq. 
Revue  International  des  Falsifications,  Amsterdam,  1888  et  seq. 
The  American  Food  Journal,  Chicago,  1906  et  seq. 
The  Food  Law  Bulletin,  Chicago,  1907  et  seq. 

Biennial  Reports  of  the  Idaho  Dairy,  Food  and  Oil  Commission,  1903  et  seq. 
Verotfentlichungendes  kaiserlichen  Gesundheitsamtes.     Berlin,  1877  et  seq. 
Arbciten  aus  dcm  kaiseslichen  Gesundheitsamtes.     Berlin,  1886  et  seq. 
Reports  of  the  Local  Government  Board  of  England,  1877  et  seq. 
Reports  of  the  Paris  Municipal  Laboratory,  1882  and  1885. 
Reports  of  the  Canton  Chemists  of  Switzerland,  1890  ct  seq. 
Annual  Reports  of  the  Massachusetts  State  Board  of  Health,  1883  et  seq. 
Monthly  Bulletins  of  the  Massachusetts  State  Board  of  Health. 
Annual  Reports  of  the  Conn.  Agric.  Exp.  Station  on  Food  Products,  1896  et  seq. 
Annual  RffX)rls  of  the  Ohio  Dairy  and  Food  Commissioner,  1890  et  seq. 
Annual  RejKirt.s  of  the  New  Jersey  Dairy  Commissioner,  1886  et  seq. 
Annual  Rejxjrts  of  New  Jersey  Laborator)'  of  Hygiene,  Chemical  Dept.,  1903  et  seq. 
Annual  RcfK)rts  of  the  Michigan  Dair}-  and  Food  Department,  1893  et  seq. 
Monthly  Bulletins  of  the  Michigan  Dairy  and  Food  Department,  Aug.,  1895  et  seq. 
Biennial  Rcjxjrts  of  the  Minnesota  Dairy  and  Food  Commissioner. 
Annual  Rc'fx)rts  of  the  Wisconsin  Dairy  and  Food  Commissioner,  1890  et  seq. 
Annual  Rejxjrts  of  the  Penn.  Board  of  Agriculture,  1894  et  seq. 
Annual  Rc|x)rts  of  the  Illinois  State  Food  Commissioner,  1899  et  seq. 
Biennial  Rcjxjrts  of  the  New  Hampshire  State  Board  of  Health,  1902  et  seq. 
Quarterly  Bulletins  of  the  New  Hampshire  State  Board  of  Health,  1902  et  seq. 
Annual  Rejxjrts  of  the  North  Carolina  State  Board  of  Agriculture  on  Food  Products, 

1900  et  seq. 
Bulletins  of  the  North  Dakota  Ex{x;riment  Station. 
Annual  Refiorts  and  Monthly  Bulletin  of  the  Indiana  State  Board  of  Health,   1905 

et  seq. 
Official  Inspections  of  the  Maine  Agricultural  Experiment  Station. 


FOOD   ANALYSIS  AND   OFFICIAL    CONTROL.  13 

Annual  Reports  of  the  Wyoming  State  Dairy  Food  and  Oil  Commission,  1904  et  seq. 
Quarterly  Bulletins  of  the  Vermont  State  Board  of  Health. 
Annual  Reports  of  the  South  Dakota  Food  and  Dairy  Commission,  1901  et  seq. 
Proceedings   and   Methods  of  Analysis  of   the   Association   of   Official   Agricultural 

Chemists,  published  as  bulletins  of  the  U.  S.  Department  of  Agriculture,  Bureau 

of  Chemistry. 
Proceedings  of  the  National  Association  of  State  Dairy  and  Food  Departments,  1902 

et  seq. 


CHAPTER  II. 
THE  LABORATORY  AND  ITS  EQUIPMENT. 

Location.— The  selection  of  a  location  for  a  food  laboratory  cannot 
always  be  made  solely  with  reference  to  its  needs  and  its  convenience, 
but  it  is  more  often  subject  to  economic  conditions  beyond  the  analyst's 
control.  Under  ver\^  best  conditions,  such  a  laboratory  should  be  situated 
in  a  building  designed  from  the  start  exclusively  for  chemical  or  biological 
and  chemical  work.  Almost  any  well-lighted  rooms  in  such  a  building 
can  be  readily  adapted  for  the  purpose.  When,  however,  as  is  freciuently 
the  case,  rooms  for  such  a  laboratory  are  provided  in  municipal,  govern- 
ment, or  office  buildings,  in  which  for  the  most  part  clerical  work  is  done, 
the  problem  of  adequately  utilizing  such  rooms  so  that  they  may  not 
at  the  same  time  prove  offensive  to  or  interfere  with  the  comfort  of  other 
occupants  of  the  building  is  sometimes  difficult.  It  is  obvious  that  base- 
ment rooms  in  such  a  building,  as  far  as  ventilation  is  concerned,  are  less 
readily  adapted  for  the  requirements  in  hand  than  are  those  of  the  top 
floor,  though,  if  the  light  is  good  and  there  are  abundant  and  well-arranged 
vcntilating-shafts,  such  rooms  may  be  made  to  serve  every  purpose.  In 
the  basement  one  may  most  easily  obtain  water,  gas,  and  steam,  and 
dispose  of  wastes  without  annoyance  to  one's  neighbors.  When,  how- 
ever, it  is  possible  to  do  so,  rooms  on  the  top  floor  of  an  office  building 
should  he  utilized  for  a  food  laboratory,  for  in  such  rooms  the  problems 
of  lighting,  heating  and  ventilating  are  comparatively  simple  and  may 
usually  be  solved  without  regard  to  other  occupants.  In  such  a  case 
ample  provision  must  be  made,  preferably  through  shafts  which  are 
readily  accessible  for  water-,  gas-,  steam-,  and  soil-pipes  ])assing  down 
below. 

The  actual  equipment  of  the  food  laboratory  depends  of  course  largely 
on  its  particular  purpose;  and  while  it  is  manifestly  impossible  to  do  other- 
wise than  leave  the  details  to  the  individual  taste  and  needs  of  the  analyst, 

14 


THE  L/1BORATORY  AND  ITS  EQUIPMENT.  15 

modified  by  the  means  at  his  (Hsposal,  a  few  general  suggestions  regarding 
important  essentials  may  prove  helpful.  These  imply  a  fairly  hberal 
though  not  extravagant  outlay,  with  a  view  to  saving  both  time  and  energy 
by  convenient  surroundings  well  adapted  to  the  work  in  hand.  At  the 
same  time  equally  satisfactory  work  is  possible  under  simpler  conditions 
than  those  described. 

Floor. — The  best  material  for  the  floor  of  the  working  laboratory 
is  asphalt.  Such  a  floor  is  firm  but  elastic,  is  readily  washed  by  direct 
application  of  running  water,  if  necessary',  and  resists  well  the  action  of 
ordinary  reagents.  An  occasional  thin  coating  of  shellac  with  lampblack 
applied  with  a  brush  gives  the  asphalt  floor  a  smooth,  hard  surface  and 
may  be  applied  locally  to  cover  spots  and  blemishes. 

Lighting. — The  lighting  of  the  rooms,  if  on  the  top  floor,  is  best  effected 
by  both  wall  windows  and  skylights.  North  windows  furnish  the  best 
hght  for  the  microscope;  the  skylight,  when  available,  is  the  ideal  light 
for  the  balance  and  for  general  laborator}-  work. 

Ventilation  by  forced  draft  is  a  great  convenience.  For  this  purpose 
an  exhaust-fan  driven  by  an  electric  motor  and  controlled'  in  speed  by 
a  fractional  rheostat  is  admirable.  Such  a  fan  had  best  be  located  in  a 
small  closed  compartment  or  closet  near  the  centre  of  the  series  of  rooms 
designed  to  be  ventilated  by  it,  and  this  closet  should  have  directly  over  the 
fan  an  outlet-shaft  passing  through  the  roof  of  the  building.  With  such 
a  system,  a  series  of  branching  air-ducts  should  radiate  from  the  fan  closet, 
conveniently  arranged  either  above  or  along  the  ceihng  and  communicat- 
ing with  the  various  hoods,  closets,  and  rooms  near  the  top. 

Benches. — The  working  benches  should  have  wooden  or  glazed  tile 
,  tops.  White  glazed  tile,  if  properly  laid,  furnish  a  \Qvy  clean,  sanitary-, 
and  resistant  surface,  besides  being  often  convenient  for  color  tests.  If 
laid  on  a  plank  surface,  cement  should  not  be  applied  directly,  as  it  swells 
the  wood  before  drying  out  and  results  in  a  loose  and  often  uneven  surface. 
Cement  may  be  avoided  altogether  and  the  tiles  after  first  soaking  in  oil  may 
be  laid  in  putty  directly  on  the  wood.  Tiles  may  be  laid  in  cement  by  first 
covering  the  plank  surface  with  cheap  tin  plate,  overlapping  the  edges  and 
securing  by  tacks.  This  prevents  swelling  of  the  wood.  The  tin  may  be 
covered  to  advantage  with  cheap  paint.  The  tiles  may  then  be  embedded 
in  a  layer  of  cement  spread  over  the  tin  surface. 

Soft  encaustic  glazed  tiles  commonly  used  for  wall  finish  are  not  as 


1 6  FOOD   INSPECTION  /iND   .ANALYSIS. 

effective  as  hard  floor  tiles,  since  the  former  crackle  and  lose  color  when 
subjected  to  heat.  If  the  hard  floor  tiles  can  be  specially  glazed,  they  make 
by  far  the  most  satisfactory  and  enduring  surface. 

When  wooden  bench  tops  are  used  they  may  be  treated  to  advantage 
by  staining  with  the  following  solutions: 

Solution  I.  IOC  grams  of  anilin  hydrochloride,  40  grams  of  ammonium 
chloride,  650  grams  of  water. 

Solution  2.  100  grams  of  copper  sulphate,  50  grams  of  potassium 
chlorate,  615  grams  of  water. 

Apply  solution  i  thoroughly  to  the  bare  wood  and  allow  it  to  dry;  then 
applv  2  and  dry.  Repeat  these  ap])lications  several  limes.  Wash  with 
plentv  of  hot  soap  solution,  let  dry  and  rub  well  with  vaseline.  It  is  claimed 
that  wood  so  treated  is  rendered  flre-proof  and  is  not  acted  on  by  acids  and 
alkalies.  When  the  finish  begins  to  wear,  an  application  of  hot  soap  solu- 
tion or  vaseline  will  bring  back  the  deep  black  color. 

The  benches  should  naturally  be  located  with  reference  to  best  light 
from  skvlights  or  windows.  Gas  and  water  outlets,  sinks  and  waste-pipes 
should  be  conveniently  arranged  with  reference  to  the  working  benches,  as 
well  as  suitable  provisions  for  air-blast  and  exhaust,  while  in  the  space  be- 
neath the  benches  such  drawers,  cupboards,  and  receptacles  as  are  required 
should  be  provided.  A  clear  bench  width  of  24  inches  is  ample  for  most 
work;  if  wider  there  is  a  temi)tation  to  allow  apparatus  to  accumulate  at  the 
back.  At  the  back  of  the  bench  and  within  easy  reach,  a  raised  narrow 
shelf  should  be  provided  to  be  used  exclusively  for  common  desk  reagents. 
This  again  should  not  be  so  wide  as  to  allow  the  accumulation  of  useless 
bottles.  A  narrow  raised  guard  or  beading  at  the  edge  of  the  reagent  shelf 
prevents  the  bottles  from  accidently  slipping  ofT. 

Hoods. — Closed  hoods  with  sliding  sash  fronts  are  almost  indispensable. 
These  hoods  should  be  directly  connected  with  the  ventilating  shafts  or 
pifK-s,  or  with  the  air-ducts  that  radiate  from  the  exhaust-fan  closet,  when 
such  a  .system  is  [jrovided.  Gas  outlets  inside  the  hoods  are  neces- 
sar\-. 

When  there  is  a  good  flrafl,  either  natural  or  forced,  a  hooded  top 
over  the  working  bench,  such  as  that  shown  in  Fig.  3,  is  quite  as  eflicient 
as  a  closed  hood  for  most  purposes.  This  is  best  made  of  galvanized 
iron,  painted  on  the  outside  and  treated  on  the  inside  with  a  j^reparation 
of  graphite  ground  in  oil.  Here  are  best  carried  out  all  the  processes 
involving  the  giving  ofl"  of  fumes  and  gases,  which,  if  the  ventilation  is 
efhcient,  should  pass  directly  up  the  flues  and  not  come  out  in  the  room. 


THF.   LABOR/iTORY  AND  ITS  EQUIPMENT.  17 

Sinks  and  Drains. — The  sinks  should  preferably  be  of  iron  or  porce- 
lain.    If  iron,  Ihcy  should  at  frequent  intervals  be  treated  with  a  coat  of 


Fig,  3. — Hooded  Top  of   Galvanized   Iron  over  Working-bench,  Connected  -w-ith 
\'entilating  Air-ducts. 

asphalt  varnish.     A  great  convenience  is  a  hooded  sink  (Fig.  4)  in  which 
foul- smelling  bottles,  or  vessels  giving    off   noxious    or   offensive  fumes 


FOOD  ISSPECTION  AND  ANALYSIS. 


or  gases,  may  be  rinsed  under  the  tap  while  completely  closed  in.  Open- 
'.vork  rubber  mats  at  the  bottom  of  the  sinks  help  to  insure  against  break- 
age. Open  plumbing  of  simplest  design  should  be  used,  and  u  multi- 
plicity of  traps  should  be  a\-oided.     Sinks  may  be  variously  located  for 


Fig.  4. — A  Hooded  Sink.     An   injector-like    arrangement  of  steam   and   cold-water  pipes 
furnishes  water  of  any  desired  tem{)erature. 

convenience  without  regard  to  situation  of  soil-pipes,  if  the  floor  is  thick 
enough  to  allow  an  open  drain  with  sufficient  pitch  to  flow  readily.  Such 
open  drains  are  much  more  readily  cleaned  than  closed  ])ipes,  and  are 
best  constructed  by  splitting  a  lead  pipe  anrl  laying  it  in  an  iron  box  which 
is  sunk  into  the  floor.  The  erlges  of  the  lead  pipe  are  rounded  over  those 
of  the  box  as  in  PMg.  5,  flUing  the  joints  with  hydraulic  cement,  and 
the  lop  of  the  drain  is  covered  by  a  series  of  readily  removable  iron  plates 


THE  LABORATORY  AND  ITS  EQUIPMENT. 


19 


flush  with  the  top  of  the  lloor.  Waste-pipes  from  sinks,  still- condensers, 
refrigerators,  and  various  forms  of  apparatus  involving  flowing  water  may 
be  led  into  this  drain,  holes  being  drilled  in  the  iron  cover  for  their  insertion. 
Steam  and  Electricity. — These  are  useful  but  not  indispensable.  Steam, 
when  available,  may  be  used  to  advantage  for  boiling  ether  or  benzine 
in  connection  with  continuous  fat-extraction  apparatus,  for  furnishing 
the  motive  power  for  driving  the  Babcock  centrifuge,  for  heating  water- 
baths  and  hot  closets,  and,  in  connection  with  cold  water,  to  furnish  a 


Fig.  5. — Section  of  Open  Drain-pipe  in  Floor. 

supply  of  hot  water  when  wanted  at  the  sink.  The  latter  application 
is  illustrated  in  Fig.  4. 

If  electricity  is  used  for  lighting,  it  may  also  be  applied  in  a  variety 
of  useful  ways  in  the  laboratory,  as,  for  instance,  for  heating  coils  or  electric 
stoves,  for  electrolysis,  and  for  running  small  motors,  which  in  turn  may 
be  employed  for  driving  centrifuges,  shaking  apparatus,  ventilating-fans, 
air-pumps,  etc. 

Suction  and  Blast. — If  the  water-pressure  is  ample,  both  air-pressure 
and  exhaust  for  blast-lamps,  vacuum  filtration,  and  other  purposes  are 
readily  available  through  the  agency  of  the  various  devices  used  in  con- 
nection with  the  flow  of  water,  as,  for  instance,  the  Richards  pump.  When, 
however,  the  water  pressure  is  insufiicient,  other  means  must  be  employed 
for  furnishing  these  much-needed  requisites.  Fig.  6  illustrates  a  simple 
and  almost  noiseless  pressure  and  exhaust  pump  run  by  a  |-H.P.  electric 
motor,  which  with  the  pressure-equalizing  tank  and  the  appropriate 
connections  are  mounted  on  a  light  wheel  truck,  and  readily  movable 
to   any  part  of  the  laboratory.     By  simply  screwing  the  plug  into  an 


ao 


FOOD  INSPECTION  yfND  AN/i LYSIS. 


electric-light  outlet,  either  suction  or  blast  may  be  had  at  will,  depending 
on  the  position  of  a  knife-edge  switch  which  determines  the  direction  of 
the  current.  By  means  of  a  fractional  rheostat  the  speed  may  be  varied 
and  the  pressure  thus  controlled.  t,^ 


Fig.  6. — Portable  Pressure-  and  Exhaust-pump  Run  by  Electric  Motor.     Useful  for  blast- 
lamps,  vacuum  filtration,  etc. 


APPARATUS. 

The  laboratory  is  of  course  to  be  supplied  with  the  usual  assortment 
of  test-tubes,  flasks,  beakers,  evaporating  and  other  dishes  of  porcelain, 
platinum  and  glass,  funnels,  casseroles,  crucibles,  mortars,  burettes, 
pipettes,  graduates,  rubber  and  glass  tubing,  lamps,  ring-stands  and 
various  supports,  clamps  and  holders,  the  nature,  number,  and  sizes  of 
which  are  determined  by  individual  requirements.  Special  forms  of 
apparatus  peculiar  to  certain  processes  of  analysis  or  to  the  examination 
of  special  foods  will  be  described  in  their  appropriate  connection.  The 
following  apparatus  of  a  general  nature  may  be  regarded  as  indispensable 
for  the  proper  fitting  out  of  the  food  laboratory: 

Balances. — These  should  include  (i)  an  open  pan  balance  for  coarse 
weighing,  having  a  capacity  up  to  i  kilogram  and  sensitive  to  o.i  gram, 
with  a  set  of  weights;  and  (2)  an  analytical  balance,  enclosed  in  a  case, 
sensitive  to  .0001  gram  under  a  load  of  100  grams,  with  an  accurate  set 
of  non-corrosive  weights.     The  short-beam  analytical  balance  is  prefer- 


THE  LABORATORY  AND  ITS  EQUIPMENT. 


■2i 


able  for  quick  work,  and  as  constructed  by  the  best  modern  makers  leaves 
nothing  to  be  desired. 

The  Water-hath. — This    is    such  an  important  accessory  to  the  food 
analyst  that  it  should,  if  possible,  be  specially  designed  to  meet  his  require- 


FlG.  7. — ^Water-bath,    Enclosed   in   Hood,    with   Sliding-sash   Front. 

ments,  though  the  ordinar}'  copper  baths,  supported  on  legs  and  designed 
to  be  heated  by  gas-burners,  as  kept  in  regular  stock  by  the  dealers,  will 
sometimes  serve  the  purpose.  For  nearly  all  moisture  determinations  the 
platinum  dishes  described  on  page  133  and  the  somewhat  larger  wine-shells 
of  100  cc.  capacity  are  most  used,  and  for  this  purpose  the  top  of  the 
bath  should  have  plenty  of  openings  of  the  right  size  for  these.  A  very 
economical  construction  of  bath  admirably  adapted  for  the  food  analyst's 
use  is  shown  in  Fig.  7,  being  the  form  employed  by  the  writer. 


22 


FOOD  INSPECTION   AND  ANALYSIS. 


The  size  and  number  of  openings  are  determined  by  the  number  of 
samples  to  be  simuhaneously  analyzed.  A  steam  coil  within  the  body 
of  the  bath  serves  to  boil  the  water.  Fig.  7  also  shows  the  hood  for 
carrying  olT  the  steam  and  fumes,  the  sliding  front  of  which  is  furnished 
with  a  liasp  and  a  padlock,  so  that  it  may  always  be  kept  locked  by  the 
analyst  whenever  he  is  temporarily  absent  from  the  laboratory.  This 
is  a  useful  precaution,  when  the  residues  left  thereon  arc  from  samples 
which  are  to  form  subjects  for  possible  prosecution  in  court  later. 

Steam,  if  available  at  all  seasons  of  the  year,  or  electric  immersion 


Fig.  8. — Freas  Electrically  Heated  Drying  Oven  with  Accurate  Temperature  Control. 

coils  furnish  a  ready  means  of  heating  the  bath.  In  the  absence  of  both 
steam  and  electricity,  the  bath  must  be  boiled  by  gas  burners. 

The  Drying-oven. — Water  ovens  heated  by  gas  and  steam  ovens  have 
the  disadvantage  that  the  drying  cell  seldom  reaches  a  temperature  above 
98*^  C.  The  electric  oven  shown  in  Fig.  8  obviates  this  difficulty,  the 
regulator  permitting  of  adjustment  so  that  full  100°,  as  well  as  any 
desired  temperature,  can  be  attained.  Fig.  9  shows  an  asbestos-covered, 
jacketed  air-oven,  heated  by  a  gas  burner,  with  an  efficient  form  of  gas- 
pressure  regulator. 

The  Water-still  — An  efficient  still  should  be  provided,  capable  of 
supplying  the  laboratory  with  an  ample  cjuantity  of  pure  water  for  analyti- 
cal puqjoscs.  Fig.  10  illustrates  a  compact  form  of  still,  which  is  particu- 
larly economical  in  view  of  the  fact  that  a  single  stream  of  inflowing  cold 


THE  LABORATORY  AND  ITS  EQUIPMENT.  23 

water  first  serves  to  cool  the  condenser,  and,  rising,  becomes  vaporized 
in  the  boiler  directly  connected  with  the  condenser  at  the  top.  This 
apparatus  is  capable  of  distilling  six  gallons  of  water  in  twelve  hours. 


Fig.  9. — Asbestos-covered   Air-oven,   with  Gas-pressure  Regulator. 

The  list  of  indispensable  requisites  in  addition  to  the  above  should 
include  the  following: 

Continuous  Extraction  Apparatus  (Figs.  20,  21,  and  22), 

Apparatus  for  Nitrogen  Determination  (Figs.  26,  27a,  and  276). 

Apparatus  for  Distilling  Various  Food  Products  (pp.  71  and  660), 

A  Babcock  or  other  Milk  fat  Centrifuge  (Figs.  11  and  45). 

A  Butyro  Refractometer  (Fig.  38). 

An  Immersion  Refractometer  (Fig.  42). 

A  Microscope  and  its  Appurtenances  (Chapter  V)o 

A  Polariscope  and  its  Accessories  (Figs.  102,  103,  and  104). 

Apparatus  for  Specific  Gravity  Determination  (Figs.  14,  15,  16,  and  17). 

Apparatus  for  the  Determination  of  Carbon  Dioxide  (Fig.  71). 

Apparatus  for  the  Determination  of  Melting-points  (Fig.  93). 

Marsh  Arsenic  Apparatus  (Fig.  28). 

Electrolytic  Apparatus  (Fig.  no). 

Separatory  Funnels  (Figs.  24  and  25). 

Following  is  a  Ust  of  apparatus  and  appliances  which,  while  not  in- 
dispensable, are  convenient  and  at  times  desirable; 


24 


FOOD.  INSPECTION  AND   /ANALYSIS. 


A  Spectroscope,  either  of  the   direct-vision  variety  for   the  pocket,  or 
the  KirscholT   &  Bunsen  style  on  a  stand. 

Spectroscope  Cells,  parallel-sided,  for  observation  of  absorption  spectra. 
A   Pliolomicroi^raphic  Camera  and  Appurtenances*   (pp.  96  to  98). 
A  Muffle  Furnace,  gas  (Fig.  3)  or,  preferably,  electric  (Fig.  19). 


Fig.  10. — A  Convenient  Laboratory  Water-still  with  Earthenware  Receptacle,  Provided  with 

Faucet  and  Glass  Gauge. 

An  Incinerator  for  a  Large  Number  of  Residues  (Fig.  52). 

An  Rbullioscope  (Fig.  113). 

An  Assay  Balance,  for  weighing  arsenic  mirrors  to  o.oi  mg. 

An  Abbe  Refractometer  (Fig.  39). 

A    Schreiner  Colorimeter  (Fig.  30). 

A  Lovibond  Tintometer  (p.  78). 


*  A  photographic  dark  rrxjm  is  also  necessary  if  jjhotomicrographic  work  is  to  be  done- 


THE  L/fBOR/fTORY  AND  ITS  EQUIPMENT. 


25 


A  Universal  Cenlrijuge. — This  convenient  apparatus  merits  a  separate 
brief  description,  being  useful  for  a  wide  variety  of  purposes,  such  as 
breaking  up  ether-  and  other  emulsions,  quickly  setthng  out  precipitates, 
and  roughly  estimating  chlorides,  sulphates,  phosphates,  etc.,  by  the 
volume  of  the  precipitate  in  graduated  tubes.  Various-sized  aluminum 
frames,  carrying  hinged  sliields,  are   interchangeably  adjustable  to  the 


Fig.  II. — The  Universal  £entrifuge.     Driven  by  an  electric  motor. 

spindle  of  a  vertical  electric  motor.*  The  smallest  frame  has  shields 
adapted  to  hold  two  graduated  glass  tubes  of  15  cc.  capacity  (see  Fig.  11). 
This  is  for  the  quantitative  estimation  of  small  precipitates  and  the  quick 
settling  of  sediments.  A  medium-sized  and  large  frame  carry  tubes  of 
80  cc.  and  120  cc.  capacity  respectively.  A  frame  is  also  provided 
with  shields  adapted  for  various-sized  beakers  to  be  used  in  settling  pre- 
cipitates. The  various  types  of  centrifuges  used  for  the  Babcock  test 
(P-  137)  n^^y  ^Iso  be  used  for  general  work. 

*  In  the  absence  of  electricity  a  water-motor  may  be  used. 


s6 


FOOD  INSPECTION  /IND  ANALYSIS. 


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THE  L^BOR^TORY  AND   ITS  EQUIPMENT. 


35 


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THE  LABORATORY  AND  TfS  EQUIPMENT. 


35 


REAGENTS. 

The  foregoing  list  includes  the  general  reagents  used  in  carrjang 
out  the  processes  treated  of  in  this  volume,  together  with  their  strength, 
mode  of  preparation  when  necessary,  and  other  data. 
Reagents,  especially  those  constantly  employed,  should 
be  assigned  to  regular  places  on  the  shelves,  and 
should  invariably  be  kept  in  place  when  not  in  use. 

Among  the  standard  solutions  for  volumetric  work, 
none  is  more  frequently  of  service  in  the  food  labora- 
tory than  a  tenth-normal  solution  of  sodium  hydrox- 
ide, and  a  large  supply  of  this  reagent,  carefully 
standardized,  should  be  at  all  times  conveniently  at 
hand.  Besides  being  useful  for  standardizing  tenth- 
normal solutions,  it  is  constantly  needed  for  deter- 
mining various  acids  in  food  products,  such  as  milk, 
vinegar,  butter,  lime  juice,  cream  of  tartar,  liquors, 
and  many  others.  Time  is  well  spent  in  carefully  ad- 
justing this  solution  to  its  exact  tenth-normal  value, 
thus  simphfying  the  calculation  of  results.  A  large 
stock  bottle  (say  of  two  gallons  capacity)  containing 
the  standard  tenth-normal  sodium  hydroxide,  is  con- 
veniently mounted  with  a  side-tube  burette  in  con- 
nection, in  some  such  manner  as  shown  in  Fig.  12.  A 
small  connecting  side  bottle  contains  a  strong  solution 
of  sodium  hydroxide  (reagent  No.  240)  through  which 
the  air  that  enters  the  large  bottle  is  passed,  thus  depriving  it  of  COj. 
In  this  manner  the  standard  solution  may  readily  be  kept  of  unvarjdng 
strength  for  a  year  or  more. 


Fig.  12. — Stock  Bot- 
tle of  Tenth-nonnal 
Alkali. 


36  FOOD  INSPECTION  AND  ANALYSIS. 


EQUIVALENTS  OF  STANDARD  SOLUTIONS. 

No.  31.   Decinormal  Sulphuric  Acin.     One  cc.  is  equivalent  to 

Ammonia  gas NH3 0.0017  granx 

Ammonia NH.OH 0.0035 

Ammonium  carbonate (NIIj^COj 0.0046 

(NH,\CO^H,0. 0.0057 

Calcium  carbonate CaC03 0.0050 

Calcium  hydro.xide Ca(OH), o .  0037 

' '        o.xidc CaO o .  0028 

Lead  acetate Pb( 0,11302)2,31120 0.0189 

Magnesia MgO o .  0020 

Magnesium  carbonate MgCOj 0.0042 

Nitrogen X 0.0014 

Potassium  acetate  * KCjIIjO, 0.0098 

"  bicarbonate KHCO3 o.oioo 

bitartrate  * KHC^H^e 0.0188 

"  carbonate K0CO3 0.0069 

"  citrate* K3CeH507,H20 0.0106 

"  hydroxide KOH 0.0056 

"  and  sodium  tartrate  .   KNaC^H^08,4HoO 0.0141 

Sodium  acetate NaC2H302,3H^,0 0.0136 

benzoate  * NaC^Hr.O^ 0.0144 

bicarbonate NaHC03 0.0084 

borate Na^BjOj.ioHoO 0.0191 

carbonate Na^COj 0.0053 

"        NajCOgjioH^O 0.0143 

hydroxide NaOH 0.0040 

salicylate* XaC7H503 0.0160 

No.  241,   Decinormal  Sodium  Hydroxide  Solution.     One  cc  is  equivalent  to 

Acid,  acetic H,C2H302 0.0060  gram. 

"      boric II3BO3 0.0062 

"      citric 1 1., C  "oil  ,07,1120 o!oo7o 

"      hydrobromic IIBBr 0.0081 

"      hydrochloric HCI 0.00365 

"      hydriodic Ill 0.0128 

"      lactic nCallsOa 0.0090 

"      malic CJIgO.5 0.0067 

"      nitric IINO3 0.OC63 

"      oxalic ir2C20,,2lI,,0 0.0063 

.,       ,        ,      .  -.  -,,^    \  to  form  K,.HPO,with  / 

'       phrjsnhonc Ji.,r(J. -,         ,         ,  T    ,     ,   .  .0,0049 

'        '  •*       M       phcnol[)hthalcm        )  ■' 

..       ,        ,      .  TT  x,^  J  to  form  KHjPO.with ) 

"     phosphoric U,VO,,  ,    ,  ,0.0098 

'        '  ■'       M       methyl  orange         )  ■' 

"     sulphuric ILSO^ 0.0049 

"     tartaric II^C^H^Oe 0-0075 

Potassium  bitartrate KHC^H^Oj 0.0188 

Sodium  Ixjratc Na2B^07,ioH20 0.00955 

♦  To  be  ignited. 


THE  LABORATORY  AND  ITS  EQUIPMENT.  37 

No.  142.    Decinormal  Iodine  Solution.     One  cc.  is  cfjuivalent  to 

Arsenious  oxide AsjOj 0.00495  gram. 

Potassium  sulphite KaSOsjaH^O 0.0097 

Sodium  bisulphite NaHSOj 0.0052 

"        sulphite, Na2S03,7H20 0.0126 

"        thiosulphate Na^SjOajSHjO 0.0248 

Sulphur  dioxide SO, 0.0032 

Sulphurous  acid HoSOj o .  004 1 

No.  245.   Decinormal  Sodium  Thiosulphate  Solution.     One  cc.  is  equivalent  to 

Bromine Br o. 0080  gram. 

Chlorine CI 0.00355     " 

Iodine I 0.01266    " 

Iron  (in  ferric  salts) Fe 0.0056      " 

No.  230.    Decinormal  Silver  Nitrate  Solution.*     One  cc.  is  equivalent  to 

Ammonium  bromide NH^Br o .  0098  gram. 

chloride NH^Cl 0.00535     " 

Chlorine CI 0.00355     " 

Cyanogen (CN)2 0.0052       " 

Hydrocyanic  acid HCN  with  indicator 0.0027       " 

Ar-vT  i  'o  formation  of  precip-  } 

"  "      HCN-'  '^  ro.0054      " 

(      itate  '  ^ 

Hydrobromic  acid HBr o.ooSo  " 

Potassium  bromide KBr 0.0119  " 

"  chloride KCl 0.00745  " 

"  cyanide KCN  with  indicator 0.0065  " 

T-^xT  (  to  formation  of  precip-)  ,, 

"  "      KCN-       .  '.  o.oi^o 

I      itate )  -^ 

Sodium  bromide NaBr 0.0103      " 

"        chloride NaCl 0.00585     " 

No.  201.   DEcixoRii.A.L  Potassium  Bichrom,a.te  Solution.!     One  cc.  is  equivalent  to 

Ferrous  carbonate FeCOj 0.0116  gram. 

Ferric  oxide Fe203 0.0080       " 

Ferrous  oxide FeO o . 007 2       " 

"        sulphate FeSO^ 0.0152       " 

FeSO^jHoO 0.0278      *' 

Iron  (ferrous) Fe 0.0056       " 

No.  220.   Decinormal  Potassium  Peejjang.^nate  Solution.     One  cc.  is  equivalent  to 

Oxalic  acid H2C20^,2HoO o. 0063  gram, 

and  to  same  weights  for  iron  salts  as  given  under  N/io  K^Ct^Ot 

*  Use  potassium  chromate  solution  as  an  indicator,  or  add  till  precipitate  appears. 

t  Use  a  freshly  prepared  solution  of  potassium  ferricyanide  as  an  indicator,  applying  a  drop  of  titrated  solu- 
tion to  a  drop  of  indicator  on  a  white  surface. 


o8 


FOOD   INSPECTION  ^ND  ^N.^ LYSIS. 


The  following  table  from  Talbot  *  shows   the  reactions  of    the  com- 
mon indicators  used  in  acidinietrv; 


Indicator. 

Reaction  with 
Acids. 

Reaction 

with 
Alkalies. 

Use  with 

Carbonic 

Acid  in  Lold 

Solution. 

Use  witli 

Carbonic 

Acid  in  Hot 

Solution. 

Use  with 

Ammonium 

Salts. 

Use  with 
Organic  ."icid. 

Red 

Blue 
Yellow 
Pink 
Blue 
Blue 
Pink 
Red 

Unreliable 
Reliable 
Unreliable 
Unreliable 
Reliable 
Unreliable 
Unreliable 

Reliable 

Unreliable 
Reliable 
Reliable 
Reliable 
Reliable 
Reliable 

Reliable 
Reliable 

Unreliable 
Reliable 
Reliable 

I'nreliable 
Reliable 

ReliabiS 

Mcihyl  orange.  . . 
Phenolphtlialein.  . 

Lacinoiil 

Cmhineal 

Rosolic  acid 

Alizarine 

Pink 

Colorless 

Purple-red 

Purple-red 

Yellow 

Yellow 

Unreliable 

Reliable 

Unreliable  ( ?) 

Unrelial)le 

Unreliable! 

Reliable 

*  Talbot,  Ou.mtitative  Analysis,  page  75. 
■f  Reliable  wiih  oxalic  acid. 

REFERENXES    ON    L.\BORATORV    EQUIPMENT,    RE.\GENTS,    ETC. 

AoRiANCE,  J.  S.     Laboratory  Calculations.     New  York,  1897. 

AfKiNsox,  E.  Suggestions  for  the  Establi.shnicnt  of  Food  Latjoratorics.  U.  S.  Dept. 
of  .\gric.,  Off.  of  E.xp.  Sta.,  Bui.  17. 

C')iiN",  .\.  J.  Tests  and  Reagents,  Chemical  and  Microscopical,  known  by  their  Authors* 
Names.     New  York,  1903. 

K  CN'WuOD,  II.  R.  Public  Health  Laboratory  Work.  The  Hygienic  Laboratory.  Phila- 
delphia, 1893. 

Frauch,  C.     Testing  of  Chemical  Reagents  for  Purity.     London,  1903. 

1  CNGE,  G.,  and  HuRTf:R,  F.     AlkaU-maker's  Handbook.     London,  1891. 

^lAYRHOFER,  J.  Instrumcnte  und  Apparale  zur  Nahrungsmittel  Untersuchung. 
Leipzig,  1894. 

Mercks  1907  Index.     Merck   &  Co.,  New  York. 

ScHNTCHJER,  A.     Reagents  and  Reactions  known  by  the  Names  of  their  Authors.     1897. 

S'.'TTO.N",  F.     \'olumetric  Analysis.     8th  Ed.     Philadelphia,  1900. 

TiORPE,  T.  E.     Dictionary  of  Applied  Chemistry.     London,  1912. 


CHAPTER  III. 

FOOD,  ITS  FUNCTIONS,  PROXIMATE  COMPONENTS,  AND 
NUTRITIVE  VALUE. 

Nature  and  General  Composition. — Food  is  that  which,  when  eaten, 
serves  by  digestion  and  absorption  to  support  the  functions  and  powers 
of  the  body,  by  building  up  the  material  necessary  for  its  growth  and 
by  supplying  its  wastes.  The  raw  materials  that  constitute  our  food- 
supply  are  not  all  available  for  nourishment,  but  often  contain  a  propor- 
tion of  inedible  or  refuse  matter,  which  it  is  customar}'  to  remove  before 
eating,  such  as  the  bones  of  fish  and  meat,  the  shells  of  clams  and  oysters, 
eggshells,  the  bran  of  cereals,  and  the  skins,  stones,  and  seeds  of  fruits 
and  vegetables.  The  proximate  components  which  make  up  the  edible 
portion  of  food  include  in  general  water,  fat,  various  nitrogenous  bodies 
consisting  chiefly  of  proteins,  carbohydrates,  organic  acids,  and  mineral 
matter.  Of  these  water  is  hardly  to  be  considered  as  a  nutrient,  though 
it  plays  an  important  part  in  nearly  all  foods  as  a  diluent  and  solvent. 
The  fats,  proteins,  and  carbohydrates  all  contribute  in  varying  degree  to 
the  supply  of  fuel  for  the  production  of  heat  and  energy.  Besides  this 
universal  function,  the  fats  and  the  carbohydrates  serve  especially  to  fur- 
nish fatty  tissue  in  the  body,  while  the  proteins  are  the  chief  source  of 
muscular  tissue. 

Liebig's  classification  of  foods  into  nitrogenous,  or  flesh  formers,  and 
non-nitro  gene  oils,  or  heat  generators,  is  now  no  longer  accepted  as  strictly 
logical,  in  view  of  the  w^ell-known  fact  that  the  nitrogenous  materials, 
besides  building  up  the  body,  aid  in  supplying  the  wastes  and  yielding 
energy,  and  may  even  be  converted  into  fats  or  carbohydrates,  while  the 
non-nitrogenous  aid  in  furnishing  tissue  growth  in  addition  to  serving  as 
fuel. 

The  Fat  of  Food. — Fats  are  the  glycerides  of  the  fatty  acids,  the 
characteristics  of  the  various  edible  fats  and  oils  being  treated  of  under 

39 


40  FOOD   IKSPFCTION  AND   ANALYSIS. 

their  appropriate  headings  elsewhere.  Fat  in  human  food  is  supphed  by 
milk  and  its  protluets,  by  the  adipose  tissue  of  meat,  and  in  slight  extent 
by  the  oil  of  eereals  and  by  the  edible  table  oils.  The  term  "ether  extract" 
is  sometimes  used  in  stating  the  results  of  the  analysis  of  foods  and  this 
includes  other  substances  than  fat  which  when  present  are  extracted  by 
ether,  such  as  chloroj)hyl  and  other  coloring  matters,  lecithin,  alkaloids,  etc, 

NITROGENOUS  COMPOUNDS  AND  THEIR  CLASSIFICATION.— These  sub- 
Stances  may  for  convenience  be  grouj)ed  as  follows: 

A  Proteins,  B  Amino-acids  and  Amides,  C  Alkaloids,  D  Nitrates, 
E  Ammonia,  and  F  Lecithin. 

A.  Proteins. — This  term  includes  a  large  number  of  nitrogenous  bodies 
consisting,  according  to  our  present  knowledge,  essentially  of  combinations 
of  «-amino-acids  and  their  derivatives.  Proteins  in  one  form  or  another 
exist  in  nearly  all  natural  foods  both  animal  and  vegetable.  The  terms 
"proteids"  or  "albuminoids"  were  formerly  used  genericallyas  synonymous 
vith  "protein"  to  include  all  nitrogenous  bodies  of  this  group,  but  recently 
a  joint  committee  on  protein  nomenclature  of  the  American  Physiological 
Society  and  the  American  Society  of  Biological  Chemists  recommended 
that  the  word  "proteid"  be  abandoned;  that  "protein  "be  used  todesignate 
the  entire  group;  and  that  the  word  "albuminoids"  be  restricted  to  a  sub- 
group of  proteins.  A  committee  of  the  Physiological  Society  of  England 
also  made  the  same  recommendation  as  to  the  use  of  the  term  protein. 
The  classification  and  most  of  the  defmilions  here  given  are  those  adopted 
by  the  American  committee.* 

Proteins  available  for  food  are  sup])lied  chieOy  by  the  flesh  of  meat  and 
fish,  by  milk,  cheese,  and  eggs,  and  in  the  vegetable  kingdom  by  seeds, 
nuts,  and  vegetables,  especially  the  legumes.  The  ])roportion  of  crude 
protein,  often  designated  merely  as  "protein,"  is  conimonly  estimated  by 
multiplying  by  6.25  the  percentage  of  nitrogen  found  in  the  material 
analyzed.  This  is  done  on  the  assumption  that  all  of  the  nitrogen  present 
in  the  substance  belongs  to  protein  containing  16  per  cent  of  nitrogen. 

There  is  no  marked  distinction  in  chemical  constitution  between  animal 
anrl  vegetable  jjroteins,  although  some  of  the  types  have  as  yet  been  found 
only  in  one  or  the  other  kingdom.  All  proteins  are  insoluble  in  pure 
alcohol  or  in  ether.  A  few  are  soluble  in  water  but  most  are  not.  Nearly 
all  are  .soluble  in  very  dilute  acids  or  alkalies,  while  all  are  decomposed  by 
boiling  with  concentrated  mineral  acids  or  concentrated  caustic  alkalies. 
All  proteins  are  la.-vo-rotary  with  polarized  light. 

*  Am.  Jour.  I'hys.,  21,  1908,  \).  xxvii. 


FOOD,  ITS   FUNCTIONS,  I'ROXIMATE    COVIPONENTS,  FTC.  41 

Qualitative  Test  for  Proteins.  —  Xanthoproteic  Reaction. — Concen- 
trated nitric  acid  added  to  a  solution  of  a  protein  may  or  may  not  form  a 
precipitate.  It,  however,  produces  a  yellow  coloration  on  boiling.  Addi- 
tion of  ammonia  in  excess  turns  the  precipitate  or  liquid  yellow  or  orange. 

Millon's  Reaction. — Millon's  reagent  No.  184,  page  30,  when  added  to 
a  protein  solution  produces  a  white  precij^itate,  which  Ijccomes  brick-red 
on  heating.  Sodium  chloride  ])revents  the  reaction.  X'arious  organic 
substances  are  precipitated  by  Alillon's  reagent,  but  these  precipitates  do 
not  turn  red  on  heating. 

Biuret  Reaction. — If  a  solution  of  a  protein  in  flilute  sulphuric  acid  be 
made  alkaline  with  potassium  or  sodium  'nydroxide  and  very  dilute  copper 
sulphate  be  added,  a  reddish  to  violet  coloration  is  produced,  similar  to 
that  formed  if  biuret*  be  treated  in  the  same  way,  hence  the  name.  An 
excess  of  copper  sulphate  should  be  avoided  lest  its  color  obscure  that  of 
the  reaction. 

In  solutions  which  are  strongly  colored  this  reaction  is  of  little  use 
unless  modified  as  follows:  A  considerable  quantity  of  the  dilute  copper 
sulphate  solution  is  added  to  the  solution  made  alkaline  with  a  large  excess 
of  potassium  hydroxide,  and  then  solid  potassium  hydroxide  is  dissolved 
to  almost  complete  saturation  in  the  solution.  The  mixture  is  then  shaken 
with  about  one  half  its  volume  of  strong  alcohol.  On  standing  the  alcohol 
separates  as  a  clear  layer  of  a  violet  or  crimson  color  if  proteins  are  present. 

I.  THE  SIMPLE  PROTEINS.— Protein  substances  which  yield  only  a- 
amino  acids  or  their  derivatives  on  hydrolysis. 

Although  no  means  are  at  present  available  whereby  the  chemical 
individuality  of  any  protein  can  be  established,  a  number  of  simple  pro- 
teins have  been  isolated  from  animal  and  vegetable  tissues  which  have  been 
so  well  characterized  by  constancy  of  ultimate  composition  and  uniformity 
of  physical  properties  that  they  may  be  treated  as  chemical  individuals 
until  further  knowledge  makes  it  possible  to  characterize  them  more  defi- 
nitely. 

(a)  Albumins. — Simple  proteins  soluble  in  pure  water  and  coagulable 
by  heat. 

Examples. — Seralbumin  of  blood  and  other  animal  fluids;  lactalbumin 
of  milk;  leucosin  of  the  seeds  of  wheat,  rye,  and  barley;  legumelin  of  legu- 
minous seeds. 

*  Biuret  is  the  substance  formed  by  heating  urea  to  160°  according  to  the  following 
reaction: 

2C()X2H,     =  CjO.NjHs     +      NH3. 

Urea  Biuret                Ammonia 


42  FOOD  INSPECTION  AND  ANALYSIS. 

Coagulation. — Animal  albumins  usually  coagulate  at  about  75°; 
■vegetable  albumins  at  about  65°. 

Miscellaneous  Reactions. — Very  dilute  acids  precipitate  albumins  with 

the   aid  of   heat.     Nitrate   of  mercury  (in  dilute  nitric  acid)  precipitates 

albumins  from  their  solutions;  also  Mayer's  solution  acidified  with  acetic 

acid.     Thcv   are   precipitated   by   saturation   with   ammonium   sulphate. 

These  reactions  are  not,  however,  characteristic  of  the  group. 

(b)  Globulins. — Simple  proteins  insoluble  in  pure  water,  but  soluble  in 
neutral  solutions  of  salts  of  strong  bases  with  strong  acids. 

E.vamples. — Myosin  of  muscle  substance;  legumin  of  leguminous  seeds; 
amandin  of  almonds. 

Qualitative  Tests. — Globulins  are  precipitated  from  their  solution  by 
dialysis  or  dilution.     Albumins  are  not  thus  preci{)itated. 

(c)  Glutelins. — Simple  proteins  insoluble  in  all  neutral  solvents,  but 
rcadilv  soluble  in  very  dilute  acids  and  alkalies. 

Examples. — Glutenin  of  wheat  is  the  only  well  defined  protein  of  this 
group. 

(d)  Prolamins. — Simple  proteins  soluble  in  relatively  strong  alcohol 
(70-80  per  cent),  but  insoluble  in  water,  absolute  alcohol,  and  other 
neutral  solvents. 

E.xamples. — Gliadin  of  wheat;  zein  of  maize;  hordein  of  barley.  Found 
as  vet  only  in  the  seeds  of  cereals. 

The  use  of  appropriate  prefixes  will  sufike  to  indicate  the  origin  of 
compounds  of  sub-classes  a,  b,  c,  and  d,  as  for  exam[)le:  ovoglobulin, 
myalbumin,  etc. 

(e)  Albuminoids. — Simple  j^roteins  which  possess  essentially  the  same 
chemical  structure  as  the  other  proteins,  but  are  characterized  by  great 
insolubility  in  all  neutral  solvents. 

E.xamples. — Keratins  of  hair,  nails,  hoofs,  horn,  feathers,  etc.;  elastin 
of  connective  tissues;  collagen  of  connective  tissues  and  cartilage;  fibroin 
and  sericin  of  raw  silk.    No  albuminoids  have  yet  been  discovered  in  plants. 

Gelatin  is  usually  regarded  as  an  albuminoirl  but  does  not  come  strictly 
within  the  requirements  of  the  above  definition.  It  is  an  artificial  deriva- 
tive of  collagen  and  is  formed  from  it  by  boiling  with  water  or  subjecting 
to  steam  under  pressure.  It  is  prepared  frf)m  bones  anrl  oilier  animal 
parts,  and  is  insoluble  in  cold,  but  soluble  in  hot  water.  When  the  hot 
water  solution  containing  one  per  cent  or  more  of  gelatin  cools,  it  forms  a 
jelly.  By  prolonged  boiling  the  gelatinizing  power  is  lost.  Aqueous 
solutions  are  strongly  kevo-rotary. 


FOOD,  ITS   FUNCTIONS,   PROXIMATE  COMPONENTS,  ETC.  43 

Gelatin  in  common  with  most  i)rotein.s  is  precipitated  from  its  solution 
by  mercuric  chloride,  picric  acid,  and  tannic  acid.  It  is  readily  distin- 
guished from  soluble  proteins,  in  that  it  is  not  precipitated  from  its  solution 
by  lead  acetate,  nor  by  most  of  the  metallic  salts  that  throw  down  proteins. 

(f)  Histones. — Soluble  in  water  and  insoluble  in  very  dilute  ammonia, 
and,  in  the  absence  of  ammonium  salts,  insoluble  even  in  an  excess  of 
ammonia;  yield  precipitates  with  solutions  of  other  porteins,  and  acoagu- 
lum  on  heating,  which  is  easily  soluble  in  very  dilute  acids.  On  hydrolysis 
they  yield  a  large  number  of  amino-acids,  among  which  the  basic  ones 
predominate. 

Examples. — Thymus  histone.     Not  found  in  plants. 

(g)  Protamins. — Simpler  polypeptides  than  the  proteins  included  in 
the  preceding  groups.  They  are  soluble  in  water,  uncoagulable  by  heat, 
have  the  projjerty  of  precipitating  a(iueous  solutions  of  other  proteins, 
possess  strong  basic  properties,  and  form  stable  salts  with  strong  mineral 
acids.  They  yield  comparatively  few  amino-acids,  among  which  the  basic 
amino-acids  greatly  predominate. 

Examples. — Salmin,  clupein,  and  other  protamins  of  fish  spermatozoa. 
Not  found  in  plants. 

II.  Conjugated  Proteins. — Substances  which  contain  the  protein 
molecule  united  to  some  other  molecule  or  molecules  otherwise  than  as  a 
salt. 

(a)  Nucleoproteins. — Compounds  of  one  or  more  protein  molecules 
with  nucleic  acid. 

Examples. — The  nucleins  formed  by  pepsin  digestion. 

(b)  Glycoproteins. — Compounds  of  the  protein  molecule  with  a  sub- 
stance or  substances  containing  a  carbohydrate  group  other  than  a  nucleic 
acid. 

E.xamplcs. — ^lucins;  ovomucoid;  ovalbumin. 

(c)  Phosphoproteins. — Compounds  of  the  protein  moiCCule  with  some 
yet  undefined  phosphorus-containing  substance  other  than  a  nucleic  acid 
or  lecithins. 

Examples. — Casein  of  mill-:;  vitellin  of  egg  yolk. 

(d)  Haemoglobins. — Compounds  of  tlie  protein  molecule  with  haematin 
or  some  similar  substance. 

Example. — Oxyhaemoglobin  of  red  blood  corpuscles. 

(e)  Lecithoproteins. — Compounds  of  theprotein  moleculewith  lecithins, 
(lecithans,  phosphatides). 

Examples. — Lecithalbumin;  lecithin-nucleovitellin. 


44  FOOD   INSPECTION   AND   ANALYSIS. 

III.  Derived  proteins. 

1.  Primary  Protein  Derivatives. — Derivatives  of  the  protein  mole- 
cule, apparently  formed  through  hydrolytic  changes  which  involve  only 
slight  altteraiions  of  the  molecule. 

(a)  Proteans. — Insoluble  products  which  apparently  result  from  the 
incipient  action  of  water,  very  (Hlute  acids  or  enzymes. 

Exam  pits. — Edestan;    blood  fibrin;    insoluble  myosin. 

(b)  Metaproteins. — Products  of  the  further  action  of  acids  or  alkalies, 
whereby  the  molecule  is  so  far  altered  as  to  form  products  soluble  in  very 
weak  acids  and  alkalies,  but  insoluble  in  neutral  lluids. 

Examples. — Acid  albumin;  alkali  albumin. 

This  group  will  thus  include  the  familiar  "acid  proteins"  and  "alkali 
proteins."  not  the  salts  of  proteins  with  acids. 

(c)  Coagulated  Proteins. — Insoluble  products  which  result  from  (i) 
the  action  of  heat  on  their  solutions,  or  (2)  the  action  of  alcohol  on  the 
protein. 

Examples. — Albumin  coagulated  by  heat  or  alcohol. 

2.  Secondary  Protein  Derivatives.  Products  of  the  further  hydro- 
lytic cleavage  of  the  protein  molecule. 

(a)  Proteoses. — Soluble  in  water,  uncoagulated  by  heat,  and  precipi- 
tated by  saturating  their  solutions  with  ammonium  or  zinc  sulphate. 

As  thus  delined  this  term  does  not  strictly  cover  all  the  protein  deriva- 
tives commonly  called  proteoses,  e.g.  heteroproteose  and  dysproteose. 

Subdivision  of  the  Proteoses. — According  to  the  i)roteins  from  which 
they  are  derived  the  proteoses  may  be  designated  albiimose,  from  albumin, 
globulose,  from  globulin,  vi/cllosc,  from  vitellin,  caseose,  from  casein,  etc. 

Proteoses  are  subdi\ided  mio  proto- proteose ,  soluble  in  water  (both  cold 
and  hot)  or  in  dilute  salt  solutions,  but  precipitated  by  saturation  with 
salt;  hetero- proteose,  insoluble  in  water,  and  deutero-proteose,  soluble  in 
water,  but  not  precipitated  by  saturation  with  salt. 

Vegetable  proteoses  are  sometimes  called  phyt-albumoses. 

Qualitative  Tests. — Besides  responding  to  the  biuret  reaction  (p.  41) 
proteoses  are  precipitated  by  nitric  acid,  the  precipitate  being  soluble  on 
heating,  but  reappearing  on  cooling. 

Proto- proteose  is  precipitated  from  its  solution  by  mercuric  chloride 
and  copper  sulphate;  hetero-proteose  is  precipitated  by  mercuric  chloride, 
but  not  by  copper  sul]>hate. 

(bj  Peptones. — Soluble  in  water,  uncoagulated  by  heat,  and  not  pre- 
cipitated by  saturating  their  sc^lutions  with  ammonium  sulphate. 


FOOD,  ITS  FUNCTIONS,  PROXIMATE    COMPONENTS,  ETC. 


AS 


Qualitative  Tests. — Besides  giving  the  biuret  reaction,  peptones  are 
precipitated  from  their  solution  by  tannic  acid,j)icric  acid,phosphomolybdic 
acid,  and  by  sodium  phosphotungstate  acidified  by  acetic,  phosphoric,  or 
sulphuric  acid. 

Peptones  are  the  only  soluble  proteins  not  jjrecipitated  by  saturation 
with  ammonium  sulphate.  The  following  table,  showing  the  reaction  of 
proteoses  and  peptones,  is  due  to  Halliburton:* 


Variety 

of 
Protein. 


Proto- 
albumose 


Hetero- 
albumose 


Deutero- 
albumose 


Peptone 


Hot  and 
Cold  Water. 


Soluble 


Insoluble;  i.e. 
precipitated 
by  dialysis 
from  saline 
solutions 


Soluble 


Soluble 


Hot  and 

Cold  Saline 

Solutions, 

e.g.,  io% 

NaCl. 


Soluble 


Soluble;  part- 
ly precipita- 
ted, but  not 
coagulated 
o  n  heating 
to  6s°  C. 

Soluble 


Soluble 


Satura- 
tion with 
NaCl  or 
MgS04. 


Precipi- 
tated 


Precipi- 
tated 


Not  pre- 
cipitated 


Not  pre- 
cipitated 


Satura- 
tion with 

(NH4)2S04 


Precipi- 
tated 


Precipi- 
tated 


Precipi- 
tated 


Not  pre- 
cipitated 


Nitric  Acid. 


Precipitated 
in  cold;  pre- 
cipitate dis- 
solves with 
heat  and  re- 
appears on 
cooling 

Ditto 


This  reaction 
occurs  only 
in  presence 
of  excess  of 
salt 

Not  pre- 
cipitated 


Copper 
Sulphate. 


Precipi- 
tated 


Precipi- 
tated 


Not  pre- 
cipitated 


Not  pre- 
cipitated 


Copper 

Sulphate 

and  Caustic 

Potash. 


Rose-red 
color  (biu- 
ret reac- 
tion) 


Ditto 


Ditto 


Ditto 


(c)  Peptides. — Definitely  characterized  combinations  of  two  or  more 
amino-acids,  the  carboxyl  group  of  one  being  united  with  the  amino  group 
of  the  other,  with  the  elimination  of  a  molecule  of  water. 

The  peptones  are  undoubtedly  peptides  or  mixtures  of  peptides,  the 
latter  term  being  at  present  used  to  designate  those  of  definite  structure. 

B.  AMINO-ACIDS,  Amides,  and  Allied  products.  —  Under  this 
head  are  included  products  derived  from  acids  or  bases,  the  radicles  of 
which  replace  one  or  more  of  the  hydrogen  atoms  in  ammonia.  The  most 
common  bodies  of  this  class  occuring  in  food  products  are: 

(i)  Cholin  (C5Hj5N02),  found  in  the  mu.scular  tissue  of  cattle  and  in 
yolk  of  eggs,  also  in  certain  fungi. 

(2)  Betaine  (C5H^^N02),  found  in  certain  mollusks,  as,  for  instance, 
the  mussel,  in  putrefying  fish,  and  (in  the  vegetable  kingdom)  in  beets  and 
hops.    It  is  formed  by  the  oxidation  of  cholin. 

(3)  Asparagin  (C^HgNoOg),  found  in  the  shoots  of  asparagus,  lettuce, 
peas  and  beans,  and  in  the  root  of  the  marshmallow.    It  may  be  crystal- 


*  Chemical  Physiology  and  Pathology,  page  131. 


46  FOOD   INSPECTION  AND   ANALYSIS. 

lized  out  from  the  expressed  juice  of  the  asparagus  shoots  by  evaporation, 
after  having  removed  the  albumin  by  coagulation  (by  boiling)  and  by- 
filtration.* 

Asparagin  when  heated  with  alkalies  forms  ammonia,  and  with  acids 
forms  ammcmium  salts.  Freshly  prepared  copper  hydroxide  is  dissolved 
by  an  aqueous  solution  of  asparagin  by  the  aiil  of  heal.  If  sections  of 
vegetable  tissues  containing  asparagin  are  placed  in  alcohol,  crystals 
cf  asparagin  arc  formed  in  such  a  manner  as  to  be  detected  under  the 
microscope.f 

Closely  allied  to  the  amides  are  the  flesh  bases  of  meat,  chief  among 
v.hich  are  creatin  (C^HyNaO,),  crcatinin  (C4H7N3O),  derived  from  crea- 
tin  by  the  action  of  mineral  acids  and  existing  in  some  fish,  carnin 
(C^HsN.Os),  and  xanthin  (CsH.N.Oj). 

C.  AlkaloidAL  Nitrogen,  —  Alkaloids  do  not  naturally  occur  in 
foods,  with  the  exception  of  tea,  coflee,  and  kola-nuts,  which  contain 
caffeine,  and  cocoa,  which  contains  theobromine. 

D.  Nitrogen  as  Nitrates. — Foods  in  their  natural  condition  rarely 
contain  nitrates.  Meats  cured  wdth  saltpetre  furnish  the  most  common 
instance  of  nitrates  in  food.  Nitrates  are  tested  for  by  extracting  the 
sample  with  water,  and  treating  the  extract  with  ferrous  sulphate  and 
sulphuric  acid  in  the  usual   manner. 

E.  Nitrogen  as  Ammonia.  —  Ammonia  occurs  very  sparingly  in 
food,  unless  the  latter  has  undergone  some  form  of  decomposition.  In 
ripened  cheese  and  in  sour  milk  one  sometimes  finds  it  in  minute  quan- 
tities. Its  presence  is  tested  for  by  distilling  the  finely  divided  sample  in 
water  free  from  ammonia,  and  testing  the  distillate  with  Nessler's  reagent. 

F.  Lecithin.— This  substance  (Q^H^oNPOg)  is  a  phosphorized 
fat,  and  forms  a  part  of  the  cell  material  in  certain  animal  and  vegetable 
foods.  It  is  found  in  consideraljle  quantity  in  the  yolk  of  egg,  and,  in 
traces,  in  cereals,  peas,  and  beans.  It  is  a  yellowish-white  solid,  soluble 
in  ether  and  alcohol.  Treated  with  water  it  swells  up,  forming  an  opales- 
cent solution  or  emulsion,  from  which  it  is  j)recipitatcd  by  salts  of  the 
alkali  metals. 

The  Carbohydrates  and  their  Classification.— The  carbohy- 
drates supplied  by  food  are  milk  sugar  and  the  various  sugars,  starches, 
and  gums  from  plant  juices,  cereals,  fruits,  and  vegetables.  Carbohy- 
drates are  generally  understood  as  being  compounds  of  carbon,  hydrogen, 
and  oxygen,  the  last  two  elements  being  present  in  the  proportion  in 

♦  Zeits.  fur  analytische  Chemie,  22,  page  325. 

t  Wiley,  Principles  of  Agric'l  Analysis,  \'ol.  III.  p.  427. 


FOOD,  nS   ('UNCTIONS,  PROXIMATE   COMPONENTS,  ETC.  aJ 

which  they  occur  in  watcn     They  arc  divided  into  three  main  classes,  as 
follows : 

A.  The  Glucose  Group,  or  Monosaccharids  (CeHizOj),  including 
dextrose,  levulose,  and  galactose. 

B.  The  Cane  Sugar  Group,  or  Disaccharids  (C12H22O11),  including 
cane  sugar,  milk  sugar,  and  maltose. 

C.  The  Cellulose  Group  (CeHigOj),  including  starch,  cellulose,  dex- 
trin, gums,  etc. 

Closely  allied  to  the  carbohydrates,  if  not  actually  belonging  to  them, 
are  inosite  (CgHijOe),  occurring  in  muscular  tissue,  and  peclose,  found 
in  green  fruits  and  vegetables. 

The  Organic  Acids. — These  acids  are  minor  though  important 
constituents  of  foods.  From  their  conversion  into  carbonates  within 
the  body,  they  are  useful  in  furnishing  the  proper  degree  of  alkalinity 
to  the  blood  and  to  the  various  other  fluids,  besides  being  of  particular 
value  as  appetizers.  They  exist  in  foods  both  in  the  free  state  and  as 
salts.  Acetic  acid  is  supplied  by  vinegar;  lactic  acid  by  milk,  fresh  meat, 
and  beer;  citric,  malic,  and  tartaric  acids  by  the  fruits. 

Mineral  or  Inorganic  Materials.  —  These  substances  occur  in 
food  in  the  form  of  chlorides,  phosphates,  and  sulphates  of  sodium,  potas- 
sium, calcium,  magnesium,  and  iron,  and  are  furnished  by  common  salt,  as 
well  as  by  nearly  all  animal  and  vegetable  foods.  The  inorganic  salts  are 
necessary  to  supply  material  for  the  teeth  and  bones,  besides  having  an 
important  place  in  the  blood  and  in  the  cellular  structure  of  the  entire  body. 

FUEL  Value  of  Food. — In  order  to  express  the  capacity  of  foods  for 
yielding  heat  or  energy  to  the  body,  the  term  fuel  value  is  commonly  used. 
By  the  fuel  value  of  a  food  material  is  meant  the  amount  of  heat  expressed 
in  calories  equivalent  to  the  energy  which  we  assume  the  body  could  obtain 
from  a  given  weight  of  that  food  material,  if  all  of  its  nutritents  were 
thoroughly  digested,  a  calorie  being  the  amount  of  heat  required  to  raise  a 
kilogram  of  water  1°  C.  This  definition  applies  to  what  is  known  as  the 
large  calorie,  which  is  one  thousand  times  as  large  as  the  small  calorie. 
Large  calories  are  meant  wherever  the  term  occurs  in  this  volume.  The 
fuel  value,  or,  as  it  is  sometimes  called,  "heat  of  combustion,"  may  be 
determined  experimentally  with  a  calorimeter,  or  may  be  calculated  by 
means  of  factors  based  on  the  result  of  many  experiments  showing  the 
mean  values  for  protein,  fats,  and  carbohydrates. 

The  Bomb  Calorimeter.'^ — This  apparatus  in  its  most  approved  form, 

*  U.  S.  Dept.  of  Agric,  Off.  of  Exp.  Sta.,  Bui,  21,  pp.  120-126. 


4S 


hOOD   ISSPECTION    ^ND    ANALYSIS. 


Fig.  13,  consists  of  a  water-tight,  cylindrical,  platinum  lined,  Sceel  bomb, 
adapted  to  hold  in  a  capsule  the  substance  whose  heat  is  to  be  determined, 
and  containing  also  oxygen  under  pressure.  This  bomb  is  immersed  in 
water  contained  in  a  metal  cylinder,  which  is  in  turn  placed  inside  of 
concentric  cylinders  containing  alternately  air  and  water.  The  heat  for 
igniting  the  substance  is  supplied  by  the  electric  current  passing  through 
wires  to  the  interior  of  the  bomb  and  acting  upon  a  cleverly  devised 
mechanism  therein.     The  heat  developed  by  the  ignition  is  measured  by 


Fig.  13. — Boml.)  Calorimeter  of  Hempel  and  Atwater 

the  rise  in  temperature  of  the  water  surrounding  the  bomb,  as  indicated 
by  a  ver)'  delicate  thermometer  graduated  to  hundredths  of  a  degree, 
certain  corrections  being  made,  as,  for  instance,  for  the  heat  absorbed  by 
the  metal  of  the  apparatus.  A  mechanical  stirrer  serves  to  equalize  the 
temyx-'raturc  of  the  water  surrounding  the  bomb. 

Calculation  0}  Fuel  Value. — By  reason  of  its  great  expense  the  calo- 
rimeter is  beyond  the  reach  of  many  laboratories,  and  on  this  account  the 
expression  of  fuel  values  by  calculation  is  the  most  common  method  cm- 
ployed.  For  this  the  factors  of  Rubner  are  generally  used,  in  accordance 
with  which  the  amount  of  energy  in  one  gram  of  each  of  the  three  principal 


FOOD,  ITS    FUNCTIONS,  FROXIM^TF   COMPONENTS,  ETC.  49 

classes  of  nutricnls  arc,  for  carbohydrates  4.1,  for  j^rolein  4.1,  and  for  fats 
9.3.  Expressed  in  pounds,  each  pound  of  carbohydrate  or  i)rotein  has  a 
fuel  value  of  i860  calories,  while  each  pounrl  of  fat  has  a  fuel  value  of 
4220  calories. 


REFERENCES  ON  DIETETICS  AND  ECONOMY  OF  FOOD. 

Albu,  a.,  u.  Neuberg,  C.     MineralstofTwcchsel.     Berlin,  1906. 

Armsby,  H.  p.     The  Principles  of  Animal  Nutrition.     New  York,  1903. 

Atwater,  W.   O.     Dietaries  in   Public  Institutions.     Yearbook  of  U.   S.   Dept.  of 

Agric,  1 90 1,  page  393. 

Food  and  Diet.     Yearbook  of  U.  S.  Dept.  of  Agric,  1894,  page  357. 

Principles  of  Nutrition  and  Nutritive  Value  of  Food.     Farmer's  Bulletin,  142. 

Bellows,  A.  J-     The  Philosophy  of  Eating.     Boston,  1867. 

Burnet,  R.  W.     Foods  and  Dietaries.     Phil.,  1893. 

Bryant,  A.  P.     Some  Results  of  Dietary  Studies  in  the  United  States.     Yearbook  of 

U.  S.  Dept.  of  Agric,  1898,  page  439. 
Chittenden,  R.  H.     The  Nutrition  of  Man.     New  York,  1907. 

Physiological  Economy  in  Nutrition.     New  York,  190^. 

Halliburton,  W.  D.     Text-book  of  Chemical  Physiology  and  Pathology.     London, 

1891. 
Hammarsten,  O.     a  Text-book  of  Physiological  Chemistry.     New  York,  191 2. 
Hutchinson,  Robt.     Food  and  the  Principles  of  Dietetics.     New  York,  1901. 
Jaffa,  M.  E.     The  Study  of  Human  Foods  and  Practical  Dietetics.     Cal.  Exp.  Sta. 

Bui.  no. 
Knight,  J.     Food  and  its  Functions.     London,  1895. 
LusK,  G.     The  Science  of  Nutrition.     Philadelphia  and  London,  1910. 
Neumeister,  a.     Lehrbuch  der  physiologische*  Chemie.     1897. 
Pav\',  F.  W.     a  Treatise  on  Food  and  Dietetics.     London,  1874. 
Richards,  E.  H.     The  Cost  of  Living  as  ^Modified  by  Sanitary  Science.     New  York, 

1900. 

The  Cost  of  Food:  A  Study  in  Dietaries.     New  York,  1901. 

Rubner,  M.     Die  Gesetze  des  Energieverbrauchs  bei  Ernahrung.     Leipzig,  1902. 

Sherman,  H.  C.     Chemistry  of  Food  and  Nutrition.     New  York,  191 1. 

Strohmer,  F.     Die  Ernahrung  des  Menschen. 

Thompson,  W.  G.     Practical  Dietetics.     New  York,  1895. 

Townshend,  S.  H.     The  Relation  of  Food  to  Health.     St.  Louis,  1897. 

True,  A.  C,  and  Milner,  R.  D.     Development  of  Nutrition  Investigations  of  the 

Dept.  of  Agric.     Yearbook  of  V.  S.  Dept.  of  Agric,  1899,  page  403. 
Storrs  Exp.  Station  Annual  Reports,  1888  et  seq. 
Dietetic  and  Hygienic  Gazette. 
Hygienische  Rundschau. 

Revue  de  la  Soc.  Scientifiqite  d'Hygiene  .'X.liment.aire,  1904  et  seq. 
Zeitschrift  fur  Physiologische  Chemie,  1877  et  seq. 


5 2  fOOD    IXSPECT/ON  AND   ANALYSIS. 

Also  the  following  bulletins  of  the  Office  of  Kxprriment  Stations,  U.  S.  Department 
of  Agriculture. 
Bui.  21.     Methods  and  Results  of  Investigations  on  the  Chemistry  and  Economy  of 

Food.     By  \\'.  O.  Atwater.     Pp.  222. 
Bui.  2S.     (Revised  edition.)     The  Chemical  Composition  of  American  Food  Materials. 

By  W.  O.  Atwater  and  A.  P.  Bryant.     Pp.  87. 
Bui.  2Q.     Dietary  Studies  at  the  University  of  Tennessee  in   1895.      By  C.  E.  Wait, 

with  comments  by  \V.  O.  Atwater  and  C.  D.  Woods.     Pp.  45. 
Bui.  31.     Di^nary  Studies  at  the  University  of  Missouri  in  1895,  and  Data  Relating 

to  Bread  and  Meat  Consumption  in  Missouri.     By  H.  B.  Gibson,  S.  Calvert, 

and  n.  W.  May,  with  comments  by  W.  O.  Atwater  and  C.  D.  Woods.     Pp.  24. 
liul.  7,2.     Dietary  Stutlies  at  Purdue   University,  Lafayette,  Ind.,  in  1895.     By  W.  E. 

Stone,  with  comments  by  W.  O.  Atwater  and  C.  D.  Woods.     Pp.  28. 
Bui.  35.     Food  and  Nutrition  Investigations  in  New  Jersey  in  1895  and  1896.     By 

E.  B.  Voorhees.     Pp.  40. 
Bui.  37.     Dietary  Stmlies  at  the  Maine  State  College  in  1895.     By  W.  H.  Jordan.     Pp 

57- 

Bui.  38.  Dietary  Studies  with  Reference  to  the  Food  of  the  Negro  in  Alabama  in  1895 
and  1896.  Conducted  with  the  cooperation  of  the  Tuskegee  Normal  and 
Industrial  Institute  and  the  Agricultural  and  Mechanical  College  of  Alabama. 
Reported  by  W.  O.  Atwater  and  C.  D.  Woods.     Pp.  69. 

Bui.  40.     Dietary  Studies  in  New  Mexico  in  1895.     By  A.  Goss.     Pp.  23. 

Bui.  44.  Report  of  Preliminary  Investigations  on  the  Metabolism  of  Nitrogen  and 
Carbon  in  the  Human  Organism  with  a  Respiration  Calorimeter  of  Special 
Construction.     By  W.  O.  Atwater,  C.  D.  Woods,  and  F.  G.  Benedict.     Pp.  64. 

Bui.  45.  A  Digest  of  Metabolism  Experiments  in  which  the  Balance  of  Income  and 
Outgo  was  Determined.     By  W.  O.  Atwater  and  C.  F.  Langworthy.     Pp.  434. 

Bui.  46.  Dietary  Studies  in  New  York  City  in  1895  and  1896.  By  W.  O.  Atwater  and 
C.  D.  Woods.     Pp.  117. 

Bui.  52.  Nutrition  Investigations  in  Pittsburg,  Pa.,  1894-1896.  By  Isabel  Bevier. 
^  Pp.  48- 

Bui.  53.  Nutrition  Investigations  at  the  University  of  Tennessee  in  1896  and  1897. 
By  C.  E.  Walt.     Pp.  46. 

Bui.  54.     Nutrition  Investigations  in  New  Mexico  in  1897.     By  A.  Goss.     Pp.  20. 

Bui.  55.  Dietar)'  Studies  in  Chicago  in  1895  and  1896.  Conducted  with  the  coopera- 
tion of  Jane  Addams  and  Caroline  L.  Hunt,  of  Hull  House.  Reported  by 
W.  O.  Atwater  and  A.  P.  Bryant.     Pp.  76. 

Bui.  56.  Histor)'  and  Present  Status  of  Instruction  in  Cooking  in  the  Public  Schools 
of  New  York  City.  Reported  by  Mrs.  Louise  E.  Hogan,  with  an  introduction 
by  A.  C.  True,  Ph.D.     Pp.  70. 

Bui.  63.  Description  of  a  New  Respiration  Calorimeter  and  Experiments  on  the 
Conservation  of  Energy  in  the  Human  Body.  By  W.  O.  Atwater  and  E.  B. 
Rosa.     Pp.  94. 

Bui.  68.  A  Description  of  Some  Chinese  Vegetable  Food  Materials  and  their  Nutri- 
tive and  fc^conomic  Value.     By  W.  C.  Blasdale.     Pp.  48. 


FOOD,  ITS    FUNCTIONS,  PXOXlMylTE  COMPOXENTS,  FTC.  51 

Bui.  69.     Experiments  on  the  Metabolism  of  Matter  and  Energy  in  the  Human  T^ody. 
By  W.  O.  Atwater  and  F.  G.  Benedict,  with  the  cooperation  of  A.  W.  Smith 

and  A.  P.  Bryant.     Pp.  112. 
Bui.  71.     Dietary  Studies  of  Negroes  in  Eastern  Virginia  in  1897  and  1898.     liy  H.  B. 

Frissell  and  Isabel  Bevier.     Pp.  45. 
Bui.  75.     Dietary  Studies  of  University  Boat   Crews.       By  W.  O.  Atwater  and  A.  P. 

Hryant.     Pj).  72. 
Bui.  84.     Nutrition  Investigations  at  the  California  Agricultural  Experiment  Station, 

1896-1898.     By  M.  E.  Jaffa.     Pp.  39. 
Bui.  85.     A  Report  of  Investigations  on  the  Digestibility  and  Nutritive  Value  of  Bread. 

By  C.  D.  Woods  and  L.  H.  Merrill.     Pp.  51. 
Bui.  89.     Experiments  on  the  Effect  of  Muscular  Work  upon  the  Digestibility  of  Food 

and  the  Metabolism  of  Nitrogen.     Conducted  at  the  University  of  Tennessee, 

1897-1899.     By  C.  E.  Wait.     Pp.  77. 
Bui.  91.     Nutrition  Investigations  at  the  University  of  Illinois,  North  Dakota  Agricul- 
tural College,  and  Lake  Erie  College,  Ohio,  1896-1900.     By  H.  S.   Grindley 

and  J.  L.  Sammis,  E.  F.  Ladd,  and  Isabel  Bevier  and  Elizabeth  C.  Sprague. 

Pp.  42. 
Bui.  98.     The  Effect  of  Severe  and  Prolonged  Muscular  Work  on  Food  Consumption, 

Digestion,  and  Metabolism,  by  W.  O.  Atwater  and  H.  C.  Sherman,  and  the 

Mechanical  Work  and  Efficiency  of  Bicyclers,  by  R.  C.  Carpenter.     Pp.  67. 
Bui.  107.     Nutrition  Investigations  among  Fruitarians  and    Chinese  at  the  California 

Agricultural  Experiment  Station,  1895^1901.     By  M.  E.  Jaffa.     Pp.  43. 
Bui.  109.     Experiments  on  the  Metabolism  of  Matter  and  Energy  in  the  Human  Body, 

1898-IQ00.     By  W.  O.  Atwater  and  F.  G.  Benedict,  with  the  cooperation  of 

A.  P.  Bryant,  A.  W.  Smith,  and  J.  F.  Snell.     Pp.  147. 
Bui.  116.     Dietary  Studies  in  New  York  City  in  1896  and  1897.     By  W.  O.  Atwater  and 

A.  P.  Bryant.     Pp.  83. 
Bui.  117.     Experiments  on  the  Effect  of  Muscular  Work  upon  the  Digestibility  of  Food 

and  the  Metabolism  of  Nitrogen.     Conducted  at  the  University  of  Tennessee, 

1899-1900.     By  C.  E.  Wait.     Pp.  43. 
Bui.  121.     Experiments  on  the  MetaboHsm  of  Nitrogen,  Sulphur,  and  Phosphorus  in 

the  Human  Organism.     By  H.  C.  Sherman.     Pp.  47. 
Bui.  126.     Studies  on  the  Digestibility  and  Nutritive  Value  of  Bread  at  the  University 

of  Minnesota  in  1900-1902.     By  Harry  Snyder.     Pp.  52. 
Bui.  129.     Dietary  Studies  in  Boston  and  Sj)ringfield,  Mass.,  Philadelphia,  Pa.,  and 

Chicago,  111.     By  Lydia  Southard,  Ellen  H.  Richards,  Susannah  Usher,  Bertha 

M.  Terrill,  and  Amelia  Shapleigh.     Pp.  103. 
Bui.    132.     Further  Investigations  Among  Fruitarians  at  the  California  Agricultural 

Experiment  Station.     By  M.  E.  Jaffa.     Pp.  81. 
Bui.  136.     Experiments  on  the  Metabolism  of  Matter  and  Energy  in  the  Human  Body, 

1900-1902.     By  W.  O.  Atwater  and  F.  G.  Benedict.     Pp.  357. 
Bui.   143.     Studies  on  the  Digestibility  and  Nutritive  Value  of  Bread  at  the  Maine 

Agricultural   Experiment   Station,    1899-1903.     By   C.   D.   Woods  and   L.   H. 

Merrill.     Pp.  77. 


52  FOOD   INSPECTION  .4ND  /I  \' A  LYSIS. 

Bui.  140.  Studies  of  the  Food  of  Maine  Lumbermen.  By  C.  D.  Woods  and  E.  R. 
Manst'ield.     Pp.  60. 

Bui.  150.  Dietary  Studies  at  the  Government  Hospital  for  the  Insane,  Washington, 
D.  C.     By  H.  A.  Pratt  and  R.  D.  Milner.     Pp.  170. 

Bui.  152.  Dietary  Studies  with  Harvard  University  Students.  By  E.  Mallinckrodt, 
jr.     Pp.63' 

Bui.  156.  Studies  on  the  Digestibility  and  Nutritive  Value  of  Bread  and  Macaroni 
at  the  University  of  Minnesota,  1903-1905.     By  Harry  Snyder.     Pp.  80. 

Bui.  15Q.  .\  Digest  of  Japanese  Investigations  on  the  Nutrition  of  Man.  By  K. 
Oshima.     Pp.  224. 

Bui.  162.  Studies  on  the  Influence  of  Cooking  upon  the  Nutritive  Value  of  Meats 
at  the  University  of  Illinois,  1903-1904.  By  H.  S.  (irindley  and  A.  D.  Emmett. 
Pp.  230. 

Bui.  175.  E.xperiments  on  ihe  Metabolism  of  Matter  and  Energy  in  the  Human  Body. 
1903-1904.     By  F.  G.  Benedict  and  R.  D.  Milner.     Pp.  335. 

Bui.  185.     Iron  in  Food  and  Its  Functions  in  Nutrition.     By  H.  C.  Sherman.     Pp.  80. 

Bui.  187.  Studies  of  the  Di:;eslibility  and  Nutritive  Value  of  Legumes  at  the  Uni- 
versity of  Tennessee,  1901-1905.     By  C.  E.  Wait.     Pp.  55. 

Bui.  193.  Studies  of  the  ElTect  of  Different  Methods  of  Cooking  upon  the  Thorough- 
ness and  Ease  of  Digestion  of  Meat  at  the  University  of  Illinois.  By  H.  S. 
Grindley.     Pp.  100. 

Bui.  208.  The  Influence  of  Muscular  and  Mental  Work  upon  Metabolism  and  the 
ElTiciencv  of  the- Human  Body  as  a  Machine.     By  F.  G.  Benedict. 


CHAPTER  IV. 
GENERAL  ANALYTICAL  METHODS. 

Bxtent  of  a  Proximate  Chemical  Analysis.—  For  purposes  of  studying 
the  proximate  composition  of  food  for  its  dietetic  value,  it  is  nearly  always 
necessary  to  make  determinations  of  moisture,  ash,  fat,  total  nitrogen,  and 
carbohydrates  (when  present),  as  well  as  of  the  fuel  value.  In  some  cases 
it  may  be  desirable  to  proceed  further,  to  make  an  analysis  of  the  ash,  for 
instance,  to  separate,  at  least  into  classes,  the  various  nitrogenous  bodies, 
especially  in  flesh  foods,  and  perhaps  to  subdivide  the  starch,  sugar,  gums, 
and  cellulose  or  crude  fiber  that  make  up  the  carbohydrates  in  the  case  of 
cereals. 

An  analysis  is  considered  complete  whenever  the  purpose  for  which 
the  examination  has  been  made  has  been  accomplished,  and  on  that  pur- 
pose depends  solely  the  extent  to  which  the  various  compounds  present 
shall  be  subdivided  and  determined.  Such  a  subdivision  may  be  extended 
almost  indefinitely.  For  example,  a  milk  analysis  may  consist  simply  in 
the  determination  of  the  total  solids  and  (by  difference)  the  water.  Again, 
it  may  be  desirable  to  divide  the  milk  solids  into  fat  and  solids  not  fat, 
and  in  some  cases  to  carry  the  subdivision  still  farther  and  separate  the 
solids  not  fat  into  casein,  albumin,  milk  sugar,  and  ash. 

Determinations  of  one  or  more  of  the  proximate  components  natural 
to  food  are  frequently  of  great  service  in  proving  their  purity  or  freedom 
from  adulteration.  For  the  latter  purpose,  especially  in  such  foods  as  milk, 
vinegar,  oils,  and  fats,  the  determination  of  specific  gravity  is  also  an 
important  factor.  Special  methods  of  a  peculiar  nature  are  often  neces- 
sary in  the  examination  of  particular  foods,  and  such  methods  will  be 
treated  subsequently  under  the  appropriate  headings.  In  the  present 
chapter  only  such  general  methods  as  are  applicable  to  a  large  variety  of 
cases  will  be  discussed. 

Expression  of  Results  of  a  Proximate  Analysis.^Howcvcr  complete  the 
division  of  the  various  proximate  compounds  or  classes  of  compounds 

S3 


54  FOOD  INSPECTION  AND  ANALYSIS. 

which  the  analyst  sees  lit  to  make,  the  results  of  his  various  determina- 
tions in  a  proximate  analysis  are  expected  to  aggregate  about  ioo%. 
If  e\cry  determination  be  directly  made,  the  result  will  rarely  be  exactly 
loo,  but  the  precision  of  the  work  is  apt  to  be  judged  by  its  approach 
to  lOO. 

It  is  often  the  custom  to  determine  certain  compounds  or  classes  of 
comjwunds  by  dilTerence,  Thus  in  cereals  moisture,  uroleins,  fat,  crude 
fiber  and  ash  may  be  determined  by  the  regular  analytical  methods, 
and  by  subtracting  their  sum  from  loo  the  difference  may  be  expressed  as 
*•  nitrogen-free  extract"  or  carbohydrates.  It  has  long  been  customary 
in  food  analysis  to  calculate  the  protein  by  multiplying  the  total  nitrogen 
by  the  factor  6.25,  and  on  this  basis  analyses  of  thousands  of  animal  and 
vegetable  foods  have  been  made.  While  the  figure  thus  obtained  is  an 
arbitrar}-  one,  being  at  best  but  a  rough  approximation  of  the  amount  of 
protein  present,  yet  for  many  reasons  there  is  much  to  commend  this 
practice  of  reporting  results.  In  the  first  place,  in  most  cases  it  actually 
does  approach  the  truth.  Again,  the  nitiogenous  ingredients  of  many  foods 
are  so  numerous  and  varied,  that  for  the  every-day  study  of  dietaries  and  food 
values  it  would  be  well-nigh  impossible  with  our  present  knowledge  to 
subdivide  these  compounds  with  any  degree  of  accuracy,  and  especially 
with  uniformity  between  different  chemists,  to  say  nothing  of  the  time 
involved. 

From  the  fact  that  so  many  valuable  analyses  have  already  been 
expressed  on  the  basis  of  NX6.25  for  j)rotein,  the  advantage  of  comparison 
with  the  results  thus  recorded  would  seem  to  be  in  itself  a  good  reason 
for  continuing  the  practice,  especially  until  a  factor  that  gives  better 
average  results  can  be  adopted.  By  recording  the  actual  nitrogen  found 
as  well  as  the  "protein,"  old  results  may  at  any  time  be  recalculated 
under  new  conditions,  if  found  desirable. 

In  flesh  foods,  when  carbohydrates  are  known  to  be  absent,  the  total 
protein  may  conveniently  be  determined  by  difference.  Rather  more 
progress  has  been  made  in  the  separation  of  the  nitrogenous  compounds 
of  meats  than  of  the  vegetables  and  cereals,  though  the  methods  are  by 
no  means  accurate  or  uniform. 

Most  of  the  recorded  analyses  of  vegetable  foods  express  the  carbohy- 
drates as  a  whole  without  attem])ting  to  subdivide  them,  at  least  further 
than  possibly  to  express  the  crude  fiber  or  cellulose  separately.  A  much 
more  intelligible  idea  of  the  dietetic  value  of  these  foods  would  be  gained 
by  a  further  separation  into  starch  and  sugars. 


GENERAL   y^N^LYTICAL   METHODS.  5$ 

Preparation  of  the  Sample. — It  is  at  the  outset  of  the  utmost  iniportance 
in  all  cases  that  a  strictly  representative  portion  of  the  food  to  be  examined 
should  be  submitted  to  analysis.  All  refuse  matter,  such  as  bones,  shells, 
bran;  skins,  etc.,  are  removed  as  completely  as  possible  from  the  edible 
portion  and  discarded. 

If  the  composition  of  the  entire  mass  cannot  be  made  homogeneous 
throughout,  it  may  be  best  to  select  from  various  portions  in  making  up 
the  sami^le  for  analysis,  in  order  to  represent  as  fair  an  average  of  the 
whole  as  possible. 

Finally  the  sample,  if  solid  or  semi-solid,  should  be  divided  as  finely 
as  possible,  by  chopping,  shredding,  puli)ing,  grinding,  or  pulverizing 
according  to  its  nature  and  consistency. 

For  disintegrating  such  substances  as  vegetables  and  meats  for  analysis, 
the  common  household  rotary  chopping-machine  is  admirably  adapted. 
For  pulverizing  cereals,  tea,  coffee,  whole  spices,  and  the  like,  the  mortar 
and  pestle  may  be  used,  or  a  rotary  disk  mill  or  spice-grinder. 

Specific  Gravity  or  Density  of  Liquids. — Where  formerly  it  was  cus- 
tomary to  compare  the  density  of  liquids  with  that  of  water  at  4°  C.  (its 
maximum  density)  it  is  now  more  common  to  refer  to  water  at  15.5°  C. 
or  20°  C,  making  the  determination  at  that  temperature.  A  common 
form  of  expressing  the  temperature  of  the  determination  and  the  tempera- 
ture of  the  standard  volume  of  water  with  which  that  of  the  substance  is 
to  be  compared,  is  the  employment  of  a  fraction,  the  numerator  of  which 
expresses   the   temperature   of  the   determination   and   the   denominator 

that    of   the   standard   volume  of   water,  as    --"  o  ,    -^-^"hi   o'  ~T,  C.* 

4°       15-5       15-5     4° 

When  extreme  accuracy  in  the  determination  of  density  is  required,  the 
pycnometer  or  Sprengel  tube  should  be  employed. 

The  Hydrometer. — This  instrument  furnishes  the  most  convenient  and 
ready  means  of  determining  the  density  of  liquids  where  extreme  nicety 
is  not  required.  If  well  made  and  carefully  adjusted,  the  hydrometer 
may  be  depended  on  to  three  decimal  places,  but  before  relying  on  its 
accuracy,  it  should  be  tested  by  comparison  with  a  standard  instrument, 
or  with  the  pycnometer. 

The  liquid  whose  density  is  to  be  determined  is  contained  in  a  jar 
whose  inner  diameter  should  be  at  least  |"  larger  than  that  of  the  spindle- 

*  Unless  otherwise  stated,  all  specific  gravities  in  this  volume  are  assumed  to  be  expressed 


on  the  basis  of 


15-5" 


56  FOOD   INSPECTION  yiND   ANALYSIS. 

bulb,  and  the  temperature  of  the  liquid  should  be  exactly  15.5°  when  the 
reading  is  taken. 

For  best  results  for  use  with  liquids  of  varying  densities,  the  laboratory 
should  be  furnished  with  a  set  of  finely  graduated  hydrometers,  each 
limited  to  a  restricted  part  of  the  scale,  together  with  a  universal  hydrom- 
eter coarsely  graduated,  covering  the  entire  range,  to  show  by  preliminary 
test  which  of  the  special  instruments  should  be  used. 

A  convenient  set  of  seven  such  hydrometers  are  graduated  as  follows: 
0.700-0.850,  0.850-1.000,  1. 000-1.200,  1. 200-1. 400,  1. 400-1. 600,  1.600- 
1.800,  1.800-2.000,  while  the  universal  hydrometer  has  a  scale  extending 
from  0.700  to  2.000.  Another  less  delicate  set  of  three  only  has  one  for 
liquids  lighter  than  water  and  two  for  heavier  liquids.  Some  instruments 
have  thermometers  in  the  stem.     Others  require  a  separate  thermometer. 

The  Westphal  Balance  (Fig.  14). — This  instrument  consists  of  a 
scale-beam  fulcrumed  upon  a  bracket,  which  in  turn  is  upheld  by  a  sup- 
porting pillar.  The  scale-beam  is  graduated  into  ten  equal  divisions. 
From  a  hook  on  the  outer  end  of  the  beam  hangs  a  glass  plummet  pro- 
vided with  a  delicate  thermometer,  the  beam  being  so  adjusted  that  when 
the  dr}'  plummet  hangs  in  the  air,  the  beam  is  in  exact  equilibrium,  i.e., 
perfectly  horizontal  as  shown  by  the  indicator  on  its  inner  end.  If  the 
large  rider  be  placed  on  the  same  hook  as  the  plummet  and  the  latter 
immersed  in  distilled  water  of  the  standard  temperature  at  which  the 
determinations  arc  to  be  made  (say  15.5°  C),  the  scale-beam  should 
again  be  in  equilibrium  if  the  instrument  is  accurately  adjusted.  As 
commonly  made,  the  weight  of  the  plummet  including  the  platinum  wire 
to  which  it  is  attached  amounts  to  15  grams,  and  the  displacement  of 
its  volume  to  5  grams  of  distilled  water  at  15.5°  C,  the  normal  temperature 
on  which  the  determinations  are  based.  Thus  the  unit  (or  largest)  rider 
should  weigh  5  grams,  while  the  others  weigh  0.5,  0.05,  and  0.005  gram 
respectively. 

If,  instead  of  distilled  w-ater,  the  plummet  be  immersed  in  the  liquid 
whose  density  is  to  be  determined,  the  position  of  the  riders  on  the  scale- 
beam,  when  so  placed  as  to  bring  the  same  into  equilibrium,  and  when 
read  in  the  order  of  their  relative  size  (beginning  at  the  largest),  indicates 
directly  the  specific  gravity  to  the  fourth  decimal  place. 

If  the  liquid  is  lighter  than  water,  the  large  rider  is  first  placed  in  the 
notch  where  it  comes  closest  to  restoring  the  equilibrium  of  the  beam, 
but  with  the  plummet  still  underbalanced.  The  rider  next  in  size  is 
then  applied  in  a  similar  manner,  and,  unless  equilibrium  is  exactly  re- 


GENER/IL   ANALYTICAL  METHODS. 


57 


Stored,  the  third  and  the  fourth  riders  successively.  If  it  happens  that 
two  riders  should  occupy  the  same  position  on  the  beam,  the  smaller 
is  suspended  from  the  larger. 

If  the  liquid  is  heavier  than  water,  the  method  employed  is  the  same 
except  that  one  of  the  largest  or  unit  riders  is  in  this  case  always  hung 
from  the  hook  which  supports  the  plummet,  while  the  others  cross  the 


Fig.  14. — The  Westphal  Balance. 

beam  at  the  proper  points.  If  carefully  made  and  adjusted,  the  Westphal 
balance  is  capable  of  considerable  accuracy. 

A  delicate  analytical  balance  can  be  used  in  place  of  the  less  carefully 
adjusted  Westphal  instrument,  by  hanging  the  Westphal  j)lummet  from 
one  of  the  scale-hooks  of  the  same,  and  employing  a  fixed  support  for  the 
glass  jar  that  holds  the  hquid  in  which  the  plummet  is  to  be  immersed. 
The  support  is  so  arranged  that  the  scale-pan  below  it  can  move  freely 
without  coming  in  contact  with  it.     This  arrangement  is  shown  in  Fig.  15. 

The  Pycnometer,  or   Specific-gravity  Bottle.  —  Fig.  16  shows  the  two 


58 


FOOD  INSPECTION  AND  ANALYSIS. 


forms  of  pycnometcr  commonly  made.  The  plain  form  has  a  ground- 
glass  stopper  \\\\.h.  a  capillary  passage  through  it,  the  other  has  a  fine  ther- 
mometer connected  with  the  stopper  and  a  capillary  side  tube  provided 
with  a  ground  hollow  cap.  Both  are  made  in  different  sizes  to  hold 
respectively  lo,  25,  50,  and  100  grams  of  distilled  water  at  the  standard 


Fig.  15. — ^The  Analytical  Balance  Arranged  for  Detenmning  Specific  Gravity  with  the 

Westphal  Plummet. 

temperature.  It  is  convenient  to  have  a  countenveight  for  each  pycnom- 
etcr as  fitted  with  its  stopper,  thus  avoiding  much  trouble  in  calculation. 
The  calculation  of  results  is  simplified  also  if  the  pycnometers  are  accurately 
constructed  to  contain  exactly  the  weight  of  distilled  water  which  they 
purport  to  contain  at  the  standard  temperature,  but  it  is  rather  difficult  to 
procure  such  instruments,  especially  of  the  form  furnished  with  the  ther- 
mometer. Most  instruments  hold  approximately  the  amount  specified, 
the  exact  net  weight  of  distilled  water  which  they  hold  at  standard  tem- 
perature being  found  by  careful  test  and  kept  on  record.  In  determining 
the  density  of  a  lifjuid,  the  pycnometer  is  carefully  filled  with  it  at  a  tem- 
perature below  the  standard,  the  stopper  carefully  inserted,  and  the  bottle 
wiped  dr)'.  Care  should  be  taken  that  the  liquid  completely  fills  the  bottle 
and  is  free  from  air-bubbles.     The  net  weight  of  the  liquid  is  then  taken 


GENERAL   ANALYTICAL   METHODS. 


59 


on  the  balance,  when  the  temperature  has  reached  the  standard  (say  15.5° 
C),  being  careful  to  wipe  off  the  excess  of  liquid  that  exudes  from  the  capil- 
lary due  to  expansion.  The  net  weight  of  the  liquid  is  divided  by  that  of 
the  same  volume  of  distilled  water,  previously  ascertained  under  the  same 
conditions  at  the  same  temperature,  the  result  being  the  density  of  the 
liquid. 

The  pycnometer  with  thermometer  attachment  is  obviously  susceptible 
of  a  greater  degree  of  accuracy  than  the  other  form,  since  the  temperature 
of  the  liquid,  even  though  15.5°  C.  at  the  start,  soon  rises. 


Fig.  16. — Types  of  Pycnometer. 

The  writer  prefers  to  use  the  pycnometer  provided  with  the  ther- 
mometer, but  without  the  hollow  cap  that  covers  the  capillary  side  tube, 
unless  liquids  like  strong  acids  are  to  be  operated  on,  that  might  other- 
wise injure  the  balance.  By  keeping  the  liquid  to  be  tested  for  some  time 
in  a  refrigerator,  it  acquires  a  temperature  of  from  10  to  12°  C.  It  is 
then  transferred  in  the  regular  manner  to  the  pycnometer  and  the  ther- 
mometer-stopper inserted  (but  not  the  hollow  cap)  and  the  bottle  wiped 
drv.  There  is  ample  time  to  adjust  the  balance-weights  with  extreme 
care    while  the  temperature  of  the  liquid  is  rising,  leisurely  wiping  off 


Co  FOOD  INSPECTION  AND  ANALYSIS. 

at  inten^als  with  a  soft  towel  the  excess  that  exudes  from  the  capillary 
tube,  the  linal  weight  of  the  dry  bottle  and  contents  being  made  at  the 
exact  temi)eralure  of  15.5°  C. 

In  taking  the  tare  or  adjusting  the  counterweight  of  a  specific-gravity 
bottle,  the  latter  should  be  perfectly  clean  and  dry.  It  had  best  be  rinsed 
first  with  water,  then  with  alcohol,  and  finally  with  ether,  all  traces  of  the 
latter  being  removed  by  a  current  of  dry  air,  or  otherwise,  before  weighing. 
In  making  successive  determinations  of  density  of  a  number  of  different 
liquids  with  the  same  pycnometer,  it  is  sufTicient  to  rinse  the  bottle  once 
with  a  little  of  the  liquid  to  be  tested  before  making  each  determination, 
when  the  various  liquids  are  miscible.  When  the  liquids  are  immiscible, 
the  bottle  should  be  carefully  cleaned  in  the  manner  described  in  th(^ 
previous  paragraph  before  making  each  test. 

The  Sprengel  Tube. — The  Sprengel  tube  is  a  variety  of  pycnometer 
useful  when  only  a  small  quantity  of  the  liquid  to  be  tested  is  available. 
It  is  susceptible  of  great  accuracy.  It  consists  of  a 
U-shaped  tube  (Fig.  17),  each  branch  of  which  termi- 
nates in  a  horizontal  capillary  tube  bent  outward. 
One  of  the  capillaries,  h,  has  a  mark  m  thereon  and 
has  an  inner  diameter  of  about  0.5  mm.  The 
diameter  of  the  other  capillary,  a,  should  not  exceed 
0.25  mm.  The  liquid  at  room  temperature  is  as- 
])iratcd  into  the  tube  so  as  to  fill  it  completely,  the 
end  h  being  dipped  in  the  liquid  while  suction  is 
applied  at  the  end  a.  The  tube  is  then  placed  in  a 
beaker  of  water  kept  at  the  standard  temperature, 
the  beaker  being  of  such  size  that  the  capillary 
ends  rest  on  the  edge.  The  temperature  of  the 
^  liquid  in  the  tube  may  be  assumed  to  be  constant 

f\G.  17.— Sprengel  Tuijc  when  there  is  no  further  movement  due  to  contrac- 
for  Determining  spe-  tion  in  the  larger  capillary  end,  h.  The  meniscus  of 
cific  Gravity.  ^^^  liquid,  when  cooled,  should  not  be  inside  the 

mark  m,  and  is  brought  exactly  to  the  mark  by  applying  a  piece  of  bibulous 
paper  to  the  other  end,  a.  If  a  drop  or  two  of  li(|uid  has  to  be  added,  this 
may  Vx*  done  by  ap]jlying  to  the  end  a  a  glass  rod  dipped  in  the  liquid. 
When  exactly  adjusted,  the  whole  is  wiped  dry  and  quickly  weighed, 
hung  from  the  arm  of  the  analytical  balance.  To  avoid  evaporation  by 
contact  with  the  air,  the  ends  of  the  capillaries  are  sometimes  ground 
to  receive  hollow  glass  caps  not  shown  in  the  figure. 


GFJ^IERAL    /{NALYTICAL   METHODS. 


6i 


Determination  of  Moisture.— This  is  usually  calculated  from  the 
loss  in  weight  at  the  temperature  of  boiling  water.  Platinum  dishes 
(Fig.  51)  are  well  adapted  for  the  drying  as  the  residue  can  be  ignited 
for  the  determination  of  ash.  If  only  the  moisture  is  desired,  dishes  of 
other  metals  or  glass  weighing  bottles  may  be  used.  Caps  for  wide- 
mouthed  bottles  made  of  tinned  lead  are  convenient  and  can  be  thrown 


Fig.  18. — .'\pparatus  for  Drying  in  Hydrogen. 


away  after  using.     \^iscous  substances  are  best  spread  over  asbestos  or 
sand  to  hasten  the  drying. 

Some  materials  must  be  heated  above  100°  C,  while  certain  saccharine 
products  are  dried  at  70°  C.  in  vacuo  to  avoid  decomposition.  If  alcohol, 
acetic  acid,  essential  oils,  or  other  volatile  substances  are  present  the  loss 
includes  these  as  well  as  moisture.  As  the  water  or  steam  oven  seldom 
attains  a  temperature  above  98°,  the  loss  sustained  in  these  is,  strictly 
speaking,  at  the  "  temperature  of  boiling  water."  Figs.  8  and  9  show 
electric  and  gas  ovens  for  heating  at  full  100°.  Benedict  has  shown  that 
certain  materials  can   best  be  dried  at  room-temperature  over  sulphuric 


62 


FOOD    INSPECTION   AND   ANALYSIS. 


acid  /;/  vacuo.      Trowbridge*  has  shortened  this   process  in  the  case  of 
meat,  by  gently  agitating  the  desiccator  during  the  drying. 

Drying  in  Hydrogen. — Fig.  i8  shows  the  apparatus  devised  by  Win  ton  f 
for  drying  cereal  products,  cattle  foods,  etc.  (p.  276).  The  material  is 
weighed  out  on  a  watch  glass  and  transferred  to  the  drying  tube  (G), 
wisps  of  cotton,  too  small  to  contain  an  appreciable  amount  of  moisture, 
being  used  at  both  ends  to  prevent  mechanical  loss.  The  hydrogen  is 
purified  by  passing  through  sodium  hydroxide  solution  (A)  and  dried  by 

sul[)huric  acid  in  the  jar  (B).  The 
acid  drops  over  the  glass  beads 
into  the  chamber  at  the  bottom  of 
the  jar  where  the  gas  bubbles 
through  it  before  passing  out  over 
the  beads.  A  siphon  automatically 
removes  the  excess  of  acid.  The 
drying  tubes  pass  through  the  cop- 
per tubes  of  the  water  oven  and 
are  fitted  at  the  posterior  ends  with 
capillary  exit  tubes  of  0.5  mm. 
bore,  thus  creating  a  slight  pressure 
and  insuring  even  distribution  of 
current.  When  the  drying  is  begun 
the  exit  tubes  should  be  within  the 
Fig.  19.— Hoskins  Electric  Fumace.  copper  tubes  to  avoid  Stoppage  of 
the  current  by  condensed  moisture,  but  later  they  should  be  pushed  out, 
as  in  the  cut,  and  each  tested  by  lighting. 

Determination  of  Ash. — The  residue  from  the  determination  of  moisture 
or  else  a  new  portion,  is  burned  at  a  very  faint  red  heat  until  white  or  gray, 
cooled  in  a  desiccator  and  weighed.  A  flat-bottomed  platinum  dish  is 
most  convenient  for  the  purpose.  Platinum,  however,  is  attacked  by  free 
chlorine,  bromine,  and  iodine,  sulphur  and  phosphorus,  sulphates  and 
phosphates  with  reducing  agents,  all  sulphides,  sodium  or  potassium 
hydroxide,  nitrate  and  cyanide,  metals,  and  metallic  compounds  reduced 
in  fusion,  such  as  lead,  tin,  zinc,  bismuth,  mercury,  arsenic,  and  antimony. 
In  such  cases  porcelain  must  be  used. 

The  degree  of  heat  employed  in  ashing  should  be  the  lowest  possible  to 


*  A.  O.  A.  C.  Proc.  1908,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  p.  219. 
t  Conn.  Agr.  Exp.  Sta.,  Rep.  1889,  p.  187. 


GENERAL   ANALYTICAL   METHODS.  63 

insure  complete  oxidation  of  tlie  carbon,  so  as  to  avoid  driving  off  certain 
volatile  salts  that  are  sometimes  present  and  that  would  be  lost  if  the  heat 
were  too  high.  At  a  bright  red  heat  potassium  and  sodium  chloride  are 
slowly  volatilized,  and  calcium  carbonate  is  converted  into  oxide;  further- 
more alkali  phosphates  fuse  about  particles  of  carbon,  protecting  them 
from  oxidation.  To  avoid  overheating  it  is  recommended  not  to  allow 
the  flame  to  impinge  directly  against  the  dish,  but  to  carry  out  the  burn- 
ing on  a  piece  of  asbestos  paper  supported  on  a  triangle.  The  asbestos 
also  serves  to  distribute  the  heat  and  to  protect  the  dish  from  the  injurious 
action  of  the  direct  flame  on  long  heating.  In  order  to  burn  off  the  last 
traces  of  carbon,  a  second  piece  of  asbestos  paper  may  be  placed  over  the 
top  of  the  dish,  or  the  incineration  may  be  completed  in  a  gas  or 
electric  muf!le  furnace  (Figs.  3  and  19).  Heating  should  be  con- 
tinued till  the  carbon  is  all  oxidized,  which  is  in  most  cases  indicated 
by  a  white  ash.  It  is,  however,  sometimes  impossible  to  obtain  a 
perfectly  white  ash,  but  the  appearance  of  the  ash  usually  indicates 
when  all  the  carbon  has  been  burnt  off.  It  is  sometimes  necessary  to 
stir  the  contents  of  the  dish  with  a  stiff  platinum  wire  from  time  to  time 
during  the  ignition. 

Methods  for  the  detection  and  determination  of  the  various  ash  ingre- 
dients are  considered  on  pages  301  to  305.  Such  cases  as  are  peculiar  to 
certain  foods,  like  the  metalhc  impurities  that  occur  in  canned,  bottled, 
and  preserved  foods  under  certain  conditions,  will  be  considered  in  their 
appropriate  place. 

Extraction  with  Volatile  Solvents.  —  Whenever  it  is  necessary  to 
exhaust  a  substance  of  its  ether-soluble  or  alcohol -soluble  ingredients, 
some  form  of  continuous  extraction  apparatus  is  employed  with  ad- 
vantage. 

Preliminary  Drying. — In  the  case  of  cereal,  legume,  and  oil-seed 
products,  meats,  etc.,  the  portion  of  the  material  dried  in  hydrogen,  in 
vacuo,  or  in  contact  with  air  in  an  ordinary  oven,  for  the  determina- 
tion of  moisture,  may  be  used  for  extraction.  If  volatile  oil  is  present, 
as  in  spices,  the  drying  must  be  performed  at  room  temperature  in  a 
desiccator. 

Milk  and  other  liquids  are  absorbed  in  a  roll  of  bibulous  paper,  in 
asbestos,  or  in  sand,  previous  to  drying  (page  134).  The  evaporation 
may  be  carried  on  in  shells  of  thin  glass  (Hoffmeister  Schalchen)  which 
are  finally  broken  previous  to  extraction,  or  in  tinned  lead  bottle  caps 
which  may  be  crumpled  up  and  inserted  in  the  extractor. 


64 


FOOD  INSPECTION   /1ND  ANALYSIS. 


The  Soxhkt  Extractor.  — This  apparatus  is  shown  in  Fig.   20.     The 
substance  to  be  extracted  is  subjected  to  successive  treatment  with  freshly 

distilled  portions  of  the  solvent  in  the  tube  ^. 
Dry  powders  arc  contained  in  extraction 
thimbles  of  filter  paper  or  in  filters  folded 
over  the  end  of  a  llat-bottomed  cylinder  so  as 
to  form  a  cartridge;  liquids,  such  as  milk, 
previously  dried  in  a  paper  coil  or  in  a  wad 
of  asbestos,  are  extracted  without  a  filter. 
The  vapor  from  the  solvent,  boiling  in  the 
flask  C,  passes  up  through  the  side  tube  a' 
into  the  condenser  B,  where  it  is  hquefied  and 
falls  drop  by  drop  on  the  substance. 

When  the  level  of  the  solvent  in  the  tube 
A  reaches  the  top  of  the  siphon  the  liquid 
drains  off  into  the  tared  flask  C,  carrying  with 
it  whatever  it  dissolves.  The  operation  is 
automatically  repeated,  the  substance  being 
successively  extracted  with  freshly  distilled 
portions  of  the  solvent,  w^hich  leaves  behind 
in  the  flask  C  the  material  in  solution. 

The  heater  employed  should  be  a  hot 
j)late  heated  by  steam,  or,  as  shown  in  Fig. 
20,  an  electric  stove,  which  may  be  provided 
with  a  fractional  rheostat  for  varying  the 
amount  of  heat.  If  neither  of  these  is 
available  the  extraction  flask  may  be  rested 
on  a  piece  of  asbestos  paper  supported  by  a 
lamp  stand,  the  heat  being  supplied  by  an 
ordinary  Bunsen  burner. 
The  degree  of  ebullition  is  so  regulated  as  to  allow  the  solvent  to  saturate 
the  sample  and  siphon  over  into  the  flask  C  from  six  to  twelve  times  an 
hour,  the  extraction  being  continued  from  tv/o  to  six  hours,  or  until  all  the 
ether-soluble  material  has  been  removed.  Care  should  ])q  taken  also  that 
the  rate  of  boiling  and  the  rate  of  condensation  are  so  regulated  that  no 
appreciable  loss  of  reagent  occurs  during  the  extraction.  A  strong  smell  of 
ether  perceptible  al  the  top  of  the  condenser  indicates  a  loss.  The  solvent 
is  recovered  at  the  end  of  the  extraction  by  disconnecting  the  weighing 
flask  at  a  time  when  nearly  all  of  the  solvent  is  in  the  part  A  and  before 


Fig.  20. — The  Soxhlet  Extractor 
with  Electric  Heater. 


GENFRAl.    XNAi.YTlCAL    METHODS. 


0$ 


it  is  ready  to  siphon  over.  The  weighing-flask  is  then  freerl  from  all 
traces  of  the  solvent  by  drying  first  on  the  water-bulh  and  then  in  the 
oven,  after  v^hich  it  is  cooled  in  the  desiccator  and  weighed,  the  difference 
between  this  and  the  first  weighing  re])rescnting  the  weight  of  the  fat  or 
ether  extract. 

The  Johnson  Extractor. — This  form  of  apparatus  (Figs.  21  and  22)  has 
the  advantage  of  the  Soxhlet  extractor  in  that  it  is  simpler  and  employs  a 
much  smaller  amount  of  ether.  The  substance  is 
contained  in  the  inner  tube  of  the  extractor  (Fig. 
21),  which  is  closed  at  the  lower  end  by  one  thick- 
ness each  of  filter  paper  and  cheese  cloth,  held  tightly 
in  place  by  means  of  a  linen  thread  wrapped  several 
times  about  the  tube  in  the  constriction  and  tied  in 
a  fast  knot.  This  innner  lube  properly  prepared 
can  be  used  over  and  over  for  extractions.  The 
outer  tube,  also  shown  in  Fig.  21,  is  of  such  a  size 
that  the  inner  tube  fits  loosely  within  it.  A  slight 
bulge  on  one  side  prevents  trapping  by  means  of 
the   condensed    soh-ent.      The    extraction    llask    is 


preferably  of  only  30  to  35  cc.  capacity.  It  is 
attached  to  the  extractor,  as  is  also  the  extractor  to 
the  condenser  tube,  by  means  of  a  carefully  bored 
cork  stopper.  For  ordinary  determinations  of  ether 
extract  the  outer  tube  should  have  an  inside  diam- 
eter of  26  mm.  and  the  inner  tube  an  outside  diam- 
eter of  22  m.m,  only  8  to  10  cc.  of  the  solvent  being 
required.  If,  however,  large  amounts  of  material  fig.  21.— Johnson  Extrac- 
(25  to  50  grams')  are  to  be  extracted,  the  diameters  ^■""  i'u^'cs. 

may  be  made  32  mm.  and  28  mm.  respectively  and  a  larger  amount  of  sol- 
vent employed. 

Where  only  a  few  extractions  are  made,  the  heating  can  be  performed 
over  (but  not  on)  a  metal  plate  heated  by  a  Bunsen  burner,  and  the  conden- 
sation effected  by  an  ordinary  Liebig  condenser.  If,  however,  a  considerable 
number  of  extractions  are  carried  out,  the  set  apparatus  shown  in  Fig.  22 
will  be  found  convenient  and  also  economical  of  space.  It  may  be  attached 
to  the  wall  or  placed  at  the  back  of  a  working  desk.  The  heating,  as  shown 
in  the  cut,  is  elTected  by  means  of  two  steam  pipes,  but  some  form  of  elec- 
tric heater  answers  equally  well.  The  case  with  glazed  door  prevents  the 
radiation  of  heat.     At  the  top  is  shown  the  multiple  condenser  consisting 


C6 


FOOD    INSPECTION  ^ND   /1N.4 LYSIS. 


of   a   copper  tank  with   l^lock   tin   tubes,     \\alcr   is  introduced  at  tlie  left 
and  carried  olY  at  the  right. 

The  solvent  is  best  jioured  through  the  material,  thus  obviating  in  large 
degree  the  crawling  of  the  extract.  The  door  should  be  0])ened  several 
times  during  the  extraction  and  kept  oj)en  for  a  few  minutes  for  the  pur- 


^^^^^^ 


Fig.  23. — Johnson  Multiple  Extmction  Apparatus  with  Heating  Closet  and  Condenser. 

pose  of  rinsing  down  the  sides  of  the  tubes  by  means  of  the  condensed 
vapors. 

Pre paralion  of  Solvents.— In  taking  the  so-called  ether  extract,  some- 
times reckoned  as  fat,  the  solvent  employed  is  cither  ethyl  ether  o-  the 
cheaper  petroleum  ether.  Whichever  reagent  is  employed,  certain 
precautions  are  necessary  for  the  purity  of  the  reagent.  If  ethyl  ether 
is  used,  it  should  be  entirely  freed  from  moisture  and  alcohol  by  first 
shaking  with  water  to  remove  the  larger  j^ortion  of  the  alcohol,  allowing 
it  to  stand  for  some  time  over  dr}'  calcium  chloride,  and  then  distilling 
over  metallic  .sodium.  The  ether  thus  prepared  should  be  kept  till  used 
with  sodium  in  the  container,  the  latter  being  somewhat  loosely  corked, 
to  allow  escape  of  the  hydrogen  formed. 

Petroleum  ether  is  \ariously  termed  ]jen;iine,  naphtha,  or  gasoline.  It 
should  be  low-boiling,  jjreferably  between  35°  and  50°,  and  it  is  always 
best  to  redistil  it  before  using,  in  cjrder  to  be  sure  it  is  free  from  residue. 
As  to  the  cbr)ice  of  the  two  reagents  for  use  in  fat  extraction,  it  may  be 
said  that  ethyl  ether  is  the  solvent  most  used,  but  if  a  large  number  of 
determinations  are  to  be  made,  the  lower  cost  of  petroleum  ether  is  to 


GENERAL   ANALYTICAL    METHODS. 


67 


Fig.  23. — Fractionating-still,  Arranged  for  Petroleum  Ether. 


Fig.  24. — A  Convenient 
Form  of  Separatory 
Funnel. 


6S 


FOOD   IXSPECTION  Ah'D   AN.4 LYSIS. 


be  considered.     A  convenient  still  for  fractionating  such  substances  as 
jK'lroleum  ether  is  siiown  in  Y\<-j,.  23. 

Extraction  with  Immissible  Solvents. — It  is  freciuently  necessary  to 
dissolve  out  a  substance  from  a  li([u:(l  by  sliaking  il  wilii  an  immiscible 
solvent,  as,  for  example,  in  the  extraction  of  certain  preservatives  from 
aqueous  or  acid  solutions  with  ether,  j)etroleum  ether,  or  chloroform. 
This  can  be  done  by  shaking  in  ordinary  llasks,  but  is  attended  by  some 
ditVicultv  and  loss  on  decantation.  A  separatory  funnel  of  the  type  shown 
in  Fig.  ^4  is  almost  indispensible  for  this  kind  of  extraction.     The  liquid 


Fig.  25. — Separatory  Funnel  Sujjjjort. 


and  .solvent  arc  transferred  to  the  funnel,  whicli  is  then  stoppered  and 
shaken.  If  the  .solvent  is  heavier  than  water,  as  in  the  case  of  chloroform, 
it  is  drawn  off  from  beneath  through  the  outlet-tube  of  the  funnel,  or,  if  the 
solvent  is  the  lighter,  as  in  the  case  of  ether,  the  atjueous  liquid  lying 
beneath  is  first  drawn  off  and  finally  the  solvent  is  poured  out  through 
the  top.  If  troublesome  emulsions  form  when  shaken,  they  may,  frequently 
be  broken  up  by  adding  an  excess  of  the  solvent  and  again  very  gently 
shaking,  or  by  careful  manipulation  with  a  stirring  rod,  or  by  centrifug- 
Ing.  If  the  solvent  is  ether,  and  an  obstinate  emulsion  forms,  it  may 
frequently  be  broken  by  the  addition  of  chloroform.  Such  a  mixture  of 
ether  and  <  hloroform  sinks  to  the  bottom  and  may  be  drawn  off  as  in  the 
case  of  chloroform  alone. 


GENERAL  ANALYTICAL   METHODS.  69 

A  separatory  funnel  support,  devised  by  Winton,  is  shown  in  Fig.  25. 
It  serves  for  holding  the  separatory  funnels  while  drawing  from  one  into 
another,  and  also  as  a  support  for  ordinary  funnels.  The  two  shelves 
are  adjustable  by  means  of  thumbscrews.  The  holes  in  these  shelves 
are  somewhat  wider  than  the  slots,  so  that  the  separatory  funnels  after 
being  introduced  through  the  latter  drop  into  position  and  are  held  firmly 
while  manipulating  the  stop-cock. 

Winton  attaches  all  stop-cocks  and  stoppers  to  the  funnel  by  means  of 
small  brass  chains,  thus  preventing  breaking  and  interchange  of  these  parts 
during  washing. 

Determination  of  Nitrogen  by  Moist  Combustion. — In  thus  determin- 
ing nitrogen,  the  organic  matter  is  first  decomposed  by  digestion  with 
sulphuric  acid  and  an  oxidizer,  the  carbon  and  hydrogen  being  driven  off 
as  carbon  dioxide  and  water  respectively,  while  the  nitrogen  is  converted 
into  an  ammonium  salt,  from  which  free  ammonia  (NH3)  is  later  liberated 
by  making  alkaline.  The  ammonia  is  then  distilled  into  an  acid  solution 
of  known  value  and  calculated  by  titrating  the  excess  of  acid. 

In  the  Kjeldahl  process  the  oxidation  is  effected  by  means  of  a  mercury 
compound,  in  the  Gunning  method,  by  potassium  sulphate  which  forms 
the  bisulphate  with  the  acid. 

Neither  method  in  its  simplest  form  is  ap])licable  in  the  presence  of 
nitrates;  if  these  are  present,  a  modification  must  be  used.  The  Gunning- 
Arnold  method  (page  432)  is  employed  for  the  determination  of  nitrogen 
in  pepper,  as  the  piperin  is  not  completely  decomposed  by  the  usual 
processes. 

The  Gunning  Method. — Reagents: 

Standard  alkali  solution,  N/io  NaOH.* 
Pulverized  potassium  sulphate. 
Sulphuric  acid,  concentrated. 
Sodium  hydroxide,  saturated  solution. 
Standard  acid  solution,  N/io  H2SO4  or  HCl.* 
An  indicator,  cochineal. 
Granulated  zinc. 

*  Winton  employs  standard  acid  of  such  a  strength  that  i  cc.  is  equivalent  to  1%  of 
nitrogen,  working  on  a  gram  of  material,  and  titrates  back  with  standard  alkali  two  and 
one-half  times  weaker  than  the  acid.  In  order  to  insure  accurate  readings,  burettes  of 
narrow  bore  (i  cc.=  2.6cm.)  are  employed.  The  alkali  burette  is  so  graduated  that  a 
reading  of  i  corresponds  to  2.5  cc,  thus  allowing  for  the  greater  dilution.  The  advantage 
of  this  system  is  that  the  per  cent  of  nitrogen  is  obtained  by  simply  subtracting  the  alkali 
reading  from  the  number  of  cc.  of  acid  employed. 


70  FOOD   IKSPECT.ON  /'.ND  ANALYSIS. 

The  digestion  and  distillation  arc  preferably  carried  out  in  the  same 
flask,  which  should  be  pear-shaped  with  flat  or  round  bottom  and  made  of 
moderately  thick  Jena  glass.  A  convenient  size  has  the  following  dimen- 
sions: length  2g  cm.,  ma.ximum  diameter  lo  cm.,  tapering  gradually  to  a 
long  neck,  which  near  the  end  is  28  mm.  in  diameter  with  a  flaring  edge. 
Its  caj^acity  is  about  550  cc. 

If  desired,  the  digestion  may  be  conducted  in  a  smaller  hard-glass 
flask  of  about  250  cc.  capacity  and  of  the  same  shape  as  the  above, 
and  the  distfllation  in  an  ordinary  round-bottomed  flask  of  500  cc. 
capacity. 

Introduce  from  0.5  to  3.5  grams  of  the  sample  into  the  digestion-flask 
with  10  grams  of  potassium  sulphate  and  from  15  to  25  cc.  of  concentrated 
sulphuric  acid.  The  flask  is  incHned  over  the  flame  and  heated  gently 
for  a  few  minutes  "below  the  boiHng-point  of  the  acid  till  the  frothing 
has  ceased,  after  whicli  the  heat  is  gradually  increased  till  the  acid  boils, 
and  the  boiling  is  continued  till  the  contents  have  become  practically 
colorless  or  at  least  of  a  pale  straw  color.  \\'ire  gau7,e  may  be  interposed 
between  the  flask  and  flame,  but  a  triangle  or  a  similiar  support  is  to  be 
preferred. 

The  contents  of  the  flask  are  then  cooled,  and,  if  the  digestion  has 
been  conducted  in  the  larger  flask  suitable  also  for  distiUing,  as  above 
recommended,  300  cc.  of  water  are  added  and  sufiicicnt  strong  sodium 
hydroxide  to  make  the  contents  strongly  alkaline,  using  phenolphthalein  as 
an  indicator.  If  a  separate  flask  is  used  for  the  distillation,  the  contents 
of  the  digestion-flask  are  transferred  thereto  with  the  water  and  the  alkali 
added.  A  few  pieces  of  granulated  zinc  should  also  be  introduced,  which 
by  the  evolution  of  gas  prevents  bumping  and  the  sucking  back  of  the 
distillate.  The  flask  is  then  well  shaken  and  connected  with  the  con- 
denser, the  bottom  of  which  is  provided  with  an  adapter,  dipping  below 
the  surface  of  the  standard  hydrochloric  or  sulphuric  acid,  a  measured 
quantity  of  which  is  contained  in  the  receiving- flask.  The  distillation  is 
then  continued  till  all  the  ammonia  has  passed  over  into  the  acid,  this 
part  of  the  operation  requiring  from  forty-flve  minutes  to  an  hour  and 
a  half.  As  a  rule  the  first  250  cc.  of  the  distillate  will  contain  all  the 
ammonia. 

The  excess  of  acid  in  the  receiving-flask  is  then  titrated  with  standard 
alkali,  and  the  amount  of  nitrogen  absorbed  as  ammonia  is  calculated.  The 
reagents,  unless  known  to  be  absolutely  pure  and  free  from  nitrates  and 


GENERAL   ANALYTICAL    METHODS. 


71 


ammonium  salts,  should  be  tested  by  conducting  a  blank  e.\i)criment  with 
sugar,  by  means  of  which  any  nitrates  [)resent  are  reduced.  Any  nitrogen 
due  to  impurities  should  be  corrected  for. 

In  purchasing  sulphuric  acid  for  nitrogen  determination  it  is  important 
to  specify  that  it  be  "nitrogen-free"  as  the  so-called  chemically  pure  acid 
often  contains  a  considerable  amount  of  nitrogen, 

Modijicalion  of  Gunning  Mclliod  to  include  Nitrogen  of  Nitrates. — In 
addition  to  the  reagents  used  in  the  simpler  Gunning  method,  sodium 
thiosulphate  and  salicylic  acid  are  required. 

A  mixture  of  sahcylic  and  sulphuric  acids  is  made  in  the  proportion  of 
30  cc.  of  concentrated  sulphuric  to  i  gram  of  salicylic.     From  30  to  35  cc.  of 


Fig,  a6. — Bank  of  Stills  for  Nitrogen  Determination  by  Gunning  Process. 

the  mixture  are  added  to  the  0.5  to  3.5  grams  of  the  substance  in  the  di- 
gestion-flask, the  flask  is  well  shaken  and  allowed  to  stand  a  few  minutes, 


7a 


FOOD   INSPECTION   AND   ANALYSIS. 


occasionallv  shaking.  Then  5  grams  of  sodium  thiosulphatc  are  added, 
and  10  grams  of  potassium  sulphate,  after  which  the  heat  is  apj)lied,  at 
first  verv  gentlv  and  afterwards  increasing  slowly  till  the  frothing  has 
ceased.  The  heating  is  then  continued  till  the  contents  have  been  boiled 
practically  colorless.  From  this  point  on,  proceed  as  in  the  (Running 
method. 

The  Kiddahl  MtihoJ. — One  gram  of  the  air  dry  substance, or  a  proi)or- 
tionatelv  larger  amount  of  a  moist  or  li([ui(l  substance,  and  0.7  gram  of 
mercuric  oxide  (or  an  etjuivalent  amount  of  metallic  mercury)  are  j)laced 


Fig.  270. — Johnson  Digestion  Siand  forXitrogen    Dettrmination  with  I^ad  I'ipc  I'^r  Cny..  j^ 

off  Fumes. 


in  a  550  cc.  Jena  flask  and  20  cc.  of  suly)huric  acid  added.  The  flask  is 
placed  in  an  inclined  ]josition  over  a  Bunscn  burner,  and  the  mixlurc 
healed  below  boiling  for  5  to  15  minutes  or  until  the  frothing  ceases,  after 
which  the  heat  is  rai.scd  until  the  mixture  boils  briskly.  The  boiling  is 
continued  until  the  liciuid  has  become  nearly  colorless  and  for  a  half 
hour  in  addition.  The  lamp  is  then  turned  out,  the  flask  placed  in  an 
upright  [X)sition,  anrl  potassium  permanganate  .slowly  added  with  shaking 
until  the  .solution  takes  on  a  jicrmanent  green  or  pur[)lc  color. 

•After  cooling,  250  cc.  of  water  are  added,  then  25  cc.  of  potassium 
sulphide  solution  (40  grams  of  the  commercial  salt  in  i  liter  of  water), 


GHNER^L   ANALYTICAL   METHODS. 


73 


sufficient  saturated  sodium  hydroxide  solution  to  render  the  solution 
alkaline,  and  finally  a  few  grains  of  granulated  zinc,  shaking  the  ilask 
after  each  addition.  Without  delay  connect  with  the  distillation  ajjpa- 
ratus,  and  proceed  as  in  the  Gunning  method. 

Apparatus  for  Nitrogen  Determination. — A  bank  of  stills  used  by 
the  author  in  nitrogen  determination  and  in  other  j)rocesscs  is  shown  in 
Fig.  26. 

The  digestion  apparatus  shown  in  Fig.  27a  is  that  devised  by  Johnson, 
Winton,  and  Boltwood.     The  stand  is  of  cast  iron,  with  holes  provided 


Fi';.  2yb. — Johnson  Distilling  Apparatus  for  Nitrogen  Determination. 


with  three  projections  that  suiJ^oort  the  flask.  The  lead  pipe  with 
holes  for  receiving  the  ends  of  the  flasks  serves  to  carry  off  the  acid 
fumes. 

The  Johnson  distilling  apparatus  with  accessories  by  Winton  is  show^n 
in  Fig. 275.  The  distillation  tubes,  except  for  the  glass  traps  and  bulb 
receiver  tubes,  are  of  block  tin,  and  are  cooled  in  a  copper  tank  filled 
with  water.  The  receivers  for  the  distillate  are  ordinary  pint  milk 
bottles. 

At  the  left  are  two  bottles  with  suspended  tubes  for  measuring  the 
potassium  sulphide  and  sodium  hydroxide  solutions. 


74  FJOD   INSPECTION  .-IND   /1N/ILY>IS. 

Determination  of  Ammonia. — A  weighed  (luanlity  of  the  fmclv 
divided  sample,  treated  with  ammonia-free  water  and  made  alkahnc  with 
magnesium  oxide  free  from  carbonate,  is  distilled  into  a  measured  (quan- 
tity of  standard  acid  (tenth-normal  hydrochloric  or  sulphuric  acid)  and 
the  amount  of  ammonia  determined  by  titration. 

Determination  of  Amido-nitrogen.* — In  the  absence  of  ammonia,  or 
after  the  removal  of  the  ammonia  as  described  in  the  preceding  section, 
the  sample  is  boiled  for  an  hour  with  5%  hydrochloric  or  sulphuric  acid, 
which  converts  the  amido-compounds  into  ammonium  salts  (chloride  or 
sulphate).  Assuming  asparagin  to  be  the  amido-com]K)und  acted  upon, 
the  reaction  is  as  follows: 

2C,HgX,03+  HoSO.-f-  2H20  =  (NH,)2SO,-f  2C,H,NO,. 

Asparagin  Ammonium  Aspartic  acid 

sulphate 

Exactly  neutralize  the  free  acid  with  sodium  carbonate,  add  magnesia 
(free  from  carbonate),  and  distil  into  standard  tenth-normal  acid.  The 
ammonia  is  determined  by  titration  in  the  usual  manner,  and  its  nitrogen 
represents  half  of  the  nitrogen  contained  in  the  amido-compound,  which 
it  is  customan'  to  calculate  as  asparagin. 

Determination  of  the  Various  Carbohydrates. — Under  title  of  "  Cereals" 
in  Chajjter  X  are  given  in  detail  methods  for  separation  and  determination 
of  sugar,  dextrin,  crude  fiber,  etc. 

Detection  of  Poisons. — Metallic  impurities  present  in  foods  incidental 
to  their  preparation,  or  as  adulterants,  are  considered  under  title  of  foods 
liable  to  such  adulteration.  The  detection  of  highly  toxic  substances, 
such  as  arsenic,  corrosive  sublimate,  and  alkaloids,  added  with  crimnnal 
intent,  comes  within  the  province  of  the  medico-legal  chemist  or  toxicologist 
and  is  beyond  the  scope  of  this  work.  The  methods  involved  are  fully 
described  in  the  treatises  of  Autenrieth  and  Blyth  (see  p.  79),  only  those 
for  arsenic,  which  occurs  also  as  an  accidental  impurity,  being  here 
considered. 

Detection  and  Determination  of  Arsenic. — Methods  of  Solulion. — 
.Syrup.>,  bilking  jwjwders  and  other  materials  soluble  in  water  or  acid  do 
not  need  preliminary  treatment.  Beer  is  treated  as  described  on  page 
728.     Other  methods  of  solution  are  as  follows: 

I.  Johnson-Chiltenden-GaiUier  Melhod.-\  —  This  method  is  suitable 
for  meat,  vegetables,  and  the  like,  the  proportion  of  acids  used  being 

*  Wiley,  Agricultural  Analysis,  Vol.  III.  p.  424. 
t  Am.  Chem.  Jour.,  2,  p.  250. 


GENERAL   ANALYTICAL  METHODS. 


75 


varied  to  suit  conditions.  Heat  at  i5o°-i6o°  C,  in  a  porcelain  dish,  loo 
grams  of  tlie  finely  divided  material  with  23  cc.  of  pure  concentrated, 
nitric  acid,  stirring  occasionally.  \Vlicn  the  mixture  assumes  a  deep 
orange  color,  remove  from  the  heat,  add  3  cc.  of  pure  concentrated  sul- 
phuric acid,  and  stir  while  nitrous  fumes  are  given  off.  Heat  to  iSo*' 
and  add  while  hot,  drop  by  drop,  with  stirring,  8  cc.  of  nitric  acid,  then 
heat  at  200°  till  sulphuric  fumes  come  off  and  a  dry  charred  mass  remains. 
Pulverize  the  mass,  exhaust  with  hot  water,  filter,  evaporate  to  small 
volume,  take  up  in  cold  20%  sulphuric  acid  and  treat  Ijy  the  modified 
Marsh  or  Gutzeit  method. 

2.  Sanger    Method* — Digest    at    room-temperature    for    some   hours 
5  to  20  grams  of  the  material  in  a  casserole  with  about  an  equal  bulk  of 


Fig.  28. — Marsh  Apparatus  for  Arsenic. 

concentrated  nitric  acid,  add  20  cc.  of  concentrated  sulphuric  acid  and 
digest  further  at  a  gentle  heat  until  the  mixture  begins  to  char.  Add  about 
2  cc.  of  nitric  acid  and  heat  until  sulphuric  fumes  appear,  repeating  the 
addition  of  acid  and  heating  until  oxidation  appears  to  be  practically 
complete.  Remove  all  nitric  acid  by  dilution  and  evaporation  to  the 
fuming  st^ge,  then  dilute  with  4  volumes  of  water.  At  this  point  about 
twice  the  bulk  of  saturated  sulphurous  acid  solution  may  be  added  and  the 
evaporation  repeated,  thus  reducing  to  the  arsenious  condition,  but  this 
is  not  usually  necessary. 

Methods  of  Determination. — i.  Marsh  Test. — The  apparatus  (Fig.  28) 
consists  of  a  generating  flask  with  funnel  tube,  a  U-tube  containing  cotton 
*  Proc.  Am.  Acad.  Arts,  Sci.,  26,  1891,  p.  24. 


76 


FOOD   INSPECTION  AND  ANALYSIS. 


H 


moistened  with  lo' j  lead  acetate  solution  (to  remove  hydrogen  sulphide), 
a  calcium  chloride  drying  tube,  and  a  hard  glass  tube  of  6  mm.  bore, 
drawn  down  near  the  end  to  a  uniform  constriction 
about  4  cm.  long  and  i  mm.  inside  diameter  and  also  at 
the  very  end  to  a  narrow  exit  tube.  The  tube  is  sup- 
ported over  a  three-burner  furnace  the  part  in  contact 
with  the  flame  being  wrapped  with  wire  gauze. 

Introduce  into  the  generating  flask  from  20  to  t^o  grams 
of  arsenic-free  stick  zinc  and  a  perforated  platinum  disk 
to  form  an  electric  couple.  Stopper  and  add  through 
the  funnel  -tube  20*^  ,^  sul])huric  acid  sufficient  io  start  the 
reaction  and  drive  out  all  air.  When  danger  of  explosion 
is  over  heat  the  tube  to  bright  redness.  After  running 
the  current  long  enough  to  prove  the  absence  of  arsenic 
in  the  reagents  add  slowly  from  the  funnel  tube  the  solu- 
tion of  the  material  in  20%  sulphuric  acid  or  the  solu- 
tion obtained  by  one  of  the  foregoing  methods  containing 
about  20'  t  of  that  acid,  keeping  a  steady  evolution  of  gas, 
WTien  the  flow  slackens  add  30^  v  sulphuric  acid  and  later 
40^^  acid  until  all  arsenic  has  been  expelled,  which  usually 
requires  2  to  3  hours.  If  no  arsenic  mirror  forms  in  the 
constriction  of  the  tube  in  one  hour,  further  test  may  be 
abandoned. 

If  more  than  o.i  mg.  of  arsenic  appears  to  be  present 
cut  off'  the  constriction  from  the  tube  and  weigh  it  on  an 
assay  balance;  then  dissolve  the  arsenic  in  a  solution  of 
sodium  hypochlorite,  (antimony  being  insoluble), wash  with 
water  and  then  with  alcohol,  dry,  cool,  and  weigh.  The 
loss  is  arsenic. 

If  the  amount  of  arsenic  is  very  small  Sanger  com- 
pares the  mirror  with  a  series  of  standard  mirrors  pre- 
j>ared  in  the  same  apparatus  using  quantities  of  a  stand- 
ard solution  containing  from  0.005  ^o  o-^S  ^ng.  of 
To  [jreparc  the  standard  solution  i  gram  of  pure  AsoO.j  is  dis- 
in     arsenic-free     sodium     hydroxide,     acidified    with    sulf}]iuric 


Fic.  29. — Bishop 
Apparatus  for 
Arsenic. 


AS2O3 

solved 

acid,  made  up  to  one  liter  and  10  cc.  of  this  stock  solution  further  diluted 

to  I  liter;   i  cc.  =  o.oi  mg.  AS2O3. 

2.  Sanger- Black  Gulzeit  Method* — The    apparatus  (Fig.  29),  devised 
by  Bishop,  consists  of  a  30  cc.  salt-mouth  bottle  provided  with  three  upright 

*  Jour.  Soc.  Chem.  Ind.,  26,  1907,  p.  11 15. 


GENERAL   ANALYTICAL   METHODS.  77 

tubes  one  above  the  other.  Tiie  lower  tube  is  7  cm.  long,  i  cm.  in  bore,  and 
contains  strips  of  lilter-jjaper  previously  soaked  in  5'  ^  lead  acetate  solution 
and  dried.  The  middle  tube  is  of  the  same  size  as  the  lower  but  shorter. 
It  is  loosely  filled  with  cotton  moistened  with  1%  lead  acetate  solution. 
The  upper  tube  has  a  uniform  bore  of  2.5  mm.  and  is  bent  twice  so  that 
the  upper  end  is  vertical.  In  this  tul)e  is  placed  a  strip  of  cold-pressed 
drawin,'5  paper  2  mm.  wide  which  has  been  soaked  in  5 /(,  alcoholic  mur- 
curic  chloride  (or  bromide)  and  dried. 

Place  in  the  evolution  bottle  10  grams  of  stick  zinc,  a  few  crystals  of 
stannous  chloride,  a  perforated  platinum  disk  and  from  2  to  5  grams  of 
the  material  or  else  the  extract  of  the  charred  or  digested  material  pre- 
pared as  described  in  the  foregoing  sections,  containing  about  20%  of 
sulphuric  acid.  Add  enough  20'^'^,  (1:4)  sulphuric  acid  to  nearly  fill  the 
bottle,  attach  the  three  tubes  and  allow  to  react  for  45  minutes.  Com- 
pare the  color  on  the  sensitized  strip  with  that  of  standard  strips  obtained 
vv^ith  from  0.005  to  0.05  mg.  of  AS2O3  in  the  same  apparatus,  using  measured 
quantities  of  the  standard  solution  described  under  the  Marsh  test. 

Colorometric  Analysis. — Certain  analytical  processes  depend  on  the 
formation  of  a  compound  of  the  substance  to  be  determined  having  a 
definite  color,  and  the  calculation  of  the  quantity  present  from  the  inten- 
sity of  the  color  of  the  solution,  compared  with  that  of  a  solution  contain- 
ing a  known  amount.  The  comparisons  may  be  made  in  a  special  form 
of  cylinder  or  in  a  colorimeter.  The  latter  has  the  advantage  that  a  single 
solution  of  known  strength  serves  within  reasonable  limits  for  matching 
any  shade  in  the  unknown  solution,  and  for  any  number  of  determina- 
tions, the  desired  depth  of  the  color  being  secured  by  varying  the  length 
of  the  column. 

Schreiner's  Colorimeter.* — This  apparatus,  shown  in  Fig.  30,  consists 
of  two  graduated  tubes  {B),  containing  the  standard  and  unknown  colori- 
melric  solutions,  the  height  of  the  column  of  lic|uid  in  both  tubes  being 
changed  by  two  immersion  tubes  {A),  which  remain  stationary  while 
the  graduated  tubes  are  raised  or  lowered  in  the  clamps  (C).  The  mirror 
D  reflects  the  light  through  the  tubes,  and  the  mirror  E  reflects  it  again 
to  the  eye  of  the  operator  at  F. 

In  making  the  comparisons,  the  tube  containing  the  solution  of  either 

known  or  unknown  strength  is  set  at  a  definite  point,  and  the  other  tube 

is  raised  or  lowered  until  the  colors  match.     If  R  is  the  reading  of  the 

standard  solution  of  the  strength  S,  and  r  the  reading  of  the  colorometric 

j> 

solution  of  unknown  strength  s.  then  s  =  —S. 

r 

*  Jour.  Am.  Chem.  Soc.  27,  1905,  p.  1192. 


7S 


FOOD    INSPECTION  AND   ANALYSIS. 


If  desired,  standard  slides  of  colored  glass,  such  as  accompany  the 
Lovibond  tintometer,  may  be  used  at  G  for  matching  the  solution  of  un- 
known strength,  the  value  of  these  slides  being 
determined  by  comparison  with    a    standard 
solution. 

The  Lovibond  Tintometer  may  be  used 
for  coloromclric  chemical  analysis,  but  is  not 
so  well  suited  for  this  purpose  as  the  Sclireiner 
colorimeter.  It  is  especially  designed  for  deter- 
mining the  color  value  of  liquid  and  solid 
technical  products,  such  as  beer,  wine,  oil, 
flour,  paper,  etc. 

The  instrument  itself  is  of  simple  construc- 
tion, consisting  of  an  elongated  box  with  an 
eyepiece  at  one  end  and  two  rectangular 
openings  at  the  other,  one  for  the  solution  or 
substance  to  be  examined,  the  other  for  the 
standard  glass  shdes  used  for  matching  the 
color.  Light  is  reflected  through  the  openings 
by  means  of  a  square  piece  of  opal  glass 
mounted  on  a  jointed  standard.  Liquids  are 
examined  in  rectangular  cells  with  glass  sides 
by  transmitted  light,  while  powders  are  pressed 
into  a  form  and  examined  by  reflected  light. 

The  standard  slides  used  in  general  work 
are  red,  yellow,  and  blue  in  even  graduation 
from  .006  to  20  tint  units  which  can  be  combined  so  as  to  produce  any 
desired  tint  or  shade  of  any  color.  The  results  are  expressed  in  terms 
of  standard  dominant  colors  (red,  yellow,  and  blue),  subordinate  colors 
(orange,  green,  and  violet)  obtained  by  combining  equal  values  of  two 
dominant  colors,  and  neutral  tint  (black)  obtained  by  combining  equal 
values  of  the  three  dominant  colors. 


Fig.  30. — Schreincr's  Colori- 
meter with  a  Tube  showing 
Graduation. 


Thus 


o.6/?-f  5.6F-0.6O  +  5.0F 
o.o8i?  +  i.5F  +  o.27^  =  o.o8A^-fo.i2G+i.3F 
i.2R+i.oB=i.oV-\-o.2R 


in  which  /?  =  red,  F=yellow,  .S^blue,  0  =  orange,  G  =  green,  F  =  vioIet, 
TV  ==  neutral    tint    or    black. 


GENf-R/iL   AhlALYTIC/iL    METHODS.    '  79 

Special  slides  may  be  obtained  for  the  examination  of  any  desired 
product.  For  examjjle,  slides  of  brown  shades  are  furnished  for  beer, 
of  yellow  shades  for  oils,  and  so  on. 

REFERENCES  TO  GENERAL  FOOD  ANALYSIS. 

Allen,  A.  H.     Commercial  Organic  Analysis.     Philadelphia,  1909. 

AuTENRiETH,  W.     The  Detection  of  Poisons  and  Strong  Drugs.     Trans,  by  W.  H. 

Warren.     Philadelphia,  1905. 
Balland,  a.     Les  Aliments.     Paris,  1907. 

Battershall,  J.  P.     Food  Adulteration  and  its  Detection.     New  York,  1887. 
Bell,  Jas.     The  Analysis  and  Adulteration  of  Foods,  Pts.  I  and  II.     London,  1881. 
Blyth,   a.    W.    and   M.    W.     Foods,    their  Composition  and  Analysis.     New  York, 

1903. 

Poisons,  their  Effects  and  Detection.     London,  1906. 

BOHMER,   C.     Die  Kraftfuttermittel,   ihre  Rohstoffe,  Herstellung,  Zusammensetzung, 

etc.     Berlin,  1903. 
Breteau,   p.     Guide  Pratique  des  Falsifications    et   Alterations  des  Substances  ali- 

mentaires.     Paris,  1907. 
BujARD,  A.,  and  Baier,  E.     Hilfsbuch  fiir  Nahrungsmittel  Chemiker.     Berlin,  1894. 
Blticker,  E.     Traite  des  Falsifications  et  Alterations  des  Substances  alimentaires  et 

des  Boissons.     Paris,  1892. 
Clark,  E.,  and  Woodman,  A.  G.     The  Estimation  of  Minute  Amounts  of  Arsenic. 

U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  99. 
Ephraim,  J.      Originalarbeiten  liber  Analyse  der  Nahrungsmittel.     Leipzig,  1894, 
GiR.ARD,  C.      Analyse  der  Matieres  alimentaires  et  Recherche  des  leurs   Falsifica- 
tions.    Paris,  1904. 
Hanausek,  T.  F.     Die  Nahrungs-  und  Genussmittel  aus  dem  Pflanzenreiche.     1884. 
Hassall,  A.  H.     Food,  its  Adulterations  and  the  Methods  for  their  Detection.     London, 

1874. 
KONIG,  J.     Chemische  Zusammensetzung  der  menschlichen  Nahrungs-  und  Genuss- 
mittel.    Berlin,  1903. 
Die  Untersuchung  landwirtschaftlich   und  gewerblich  wichtiger  Stoffe.     Berlin, 

1906. 
Leach,  A.   E.     Food:    Methods  of  Inspection  and  Analysis.     Article  in  Reference 

Handbook  of  the  Medical  Sciences,  Vol.  3,  pages  180-183. 
Leffmann,  H.,   and   Beam,   W.     Select   Methods  of  Food  Analysis.     Philadelphia, 

1905. 
Mansfeld,   M.      Die    Untersuchung  der    Nahrungs-    und    Genussmittel.      Leipzig, 

1905. 
Neufeld,  C.  a.     Der  Nahrungsmittelchemiker  als  Sachverstandigcr.     Berlin,  1907. 
PoLiN  et  Labit.     Examen  des  Aliments  suspects.     Paris,  1892. 
Richards,  E.  H.,  and  Woodman,  A.  G,    Air,  Water,  and  Food.    New  York,  1900. 
ROTTGER,  H.     Kurzes  Lehrbuch  der  Nahrungsmittel  Chemie.     Leipzig,  1903. 
Rupp,  G.     Die  Untersuchung  von  Nahrungsmitteln,  Genussmitteln   und   Gebrauchs- 

gegenstanden.     iqcxj. 


So  FOOD  INSPECTION  AND  /IN  A  LYSIS. 

Thoms,  II.,  und  Gn.G,  E.  Einfiihrung  in  die  praklische  Nahrungsmittel-Chemie. 
Leipzig,  iSqq. 

ViLLiERS,  A.,  et  Collin,  E.  Traite  des  Alterations  et  Falsifications  des  Substances 
alimentaires.     Paris,    iqoo. 

WiESNKR,  J.     Die  RohstolTe  des  Pflanzenreiches.    Leipzig,  1900. 

Wiley,  H.  \V.  Principles  and  Practice  of  Agricultural  Analysis.  Vol.  III.  Agricul- 
tural Products.     Chem.  Pub.  Co.,  Easton,  Pa.,  1906. 

The  Analyst.     London,  1877  et  seq. 

Revue  International  des  Falsifications.     Amsterdam,  1888  et  seq. 

Vicrteljahrcsschrift  der  Chemie    der  Nahrungs-  und  Genussmittels.      Berlin,  1884  et 

seq.     (Discontinued  1897.) 
Zeitschrift  fiir  Untersuchung  der  Nahrungs-  und  Genussmittcl.     1898  et  seq. 
Vereinbarungen  zur   Untersuchung  und  Beurtheilung  von  Nahrungs-  und  Genussmit- 

teln.     Berlin,  1897. 
-Mso  the  following  bulletins  of  the  Bureau  of  Chemistry,   U.  S.   Deptartment  of 
Agriculture: 

Bulletin  13,  Parts  i-io.  Food  and  Food  Adulterants.  1887-1902. 
Bulletin  46.  Methods  of  Analysis  adopted  by  the  A.  O.  A.  C.  1899. 
Bulletin  65.     Provisional  Methods  for  the  Analysis  of  Foods,  adopted  by  the  A.  O.  A.  C. 

Nov.  14-16,  1901.     1902. 
Bulletin  107,  rev.     Otlicial  and  Provisional  Methods  of  .Analysis.     A.  O.  A.  C.     1908. 


CHAPTER  V. 
THE  MICROSCOPE  IN  FOOD  ANALYSIS. 

Microscopical  vs.  Chemical  Analysis. — A  ver>'  important  means  of 
identification  of  adulterants  in  many  classes  of  food  products  is  furnished 
by  the  microscope,  which  in  many  cases  affords  more  actual  information 
as  to  the  purity  of  food  than  can  be  obtained  by  a  chemical  analysis. 
This  is  especially  true  of  coffee,  cocoa,  and  the  spices,  wherein  the  micro- 
scope serves  to  reveal  not  only  the  nature  of  the  adulterants,  but  also  not 
infrequently  the  approximate  amount  of  foreign  matter  present.  In  the 
case  of  the  cereal  and  leguminous  products  so  commonly  employed  as 
adulterants,  a  microscopical  examination  is  of  paramount  importance. 

The  chemical  constants  of  many  of  the  adulterants  of  coffee  and  the 
spices  do  not  always  differ  sufficiently  from  those  of  the  pure  foods  in 
which  they  appear  to  be  distinguished  therefrom  with  accuracv  and 
confidence  by  a  chemical  analysis  alone.  On  the  other  hand,  one  who 
is  familiar  with  the  appearance  under  the  microscope  of  the  pure  foods 
and  of  the  starches  and  various  ground  substances  used  as  adulterants, 
can,  with  certainty,  identify  ver}^  minute  quantities  of  these  materials, 
when  present,  with  the  same  ease  that  one  can  recognize  megascopically 
the  most  familiar  objects  about  him. 

A  chemical  test  may,  for  example,  indicate  the  presence  of  starch, 
but  it  cannot  reveal  the  particular  kind  of  starch.  The  microscope  will 
at  once  show  whether  the  starch  present  is  wheat  or  corn  or  potato  or 
arrowroot,  since  these  starches  differ  almost  as  much  in  microscopical 
appearance  as  do  the  physical  characteristics  of  the  grains  or  tubers  from 
which  they  are  obtained.  Again,  by  a  chemical  analysis  an  abnormal 
amount  of  crude  fiber  may  show  the  presence  of  a  woody  adulterant, 
but  only  the  microscope  will  enable  one  to  decide  whether  the  impurity 
consists  of  sawdust  or  ground  cocoanut  shells.  Not  only  in  such  in- 
stances as  these  is  the  microscopical  examination  of  greater  importance 

8i 


82  FOOD  INSPECTION  ^ND  ANALYSIS. 

than  a  chemical  analysis  in  establishing  the  purity  of  the  food,  but  it 
is  at  the  same  time  a  much  (quicker  guide. 

The  Technique  of  Food  Microscopy. — The  recognition  of  adulterants 
bv  the  microscope  requires  some  exi)erience  but  no  more  than  may  be 
accjuired  by  a  chemist  who  will  give  the  subject  serious  attention.  In 
the  examinatiiMi  of  cocoa,  cotlee,  lea,  and  llie  s])ices  for  adulteration,  a  care- 
ful study  of  the  ])Owdered  substance  in  temporary  water  mounting  will 
in  most  cases  })rove  sulTicient  to  familiarize  the  food  analyst  with  their 
characteristics  under  the  microscope,  and  it  is  not  absolutely  necessary 
for  him  to  familiarize  himself  with  the  details  of  section  cutting,  dissect- 
ing, or  permanent  mounting  unless  he  so  desires.  The  treatment  in 
tlelail  of  these  latter  branches  of  vegetable  histology  is  beyond  the  scope 
of  the  i)resent  work.  For  full  information  along  these  lines  the  reader 
is  referred  especially  to  such  works  as  those  of  Behrens*,  Zimmerman,! 
and  ChamberlainJ  together  with  the  list  of  references  on  page  98. 

Standards  for  Comparison. — For  standards  the  analyst  should  provide 
himself  with  as  complete  a  set  as  possible  of  the  various  materials  to  be 
examined,  taking  care  that  their  absolute  purity  is  established.  Where- 
cver  possible,  he  should  grind  the  sample  himself  from  carefully  selected 
whole  goods.  These,  together  with  samples  of  the  starches  and  other 
adulterants,  all  of  known  purity,  should  be  contained  in  small  vials  care- 
fully stoppered  and  plainly  labeled,  arranged  alphabetically  or  in  some 
equally  convenient  manner  in  the  desk  or  table  on  which  the  microscope 
is  commonly  used.  The  adulterants  included  in  this  set  of  standards 
should  be  not  only  those  which  experience  has  shown  most  liable  to  be 
employed,  but  any  which,  by  reason  of  their  character,  might  in  the 
analyst's  opinion  be  used  under  certain  conditions. 

APPARATUS. 

The  Microscope-stand. — An  expensive  or  complicated  stand  is  un- 
necessar}\  The  jjrime  requisites  for  good  work  in  a  microscope-stand  are 
firmness  or  rigidity,  and  accuracy  in  centering.  An  inexpensive  stand 
possessing  these  features  can  be  used  for  the  best  work,  providing  the  optical 
parts  are  satisfactory.  It  is  well,  if  economy  must  be  practiced,  to  purchase 
a  simple  stand  provided  with  the  society  screw,  and  let  the  larger  portion 
of  the  allowance  go  for  a  high  grade  of  lenses,  since  many  of  the  attach- 
ments inherent  in  a  high-y)riced  stand,  though  often  of  convenience,  may 
well  be  dispensed  with. 

*  Guide  to  the  Microscope  in  Hotany.  f  Hfjtanical  Microtechnique. 

X  Methods  in  Plant  Histology. 


THE  MICROSCOPE  IN  FOOD  /IN A  LYSIS. 


83 


A  stand  of  the  so-called  continental  type  (having  the  horseshoe  base) 
IS  preferable.  A  square  stage  is  rather  more  convenient  than  the  circular 
form,  and  the  jointed  pillar  possesses  advantages  over  the  rigid  variety 
in  ease  of  manipulation  that  are  certainly  worth  considering. 

The  smooth  working  of  both  the  coarse  and  fme  adjustments  should 
not  be  lost  sight  of.  If  the  microscope  is  to  be  used  exclusively  for  food 
work,  a  substage  condenser  is  unnecessary,  hence  the  construction  of  the 


Fig.  31. — Continental  Type  of  Microscope. 

substage  may  be  very  simple,  unless  bacteriological  work  is  to  be  done 
as    well. 

A  nose-piece,  while  not  indispensable,  is  a  great  convenience  for  the 
quick  transfer  of  objectives.  A  double  nose-piece  carrying  two  objectives 
is  ample  for  routine  food  work. 

The  Optical  Parts  are  by  far  the  most  important,  and  should  be  of 
superior  equality,  though  not  necessarily  of  the  most  expensive  makers. 
The  food  analyst  should  have  at  least  two  objectives,  one  for  high-  and 
one  for  low-power  work,  and  preferably  two  oculars. 

For  the  routine  examination  of  powdered  food  substances  the  writer 
prefers  a  ^-inch  objective,  used  with  a  medium  ocular,  the  combination 
giving  a  magnification  of  from  240  to  330  diameters,  according  to  the 
ocular  employed.     For  a  low-{)owcr  objective  the    J -inch  is  a  conven- 


84 


FOOD   INSPECTION  yIND   ANALYSIS. 


ient  size.  It  is  useful  as  a  lindc-r  j)rcliminary  to  examination  with  the 
higher  power,  and,  in  connection  with  a  low-power  eyepiece,  is  well  adapted 
for  the  examination  of  butter  and  lard,  and  for  use  with  the  j^olariscope. 

An  eyepiece  micrometer  mounted  in  an  one  inch  ocular  is  indispen- 
sable for  measuring  starch  grains  and  other  elements.  It  is  calibrated 
by  means  of  a  stage  micrometer. 

The  Micro-polariscope. — This  accessory  is  useful  in  the  identification 
of  starches  and  other  ingredients,  and  for  ascertaining  whether  or  not 
fats  haw  been  crystallized.  The  polarizer  is  held  below  the  stage,  while 
the  analyzer  is  aj)plied  above  the  objective,  either  in  the  tube  or  above 
the  ocular. 


iauiUiumiiiu 
Fig.  32. — Polarizer  and  Analyzer  for  the  Microscope. 

A  common  form  of  construction  is  one  in  which  the  substage  is  adapted 
to  carry  interchangeably  the  diaphragm  tube  and  the  polarizer.  If  the 
polari.<;cope  is  much  u.sed,  it  becomes  desirable  to  provide  means  for 
quickly  changing  the  polarizer  and  diaphragm  tube  below  the  stage,  and 
for  moving  the  analyzer  in  and  out  of  place  above  the  objective. 
Winton*  has  devised  a  microscope-stand  with  this  in  view,  especially 
afla[>ted  to  the  needs  of  the  food  analyst. 

If  the  polariscope  is  to  be  u.sed  often,  it  is  convenient  to  have  within 
**a.sy  access  two  .stands,  one  with  the  jjolariscopc  mounted  in  i)lace  in 
»'onncction  with  low-power  glasses  ready  for  use,  and  the  other  stand 
)rovifled  with   the  ordinary  high-  and  low-powx'r  objectives  only. 

Microscope  Accessories  include  of  necessity  a  large  number  of  slides 
4nd  cover  gla.sses.  The  latter  should  be  Xo.  2  thickness,  'I  inch,  either 
round   or  scjuare. 

One  or  more  dis.secting-needles  in  holders  and  a  small  hand  magni- 
fying-glass  should  also  be  provided. 


*  Journal  App.  Microscopy,  2,  p.  550. 


THE   MICROSCOTE   IN   FOOD   ANALYSIS. 


85 


Other  useful  accessories  are  a  mechanical  stage,  a  pair  of  fine  tweezers, 
knives,  scissors,  and,  if  sections  are  to  be  cut,  a  j)lano-concave  razor. 

MICROTECHNIQUE. 

Preparation  of  Vegetable  Food  Products  for  Microscopical  Examina- 
tion.— The  ground  spices  and  cocoas  of  commerce  are  usually  of  the 
requisite  fineness  for  direct  examination  without  further  treatment.  Coffee, 
chocolate,  starches,  and  similar  products  should  be  ground  in  a  mortar 
fine  enough  to  pass  through  a  sieve  with  from  60  to  80  meshes  to  the  inch. 

A  small  portion  of  the  powdered  sample  is  taken  up  on  the  tip  of  a 
clean,  dry  knife-blade,  and  placed  on  the  microscope-slide.  By  means 
of  a  medicine-dropper  a  drop  of  distilled  water  is  applied,  and  the  wetted 


Fig.  2>2f — Mechanical  Stage  for  Microscope. 

powder  is  then  rubbed  out  under  the  cover-glass  between  the  thumb  and 
finger  to  the  proper  fineness. 

The  water-mounted  shde  thus  prepared,  while  useful  only  for  tem- 
porary purposes,  has  proved  to  be  best  adapted  to  the  analyst's  require- 
ments for  routine  microscopical  examination  of  powdered  food  products 
for  adulteration,  partly  because  water  is  the  best  medium  in  most  cases 
for  showing  up  the  structural  characteristics  of  these  substances  and  their 
adulterants,  and  partly  because  it  serves  best  for  the  "rubbing  out" 
process  between  thumb  and  finger  under  the  cover-glass,  whereby  the 
sample  is  brought  to  the  requisite  degree  of  fineness. 

Experience  will  soon  show  how  far  this  rubbing  out  should  be  carried 
for  the  best  effects.  Gentle  pressure  should  be  applied,  care  being  taken 
not  to  break  the  cover-glass,  especially  if  the  sample  contain  anything  of 
a  gritty  nature.     The  rubbing  should  be  continued  till  the  coarser  par- 


S6  FOOD  INSPECTION  AND  ANALYSIS. 

tides  and  overlying  masses  arc  separated  and  distributed  uniformly,  but 
if  too  long  persisted  in,  the  forms  of  the  tissues,  starch  grains,  and  other 
characteristic  portions  will  be  partially  destroyed  and  of  too  fragmentary 
a  nature  to  be  readily  recognizable. 

Canada  Balsam  in  Xylol  is  a  useful  mountant  for  the  examination  jf 
starches  with  polarized  light.  In  this  medium,  under  ordinary  illumina- 
tion, the  starches  are  not  plainly  visible,  since  the  refractive  index  of  the 
two  are  nearly  identical,  but  with  crossed  nicols  the  starch  grains  stand 
out  clearly  and  distinctly  in  a  dark  background.  If  the  material  is  not 
perfectly  dry  it  should,  be  soaked  in  absolute  alcohol  and  then  in  chloroform 
or  xylol  until  dehydrated. 

Glyicn'n.  —  A  mixture  of  equal  parts  of  glycerin  and  water  is 
perhaps  the  best  medium  for  permanent  mounts,  but  considerable  skill  is 
required  to  finish  the  preparation  with  cement  on  the  edge  of  the  cover- 
glass. 

Glycerin  jelly  is  more  readily  handled  by  the  beginner  since  no  cement 
is  required. 

Glyier'm  Jelly  "^  is  prepared  as  follows:  i  part  by  weight  of  the  finest 
French  gelatin  is  soaked  two  hours  in  6  parts  of  distilled  water,  after  which 
7  parts  by  weight  of  C.  P.  glycerin  are  added,  and  to  each  loo  parts  of 
the  mixture  add  t  part  of  concentrated  carbolic  acid.  Heat  the  mixture 
while  stirring  till  flocculency  disappears  and  filter  through  asbestos  while 
warm,  the  asbestos  being  previously  washed  and  put  into  the  funnel 
while  wet.  The  jelly  is  sohfl  at  ordinary  temperatures,  and  must  be 
warmed  to  melt.  A  small  bit  of  this  jelly  is  removed  from  the  mass  by 
a  knife-blade  and  placed  on  the  clean-slide,  which  is  held  over  a  gas  flame 
till  the  jelly  is  melted.  The  powdered  specimen  being  then  shaken  into 
the  molten  droj),  the  cover-glass  is  gently  placed  upon  it  (being  brought 
down  obliquely  to  avoid  formation  of  air-l^ubljles)  and  pressed  down  in 
place. 

Microscopical  Diagnosis. — It  is  never  safe  to  pass  judgment  on  a 
spice  or  other  food  by  the  microscopical  examination  of  a  single  portion. 
Several  slides  should  be  prepared  with  bits  of  the  powder  taken  from 
difTcrent  parts  of  the  mass,  before  the  character  and  extent  of  the  adultera- 
tion can  be  safely  determined.  Care  should  be  taken  that  the  slide,  the 
knife-blade,  the  water,  and  the  medicine-droj)]K'r  be  jjcrfectly  clean  and 
free  from  contamination  with  j^revious  specimens. 

It  should  be  borne  in  mind  that  at  best  a  composite  powdered  sample 

*  Botan.  CcntralVjl.,  Bd.  i,  p.  25. 


THE  MICROSCOPE  IN  FOOD   ANALYSIS.  87 

is  but  a  mechanical  mixture  of  various  tissues,  and  that  no  two  portions 
will  show  exactly  the  same  composition. 

Characteristic  Features  of  Vegetable  Foods  under  the  Microscope. — 
The  structural  features  of  a  powdered  spice,  examined  microscopically, 
will  be  found  to  differ  considerably  in  appearance  from  those  of  a  thin, 
carefully  mounted  section  of  the  same  spice.  Instead  of  the  beautiful 
arrangement  of  cells  and  cell  contents  with  the  perfect  order  of  various 
parts  as  seen  in  the  mounted  section,  one  finds  in  the  powdered  sample 
under  the  microscope  what  often  appears  to  be  a  most  confusing  mass 
of  fragments  of  various  tissues.  For  this  reason  the  most  striking  charac- 
teristics seem  to  vary  with  different  observers,  and  it  is  a  well-known 
fact  that  microscopists  differ  widely  as  to  conceptions  of  size,  shape,  and 
ordinary  appearance,  even  in  the  case  of  certain  of  the  well-known  starch 
grains.  It  is  on  this  account  that,  irrespective  of  the  description  of  others, 
the  analyst  should  familiarize  himself  with  the  microsco])ical  appearance 
of  the  foods  with  which  he  is  dealing,  as  well  as  of  their  adulterants,  form- 
ing his  own  standards  as  to  what  constitute  the  recognizable  features, 
from  specimens  prepared  by  himself. 

In  the  large  variety  of  ground  berries,  buds,  tubers,  barks,  etc.,  from 
which  the  spices  and  condiments  are  prepared,  as  well  as  in  the  grains, 
legumes,  shells,  fruit  stones,  and  other  materials  forming  the  most  familiar 
adulterants,  the  kinds  of  plant  tissues  and  cell  contents  which,  under 
the  microscope,  serve  as  distinguishing  marks  or  guides  for  identification 
are  comparatively  few  in  number. 

The  most  common  of  these  varieties  of  cell  tissue  and  of  cell  contents 
to  be  met  with  by  the  food  microscopist  in  his  work  are  briefly  the  follow- 
ing: 

Parenchyma. — This  is  most  abundant  and  widely  distributed,  forming 
as  it  does  the  thin-walled,  cellular  tissue  of  nearly  all  vegetable  food  sub- 
stances. The  walls  of  parenchyma  cells  are,  as  a  rule,  colorless  and 
transparent.  The  forms  of  the  cells  are  varied  and  are  often  sufiiciently 
characteristic  in  themselves  to  identify  the  substance  under  examination. 

Sclerejichyma,  or  stone  cells,  are  the  thick- walled  woody  cells  forming 
the  hard  part  of  nut  shells,  fruit  stones,  and  seed  coverings,  occurring  also 
in  some  fruits  and  barks.  These  cells  are  more  often  colored  and  of 
various  shapes  but  almost  always  irregular,  sometimes  elongated,  as  in 
cocoanut  shells  and  olive  stones,  occasionally  nearly  rectangular,  as  ia 
pepper  shells,  and  sometimes  polygonal  or  nearly  circular. 

In  appearance  the  sclcrenchyma   cell  commonly  has  a  more  or  less 


8S 


FOOD   Ih^PF.CTiON   AND   ANALYSIS. 


deep,  centnil  or  axial   cavity,  from  which  small   fissures  extend  through 
the  thick  walls.     See  Fig.  35. 

VariouiJy   shaped  sclerenchyma  cells  are  found   in   allspice,   cassia, 

P 


Fig.  34. — T\'pical  Forms  of  \'arious  Cell  Tissues.  Longitudinal  section  through  a  clove, 
showing:  Pp,  two  ff)rms  of  parenchyma;  B,  bast  fibers;  g,  vascular  and  sieve 
tissue;    KK',  cells  with  calcium  oxalate  crj'stals.     (After  Vogl.) 

pepper,  clove  stems,  nut  shells,  etc.  Stone  cells  arc  optically  active  to 
polarized  light,  and  between  crossed  niccls  are  very  conspicuous  by  their 
bright  appearance. 


•rcnrhyma,    or    Stone-ccU    Tissue.     A    cross-section    through    the    stone-cell 
layer  of  the  fruit  shell  of  black  pepper.     (After  Vogl.) 

Fibro-vascular  Bundles  arc  compo.sed  of  thrtc  i)art,s:    the  bast  fibers, 
or  mechanical  elements,  the  phloem,  and  the  xylcm. 


THE  MICROSCOPE  IN  FOOD    /ANALYSIS. 


^1 


Bast  Fibers  arc  elongated,  pointed  s'-lerenchyma  cells,  of  which  flax 
fibers  arc  examples. 

Sieve  Tubes,  the  characteristic  elements  of  the  phloem,  are  thin- 
walled  tubes  with  perforated  partitions  known  as  sieve  plates. 

Vessels  or  Ducts  occur  in  the  xylem.  They  are  designated  as 
sjM'ral,  annular,  reticulated,  or  pitted,  according  to  the  nature  of  the 
walls. 

Corky  Tissue,  or  Subcrin,  constitutes  the  ihin-walled,  spongy  cells 
forming  the  protective,  outer  dead  layers  of  the  bark.  This  is  found 
in  cassia,  and  in  the  barks  used  as  adulterants.  Suberin  is  tested  for  by 
potassium  hydroxide  (p.  93).  |\ 

Starch  wherever  it  occurs  furnishes  the  most  charac- 
teristic feature  of  the  cell  contents,  and,  as  a  rule,  will  at    p| 


once   indicate   under  the   microscope,  by  the  shape  and  l^ 
grouping  of  its  granules,  the  particular  substance  of  which 


it  forms  a  part.  It  is  very  abundantly  distributed  through- 
out the  vegetable  kingdom  and  occurs  in  a  wide  variety  of 
forms.  It  is  particularly  conspicuous  "when  viewed  by 
polarized  light.  Between  crossed  nicols  such  starches 
as  corn,  potato,  and  arrowroot  show  out  brightly  from 
a  dark  background  with  dark  crosses,  the  bars  of  which       •  36.— Reticuia- 

,  .  ted  Ducts  of  Chic- 

mtersect  at  the  hilum  of  each  granule.  When  a  selemte  on\  (After  Voel.) 
plate  is  introduced  above  the  polarizer,  a  beautiful  play  of  colors  is 
seen  with  various  starches,  a  phenomenon  which  Blyth  appHes  as  a 
means  of  identification  and  classification,  but  which  more  modem  micro- 
scopists  regard  as  of  minor  importance  to  distinguishing  the  various 
starches  morphologically.  Starch  is  found  naturally  in  the  cereals,  legumes, 
and  many  vegetables,  in  cassia,  allspice,  nutmeg,  pepper,  ginger,  cocoa, 
and  turmeric.  The  cereal  and  leguminous  starches  from  their  inertness 
and  cheapness  constitute  the  most  common  adulterants  of  the  spices  and 
of  powdered  foods  in  general.  Starch  grains  are  found  in  the  cells  of  the 
parenchyma  and  in  other  cellular  tissues.  Iodine  is  the  special  reagent 
(p.  91). 

Gums  and  Resins  occur  in  characteristic  forms  among  the  cell  contents 
of  some  of  the  spices.  As  an  example,  the  port  wine- colored  lumps  of  gum 
in  allspice  furnish  one  of  the  most  ready  means  of  recognizing  that  spice 
microscopically.  Resin  is  tested  for  microchemically  with  alkanna  tincture 
(p.  92). 


90  FOOD  INSPECTION  AND  ANALYSIS. 

Altiironc,  or  Prolcin  Grains,  occur  in  some  of  the  spices,  but  are  noi 
especially  characteristic.  They  somewhat  resemble  small  starch  grains. 
Most  varieties  of  protein  grains  are  soluble  in  water,  but  some  are  insoluble. 
The  soluble  varieties,  which  are  not  apparent  in  w-ater-mountcd  specimens; 
must  be  examined  in  absolute  alcohol,  glycerin,  or  oil.  In  leguminous 
seeds  aleurone  occurs  closely  intermingled  with  starch  in  the  same  cells, 
while  in  the  cereals  it  occupies  the  whole  cell. 

Protein  grains  are  tested  for  under  the  microscope  by  iodine  in  potas- 
sium iodide,  which  turns  them  brown  or  yellowish  brown,  and  by  ^^lillon's 
reagent,  which  colors  them  brick  red. 

Plant  Crystals  are  not  uncommon  in  the  class  of  substances  which 
the  food  analyst  examines.  Among  the  common  forms  arc  the  pipcrin 
crystals  found  in  pepper.  Calcium  oxalate  occurs  in  many  vegetable 
j)roducts  as  prismatic  crystals,  crystal  aggregates,  or  needle-shaped 
crystals  (raphides). 

Cr}'stals  of  calcium  carbonate  are  sometimes  met  with  also,  as,  for 
example,  in  hops.  Calcium  oxalate  crystals  are  insoluble  in  acetic  acid, 
while  being  readily  soluble  in  dilute  hydrochloric.  Calcium  carbonate 
cr\'stals  are  soluble  with  effer\'escence  in  both  acids.  The  acid  reagents 
are  directly  applied  to  the  sample  in  water-mount  under  the  cover-glass, 
and  the  reaction  obser\'ed  through  the  microscope. 

Fat  Globules  are  of  common  occurrence  in  many  foods  and  appear  of 
various  sizes,  sometimes  large  and  conspicuous,  and  again  almost  lost 
sight  of  because  of  their  minuteness.  They  are  sometimes  colorless,  as  in 
mace,  and  sometimes  deeply  tinted,  as  in  cayenne.  Alkanna  tincture  is 
used  as  a  reagent  for  fat  (p.  92). 

Other  Cell  Contents  of  less  importance,  but  which  may  be  identified  by 
the  microscope  with  reagents,  are  tannic  acid  (tested  for  by  chloriodide 
of  zinc  and  lerric  acetate  (pp.  91  and  92),  and  various  essential  oils,  for  the 
detection  of  which  alkanna  tincture  is  employed. 

REAGENTS    IN    FOOD   MICROSCOPY. 

Unless  a  more  extended  microscopical  investigation  of  vegetable  food 
substances  is  contemplated  than  is  involved  in  the  mere  identification  of 
adulterants,  the  analyst  will  have  little  need  for  reagents,*  but  will  depend 
almost  entirely  on  the  form  and  appearance  of  the  various  tissues  or  tissue 
fragments,  as  well  as  on  the  abundance,  shape,  and  distribution  of  such 
distinctive  cell  contents  as  the  starches,  fat  globules,  or  cr)stals. 

*  One  reagent  that  is  really  necessary  on  the  microscope-table,  and  will  very  often  ba 
required  is  iodine  in  potassium  iodide. 


THE  MICROSCOPE  IN  FOOD   ANALYSIS.  9 1 

Analytical  reagents  are  applied  to  the  water- mounted  sample  by  means 
of  a  glass  rod  or  pipette,  with  which  a  drop  of  the  reagent  is  deposited 
on  the  sample  upon  the  slide,  having  previously  removed  the  cover, 
which  is  afterwards  replaced.  Or,  without  removing  the  cover-glass,  a 
drop  of  the  reagent  is  placed  in  contact  with  one  side  of  it  on  the 
slide.  Along  the  opposite  side  of  the  cover  is  then  placed  a  piece  of  filter- 
paper.  The  latter  withdraws  by  capillary  attraction  a  portion  of  the  water 
from  under  the  cover-glass,  and  this  is  replaced  by  the  reagent,  which 
thus  intermingles  with  the  particles  of  the  substance. 

Following  is  a  brief  list  of  the  commoner  microchemical  reagents, 
together  with  their  method  of  preparation  and  chief  uses.  For  fuller 
details  in  this  branch  of  the  subject  the  reader  is  referred  to  Poulsen's 
Botanical  Microchemistry,  translated  by  Trelease,  and  Zimmerman's 
Botanical  Microtechnique. 

A.  Analytical  Reagents. — Iodine  in  Potassium  Iodide. — Two  grams 
of  cr)'stallized  potassium  iodide  are  first  dissolved  in  100  cc.  of  distilled 
water  and  the  solution  is  saturated  with  iodine. 

This  reagent  is  indispensable  for  the  identification  of  starch,  especially 
when  the  latter  is  present  in  minute  quantities.  Starch  granules  when 
moistened  with  water  are  turned  blue  by  iodine,  the  reaction  being  exceed- 
ingly delicate  under  the  microscope,  even  when  the  starch  granules  are 
very  minute  and  insignificant  without  the  reagent. 

Iodine  in  connection  with  sulphuric  acid  is  also  useful  in  distinguishing 
pure  cellulose  from  its  various  modifications,  such  as  lignin  and  suberin. 
For  this  purpose  the  water-mounted  sample  is  first  permeated  with  the 
iodine  reagent,  after  which  concentrated  sulphuric  acid  is  applied,  with 
the  result  that  all  pure  cellulose  is  turned  a  deep-blue  color,  while  the 
modified  forms  of  cellulose  are  colored  yellow  or  brown.  The  cellulose 
is  first  converted  by  the  sulphuric  acid  into  a  carbohydrate  isomeric  with 
starch,  known  as  amyloid. 

Protein  grains  are  colored  brown  or  yellow  brown  by  the  action  of 
iodine. 

Chloriodide  0}  Zinc. — Pure  zinc  is  dissolved  in  concentrated  hydro- 
chloric acid  to  saturation,  and  an  excess  of  zinc  added.  The  solution  is 
then  evaporated  to  about  the  consistency  of  concentrated  sulphuric  acid, 
after  which  it  is  first  saturated  with  potassium  iodide,  and  finally  with 
iodine. 

This  reagent  may  be  used  instead  of  sulphuric  acid  and  iodine  for  the 


92  FOOD  INSPECTION  AND  AN.4 LYSIS. 

detection  of  cellulose,  since  the  zinc  chloride  converts   the  cellulose  into 
amyloid,  which  the  reagent  colors  blue. 

Chlorio.lide  of  zinc  is  useful  for  detecting  tannic  acid  in  cell  contents. 
For  this  purpose  the  above  reagent  is  much  diluted  by  the  addition  of 
a  20^-  solution  of  potassium  iodide.  In  this  diluted  form,  when  applied 
to  the  sample,  a  reddish  or  violet  coloration  is  imparted  to  cell  contents 
having  tannin. 

Phenol-hydrochloric  Acid  is  prepared  by  saturating  concentrated 
hydrochloric  acid  with  the  purest  cr)'stallizcd  carbolic  acid.  Wood  fiber, 
or  lignin.  when  treated  with  a  drop  of  this  reagent  under  the  cover-glass, 
and  exposed  for  half  a  minute  to  the  direct  sunlight,  will  be  colored  an 
intense  green,  which  cjuickly  fades. 

/;/(/()/. — Several  crystals  of  indol  are  freshly  dissolved  in  warm  water. 
Lignilied  cell  walls  assume  a  deep-red  color,  when  the  specimen  to  be 
examined  is  treated  first  with  a  drop  of  the  indol  reagent,  and  afterwards 
washed  with  dilute  sulphuric  acid,  1:4. 

Millons  Reagent. — This  is  prepared  by  dissolving  metallic  mercury 
in  its  weight  of  concentrated  nitric  acid,  and  diluting  with  an  equal  volume 
of  water.  This  reagent,  which  should  be  freshly  prepared,  is  of  use  in 
testing  for  protein  compounds,  which  turn  brick  red  when  treated  with  it, 
especially  on  gently  warming  the  slide. 

Tincture  oj  Alkanna. — A  70  or  80%  alcoholic  extract  of  alkanna  root, 
when  kept  in  contact  with  resins,  fixed  oils,  fats,  or  essential  oils  for  a 
short  time,  stains  these  cell  contents  a  lively  red.  The  staining  is  hastened 
by  the  aid  of  heat.  Essential  oils  and  resins  are  soluble  in  strong  alcohol, 
while  fixed  oils  and  fats  are  insoluble,  hence  the  distinction  between  these 
classes  of  cell  contents  may  be  made  by  the  application  of  alcohol  to  the 
alkanna-staincd  specimen. 

Ferric  Chloride,  Ferric  Acetate,  or  Ferric  Sulphate,  used  in  dilute  aqueous 
solution,  arc  all  applicable  as  reagents  for  tannic  acid,  which,  when  present 
in  appreciable  amount,  will  be  colored  green  or  blue  by  either  of  these 
reagents. 

B.  Clarifying  Reagents. — Many  of  the  harder  cellular  tissues  are  too 
opaque  for  careful  examination,  and  may  be  rendered  transparent  by  clarify- 
ing or  bleaching.  A  portion  of  the  powdered  sample  is  either  treated 
with  a  drop  of  the  reagent  under  the  cover-glass  or  is  allowed  to  soak 
for  hours  or  even  days  in  the  reagent,  using  a  droj)  of  the  same  reagent 
as  a  medium  for  examination  on  the  object-gla.ss,  instead  of  water. 
The  clarifying  reagents  most  commonly  used  are  the  following: 


THE   MICROSCOPE   IN  EOOD   ANALYSIS.  93 

Chloral  Hydrate. — A  60'^^  solution. 

Ammonia. — Concentrated,  or  28%  ammonia  is  commonly  used. 

Polassium  Hydroxide,  used  in  various  degrees  of  concentration,  often 
in  dilute  solution,  say  $^]'( .  This  reagent,  added  to  a  water  mount, 
causes  swelling  of  the  cell  wall,  an:!  dissolves  inlercellular  substances 
and  i^rotein.  It  bleaches  most  of  the  coloring  matters,  destroys  the 
starch,  and  forms  soluble  soaps  with  the  fats.  Potassium  hydroxide  is 
also  used  in  testing  for  suberin,  which  is  extracted  from  corky  tissue 
on  boiling  with  the  reagent,  and  appears  as  yellow  drops. 

Schulize's  Macerating  Reagefit  (concentrated  nitric  acid  and  chlorate  of 
potassium)  is  best  used  by  placing  the  powder  or  bit  of  tissue  to  be  treated 
in  a  test-tube  with  an  equal  volume  of  potassium  chlorate  crystals,  adding 
about  2  cc.  of  concentrated  nitric  acid,  and  warming  the  tube  till  bubbles 
are  evolved  freely,  or  until  the  necessary  separation  of  cells  is  effected. 
The  sample  is  then  removed  and  washed  with  water. 

By  this  treatment,  bast  and  wood  fibers  as  well  as  stone  cells  are 
readily  separated  from  other  tissues. 

Cuprammofiia  (Schweitzer's  Reagent). — This  is  prepared  by  adding 
slowly  a  solution  of  copper  sulphate  to  an  aqueous  solution  of  sodium 
hydroxide,  forming  a  precipitate  of  Gupric  hydroxide,  which  is  separated 
by  filtration,  washed,  and  dissolved  in  concentrated  ammonia.  It  should 
be  freshly  prepared,  and  is  never  fit  for  use  unless  it  is  capable  of  immediately 
dissolving  cotton.  Indeed  its  chief  use  is  as  a  test  for  cellulose,  which  it 
readil)^  dissolves.  In  observing  this  reaction  under  the  microscope,  the 
powdered  specimen  under  the  cover-glass  should  be  only  slightly  damp 
before  a  drop  of  the  fresh  reagent  is  applied.  The  cell  walls  are  seen  to 
swell  up  and  gradually  become  more  and  more  indistinct,  till  they  finally 
disappear. 

Cuprammonia  is  also  used  as  a  test  for  pectose,  which  occurs  in  many 
cell  walls,  often  intermixed  with  cellulose.  When  treated  with  this  reagent, 
cellular  tissue  containing  pectose  is  acted  upon  in  such  a  manner  that 
a  dehcate  framework  of  cupric  pectate  is  sometimes  left  behind,  after  the 
dissolution  of  the  cellulose  with  which  it  is  mingled.* 

PHOTOMICROGRAPHY. 

The  ])hotomicrograph  serves  as  a  simj)le  means  of  keeping  perma- 
nent records  of  unusual  forms  of  adulteration  encountered  in  the  course 
of  routine  examination.  Besides  this,  the  photomicrograi)h  has  at 
times  proved  its  usefulness  as  a  means  of  evidence  in  court,  showing  as  it 
does  with  faithfulness  the  presence  of  a  contested  adulterant.     It  is  true 

*  Poulsen,  Botanical  Micro-chemistry,  p.  15. 


94 


FOOD  INSPECTION  ^ND  ^N^ LYSIS. 


that  from  an  artistic  standpoint  the  photomicrograph  of  a  powdered 
sajnplc  is  often  disappointing,  due  to  the  fact  that  ordinarily  much  of  the 
field  is  out  of  focus,  unless  a  very  sim])]e  homogeneous  subject  is  photo- 
graphed, as,  for  instance,  starch.  As  compared  with  the  carefully  prepared 
drawing  of  a  section,  which  is  usually  idealized,  the  photomicrograph  is 
in  a  sense  the  more  truthful  representation. 

SUMMARY     OF     MICROCHEMICAL     REACTIONS     FOR     IDENTIFYING 
CELLULAR  TISSUE  AND  CELL  CONTENTS.     BASED  ON  BEHRENS'.* 


Iodine  in 

Potassium 

Iodide. 

Chlor- 

iodide  of 

Zinc. 

Iodine 
and  Sul- 
phuric 
Acid. 

Cupram- 
monia. 

Potassium 
Hydroxide. 

Concen- 
trated 
Sulphuric 
Acid. 

Schultze's 
Mixture. 

Cellulose,  cell  substance. 
Lignin.wood  substance. 
Middle     lamella,    inter- 

Yellow  to 

brownish 

Yellow 

Yellow 

Yellow  or 
brownish 

Blue 
Brown 
yellow 

Violet 
Yellow 

Yellow 

Yellow  or 
brown 

Blue 

Yellow  to 
brownish 

Yellow 

Brown 

Dissolves 
Insoluble 

Insoluble 
Insoluble 

Swells  up 
Dissolves 

Dissolves 
Dissolves 

Dissolves 

Dissolves 

easily 

Suberin,  cork  substance. 
Starch 

Insoluble 

in  cold. 

By  boiling 

it  comes  out 

in  drops 

Dissolves 

Dissolves 

Insoluble 

easily 
Gives 
eerie 
af  id  reac- 
tiont 

1 

Fat 

Saponifies 

Reddish 
to  violet 

Phenol- 
hydro- 
chloric 
Acid. 

Indol. 

Ferric 
Acetate 
or  Sul- 
phate. 

Alkanna 
Tincture. 

Hydro- 
chloric 
Acid. 

Acetic 
Acid. 

Millon's 
Reagent. 

Uncolored 
Green 

Green 
Uncolored 

Uncolored 

Cherry 

red 

Cherry 

red 

Uncolored 

Lignin,  wood  substance. 
Middle    lamella,    inter- 

1 

Starch 

Brick  red 

Bright  red 

Fai 

Bright  red 
Bright  red 

Blue  or 
green 

Calcium  oxalate  crystals 

S-iluble 
without  ef- 
fervescence 

Soluble 
with  effer- 
vescence 

Insoluble 

Soluble 
with  effer- 
vescence 

cbloro: 


al  Investigation  of  Vegetable  Substances,  page  356. 
•ed  with  the  reagent,  suberin  forms  masses  of  eerie  acid,  soluble  in  ether,  alcohol,  or 


While  the  analyst  examines  microscopically  the  ordinary  powdered 
spice,  for  example,  he  constantly  moves  with  his  hand  the  hne  adjustment- 
screw,  bringing  into  focus  different  parts  of  the  field  successively.     This 


THE  MICROSCOPE  IN  FOOD  ANALYSIS.  95 

he  does  unconsciously,  so  that  he  does  not  reahze  how  far  from  flat  the 
field  actually  is  till  he  undertakes  to  photograph  it,  when,  as  a  rule,  only 
a  small  portion  is  in  good  focus.  It  is  therefore  impossible  in  one  photo- 
graph to  show  successfully  many  varied  forms  of  tissue  or  cell  contents 
in  the  powder,  but  separate  photographs  should  be  made  as  far  as  possible 
with  only  a  little  in  each.  Thus,  for  example,  with  a  composite  subject 
like  powdered  cassia  bark,  it  would  be  very  difficult  to  show  starch,  stone 
cells,  and  bast  fibers  in  one  field,  all  in  equally  good  focus,  and,  for  the  best 
results  only,  one,  or  at  most  two,  such  varied  groups  of  elements  should  be 
shown  in  one  picture. 

Appurtenances  and  Methods  of  Procedure.^ — The  temporar}'  method 
of  water-mounting  employed  by  the  analyst  in  routine  examination  pre- 
sents many  difficulties  from  a  photographic  point  of  \iew.  The  vibrating 
motion  of  the  particles  is  very  annoying,  and  some  skill  is  required  in  using 
just  the  right  amount  of  water,  in  avoiding  air-bubbles,  in  waiting  the 
requisite  amount  of  time  before  exposing  the  plate  for  the  vibratory  motion 
to  cease,  and,  on  the  other  hand,  avoiding  too  long  delay,  which  would 
result  in  the  evaporation  of  the  water,  and  the  consequent  breaking  up  of 
the  field.  In  the  writer's  experience,  however,  in  spite  of  these  difficulties, 
the  water-mounting  gives  decidedly  the  clearest  results,  and,  with  patience 
on  the  part  of  the  operator,  it  is  in  many  ways  the  most  desirable  method  of 
mounting  for  photographic  purposes.  It  is  in  fact  the  method  employed  in 
making  most  of  the  photomicrographs  of  powdered  specimens  that  appear 
in  the  plates  at  the  end  of  this  volume,  though  a  few  were  mounted  in 
glycerin  jelly,  and  the  starches  for  the  poiarizcd-light  pictures  in  Canada 
balsam.  The  sections  of  tissues  shown  in  the  plates  were  mounted  some 
in  glycerin  and  others  in  glycerin  jelly. 

Experience  has  shown  that  two  degrees  of  magnification  well  cal- 
culated to  bring  out  the  chief  characteristics  of  the  spices  and  their  adul- 
terants in  a  photomicrograph  are  125  and  250  diameters.  The  starches, 
which  are  the  most  common  of  any  one  class  of  adulterants,  var\'  very 
widely  in  the  size  of  their  granules.  With  these  the  larger  magnification 
of  250  has  been  found  satisfactory,  while  the  general  appearance  of  the 
composite  ground-spice  itself  under  the  microscope,  as  well  as  that  of 
such  adulterants  as  ground  bark,  sawdust,  chicory,  pea  hulls,  and  ths 
like,  is  best  shown  with  the  lower  power  of  125.* 

*  The  degrees  of  magnification  adopted  in  the  originals  of  most  of  the  photomicrographs 
illastrated  in  the  accompanying  plates  are  accordingly  125  and  250,  but  in  the  process  of 
lithographing,  the  photographs  were  slightly  reduced,  so  that  the  actual  scales  in  the  repro- 
duction are  110  and  220  respectively. 


96 


FOOD  INSPRCTION  /IND  ANALYSIS. 


The  object,  mounted  in  the  manner  above  described,  is  best  examined 
when  held  in  a  mechanical  stage,  furnished  with  micrometer  adjust- 
ments, in  such  a  manner  that  a  ty{)ical  field  may  be  selected  and  held 
in  jilace  long  enough  to  photograph. 

The  Camera. — This  need  not  of  necessity  be  complicated,  but  may 
consist  simpl)'  of  a  horizontal  wooden  base  on  which  the  microscope 


"N 


IiG  37a. — A  Convenient  Photomicrographic  Camera. 

rests,  and  an  upright  board  firmly  secured  to  the  base,  carrying  a  frame 
for  an  interchangeaVjlc  ground  glass  and  plate-holder,  with  a  rubber 
gauze  skirt  hanging  from  the  frame,  adapted  to  be  gathered  and  tied 
about  the  top  of  the  microsco})e-tube.  Means  are  further  provided,  as 
by  a  slotted  guide  and  screw,  for  adjusting  the  frame  at  any  desired  height 
on  the  upright  board.* 

A  more  convenient  form  of  apparatus  now  employed  by  the  writer  is 
that  shown  in  Figs.  37a  and  376. 

*  Such  a  contrivance  as  this  was  employed  in  making  some  of  the  accompanying  photo- 
micrographs. 


THE   MICROSCOPE  IN  FOOD  /IN  A  LYSIS.  97 

The  base  is  a  solid  iron  ]>lalc  upon  which  the  microscope  rests  (any 
microscope  may  be  used  with  this  camera),  and  above  which  the  camera 
bellows  is  supported  on  two  solid  steel  rods.  The  bellows  is  supported 
at  either  end  on  wooden  frames. 

The  ground  glass  is  provided  with  a  central  transparent  area,  formed 
by  cementing  a  cover-glass  upon  the  ground  glass,  and  permits  the  accurate 
focusing  of  the  most  delicate  detail  by  means  of  a  hand  magnifying-glass. 
The  vertical  rods  supporting  the  bellows  are  attached  to  metal  arms, 
immovably  fixed  to  a  horizontal  axis,  thus  permitting  the  camera  to  be  tihed 


Fig  3 7 J. — Photomicrographic   Camera  in   Horizontal    Position 

to  any  angle  from  vertical  to  horizontal.  It  is  fixed  at  the  desired  angle  by 
means  of  heavy  hand-clamps. 

In  use  the  camera  is  placed  in  a  vertical  position  and  the  microscope 
adjusted  on  the  base  so  that  its  tube  wall  coincide  with  the  opening  in 
the  front  of  the  camera.  The  connection  between  microscope  and  camera 
is  made  light-tight  by  m.eans  of  a  double  chamber,  which  permits  consider- 
able vertical  motion  of  the  tube  of  the  microscope  without  readjustment. 
A  jointed  telescoping  rod  is  attached  to  the  upper  end  of  the  camera  to 
act  as  a  support,  giving  perfect  steadiness  when  in  a  horizontal  position, 
and  folding  down  parallel  wath  the  bellows  so  as  to  be  out  of  the  way 
when  in  any  other  position. 

Amplificaiion. — The  vertical  rods  are  graduated  in  inches  for  deter- 
mining the  amount  of  amplification,  and  to  show  when  the  ground  glass 
is  at  right  angles  to  the  optical  axis.  The  following  simple  rule  for  deter- 
mining the  amount  of  amplification  will  give  sufficiently  accurate  results. 
When  photographing  without  the  eyepiece,  divide  the  distance  of  the 
ground  glass  from  the  stage  of  the  microscope  in  inches,  by  the  focal  length 
in  inches  of  the  objective  used.  When  photographing  with  the  eye- 
piece, proceed  as  above  and  multiply  the  result  by  the  quotient  obtained 
by  dividing  lo  by  the  focus  in  inches  of  the  eyepiece  used. 


qS  FOOD  IXSPECTION  AND  ANALYSIS. 

Adjustment  and  Manipulation. — The  microscope  can  be  placed  in 
any  position  desired,  and  the  camera  adjusted  to  it.  The  bellows  can  then 
be  raised  and  the  microscope  used  as  though  no  camera  were  present. 
When  an  object  is  to  be  photographed,  the  bellows  may  be  slid  into  posi- 
tion without  in  any  way  disturbing  the  arrangement  of  light  or  object, 
the  linal  focusing  on  the  ground  glass  being  effected  quickly  by  means  of 
the  tine  adjustment-screw  of  the  microscope.  The  exposure  having 
been  made,  observation  through  the  microscope  may  be  continued  with- 
out interruption  by  simply  raising  the  bellows  again. 

When  a  water-mounted  specimen  is  to  be  photographed,  the  camera 
and  microscope  tulje  should  be  vertical  instead  of  inclined  as  shown  in 
the  cut. 

The  camera  is  best  kept  in  a  dark  room  where  the  exposures  arc  to 
be  made,  the  source  of  light  being  a  i6-  or  32-candle-powcr  electric  lamp, 
preferably  provided  with  a  ground-glass  bulb.  The  light  from  this  lamp 
is  first  carefully  centered  by  moving  the  reflector  of  the  microscope. 

In  making  pictures,  for  instance,  of  the  magnification  of  250  diameters, 
the  objective,  having  an  equivalent  focus  of  ^  inch,  may  be  used  in 
combination  whh  the  one-inch  ocular,  with  the  ordinary  tube  length  of 
microscope.  For  a  lower  power,  such  as  125  diameters,  the  same  objec- 
tive is  employed,  but  the  eyepiece  is  left  out,  it  being  found  necessary 
in  this  case  to  remove  the  upper  tube  of  the  microscope,  which  ordinarily 
carries  the  eyepiece,  as  otherwise  the  size  of  the  field  to  be  j)hotographed 
would  be  restricted.  In  each  case  a  diaphragm  is  used  in  the  microscope 
stage,  having  an  opening  of  about  the  same  size  as  that  of  the  front  lens 
of  the  objective.  By  means  of  a  stage  micrometer  scale,  the  proper  posi- 
tion of  the  camera  back  is  previously  determined  to  give  the  required- 
magnification. 

REFERENXES  OX  THE  MICROSCOPE  IN  FOOD  ANALYSIS. 

Alltman'x.     Die  Elementarorganismcn  iind  ihrc  Beziehungen  zu  den  Zcllcn.     Leipzig, 

1890. 
Behrexs,  J.  W.     Guide  to  the  Microscope  in  Botany.     Translated  by  Hervey.     Boston, 

1885. 
Hercen',    J.     Elements   of   Botany.     Gross   and   Microscopic   Structure.    Vegetable 

Histolog)'. 
Bessey,  C.  E.     The  Essentials  of  Botany. 

Botany  for  High  Schools  and  Colleges.     New  York,  1880. 

BoNSFiEi.n,  E.  C.     Guide  to  Photomicrography.     London. 

Chamberlain-,  C.  J.     Vegetable  Tissues. 

Methods  in  Plant  Histology.     Chicago,  1905. 


THE   MICROSCOPB  IN  FOOD   ANALYSIS.  99 

Clark,  C.  H.     Practical  Methods  in  Microscopy,  1900. 

Dammar,  O.     Illustrirtcs  Lexicon  der  Verfalschungen  unci  Vcrunrcinigungen  der  Xah- 
rungs-  und  Genussmittcl.     Leipzig,  1886. 

Detmer,  W.     Das  pflanzenphysiologische  Praktii<um.     Jena,  1885. 

DiETSCH,  O.     Die  wichtigsten  Nahrungsmittel  und  (ietninice,  deren  Verunreinigungen 
und  Verfiilschungen.      Zurich,  1884. 

Gage,  S.  H.     The  Microscope  and  Microscopical  Methods.     Ithaca,  1908. 

Greenish,  H.  G.     The  Microscopical  Eixamination  of  Foods  and  Drugs.     Philadel- 
phia, 191 1. 

Hanausek,  T.   F.     The  Microscopy  of  Technical  Products.     Translated  by  A.   L. 
Winton  and  Kate  G.  Barber.     New  York,  1907. 

Haushofer,  K.     Mikroskopische  Reaktionen.     Braunschweig,  1885. 

Hegler.     Histochemische  Untersuchungen  verholtzer  Zellmcmbranen.     Flora,    1890, 
page  31. 

Hoffmeister,  T.     Die  Rohfaser  und  einige  Formen  der  Cellulose.     Landwirtschaftl. 
Jahrbiicher,  1888,  page  239. 

Kocn,    L.     Mikrotechnische   Mittheilungen.     Pringsheim's  Jahrbiicher,    Bd.    XXIV, 
page  I,  1892. 

Kraemer,  H.     Botany  and  Pharmacognosy.     Philadelphia,  1910. 

Kraus,  G.     Zur  Kentniss  der  ChlorophyllfarbstoiTe.     Stuttgart,  1872. 

Lange,  G.     Zur  Kentniss  des  Lignins.     Zeits.  fur  physiologische  Chemie.     Bd.  XIV, 
page  15. 

Leach,   A.    E.     Microscopical   Examination  of  Foods   for  Adulteration.     An.    Rep. 
Mass.  State  Board  of  Health,  1900,  p.  679. 

Lee,  a.  B.     The  Microtomist's  Vade  Mecum.     1893. 

Mace,  E.     Les  Substances  Alimentaire  Etudies  au  Microscope.     Paris,  1891. 

Moeller,  J.     Mikroskopie  der  Nahrungs-  und  Genussmittcl  aus  dem  Pflanzenreiche. 
Berlin,  1905. 

Pharmacognostischer  Atlas.     Berlin,  1892. 

MOLISCH.     Grundriss  einer  Histochemie  der  pflanzlichen  Genussmittcl.     Jena,    1891. 

Neuhauss,  R.     Lehrbuch  der  Mikrophotographie.     Braunschweig,  1890. 

PouLSEN,  V.  %..     Botanical  Microchemistry,  translated  by  Trelease.     Boston,  1886. 

Pringle,  a.     Practical  Photomicrography.     New  York,  1890. 

ScmMPER,  A.  F.  W.     Mikroskopischen   Untersuchungen  der  Nahrungs-  und  Genuss- 
mittcl.    Jena,  1900. 

Strassburger,  E.     Manual  of  Vegetable  Histology,  translated  by  Hervey.     1887. 

Thomas  and  Dudley.     A  Laboratory  Manual  of  Plant  Histology. 

TscHiRCH,  A.,  und  Oesterle,  O.     Anatomischer  Atlas  der  Pharmakognosie  und  Nahr- 
ungsmittelkunde.     Leipzig,  1900. 

Vogl,  a.  E.     Die  wichtigsten  vegetabilischen  Nahrungs-  und  Genussmittcl.    Berlin,  1899. 

WiNSLOW,  C.  E.  A.     Elements  of  Applied  Microscopy.     New  York,  1905. 

"Winton,  A.  L.     The  Microscopy  of  Vegetable  Foods.     New  York,  1906. 

WoRMLEY,  T.  G.     The  Microchemistry  of  Poisons.     Philadelphia,  1885. 

Zimmerman,  A.     Botanical  Microtechnique.     New  York,  1893. 

Die  Morphologie  und  Physiologic  der  Pflanzenzelle.     Breslau,  1887. 

Beitrage  zur  Morphologie  und  Physiologic  der  Pflanzenzelle.     Tubingen,  1890. 


CHAPTER  VI. 

THE  REFRACTOMETER. 

The  refractive  index  ranks  in  importance  with  the  specific  gravity 
as  a  means  of  determining  the  identity  and  purity  of  various  food 
products,  as  well  as  of  estimating  the  percentage  of  valuable  constituents. 
Various  forms  of  refractometer  are  used  in  food  analysis. 

The  Abbe  refractometer  is  of  general  application  in  determining 
the  refractive  index  of  fats,  fatty  oils,  waxes,  and  essential  oils,  in  esti- 
mating the  solids  m  saccharine  substances,  and  in  other  analytical  opera- 
tions. It  em])loys  but  a  few  dro])s  of  the  material,  and  reads  the  refractive 
index  directly,  using  ordinary  white  light. 

The  immersion  refrac/ometer,  an  instrument  of  recent  introduction, 
is  suited  for  the  examination  of  milk  serum  to  detect  added  water 
therein,  the  detection  and  determination  of  methyl  alcohol  in  ethyl 
alcohol,  and  the  standardization  of  a  wide  variety  of  solutions.  The 
instrument  is  immersed  directly  in  the  liquid  to  be  examined,  the  degree 
of  refraction  being  indicated  on  an  arbitrary  scale. 

The  Pidfrich  is  used  with  the  sodium  light,  and  requires  a  larger 
amount  of  material  than  the  Abbe,  the  liquid  being  held  in  a  cylinder 
above  the  prism.  The  scale  reading  is  in  angular  degrees,  from  which 
the  index  of  refraction  is  calculated  by  a  formula  or  from  a  table.  The 
instrument  is  j^rovided  with  a  temperature-controlling  apparatus. 

In  the  Amagal  and  Jean  or  oleo-refractometer,  an  outer  and  an  inner 
cylinder  are  respectively  filled  with  an  oil  of  known  value  or  purity,  and 
with  the  oil  to  be  examined.  By  the  comparative  displac(?ment  to  the 
right  or  left  of  a  beam  of  white  light  passing  through  both  cylinders,  the 
displacement  being  read  in  degrees  on  an  arbitrary  scale,  the  refraction 
of  an  oil  may  be  measured.  Two  oils  may  thus  be  readily  compared 
under  the  same  conditions,  one  of  known  purity,  for  example,  with  a 
doubtful  samjjle  of  the  same  kind. 

T/ie  butyro-refractometer  and  the  Wollny  milk  fat  refractometer  (p.  139) 
are,  as  their  names  imply,  instruments  primarily  intended  for  more  restricted 
fields  of  work  than  the  foregoing.  They  involve  the  same  ])rinciple  as 
the  .Abbd,  but  are  simjjler  in  construction  and  have  arbitrary  scales. 

Unless  such  widely  varying  substances  as  the  waxes  and  the  essential 
oils  are  to  be  studied,  the  Zeiss  butyro-refractometer,  though  primarily 


THE  REFRACTOMF.TF.R. 


lOl 


intended  for  the  examination  of  butter  and  lard,  answers  most  of  the 
{)urj)Ose.s  of  the  Abbe  instrument  with  the  advantage  of  greater  sim- 
plicity, being  equally  well  adapted  for  examining  all  the  common  edible 
oils  and  fats,  as  well  as  other  materials. 

THE   ZEISS    BUTYRO-REFRACTOMETER. 

This  instrument  (shown  in  Fig.  38)  is  so  constructed  that  the  degree 
of  refraction  of  a  beam  of  light,  which  passes  obliquely  through  a  thin 


Fig.  38. — The  Zeiss  Butyro-refractometer. 

film  of  the  fat,  is  read  on  an  arbitrary  scale  of  sufficient  extent  to  cover 
the  widest  limits  of  deviation  possible  for  butter  fat  and  oleomargarine 
under  ordinary  temperatures. 

The  graduation  is  in  divisions  from  i  to  100,  covering  a  variation  in 
refractive  indices  of  from  1.4220  to  1.4895-  ^  and  B  are  the  two  hinged 
hollow  portions  of  the  prism  casing  of  the  instrument,  so  arranged  that 
when  closed  together  the  melted  fat  is  held  in  a  film  of  sufficient  thickness 
between  the  two  opposed  transparent  prism  surfaces,  the  beam  of  light, 
either  diffused  daylight  or  lamplight,  being  reflected  through  it  by  means 
of  the  mirror  /.  The  transparent  scale  is  within  the  telescope  tube  at 
the  height  indicated  by  G. 


10-  FOOD  INSPECTJON  AND  AX  A  LYSIS. 

The  Rlraciometcr  is  connected  to  any  kind  of  healing  arrangement, 
which  adniils  of  warm  water  being  transmitted  through  the  prism  casing, 
in  at  D  and  out  at  E.  A  simple  arrangement,  which  suffices  for  all 
ordinary  cases,  may  expeditiously  be  improvised  in  the  following  manner: 
Fill  a  vessel  of  say  2  gallons  capacity  with  water  of  40°  to  50°  C.  Into 
this  vessel  dip  the  free  end  of  an  india-rubber  tube  slipped  over  the  nozzle 
D  and  let  the  vessel  be  placed  at  a  height  of  about  one-half  or  one  yard 
above  the  refactometer.  Then  il  will  be  seen  that  suction  at  a  tube 
attached  to  E  will  cause  the  warm  water  to  How  through  the  prism  casing 
by  the  action  of  the  siphon  arrangement.  By  means  of  a  pinch  clip  the 
velocity  of  the  water  may  be  regulated  at  will.  The  waste  water 
may  be  allowed  to  flow  into  a  second  vessel  and,  provided  its  tem- 
perature does  not  fall  below  30°,  it  may  be  used  for  rej)lenishing  the 
upper  vessel. 

\\'hcn  working  with  solid  fats,  a  temperature  must  be  maintained 
by  the  heated  water  well  above  the  melting-point  of  the  fat.  With 
liquid  oils  no  heater  is  necessary',  as  determinations  may  be  made  at 
room  temperature,  but  it  is  advisable  in  all  cases  to  have  a  constant  stream 
of  water  passing  through  the  water  jacket,  which  may  be  done  by  directly 
connecting  it  with  the  water  faucet  in  the  case  of  oils,  since,  without  such 
precautions  to  insure  even  temperature,  disturbing  variations  are  liable 
to  occur,  due  to  the  warming  of  the  prisms  by  the  manipulation  of  clean- 
ing, etc. 

Refractometer  Heater. — A  regular  heater,  shown  in  Fig.  39,  is  furnished 
by  the  manufacturers,  capable  of  supplying  a  current  of  water  of  approx- 
imately constant  temperature,  and  will  be  found  of  great  convenience  when 
the  instrument  is  to  be  used  constantly,  especially  with  the  solid  fats. 

-\  supi)ly  reservoir  A  is  secured  to  the  wall  and  is  connected  by  means 
of  a  rubber  inlet  tube  G  to  the  water  faucet  C.  The  reservoir  is  provided 
with  a  waste  overflow  pipe  and  with  an  outlet  tube  D,  the  flow  through 
the  latter  being  regulated  by  the  cock  //.  The  tu])e  D  leads  to  the  spiral 
heater  //5,  which  is  heated  by  a  Bunsen  burner.  From  the  heater  the 
tulx-  E  conducts  the  warm  water  through  the  refractometer,  from  which 
it  flows  through  the  tube  F,  either  directly  into  the  sink,  or  into  the  inter- 
mediate vessel  Fi.  The  temperature  of  the  water  is  regulated  by  adjust- 
ing the  rof  k  //,  and  tlie  height  of  the  flame  of  the  Bunsen  burner. 

Manipulation  of  the  Butyro-refractometer. — The  ]:)rism  casing  is  first 
opened  by  giving  about  half  a  turn  to  the  right  to  the  j)in  F,  Fig.  38, 
until  it   meets  with  a  stop.     Then  simply  turn  the  half  B  of  the  prisni 


THE   REFRACTOMETF.R. 


1^3 


casing  aside.  Pillar  //  holds  B  in  the  jjosilion  shown  in  Fig.  38.  The 
prism  and  metallic  surfaces  must  now  be  cleaned  with  the  greatest  care, 
the  best  means  for  this  purpose  being  soft  linen,  moistened  with  a  little 
alcohol  or  benzine. 

If  the  sample  to  be  examined  is  a  solid  fat,  maintain  the  temperature 
above  the  melting-pointy  and  aj)ply  by  a  glass  rod  a  drop  or  two  of  the 
clear  melted  fat  (filtered  if  turbid)  to  the  surface  of  the  prism  contained 
in  the  casing  B.     For  this  purpose  the  apparatus  should  be  raised  with. 


fo)         (S\ 


Fig.    39. — ^The  Zeiss  Heating  Apparatus  for  all  Forms  of  Refractometer. 
cut  in  connection  with  the  Pulfrich  refractometer. 


Shown  in  tbe 


the  left  hand  so  as  to  place  the  prism  surface  in  a  horizontal  position, 
A  liquid  oil  is  directly  applied  in  the  same  manner  without  preliminary 
precautions  as  to  heating.  Now  press  B  against  A,  and  place  F  by 
turning  it  in  the  opposite  direction,  in  its  original  position;  thereby  B 
is  prevented  from  falling  back,,  and  both  prism  surfaces  are  kept  in  close 
contact.     Place  the  instrument  again  upon  its  sole  plate. 

While  looking  into  the  telescope,  give  the  mirror  /  such  a  position  as 
to  render  the  critical  line,  which  separates  the  bright  left  part  of  the  field 
from  the  dark  right  part,  distinctly  visible.  It  may  also  be  necessary 
to  move  or  turn  the  instrument  about  a  little.  First  it  will  be  necessary 
to  ascertain  whether  the  space  between  the  prism  surfaces  be  uniformly 
filled  with  oil  or  fat,  failing  which  the  critical  line  will  not  be  distinct. 
For  this  purpose  examine  the  rectangular  image  of  the  prism  surface 
formed  about   i  cm.  above  the  ocular  with  a  hand  magnifier  or  with  the 


IC4 


FOOD  INSPECTION   .4ND  AN /I  LYSIS. 


naked  eye,  placing  the  latter  at  its  '})r()per  distance  from  the  ocular. 
Finally  adjust  the  movable  front  part  of  the  ocular  so  that  the  scale 
becomes  clearly  visible. 

By  allowing  a  current  of  water  of  constant  temperature  to  flow  through 
the  apparatus  some  time  previous  to  the  taking  of  the  reading,  the  at  first 
somewhat  hazy  critical  line  approaches  in  a  short  time,  generally  after  a 
minute,  a  fixed  position,  and  quickly  attains  its  greatest  distinctness. 
When  this  point  has  been  reached,  note  the  appearance  of  the  critical 
line  (i.e.,  whether  colorless  or  colored,  and  in  the  latter  case  of  what  color); 
also  note  the  position  of  the  critical  line  on  the  centesimal  scale,  which 
admits  of  the  tenth  divisions  being  conveniently  estimated;  at  the  same 
time  read  the  position  of  the  thermometer. 

Testing  the  Adjustment  oj  the  Ocular  Scale. — It  is  imperative  that 
the  adjustment  of  the  instrument  be  tested  periodically,  and  in  particular 
when  it  is  being  used  for  the  first  time.  This  may  be  done  by  means 
of  the  standard  fluid  supplied  with  the  instrument,  the  critical  line  of 
which  is  approximately  colorless,  and  must  occupy  the  following  positions 
in  the  scale. 


Temper- 

Scale 

Temper- 

Scale 

Temper- 

Scale 

Temper- 

Scale 

ature. 

Division. 

ature. 

Division. 

ature. 

Division. 

ature. 

Division. 

30= 

68.1 

2^° 

71.2 

1        20° 

74-3 

15° 

77-3 

29° 

68.7 

24° 

71.8 

1         19° 

74-9 

14° 

77-9 

28° 

69-3 

23° 

72.4 

18° 

75-5 

13° 

78.6 

27° 

70.0 

22° 

73-0 

17° 

76.1 

12° 

79-2 

26° 

70.6 

21° 

73-6 

I         16° 

76.7 

11° 

70.8 

25- 

71.2 

20° 

; 

74-3 

15° 

77-3 

10° 

80.4 

The  fractional  parts  of  a  degree  can  accordingly  easily  be  brought 
into  calculation  (0.1=0.06  scale  div.).  Deviations  of  i  to  2  decimals 
of  the  scale  divisions  are  of  no  consequence,  and  arc  in  most  cases  due 
to  inexact  determinations  of  temperature.  Should,  however,  careful 
tests  result  in  the  discovery  of  greater  deviations,  readjustment  of  the 
scale  will  be  necessary,  which  may  be  effected  by  means  of  a  watch-key 
supplied  with  the  instrument,  in  accordance  with  the  values  given  in 
the  alx)vc  table.  The  watch-key  is  inserted  at  G  in  Fig.  38,  and  by  ils 
means  the  position  of  the  objective,  and  therefore  that  of  the  critical  line 
with  respect  to  the  scale  may  be  aLered. 

Transjormatton  oj  Scale  Divisions  into  Indices  of  Refraction. — The 
following  table,  adapted  from  that  of  Pulfrich,  enables  one  to  convert 
scale  readings  r)n  the  butyro-refractometer  into  indices  of  refraction,  w^,, 
and  vice  versa: 


THE  RHFR/ICTOMETER. 


105 


EQUIVALENTS    OF    INDICES     OF     REFRACTION    AND     BUTYRO-REFRAC- 

TOMETER  READINGS. 


Refrac- 

Im. 

iirt  h  Deuiinal  of  n 

D. 

tive 

Index. 

«/>. 

0 

1 

2 

3 

4 

0 

G 

7 

8 

9 

SCALE  READINGS 

1.422 

0.0 

o.r 

0.2 

0.4 

0-5 

0.6 

0.7 

0.9 

I.O 

I.I 

1.42,^ 

1.2 

1-4 

1-5 

1.6 

1-7 

1-9 

2.0 

2.1 

2.2 

2.4 

1-424 

2-5 

2.6 

2-7 

2.8 

3-0 

3-1 

3-2 

i-^ 

3-5 

3-6 

1-425 

3-7 

3-8 

4.0 

4-1 

4.2 

4-3 

4-5 

4-6 

4-7 

4.8 

1.426 

5-0 

5-1 

'i  -  2 

5-4 

5-5 

5-6 

5-7 

5-9 

6.0 

6.1 

1.427 

6.2 

6.4 

6-5 

6.6 

6.8 

6.9 

7.0 

7-1 

7-2 

7-4 

1.428 

7-5 

7.6 

7-7 

7-0 

8.0 

8.1 

8.2 

8-4 

8-5 

8.6 

1.429 

8-7 

8.y 

9.0 

9-1 

9-2 

9-4 

9-5 

0.6 

9-8 

9-9 

1.430 

10. 0 

10. 1 

10.3 

10.4 

10- 5 

10.6 

10.7 

10.9 

II. 0 

II. I 

1-431 

II -3 

It. 4 

II-5 

II. 6 

II. 8 

II. 9 

12.0 

12.2 

12.3 

12.4 

1.432 

12.5 

12.7 

12.8 

12.9 

13-0 

13-2 

13-3 

13-5 

13.6 

13-7 

1-433 

13-8 

14.0 

14-1 

14.2 

14-4 

14-5 

14-6 

14-7 

14.9 

15.0 

1-434 

iS-i 

15-3 

15-4 

15-5 

15.6 

15.8 

15-9 

16.0 

16.2 

16.3 

1-435 

16.4 

16.6 

16.7 

16.8 

17.0 

17. 1 

17.2 

17-4 

17-5 

17.6 

1.436 

17-8 

17.9 

18.0 

18.2 

18.3 

18.4 

18.5 

18.7 

18.8 

18.9 

1-437 

19. 1 

19.2 

19-3 

19-5 

19.6 

19.7 

19.8 

20.0 

20.1 

20.3 

1.438 

20.4 

20.5 

20.6 

20.8 

20.9 

21. 1 

21.2 

21.3 

21.4 

21.6 

1-439 

21.7 

21.8 

22.0 

22.1 

22.2 

22.4 

22-5 

22.6 

22.7 

22.9 

1.440 

23.0 

23.2 

23-3 

23-4 

23-5 

23-7 

23-8 

23-9 

24.1 

24.2 

1-441 

24-3 

24-5 

24.6 

24-7 

24.8 

25-0 

25-1 

25.2 

25-4 

25-5 

1-442 

25-6 

25.8 

25-9 

26.1 

26.2 

26.3 

26.5 

26.6 

26.7 

26.9 

1-443 

27.0 

27.1 

27-3 

27-4 

27-5 

27-7 

27.8 

27-9 

28.1 

28.2 

1-444 

28.3 

28.5 

28.6 

28.7 

28.9 

29.0 

29.2 

29-3 

29-4 

29.6 

1-445 

29-7 

29.9 

30.0 

30-1 

30-3 

30-4 

30-6 

30-7 

30-8 

30-9 

1.446 

31-1 

31.2 

31-4 

31-5 

31.6 

31.8 

31-9 

32.1 

32.2 

32.3 

1.447 

32-5 

32.6 

32.8 

32-9 

33-0 

33-2 

2,i-2> 

33-5 

33-6 

33-7 

1.448 

33-9 

34-0 

34-2 

34-3 

34-4 

34-6 

34-7 

34-9 

35-0 

35-1 

1.449 

35-3 

35-4 

35-6 

35-7 

35-8 

36.0 

36.1 

36-3 

36-4 

36.5 

1-450 

36.7 

36-8 

37-0 

37-1 

37-2 

37-4 

37-5 

37-7 

37-8 

37-9 

1-451 

38.1 

38-2 

38-3 

38-5 

38.6 

38-7 

38-9 

39-0 

39-2 

39-3 

1.452 

39-5 

39-6 

39-7 

39-9 

40.0 

40.1 

40-3 

40.4 

40.6 

40.7 

1-453 

40-9 

41.0 

41. 1 

41-3 

41-4 

41-5 

41-7 

41.8 

42.0 

42.1 

1-454 

42-3 

42.4 

42.5 

42-7 

42.8 

43-0 

43-1 

43-3 

43-4 

43-6 

1-455 

43-7 

43-9 

44.0 

44-2 

44-3 

44-4 

44-6 

44-7 

44-9 

45-0 

1.456 

45-2 

45-3 

45-5 

45.6 

45-7 

45-9 

46.0 

46.2 

46-3 

46.4 

1-457 

46.6 

46.7 

46.9 

47.0 

47-2 

47-3 

47-5 

47-6 

47-7 

47-9 

1-458 

48.0 

48.2 

48.3 

48.5 

48.6 

48.8 

48-9 

49-1 

49.2 

49  4 

1-459 

49-5 

49-7 

49-8 

50.0 

50.1 

50.2 

50-4 

50-5 

50-7 

50.8 

1.460 

51.0 

51 -I 

51-3 

51-4 

51.6 

51-7 

51-9 

52.0 

52.2 

52-3 

1. 461 

52-5 

52-7 

52-8 

53-0 

53-1 

53-3 

53-4 

53-6 

53-7 

53-9 

1.462 

54-0 

54-2 

54-3 

54-5 

54-6 

54-8 

55-0 

55-1 

55-3 

55-4 

1.463 

55-6 

55-7 

55-9 

56.0 

!;6.2 

56-3 

56-5 

56.6 

56.8 

56-9 

1.464 

57-1 

57-3 

57-4 

57-6 

57-7 

57-9 

58-0 

58.2 

58-3 

58-5 

1-465 

58.6 

58.8 

58.9 

59-1 

59-2 

59-4 

59-5 

59-7 

59-8 

60.0 

1.466 

60.2 

60.3 

60.5 

60.6 

60.8 

60.9 

61. 1 

61.2 

61.4 

61.5 

1.467 

61.7 

61.8 

62.0 

62.2 

62.3 

62.5 

62.6 

62.8 

62.9 

63-1 

1.468 

63-2 

63-4 

63 -5 

63-7 

6^8 

64.0 

64-2 

64-3 

64-5 

64-7 

1.469 

64.8 

65.0 

65.1 

65-3 

65-4 

65.6 

65-7 

65-9 

66.1 

66.2 

100 


FOOD  INSPECTION  AND  ANALYSIS. 


EQUIVALENTS    OF    INDICES    OF    REFRACTION     AND 
TOMETER    READINGS— (Co«/mz<«<0. 


BUTYRO-REFRAC 


Refrac- 

Fourth Decimal  of  «£>, 

tive 

Iii>iex. 

»»A 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

SCALE  READINGS 

1.470 

66.4 

66.5 

(6.7 

66.8 

67.0 

67.2 

67-3 

67-5 

67.7 

67.8 

I-471 

68.0 

68. 1 

68.3 

68.4 

68.6 

68.7 

68 

9 

69.1 

69.2 

69.4 

1.472 

69-5 

69.7 

69-9 

70.0 

70.2 

70-3 

70 

5 

70.7 

70.8 

71.0 

1-473 

71. 1 

71-3 

71.4 

71.6 

71. s 

71.9 

72 

I 

72.2 

72-4 

7  2 -.5 

1.474 

72-7 

72.9 

73-0 

73-2 

73-3 

73-5 

73 

7 

73-8 

74.0 

74.1 

1-475 

74-3 

74.5 

74-6 

7  +  -8 

75-0 

75 -r 

75 

3 

75-5 

75.6 

75-8 

1.476 

76.0 

76.1 

76.3 

76-5 

76.7 

76.8 

77 

0 

77-2 

77-3 

77-5 

1.477 

77-7 

77-9 

78.1 

78.2 

78-4 

78.6 

78 

7 

78-9 

79.1 

79.2 

1.478 

79-4 

79-6 

79-8 

80.0 

80.1 

80.3 

80 

5 

80.6 

80.8 

8r.o 

1-479 

81.2 

81.3 

81.5 

81.7 

81.9 

82.0 

82 

2 

82.4 

82.5 

82.7 

1.480 

82.9 

83-1 

83-2 

83-4 

83-6 

83-8 

83 

9 

84.1 

84-3 

84.5 

1.481 

84.6 

84.8 

85.0 

85-2 

85-3 

85-5 

85 

7 

85-9 

86.0 

86.2 

1.482 

86.4 

86.6 

86.7 

86.9 

87.1 

87-3 

87 

5 

87.6 

87.8 

88.0 

1.483 

88.2 

88.3 

88.5 

88.7 

88.9 

89.1 

89 

2 

89-4 

89.6 

89. 8 

1.484 

90.0 

90.2 

90-3 

90-5 

90.7 

90.9 

91 

I 

91.2 

91.4 

91.6 

1.485 

91.8 

92.0 

92.1 

92-3 

92.5 

92-7 

92 

9 

93 -o 

93-2 

93-4 

1.486 

93-6 

93-8 

94.0 

94-1 

94-3 

94-5 

94 

7 

94-8 

95-0 

95-2 

1.487 

95-4 

95-6 

95-8 

96.0 

96.1 

96-3 

96 

6 

96.7 

96.9 

97.0 

1.488 

97-2 

97-4 

97-6 

97-8 

98.0 

98. 1 

98 

3 

98-5 

98.7 

98-9 

1.489 

99-1 

99-2 

99.4 

99-6 

99.8 

100. 0 

The  Critical  Line. — It  should  be  remembered  that  the  instrument  is 
primarily  intended  for  use  with  butter,  and  that  the  prisms  arc  so  con- 
structed that  the  critical  line  of  pure  butter  is  colorless,  while  various  other 
fats  and  oils,  notably  oleomargarine,  which  have  greater  dispersive  powers 
than  natural  butter,  show  a  colored  critical  line.  When  too  great  dis- 
persion is  apparent  to  render  possible  an  accurate  reading,  or  when  the 
critical  line  presents  ver>'  broad  fringes,  as  with  linseed  oil,  poppyseed 
oil,  turpentine,  etc.,  use  a  sodium  light,  obtained  by  the  application  of 
table  salt  to  the  Bunsen  gas  flame,  or  the  diffused  daylight  may  be  re- 
flected in  the  mirror  through  a  flat  bottle  filled  with  a  dilute  solution  of 
potassium  bichromate,  to  give  a  yellow  light. 

The  advantages  of  the  refractomcter  for  exami nation  of  fats  and 
oils  consist  in  the  convenience  with  which  very  accurate  determinations 
of  the  refractive  index  may  be  made  at  any  temperature  between  10°  and 
50''  C,  inclusive  of  thermal  variations  of  refractive  powers,  and  also  in 
the  possibility  which  it  affords  of  distinguishing  substances  by  their 
different  dispersive  powers,  rendered  visible  by  the  different  coloring 
of  the  critical  line,  a  red-colored  critical  line  being  indicative  of  a  relatively 
low  dispersive  power,  a  blue  line  of  relatively  high  dispersion. 


CC    5-iE_ 


THH  REFRACT OMETER. 


107 


ri-§^t^^ 


_  N 


Fig. 


Variation  0}  Reading  with  the  Temperature. — 
No  definite  Icmperaturc  has  been  adopted  as  a 
standard  for  readings  of  this  instrument,  but  it 
is  easy  to  reduce  readings  at  any  temperature  to 
terms  of  any  other  temperature  for  j)urposes  of 
comparison.  While  the  change  in  index  of  re- 
fraction for  1°  C.  is  the  same  whatever  the 
temperature,  as  Tolman  and  Munson  have  pointed 
out,*  the  change  in  scale  reading  per  1°  C.  de- 
creases as  the  temperature  increases,  and  varies 
slightly  with  different  oils.  For  correcting  read- 
ing R'  at  a  temperature  T'  to  a  reading  R  at 
temperature  T,  their  formula  is  R  =  R'  —  X{T  — 
T),  X  being  the  change  in  scale  reading  due  to 
change  of  1°  C.  in  temperature. 

For  butter,  oleomargarine,  beef  tallow,  lard, 
and  other  fats  reading  from  40°  to  50°  or  there- 
abouts on  the  scale,  .¥  =  0.55.  For  oils  reading- 
between  60°  and  70°,  like  olive,  mustard,  rapeseed, 
cottonseed,  peanut,  etc..  A' =  0.58,  and  for  oils  read- 
ing between  70°  and  80°,  Hke  corn  oil,  A"  =  0.62. 

The  slide  rulj  f  shown  in  Fig.  40,  for  use  with 
the  refractometer,  has  been  jointly  devised  by  H, 
C.  Lythgoe  and  the  writer,  to  render  unnecessary 
the  use  of  tables  or  formulas.  The  extreme  upper 
and  lower  scale  divisions  indicate  indices  of  re- 
fraction, and  adjacent  to  these  are  the  scale 
divisions  indicating  readings  on  the  butyro- 
refractometer.  By  comparison,  therefore,  the 
values  of  either  the  Abbe  or  the  butyro  scale 
may  be  readily  ascertained  in  terms  of  the 
other. 

The  sliding  scale,  expressing  temperature 
readings  in  degrees  centigrade,  is  intended  to  be 
used  in  connection  with  the  adjacent  scale  of 
butyro-refractometer  readings,  to  readily  express 
the  butyro-scale  reading  of  any  fat  or  oil  taken 
at  a  given  temperature,  in  terms  of  that  at  any 
other  temperature.     This  is  frequently  convenient 


40. — Comparative    Re- 
fractometer Scale. 


*  Jour.  Am.  Chem.  Soc.,  XXIV,  p.  755. 
t  Manufactured  by  Messrs.  Baird  and  Tatlock,  Ltd.,  14  Cross  Street,   Hatton  Garden, 
London. 


i^S 


FOOD   INSPECTION   /iND  ANALYSIS. 


in  comparing  the  work  of  various  observers,  where  dilTerent  temperatures 
have  been  employed. 

The  correction  for  change  in  tio  on  the  scale  is  0.000365  for  1°  C, 
being  based  on  the  experimental  work  of  Tolman,  Long,  Proctor,  Lythgoe, 
and  I  he  author. 

THE   ABBE   REFRACTOMETER. 

This  instrument,  Fig.  41,  has  a  much  wider  range  in  reading  than 
citlicr   the   butyro  or   the   Wollny   instruments   already  described,   read- 


Fir,.  41. — The  Abbe  Refractometer  with  Temperature-ainlrollcd  Prisms. 


ing  a.'-,  it  does  to  the  fourth  decimal  between  the  limits  of  1.3  and  1.7  in 
indices  of  refraction.  The  equivalent  readings  of  the  Wollny  milk  fat 
refractometer,  in  indices  of  refraction,  range  from  1.3332  to  j.4220,  while 
those  of  the  butyro  instrument  run  from  1.4220  to  1.4895.  The  Abb^ 
instrument   is  thus  necessary  for  use  with   the  high-refracting  essential 


I 


THE  REFRACT OMETER.  109 

oils.  Its  construction  is  such  that  the  j)risms  can  withstand  a  higher 
heat  than  in  the  case  of  the  butyro-refractomctcr,  and  it  is  hence  better 
adapted  for  the  examination  of  sam])les  having  a  high  melting-point, 
such  as  beeswax  and  paraffin.  An  advantage  of  the  Abbe  over  the  butyro 
instrument  lies  in  the  fact  that  the  wide  dispersion,  inevitable  when  read- 
ing many  substances  on  the  butyro,  may  be  entirely  compensated  for  with 
the  Abbe,  and  a  clear  sharp  line  be  obtained.  The  construction  of  the 
prisms  in  relation  to  the  heating  jacket  is  similar  in  both  instruments, 
and  a  film  of  the  substance  to  be  examined  is  held  in  the  same  manner 
between  the  surfaces  of  the  prisms. 

Construction  and  Manipulation. — The  Abbe  refractomctcr  is  mainly 
composed  of  the  following  parts    (see  Fig.  41): 

1.  The  double  Abbe  prism  AB,  which  contains  the  fluid  and  can 
be  rotated  on  a  horizontal  axis  by  means  of  an  alidade. 

2.  A  telescope  OF  for  observing  the  border-line  of  the  total  reflec- 
tion which  is  formed  in  the  prism. 

3.  A  sector  S,  rigidly  connected  with  the  telescope,  on  which  divisions 
representing  refractive  indices  are  engraved. 

The  double  prism  {AB,  Fig.  41)  consists  of  two  similar  prisms  of 
flint-glass,  each  cemented  into  a  metal  mount  and  having  a  refractive 
index  ^^=1.75.  The  former  of  the  two  prisms,  that  farthest  from  the 
telescope,  which  can  be  folded  up  or  removed,  serves  solely  for  the 
purpose  of  illumination,  while  the  border-line  is  formed  in  the  second  flint 
prism.  A  few  drops  of  the  fluid  to  be  investigated  is  deposited  between 
the  two  adjoining  inner  faces  of  the  prisms  in  the  form  of  a  thin  stratum, 
about  0,15  mm.  thick. 

The  double  prism  is  opened  and  closed  by  means  of  a  screw-head 
V,  which  acts  in  the  manner  of  a  bayonet  catch.  In  order  to  apply  a 
small  quantity  of  fluid  to  the  prisms  without  opening  the  casing,  the 
screw  V  is  slackened  and  a  few  drops  of  fluid  poured  into  the  funnel- 
shaped  aperture  of  a  narrow  passage,  not  seen  in  the  figure.  On 
again  tightening  the  screw,  the  fluid  is  distributed  by  capillary  action 
over  the  entire  space  between  the  two  prisms.  This  arrangement  facili- 
tates the  investigation  of  rapidly  evaporating  fluids,  such  as  ether  solu- 
tions. In  the  case  of  viscous  fluids  (resins,  etc.),  a  drop  of  moderate  size 
is  applied  with  a  glass  rod  to  the  dull  prism  surface,  the  double  prism 
being  opened,  for  the  purpose.  The  prisms  are  then  closed  again,  and 
before  the  measurement  is  proceeded  with,  the  refractomctcr  is  left 
standing  for  a  few  minutes  in  order  to  compensate  for  any  cooling  or 
heating  of  the  prisms  which  might  occur  while  they  were  separated. 


no  FOOD  INSPECTION  y4ND  AN /I  LYSIS. 

The  arrangement  for  controlling  the  tempt^rature  of  the  prisms  of 
the  Abbe  refraclomeler  is  essentially  after  Dr^  R.  Woilny's  plan  of  enclos- 
ing the  prisms  in  a  metal  casing  with  double  walls,  through  which  water 
of  a  given  temperature  is  circulated. 

The  border-line  is  brought  within  the  field  of  the  telescope  OF  by- 
rotating  the  double  prism  by  means  of  the  alidade  in  the  following 
manner:  Holding  the  sector,  the  alidade  is  moved  from  the  initial 
position  at  which  the  index  points  to  Hj^^j.t^,  in  the  ascending  scale  of 
the  refractive  indices  until  the  originally  entirely  illuminated  field  of 
view  is  encroached  upon  from  the  direction  of  its  lower  half  by  a  dark 
portion;  the  line  dividing  the  bright  and  the  dark  half  of  the  field  then 
is  the  "border-line."  When  daylight  or  lamplight  is  being  employed, 
the  border-line,  owing  to  the  total  reflection  and  the  refraction  caused 
by  the  second  prism,  assumes  at  first  the  appearance  of  a  band  of  color, 
which  is  quite  unsuitable  for  any  exact  process  of  adjustment.  The 
conversion  of  this  band  of  color  into  a  colorless  line  sharply  dividing 
the  bright  and  dark  portions  of  the  field  is  the  work  of  the  compen- 
sator, which  consists  of  two  similar  Amici  prisms  of  direct  vision  for 
the  Z)-line,  and  rotated  simultaneously,  though  in  oppjosite  directions, 
round  the  axis  of  the  telescope  by  means  of  the  screw-head  M.  The 
dispersion  of  the  border-line,  which  appears  in  the  telescope  as  a  band 
of  color,  can  thus  be  counteracted  by  rotating  the  screw-head  M  till 
the  equal  but  opposite  dispersions  are  neutralized,  making  the  line  color- 
less and  sharp. 

The  border-line  is  now  adjusted  upon  the  point  of  intersection  of 
the  crossed  lines  by  slightly  inclining  the  double  prism  to  the  telescope 
by  means  of  the  alidade.  The  position  of  the  pointer  on  the  graduation 
of  the  sector  is  then  read  by  the  aid  of  the  magnifier  attached  to  the 
alidade.  The  reading  supplies  the  refractive  index  «^  of  the  substance 
under  investigation  without  any  computation,  and  with  a  degree  of 
exactness  approaching  to  within  about  two  units  of  the  fourth  decimal. 
Simultaneously,  the  reading  of  the  scale  on  the  drum  of  the  compensator 
(7"  in  Fig.  41)  enables  the  mean  dispersion  to  be  arrived  at  by  means 
of  a  special  table  and  a  short  process  of  computation. 

Injlucnce  0/  Temperature.  —  As  the  refractive  index  of  fluids  varies 
with  their  temperature,  it  is  of  importance  to  know  the  temperature 
of  the  fluid  contained  in  the  double  jjrism  during  the  j^rocess  of  measure- 
ment. 

If,  therefore,  it  is  dcsirerl  to  measure  a  fluid  with  the  highest  degree 
of  accuracy  attainable  with  the  Ahh6  rcfractometer   (to  within  one  or 


THE    REFRACTGMETER.  HI 

two  units  of  the  fourth  decimal  of  Uj^,  it  is  absolutely  necessary  to  bring 
the  fluid,  or  rather  the  double  prism  containing  it,  to  a  definite  known 
temperature,  and  to  be  able  to  control  this  temperature  so  as  to  keep 
it  constant  to  within  some  tenths  of  a  degree  for  a  })eriod  of  several 
hours;  hence  a  refractomcter  ])rincipally  required  for  the  investiga- 
tion of  fluids  must  be  provided  with  beatable  prisms. 

The  type  of  heater  shown  in  Fig.  39.  and  described  in  connection 
with  the  butyro-refractometer  on  page  102,  is  equally  adapted  for  con- 
trolling the  temperature  of  the  prisms  in  the  Abbe  instrument,  the  flow 
of  water  entering  at  D  and  passing  out  at  E,  Fig.  41. 

THE   IMMERSION    REFRACTOMETER. 

This  form  of  refractomcter  is  of  more  recent  introduction  than  the 
others  made  by  Zeiss,  and  has  many  features  that  especially  commend  it 
to  the  use  of  the  food  analyst.  The  construction  of  the  immersion  refrac- 
tomcter is  such  that,  as  its  name  implies,  it  may  be  immersed  directly  in  an 
almost  endless  variety  of  solutions,  the  strength  of  which,  within  limits,  may 
be  determined  by  the  degree  of  refraction  read  upon  an  arbitrary  scale. 
Thus,  for  example,  the  strengths  of  various  acids  and  of  a  variety  of 
salt  solutions  used  as  reagents  in  the  laboratory,  as  well  as  of  formaldehyde, 
of  sugars  in  solution,  and  of  alcohol,  are  all  capable  of  determination  by 
the  use  of  the  immersion  refractomcter. 

Figure  42  shows  the  form  used  by  the  writer.  P  is  a  glass  prism 
fixed  in  the  low^er  end  of  the  tube  of  the  instrument,  while  at  the  top  of 
the  tube  is  the  ocular  Oc,  and  just  below  this  on  a  level  with  the  vernier 
screw  Z  is  the  scale  on  which  is  read  the  degree  of  refraction  of  the  liquid 
in  which  the  prism  P  is  immersed.  The  tube  may  be  held  in  the  hand 
and  directly  dipped  in  the  liquid  to  be  tested,  this  liquid  being  contained 
in  a  vessel  with  a  translucent  bottom,  through  which  the  light  is  reflected. 
The  preferable  method  of  use  is,  however,  that  shown  in  the  cut. 

yl  is  a  metal  bath  with  inlet  and  outlet  tubes,  arranged  whereby  water 
is  kept  at  a  constant  level.  The  water  is  maintained  at  a  constant  tem- 
perature by  means  of  a  controller  of  the  same  type  as  the  refractometer 
heater  shown  in  Fig.  39.  In  the  bath  A  are  immersed  a  number  of 
beakers,  containing  the  solutions  to  be  tested.  T  is  a  frame  on  which  is 
hung  the  refractometer  by  means  of  the  hook  H,  at  just  the  right  height 
to  permit  of  the  immersion  of  the  prism  P  in  the  liquid  in  any  of  the 
beakers  in  the  row  beneath.  Under  this  row  of  beakers  the  bottom  of 
the  tank  is  composed  of  a  strip  of  ground  glass,  through  which  light  is 
reflected  by  an  adjustable  pivoted  mirror. 


FOOD  ISSPECTION  ^h'D  AN/I LYSIS. 


The  temperature  of  the  bath  is  noted  by  a  delicate  thermometer 
immersed  therein,  capable  of  reading  to  tenths  of  a  degree. 

Returning  to  the  main  refractometer-trbe,  i?  is  a  graduated  ring  or 
collar  which  is  connected  by  a  sleeve  within  the  tube  with  a  compound 
prism  near  the  bottom,  the  construction  being  such  that  by  turning 
the  collar  R  one  way  or  the  other  the  chromatic  aberration  or  dispersion  of 
any  li(iuid  may  be  compensated  for,  and  a  clear-cut  shadow  or  critical  line 
projected  across  the  scale.    By  the  graduation  on  the  collar  R,  the  degree  of 


Fig.  42. — The  Zeiss  Immersion  KL-frai  tomcter. 

di?persi(jn  may  be  read.  Tenths  of  a  degree  on  the  main  scale  of  the  in- 
stnment  may  be  read  with  great  accuracy  by  means  of  the  vernier  screw  Z, 
graduated  along  its  circumference,  the  screw  being  turned  in  each  case  till 
the  critical  line  on  the  scale  coincides  with  the  nearest  whole  number. 

The  scale  of  the  instrument  reads  from  —  5  to  105,  corresponding 
to  indices  of  refraction  of  from  1.32539  to  1.36640.  It  should  be  noted 
tb^t  the  index  of  refraction  may  be  read  with  a  greater  degree  of  accuracy 
on  [he  immersion  refractometer  than  on  the  Abbe  instrument. 


THE   REFRACT OMETER. 


1^3 


Manipulation  of  the  Immersion  Refractometer. — Before  using  the 
instrument  for  the  first  time,  it  is  necessary  to  see  that  the  refractometer 
is  correctly  adjusted.  For  this  purpose  the  bath  A  is  placed  with  its 
long  side  i)arallel  to  the  window  and  the  mirror  turned  towards  a  bright 
sky,  the  bath  is  half  filled  with  tap-water,  and  a  beaker  filled  with  dis- 
tilled water  is  then  placed  in  one  of  the  five  holes  in  the  front  row  imme- 
diately above  the  mirror.  Finally,  the  refractometer  is  hung  by  its 
hook  H  upon  the  wire  frame,  the  prism  being  totally  submerged  in  the 
water  contained  in  the  beaker. 

The  whole  apparatus  is  now  allowed  to  stand  for  ten  minutes,  or  until 
the  distilled  water  has  acquired  the  exact  temperature  of  the  bath,  and 
the  ocular  is  focussed  upon  the  divisions  of  the  scale  by  turning  the 
milled  zone  of  the  ocular  shell  until  the  lines  and  numbers  are  seen  quite 
distinctly,  the  mirror  being  adjusted  so  that  the  light  of  the  bright 
sky  is  seen  directly  through  the  beaker.  The  upper  part  of  the  field 
from  —5  to  about  15  appears  bright,  and  it  is  separated  from  the  lower 
dark  part  by  a  sharp  line  of  demarcation,  if  the  index  on  the  ring  of 
the  compensator  stands  at  5. 


SCALE  READING  AND  INDEX  OF  REFRACTION  OF  DISTILLED  WATER 
AT  10-30°  C,  ACCORDING  TO  WAGNER. 


Temper- 

Scale 

Index  of 

Hp  Differ- 

Temper- 

Scale 

Index  of 

M/)  Differ- 

ature C. 

Reading. 

Refraction,  nj). 

ence  for 

atvire  C. 

Reading. 

Refraction,  «^ 

ence  for 

i°C. 

1°  C. 

30 

II. 8 

I. 33196 

'         19 

14-7 

I  -  333075 

8-5 

29 

12 

I 

1.33208 

12.0 

1         18 

14 

9 

33316 

8.5 

28 

12 

4 

1-332195 

II-5 

17-5 

15 

0 

33320 

\Y- 

27 

12 

7 

1-33231 

II. 5 

17 

15 

I 

33324 

26 

13 

0 

1-33242 

II  .0 

16 

15 

3 

333315 

7-5 

25 

13 

25 

1-332525 

10.5 

15 

15 

5 

iil2><^ 

7 

5 

24 

13 

5 

1.332625 

lO.O 

14 

15 

7 

33346 

7 

0 

23 

13 

75 

1.33272 

9-5 

13 

15 

85 

333525 

6 

5 

22 

14 

0 

I. 33281 

9.0 

12 

16 

0 

33359 

6 

5 

21 

14 

25 

1-33290 

9.0 

II 

16 

15 

33365 

6 

0 

20 

14-5 

1-33299 

9.0 

10 

16 

3 

333705 

5 

5 

The  reading  is  taken  and  the  temperature  of  the  distilled  water 
noted.  Reference  to  the  above  table  will  show  if  the  refractometer 
is  correctly  adjusted.  Should  the  average  of  several  careful  readings 
at  a  given  temperature  deviate  from  that  contained  in  the  table,  the 
following  should  be  resorted  to: 

Readjustment  -of  the  Scale. — The  ocular  end  of  the  refractometer 
hanging  on  the  wire  frame  is  grasped  from  behind  with  the  thumb  and 
forefinger  of  the  left  hand,  the  micrometer  drum  set  to  10,  and  the  steel 


114  FOOD   INSPECTION  AND  ANALYSIS. 

spike,  housed  in  the  case  of  the  apparatus,  inserted  into  one  of  the  holes 
of  the  nickeled  cross-holed  screw  lying  on  the  inner  side  of  the  microm- 
eter drum.  The  spike  is  then  turned  anti-clockwise,  as  seen  from  the 
rear,  whereupon  the  nickeled  milled  nut,  which  governs  the  micrometer, 
becomes  loosened.  The  temperature  of  the  distilled  water  in  the  beaker 
is  taken  once  more  to  see  that  it  has  remained  constant,  and  then  the 
table  (page  113)  is  consulted  to  fmd  the  "adjusting  number"  properly 
belonging  to  the  temperature  indicated.  By  turning  the  spike,  the  border- 
line is  brought  exactly  upon  the  integer  scale  division  appertaining  to 
the  adjusting  number,  and  the  loose  micrometer  drum  is  turned  so  that 
the  index  accords  with  the  decimal  portion  of  the  adjusting  number. 
The  drum  is  now  held  firmly  with  the  thumb  and  forefinger  of  the  left 
hand,  while  the  nut  is  screwed  up  tight  again  by  the  right  hand,  taking 
care,  however,  that  the  drum  does  not  wander  off  the  index.  Finally, 
the  new  adjustment  is  tested  by  repeated  readings. 

Regulating  the  Temperature. — In  many  cases  it  suffices  to  allow  water 
at  the  temperature  of  the  room  to  How  slowly  from  a  tank  suspended 
high  upon  the  wall  through  the  bath.  Should  it  be  required,  however, 
to  maintain  a  given  temi)erature  (say  20°  C.)  for  hours  together  con- 
stant to  a  tenth  of  a  degree,  which  is  frequently  desirable  if  not  actually 
necessary,  a  more  elaborate  temperature-regulating  device  should  be 
employed.  In  cold  weather,  or  when  the  tap-water  has  a  lower  tempera- 
ture than  that  desired,  a  refractometcr  heater  of  the  type  shown  in 
Fig.  39,   and  described  on  page  102,  is  convenient. 

When,  as  in  the  summer,  the  taj)-water  temperature  is  higher  than 
that  desired  for  the  refractometcr  bath,  there  are  various  ways  of  success- 
fully controlling  the  temperature  at  a  lower  degree.  An  ice-water  tank 
placed  above  the  level  of  the  bath  may  be  employed,  the  flow  from 
which  through  the  bath  is  carefully  controlled  by  a  pinch-cock  or 
otherwise,  or  is  allowed  to  mingle,  under  careful  regulation  before 
entering  the  bath,  with  the  water  from  the  tap  direct  or  with  that  from 
the  heater. 

Investigation  of  Solutions  in  Beakers  in  Bulk. — The  first  ten  solutions 
arc  poured  into  beakers  until  two-thirds  full,  and  the  latter  are  immersed 
anfi  brought  to  the  temperature  of  the  bath  A.  When  the  first  five  solu- 
tions have  been  measured,  they  are  taken  out  of  the  water-bath  and 
the  second  series  of  five  beakers  inserted  in  their  place,  bringing  at  the 
same  time  a  third  series  into  the  water-bath.  The  second  series  are 
measured  and  so  on.  Small  gummed  labels  on  the  outside  prove  quite 
satisfactory  for  numbering  the   beakers.     It  is  absolutely  necessary  to 


THE  REFRACTOMETER.  115 

compare  the  temperature  of  the  solutions  in  the  beakers  with  the  water- 
bath  from  time  to  time. 

After  each  immersion,  the  prism  should  be  wiped  dry  with  a  clean, 
soft  piece  of  old  linen. 

Investigations  of  Solutions  Excluded  from  Air. — Quickly  evaporating 
liquids,  for  instance  ether  solutions,  should  be  treated  individually  by 
means  of  the  metal  beaker  adapted  to  fit  the  prism  end  of  the  refrac- 
tometer.  To  fill  the  beaker,  the  rcfractometer  is  held  in  the  left  hand 
with  the  prism  pointing  upwards,  and  the  metal  beaker  (M,  Fig.  42) 
is  set  and  securely  fastened  by  means  of  the  bayonet  joint.  It  is  now 
filled  quite  full  and  the  cover  D  carefully  fitted  and  locked. 

The  solution  is  now  enclosed,  air  and  water  tight.  The  rcfractometer 
as  before  is  hung  upon  the  wire  frame  of  the  bath,  with  the  metal  beaker 
submerged  in  the  bath. 

It  is  expedient  to  place  the  solutions  before  investigation  in  closed 
flasks  in  the  nine  unoccupied  holes  in  the  bath. 

After  the  measurement,  the  rcfractometer  is  held  in  the  left  hand 
with  the  prism  pointing  downwards,  and  the  beaker  together  with  its 
cover  detached  by  giving  a  slight  turn  with  the  right  hand.  The  solu- 
tion can  be  used  for  other  purposes,  since  it  has  undergone  no  change 
in  constitution.  Finally,  the  cover  is  detached  from  the  beaker,  and 
cover,  beaker,  and  prism  cleaned  by  simple  means,  and  the  rcfractometer 
made  ready  for  the  reception  of  the  next  solution,  as  above. 

Investigations  of  Small  Quantities  of  Solutions  with  the  Auxiliary 
Prism. — When  the  solution  does  not  occur  in  sufficiently  large  quan- 
tities for  investigation  in  the  glass  beaker,  or  when  the  solution  is  too 
deeply  colored,  as  in  dark  beers,  molasses,  etc.,  the  auxiliary  prism  is 
used.  As  described  under  "Solutions  Excluded  from  Air,"  the  metal 
beaker  without  cover  is  fitted  on  the  rcfractometer.  The  auxihary  prism 
is  held  horizontally,  and,  a  few  drops  of  the  solution  having  been  applied 
to  the  hypothenuse  face,  the  prism  is  inserted  into  the  metal  beaker, 
held  conveniently  for  the  purpose,  with  its  hypothenuse  face  laid  upon 
the  polished  elliptical  face  of  the  rcfractometer  prism,  and  then  locked 
in  by  the  cover.  If  an  insufficient  quantity  of  the  solution  has  been 
taken,  the  margins  of  the  out-spread  drops  lying  between  the  two  prisms 
can  be  recognized  by  looking  through  the  window  of  the  cover  on  which 
abuts  the  square  pohshed  end  of  the  auxiliary  prism.  It  is  strongly 
recommended,  wherever  possible,  to  apply  a  sufficiency  of  the  solution, 
so  that  the  space  between  the  prisms  is  completely  filled,  otherwise  a  loss 
in  brilliancy  occurs,  and,  under  certain  circumstances,  an   unavoidable 


ii6 


FOOD   IXSFECIION  ^ND   ANALYSIS. 


TABLE  OF  INDICES  OF  REFRACTION,  n^,. 
(Compared  with  Scale  Readings  of  Zeiss  Immersion  Refractometer,  according  to  Wagner.) 


Scale 

Scale 

1 

Scale 

Scale 

Scale 

Read- 

ftp. 

Read- 

**D- 

Read- 

«£)- 

\   Read- 

M^. 

Read- 

«£)• 

ing. 

ing. 

ing. 

ing. 

ing. 

o.o 

1.327360 

50 

1.329320 

10.0 

I. 331260 

15.0 

t. 333200 

20.0 

1. 335 1 68 

O.I 

f.  327.^09 

51 

1-329350 

10.  I 

I -331299 

I5-I 

1-333238 

20.  I 

1-335168 

- 

■  ^^^ 

2 

398 

2 

388 

2 

276 

2 

206 

}, 

4.^7 

3 

377 

3 

314 

3 

244 

4 

4 

476 

4 

416 

4 

352 

4 

282 

5 

55.^ 

^ 

515 

=; 

455 

5 

390 

5 

320 

6 

594 

6 

554 

6 

494 

6 

428 

6 

358 

7 

633 

7 

593 

7 

533 

7 

466 

7 

396 

8 

672 

8 

632 

8 

572 

8 

504 

8 

434 

9 

711 

9 

671 

9 

611 

9 

542 

9 

472 

I.O 

750 

6.0 

710 

II. 0 

650 

16.0 

580 

21 .0 

510 

I.I 

1.327789 

6.1 

1-329749 

II.  I 

I. 331689 

16. 1 

1-333619 

21. 1 

I  -  335549 

2 

828 

2 

788 

2 

728 

2 

658 

2 

5S8 

3 

867 

3 

827 

3 

767 

3 

697 

3 

627 

4 

906 

4 

866 

4 

806 

4 

736 

4 

666 

<; 

945 

5 

905 

5 

845 

5 

775 

5 

705 

6 

984 

6 

944 

6 

884 

6 

814 

6 

744 

7 

t. 328023 

7 

982 

7 

932 

7 

833 

7 

783 

8 

062 

8 

1.330022 

8 

962 

8 

892 

8 

822 

9 

101 

9 

061 

9 

I. 332001 

9 

931 

9 

861 

2.0 

140 

7.0 

100 

12.0 

040 

17.0 

970 

22.0 

900 

2.1 

I. 328180 

7-1 

1-330139 

12. 1 

1.332078 

17. 1 

I . 334008 

22.1 

I-3359.S8 

2 

220 

2 

178 ! 

2 

116 

2 

046 

2 

976 

3 

657 

3 

217 

3 

154 

3 

084 

3 

1. 3360 1 4 

4 

300 

4 

256 

4 

192 

4 

122 

4 

052 

5 

340 

5 

295 

■^ 

230 

5 

160 

5 

ego 

6 

380 

6 

334 

6 

268 

6 

198 

6 

128 

7 

420 

7 

373 

7 

304 

'    7 

236 

7 

166 

8 

460 

8 

412 

8 

344 

8 

274 

8 

204 

9 

500 

9 

451 

Q 

382 

9 

312 

9 

242 

30 

540 

8.0 

490 

13.0 

420 

18. c 

350 

23.0 

280 

31 

I. 328^79 

8.T 

1-330528 

13-1 

f- 332459 

18. 1 

I  -  334389 

23.1 

I -336319 

2 

618 

2 

566 

2 

498 

2 

428 

2 

358 

3 

657 

3 

604 

3 

537 

3 

467 

3 

397 

4 

6^6 

4 

642 

4 

576 

4 

506 

4 

436 

5 

735 

5 

680 

5 

615 

5 

545 

5 

475 

6 

774 

6 

718 

6 

654 

6 

584 

6 

514 

7 

813 

7 

756 

7 

693 

7 

623 

7 

553 

8 

852 

8 

794 

8 

732 

8 

662 

8 

592 

9 

891 

9 

832 

9 

771 

9 

701 

9 

631 

4.0 

930 

9.0 

870 

14.0 

810 

19.0 

740 

24.0 

670 

41 

I . 328960 

9.1 

1.330909 

14. 1 

1.332849 

19. 1 

1-334770 

24.1 

I . 336708 

2 

1.329008 

2 

948 

2 

888 

2 

818 

2 

746 

3 

OM 

3 

987 

3 

927 

3 

857 

3 

784 

4 

085 

4 

t. 331026 

4 

966 

4 

896 

4 

822 

S 

"S 

5 

104 

5 

1-333005 

5 

935 

5 

860 

6 

164 

6 

104 

6 

044 

6 

974 

6 

898 

7 

203 

7 

143 

7 

083 

7 

I -335013 

7 

936 

8 

242 

8 

182 

8 

122 

8 

052 

8 

974 

9 

281 

9 

221 

9 

161 

9 

09 1 

9 

I. 33701 2 

50 

320 

10. 0 

260 

iq.o 

200 

20.0 

130 

25.0 

050 

THB   REhRALTOMETER. 


1^7 


TABLE  OF  INDICES  OF  REFRACTION, 

rijj — {Cont 

niie^. 

Scale 

Scale 

]  Scale 

Scale 

Scale 

Read- 

n^. 

Read- 

«£>• 

1  Read- 

njj. 

Read- 

njj. 

Read- 

nl). 

ing. 

ing. 

ing. 

ing. 

ing. 

25.0 

1-337050 

30.0 

I . 338960 

35-0 

1 . 340860 

40.0 

'■342750 

45-0 

1 ■ 344630 

25.1 

1-337088 

30.1 

I  . 338998 

.35-1 

t . 340898 

40.  I 

r. 342788 

45 -I 

1.344667 

2 

126 

2 

1-339036 

2 

936 

2 

826 

2 

704 

3 

164 

3 

074 

3 

974 

3 

864 

3 

741 

a. 

202 

4 

112 

4 

1.341012 

4 

902 

4 

778 

.5 

240 

5 

150 

5 

o^o 

5 

940 

5 

818 

6 

278 

6 

188 

6 

088 

6 

978 

6 

852 

7 

316 

7 

226 

7 

126 

7 

I. 343016 

7 

889 

8 

354 

8 

264 

8 

164 

8 

054 

8 

926 

9 

392 

9 

302 

9 

202 

9 

092 

9 

963 

26.0 

430 

31.0 

340 

36.0 

240 

41.0 

130 

46.0 

1.345COO 

26.1 

t- 337468 

3I-I 

1-339378 

36.1 

r. 341278 

41. 1 

t- 343 167 

46.1 

1-345037 

2 

506 

2 

416 

2 

316 

2 

204 

2 

074 

3 

544 

3 

454 

3 

354 

3 

241 

3 

III 

4 

582 

4 

492 

4 

.392 

4 

278 

4 

148 

5 

620 

5 

530 

5 

430 

5 

315 

5 

185 

6 

6^8 

6 

■;68 

6 

468 

6 

352 

6 

222 

7 

696 

7 

606 

7 

506 

7 

389 

7 

259 

8 

734 

8 

644 

8 

544 

8 

426 

8 

296 

9 

772 

9 

682 

9 

582 

9 

463 

9 

m 

27.0 

810 

32.0 

720 

37-0 

620 

42.0 

500 

47.0 

370 

27.1 

1-337849 

32.1 

1-339758 

37-1 

1-341657 

42.1 

1-343538 

47-1 

1-345408 

2 

888 

2 

796 

2 

694 

2 

576 

2 

446 

3 

927 

3 

834 

3 

731 

3 

614 

3 

484 

4 

966 

4 

872 

4 

768 

4 

652 

4 

522 

5 

1.338005 

5 

910 

5 

80^ 

5 

690 

5 

560 

6 

044 

6 

948 

6 

842 

6 

728 

6 

598 

7 

083 

7 

986 

7 

879 

7 

766 

7 

636 

8 

122 

8 

1.340024 

8 

916 

8 

804 

8 

674 

9 

161 

9 

062 

„  9 

953 

9 

842 

9 

712 

28.0 

200 

33-0 

100 

38.0 

990 

43-0 

880 

48.0 

750 

28.1 

1-338238 

33-1 

1-340138 

38.1 

1.342028 

43-1 

t- 3439 I 8 

48.1 

1-345787 

2 

276 

2 

176 

2 

066 

2 

956 

2 

824 

3 

3U 

3 

214 

3 

104 

3 

994 

3 

861 

4 

352 

4 

252 

4 

'^' 

4 

1.344032 

4 

898 

5 

390 

5 

290 

5 

180 

5 

070 

5 

935 

6 

428 

6 

328 

6 

218 

6 

108 

6 

972 

7 

466 

7 

366 

7 

256 

7 

146 

7 

I . 346009 

8 

504 

8 

404 

8 

294 

8 

184 

8 

046 

9 

542 

9 

442 

9 

332 

9 

222 

9 

083 

29.0 

580 

34-0 

480 

39-0 

370 

44 -o 

260 

49-0 

120 

20.1 

I. 338618 

34-1 

I. 3405 18 

39-1 

1.342408 

.14.1 

1.344297 

49-1 

I. 346158 

2 

656 

2 

556 

2 

446 

2 

334 

2 

196 

3 

694 

3 

594 

3 

484 

3 

371 

3 

234 

4 

732 

4 

632 

4 

522 

4 

408 

4 

272 

5 

770 

=; 

670 

5 

560 

5 

445 

5 

310 

6 

S08 

6 

708 

6 

598 

6 

482 

6 

•  348 

7 

846 

•7 

746 

7 

636 

7 

519 

7 

386 

8 

884 

8 

784 

8 

674 

8 

556 

8 

424 

9 

922 

9 

822 

9 

712 

9 

593 

9 

462 

30.0 

960 

35-0 

860 

40.0 

750 

45 -o 

1 

630 

50.0 

500 

iiS 


FOOD    INSPECTION   .4ND    ANALYSIS. 


TABLE  OF  INDICES  OF 

REFRACTION, 

Wp — (Contiiiiicd). 

Scale 

Scale 

Scale 

Scale 

Scale 

Read- 

♦»/)• 

Read- 

»D- 

Read- 

»D- 

Read- 

n^. 

Read- 

»D- 

ing. 

1 

ing. 

ing. 

ing. 

ing. 

50.0 

I . 346500 

55 -o 

1.348360 

60.0 

I. 350210 

65.0 

1-352050 

70.0 

1-353880' 

50.1 

I ■ 346537 

55-1 

1-348397 

60.1 

1-350247 

65-1 

1.352087 

70.1 

I-353917 

2 

374 

2 

434 

2 

284 

2 

124 

2 

954 

3 

611 

3 

471 

3 

321 

3 

i6t 

3 

ggi 

4 

648 

4 

508 

4 

338 

4 

198 

4 

1.354028 

5 

685 

5 

545 

5 

303 

=; 

235 

5 

065 

6 

722 

6 

582 

6 

432 

6 

272 

6 

102 

7 

759 

7 

619 

7 

469 

7 

309 

7 

139 

8 

796 

8 

656 

S 

506 

8 

346 

8 

176 

9 

833 

9 

693 

9 

343 

9 

383 

9 

213 

510 

870 

56.0 

730 

61.0 

580 

66.0 

420 

71.0 

250 

51-1 

1.346907 

56.1 

1.348767 

61. 1 

I. 350617 

66.1 

1-352457 

71. 1 

1.354286 

2 

944 

2 

804 

2 

654 

2 

494 

2 

322 

3 

981 

3 

841 

3 

691 

3 

331 

3 

358 

4 

1.347018 

4 

878 

4 

728 

4 

568 

4 

394 

5 

055 

5 

915 

5 

765 

5 

60s 

3 

430 

6 

092 

6 

952 

6 

802 

6 

642 

6 

466 

7 

129 

7 

989 

7 

839 

7 

67Q 

7 

502 

8 

166 

8 

1 . 3-^9026 

8 

876 

8 

716 

8 

538 

9 

203 

9 

063 

9 

913 

9 

753 

9 

574 

52.0 

240 

57-0 

100 

62.0 

950 

67.0 

790 

72.0 

610 

52-1 

1-347277 

57-1 

1-349137 

62.1 

1-330987 

67.1 

1.352827 

72.1 

1.354646 

2 

314 

2 

174 

2 

I. 351024 

2 

864 

2 

682 

3 

351 

3 

211 

3 

061 

3 

901 

3 

718 

4 

388 

4 

248 

4 

098 

4 

938 

4 

754 

5 

425 

5 

285 

5 

135 

5 

973 

5 

790 

6 

462 

6 

312 

6 

172 

6 

I -35301 2 

6 

826 

7 

499 

7 

359 

7 

209 

7 

049 

7 

862 

8 

536 

8 

396 

8 

246 

8 

086 

8 

898 

9 

573 

„  9 

433 

9 

283 

9 

123 

9 

934 

530 

610 

58.0 

470 

63.0 

320 

68.0 

160 

73-0 

970 

53- 1 

1-347647 

58.1 

1-349507 

63.1 

1-351357 

68.1 

1-353196 

73-1 

1-355006 

2 

684 

2 

544 

2 

394 

2 

232 

2 

042 

3 

721 

3 

581 

3 

431 

3 

268 

3 

078 

4 

758 

4 

618 

4 

468 

4 

304 

4 

114 

5 

795 

5 

655 

5 

505 

5 

340 

5 

150 

6 

832 

6 

692 

6 

542 

6 

376 

6 

186 

7 

869 

7 

729 

7 

579 

7 

412 

7 

222 

8 

906 

8 

766 

8 

616 

8 

448 

8 

258 

9 

943 

9 

803 

9 

653 

9 

484 

9 

294 

54. 0 

980 

59-0 

840 

64.0 

690 

69.0 

520 

74.0 

330 

54.1 

I. 348018 

59-1 

1-349877 

64.1 

I. 351726 

69. 1 

1-353556 

74.1 

1-355366 

2 

056 

2 

914 

2 

762 

2 

592 

2 

402 

3 

C94 

3 

951 

3 

798 

3 

628 

3 

438 

4 

132 

4 

988 

4 

834 

4 

664 

4 

474 

5 

170 

5 

1-350025 

5 

870 

5 

700 

5 

510 

6 

208 

6 

062 

6 

906 

6 

736 

6 

546 

7 

246  1 

7 

099 

7 

942 

7 

772 

7 

582 

8 

284 

8 

136 

8 

978 

8 

808 

8 

618 

9 

322 

9 

173 

9 

I. 352014 

9 

844 

9 

659 

"JS-o 

•"^ 

60.0 

210 

65.0 

050 

70.0 

880 

75-0 

690 

THE    REFR^CTOMETER. 


119 


TABLE  OF  INDICES  OF  REFRACTION,  n r,—{Contim,ei). 


Scale 

Scale 

Scale 

Scale 

Scale 

Read- 

«/j- 

Read- 

njj. 

Read- 

«^. 

Read- 

n^. 

Read- 

n^y 

ing. 

ing. 

ing. 

ing. 

ing. 

75-0 

i- 355690 

80.0 

1-357500 

85.0 

j 

1-359300 

90.0 

[  .361090 

95-0 

1 .362870 

75-1 

1-355727 

80.1 

^•357536 

85.1 

r -  359336 

90.1 

I . 361x26 

95-1 

1 . 362906 

2 

764 

2 

572 

2 

372 

2 

162 

2 

942 

3 

801 

3 

608 

3 

408 

3 

198 

3 

978 

4 

838 

4 

644 

4 

444 

4 

2.34 

4 

1.363014 

5 

875 

5 

680 

5 

480 

^ 

270 

5 

050 

6 

Q12 

6 

716 

6 

516 

6 

306 

6 

086 

7 

949 

7 

752 

7 

552 

7 

312 

7 

122 

8 

986 

8 

788 

8 

588 

8 

378 

8 

158 

9 

1-356023 

9 

824 

9 

624 

9 

414 

9 

194 

76.0 

060 

81.0 

860 

86.0 

660 

91 .0 

450 

96.0 

230 

76.1 

I . 356096 

81. 1 

1-357896 

1  86.1 

1 .  359606 

91.1 

1.361486 

96.1 

1.363256 

2 

132 

2 

Q32 

1    2 

732 

2 

522 

2 

292 

3 

168 

3 

968 

3 

768 

3 

558 

3 

328 

4 

204 

4 

I . 358004 

4 

804 

4 

594 

4 

364 

5 

240 

5 

040 

5 

840 

5 

630 

5 

400 

6 

276 

6 

076 

6 

876 

6 

666 

6 

436 

7 

312 

7 

112 

7 

912 

7 

702 

7 

472 

8 

348 

8 

148 

8 

948 

8 

738 

8 

518 

9 

384 

9 

184 

9 

984 

9 

774 

9 

554 

77.0 

420 

82.0 

220 

87.0 

1.360020 

92.0 

810 

97-0 

590 

77.1 

1-356456 

82.1 

1.358256 

87.1 

1 .360056 

92.1 

1  361846 

97.1 

1.363625 

2 

492 

2 

292 

2 

092 

2 

882 

2 

660 

3 

^28 

3 

■  328 

3 

128 

3 

918 

3 

695 

4 

564 

4 

364 

4 

164 

4 

954 

4 

730 

5 

600 

5 

400 

5 

200 

5 

990 

5 

765 

6 

636 

6 

436 

6 

236 

6 

1 .362026 

6 

800 

7 

672 

7 

472 

7 

272 

7 

062 

7 

835 

8 

708 

8 

508 

8 

308 

8 

098 

8 

870 

9 

744 

9 

544 

9 

344 

9 

134 

9 

905 

78.0 

780 

83.0 

580 

88.0 

380 

93-0 

170 

98.0 

940 

78.1 

I. 356816 

83.1 

I. 358616 

88.1 

1.360416 

93-1 

1.362205 

98.1 

1-363975 

2 

852 

2 

652 

2 

452 

2 

240 

2 

1.364010 

3 

888 

3 

688 

3 

488 

3 

275 

3 

045 

4 

924 

4 

724 

4 

524 

4 

310 

4 

080 

5 

960 

5 

760 

5 

560 

5 

345 

5 

115 

6 

996 

6 

796 

6 

596 

6 

380 

6 

160 

7 

r-35703-' 

7 

832 

7 

632 

7 

415 

7 

195 

8 

068 

8 

868 

8 

668 

8 

450 

8 

230 

9 

104 

9 

904 

9 

704 

9 

485 

9 

265 

79.0 

140 

84.0 

940 

89.0 

740 

94.0 

520 

99  0 

290 

79.1 

1-357176 

84.1 

1.358976 

89.1 

1.360775 

94.1 

I  362555 

99.1 

1-364325 

2 

212 

2 

1.359012 

2 

810 

2 

590 

2 

360 

3 

248 

3 

048 

3 

845 

3 

625 

3 

395 

4 

284 

4 

084 

4 

880 

4 

660 

4 

43c 

5 

320 

5 

120 

5 

915 

s 

695 

5 

465 

6 

356 

6 

156 

6 

950 

6 

730 

6 

500 

7 

392 

7 

192 

7 

985 

7 

765 

7 

535 

8 

428 

8 

228 

8 

I. 361020 

8 

800 

8 

570 

9 

464 

9 

264 

9 

055 

9 

835 

9 

605 

80.0 

500 

85.0 

300 

90.0 

090 

950 

870 

100. 0 

640 

I2D 


FOOD    INSPECTION   .-IND   ANALYSIS. 


degradation  of  the  sharpness  of  the  border-line.  On  the  other  hand, 
with  a  sutTicient  quantity  of  solution,  the  border-line  is  surprisingly  sharp. 

The  rcfractometer  is  now  suspended  on  the  frame,  and  the  measure- 
ment proceeded  with  as  before  described.  After  measurement,  the  cover 
is  first  removed,  and  the  prism  allowed  to  fall  into  tlie  hollow  of  the 
hand,  then  the  beaker  is  removed  to  enable  tlie  refractometer  to  be 
conveniently  cleaned. 

Strengths  of  Various  Solutions. — The  most  extensive  work  on  the 
quantitative  determination  of  the  strength  of  a  large  number  of  common 
aqueous  solutions  with  the  immersion  refractometer  has  been  done  by 
Wagner,  who  has  published  a  large  number  of  tables.  Thei.e  tables 
show  the  ])ercentage  strength  (grams  per  loo  cc.  at  17.5°  C.)  of  a  large 
number  of  salt  solutions  and  of  acids,  corresponding  to  the  range  of  scale 
readings  of  the  instrument,  as  well  as  of  cane  sugar,  dextrose,  formalde- 

SCALE  READINGS  ON  IMMERSION  REFRACTOMETER  OF  VARIOUS  STAND- 
ARD REAGENTS  USED  IN  VOLUMETRIC  ANALYSIS.* 


Temperature  C. 


Hvdrothloric  acid: 

Normal 

Tenlh-normal 

Sulphuric  acid: 

Normal 

Fifth  normal 

Tenth-normal 

Oxalic  acid: 

Half-normal 

Tenth-normal 

Potassium  biiartratc: 

Tenth-normal 

Potassium  hydroxide: 

Norma! 

Tenth-normal 

Sodium  hydroxide: 

Tenth-normal 

Sodium  th'osulphatc; 

Tenlh-normal 

Pc  as.-.:'  u  m  hi  c  h  romate : 

Tenth-normal 

Silver  nitrate: 

Tenth-normal 

Sodium  chloride: 

Tenth-normal 

Ammonium  sulphocyanate: 

Tenth-normal 


45l37' 
80J17. 


30.60 
18-75 
17-15 


22.45 


0.40 
8.60 


95 


16, 

■75  17' 

90  4.^ 
,4518. 

.5018, 

I 
.20  24, 

I 

■75  i7' 
,20  20, 
20  18, 

60i20. 


36-95 
17.40 

30.20 

18.40 

16.75 

22.  10 
16.75 

17-35 

43-40 
18.10 

18.15 

23-85 

17-35 
19.85 


36.85 
17-30 

30. 10 
18.30 
16.65 

22.00 
16.65 

17-25 

43-25 
18.00 

18.05 

23-75 

17-25 

19-75 


17.80  17.70 

I 
20.25  20. 15 


7036 
20  17 

95^29 
20  18 
55|i6 


80142. 

70117. 

75  17- 
23- 
95 
45 


2035 
8016 


5029 

,80  17 

■i5'i5 

5021 

15:15 

75  16 

5042 
5017 


95=35 -70 
55  16.30 

25129.00 

55  17-30 
9015-65 

25  21 .00 
9015-65 

50  16.25 

2041.95 
25117.00 

30,17-05 

95,22.70 

50!  16. 25 

00  18.75 

95  16.70 


40 


19-15 


•  Accordintj  to  Wagnr-r,  all  these  solutions  were  made  up  at  17.5°  C.     Readings  at  different  tem« 
peratur«s  are  given  for  convenience. 


THF   REFRACTOMETER. 


121 


hyde,  alcohol,  etc.  All  these  observations  have  been  based  on  the  Mohr 
liter,  at  a  temperature  of  17.5°.  More  convenient  for  the  American 
analyst  would  be  tables  based  on  the  use  of  a  higher  temperature,  say  20°, 
and  the  analyst  is  recommended  to  work  out  his  own  standards  for  com- 
parison, at  the  temperature  best  suited  to  his  special  locality  and  conven- 
ience. The  instrument  is  especially  useful  in  preparing  normal  and  tenth- 
normal solutions. 

The  table   on   page   120,  from  Wagner,  shows  the  strength  of  various 
common  laboratory  reagents. 


SCALE  READINGS  AT  TEMPERATURES  FROM  10-30°  C. 
Corrected  to  17.5°,  According  to  Wagner. 


No. 

i. 

2. 

3- 

4- 

5- 

6.     1      7. 

8. 

9- 

10. 

1 1. 

12  &  13. 

No. 

k 

Scale  Reading  at  17.3°  C. 

feu 

$ 

15. 

20. 

25. 

2,0. 

35- 

40. 

45. 

SO- 

60. 

70. 

80. 

90  &.  100. 

S5 

30 

•-3. 20 

3-15 

3-25 

3 -40 

3-55 

3-65 

3-90 

4-05 

4.  20 

4.60 

4.80 

5-25 

30 

29 
28 

27 
26 

2.90 
i.ho 
i.30 
J.  00 

i-75 

2.85 

2-55 
2.25 
1.95 

2-95 
2.65 

2-35 
2.05 

3.10 
2.80 
2.50 
2.20 

3-25 
2-95 
2.65 

2-35 

3-35 
3-05 

2-75 
2.45 

3-55 
3-25 
2-95 

2-55 

3-75 
3-45 

2.80 

3-9° 
3.60 

3-3° 
2.95 

4-23 

3-9° 
3-5° 
3.10 

4-45 
4. 10 

3-75 

4.85 

4-5° 
4. 10 

3-65 

29 
28 
27 
26 

25 

1-75 

1.80 

1 .90 

2.05 

2-15 

2.25 

2.45 

2.60 

2.  70 

2-95 

3.20 

25 

24 

23 
22 
21 

i  50 
I  25 

I.JO 

0-75 

1-45 
1.25 
1. 00 
0-75 

1-55 
1.30 
1.05 
0.80 

1. 6c 

I  •  35 
1 .  10 
0.85 

1-75 
1-45 
I-I5 
0.90 

1.85 
1-55 
1-25 
0-95 

1-95 
1.65 
1.30 
1.05 

2. 10 

1-75 
1.40 
1.05 

2.25 
1.90 

1-55 
1 .20 

2-35 
2.00 
1.65 
1.25 

2-55 
2.15 

1-75 

2-75 
2-35 
1.90 

1-45 

24 
23 
22 
21 

20 

0.50 

0.50 

0.55 

0.60 

0.65 

0.65 

0-75 

0-75 

0.85 

0.90 

0-95 

I. OS 

20 

19 
18 

0.3c 
0. 10 

0.30 
0. 10 

0.30 
0. 10 

0-35 
0.15 

0.40 
0-15 

0.4c 
0.15 

0-45 
0.15 

0.45 
0.15 

0-45 
0.15 

0-55 
0.20 

0-55 
0.20 

0.60 
0.20 

19 
18 

-■■/•5 

0.00 

0.00    0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

17-5 

'7 
16 

—  0. 10 
0.30 

0. 10!    O.IO 

0.30  0.30 

O.IO 

0.30 

O.IO 

0.35 

O.IO 

0-35 

0.15 
0.40 

0.15 
0.45 

0.15 
0.45 

o.is 
0.50 

0.20 

0-55 

0.20 

0-55 

17 
16 

15 

0.50 

0.45!  0.45 

0.50 

0.60 

0.60 

0.65 

0-75 

0-75 

0.80 

0.85 

0.90 

15 

C4 
t3 

0.70 
0.85 
1 .00 
1-15 

0.60;  0.60 
0-75    0-75 

0.70 

0.85 

0.80 
1. 00 

0.85 
1 .10 

0.90 

0-95 
1.20 

1.05 
1-35 

1. 10 
1 .40 

1-25 
1-55 

1-25 
1.60 

14 
13 

[I 

u 

1 

10 

1.25 

No. 

I. 

2.         3. 

4- 

s- 

6. 

7- 

8. 

9- 

10. 

1 1. 

2  &  13. 

.\o. 

12  2  FOOD  INSPECTfON   AND   ANALYSIS. 


REFERENCES  OX  THE  BUTYRO-REFRACTOMETER. 

Lythgok,  H.  C.     The  Optical  Properties  of  Castor  Oil,  Cod-liver  Oil,  Neats-foot  Oil, 

and  a  few  Essential  Oils.     Jour.  Am.  Chem.  Soc,  27,  1905,  p.  887. 
ScHNEiPER.    C,    and    Blumknff.ld,    S.     Reitrag   zur    Kenntnis    animalischcr    Fette. 

Chem.  2^it.,  30,  iqo6,  p.  53. 
Sprinkmeyer,  H.,  and  Wagner,  H.     Beitrage  zur  Kenntnis  des  Sesamolcs.     Zeits. 

Untcrs.  Nahr.  Genuss.,  10,  1905,  p.  347. 
Ulzer,  F.,  and  Sommer,  F.     Uber  den  Nachweis  und  die  Bestimmung  des  Paraffins 

in  Mischungen  mit  Ceresin.     Chem.  Zeit.,  30,  1906,  {).  142. 

REFERENXES  ON  THE  WOLLNY  MILK  FAT  REFRACTOMETER. 

B.AJER,  E.  Untersuchungen  iiber  den  Nachweis  der  Wasserung  von  Milch  mit  Ililfe 
des  Refraktometers.  Ber.  d.  Nahr.  Unlers.  d.  Landw.  f.  d.  Provinz  Branden- 
burg, 1904,  p.  14. 

Ueber  die  Zuverlassigkeit  der  Milchunter.suchungen  mit  dem  Milch-rcfraktomcter 

von  Zeiss-Wollny.     Molk.  Zeit.,  15,  1905,  p.  386. 

COTHEREAU,  A.  Nachweis  einer  Milchwiisserung  mittels  des  Refraktometers.  Bull. 
Sci.  Pharm.,  7,  1905,  p.  68. 

Henseval,  M.,  and  Mullie,  G.  La  Refractometrie  du  Lait.  Rev.  gen.  du  Lait, 
4,  1905,  P-  529- 

REFERENCES  ON  THE  ABBE  REFRACTOMETER. 

Har\'EY,  T.  F.     Temperature  Corrections  for  Use  with  the  Abbe  Refractometer,  and 

Refractive  Indices  of  some  Fi.xed  and  Essential  Oils.    Jour.  Soc.  Chem.  Ind.,  24, 

1905,  p.  717. 
Lythgoe,  H.  C.     The  Optical  Properties  of  Castor  Oil,  Cod-liver  Oil,  Neats-foot  Oil, 

and  a  Few  Essential  Oils.     Jour.  Am.  Chem.  Soc,  27,  1905,  p.  887. 
Utz,   Fr.     Beitrage  zur  Untersuchung  von  Amylalkohol.     Allgemeine  Chem.   Zeit., 

6,  1906,  p.  106. 
■ Die    Untersuchung   von    Spiritus   mittels   des   Refraktometers.     Pharm.    Nach., 

I,  1906,  p.  74. 

REFERENCES  ON  THE  IMMERSION  REFRACTOMETER. 

Ackermann,  E.     Ueber  refraktometrische  Bieranalyse.     Zeits.  f.  d.  gcs.  Brauw.,  28, 

1905,  p.  441- 
Mcthode  refractometrique  rapide  d'analyse  de  la  biere  a  I'aide  d'un  calculateur 

automatique.     Ann.  et  Rev.  de  Chim.  Anal.,  1905,  \).  171. 
Ackermann,  E.,  et  von  Spindler,  O.    Sur  la  Determination  de  I'Extrait  de  la  Bierre. 

Jour.  Suisse  de  Chim.  et  Pharm.,  1903,  No.  30. 
Hanus,  J.,  and  CnofENSKY,  K.     Anwendung  des  Zeis.schen  Eintauchrefraktomcters 

in  der  Nahrungsmittelanalyse.     Zeits.  Unters.  Nahr.  Genuss.,  11,  1906,  p.  313. 


THE   REFRACTOMETER.  123 

"Leach,  A.  E.,  and  Lythgoe,  H.  C.  The  Detection  and  Determination  of  Ethyl  and 
Methyl  Alcohols  in  Mixtures  by  the  Immersion  Refractometer.  Jour.  Am. 
Chem.  Soc,  27,  1905,  p.  964. 

A  Comparative  Refractometer  Scale  for  Use  with  Fats  and  Oils.     Jour.  Am. 

Chem.    Soc,  26,  1904,  p.  1193. 

The  Detection  of  Watered  Milk.     Ibid.,  p.  1195. 

KlONKA,  II.  Ueber  naturliche  und  kiinstiiche  Mineralwasser.  Balneolog.  Zeit.,  14, 
Nos.  34  u.  35. 

Mansfeld,  M.  Die  Verwendbarkeit  des  Zeiss'schen  Eintauchrcfractometer  be! 
Nahrungsmittel-Untersuchung.  Unters.  Anst.  osters.  Apoth.-Vereins.  Ber., 
1904-1905,  p.  10. 

Matthes,  H.  Quantitative  Bestimmungen  wasseriger  Losungen  mit  dem  Zeiss'- 
schen Eintauch-Refraktometer.     Zeits.  Unters.  Nahr.  Genuss.,  5,  1902,  p.  1037. 

Ueber  refraktometrische  analytische  Bestimmungsmethoden.     Zeits.  anal.  Chem., 

13.  1904,  P-  73  ■ 
MoHR,  M.     Die  Anwendung  des  Zeiss'schen  Eintauchrefraktometers  im  Brauereilabo- 

ratorium.     Wochens.  Brau.,  22,  1905,  p.  616. 
MoHR,  O.     Refraktometrische  Extraktbestimmung  bei  der  Malzanalyse.     Wochens.  f. 

Brau.,  23,  1906,  p.  136. 
Wagner,   B.     Neue  Methoden   der  quantitativen   Bestimmung  mit  dem  Zeiss'schen 

Eintauchrefraktometer.     Zeits.  offentl.  Chem.,  11,  1905,  p.  404. 
Ueber  quantitative   Bestimmungen   vv^asseriger  Losungen   mit   dem   Zeiss' -schen 

Eintauch-Refraktometer.     Sondershausen,  1903. 

Tabellen  zum  Eintauch-Refraktometer.     Sondershausen,  1907. 

Wagner,  B.,  and  Rinck,  A.     Neue  Methode  der  quantitativen  Zuckerbestimmung 

mit  dem  Zeiss'schen  Eintauchrefraktometer.     Chem.  Zeit.,  30,  1906,  p.  38. 
Zeits.  Chem.  Apparat,  Berlin,  i,  1906,  p.  207. 


CHAPTER  \'ll. 
MILK  AND   ITS  PRODUCTS. 
MILK. 

Nature  and  Composition. — Milk  is  the  secretion  of  the  mammary 
glands  of  female  mammals  for  the  nourishment  of  their  young.  Con- 
taining as  it  does  all  the  requisites  for  a  complete  food,  i.e.,  sugar,  fat, 
proteins,  and  mineral  ingredients,  combined  in  appropriate  proportion, 
there  is  ample  reason  why  it  occupies  so  high  a  place  in  the  scale  of  human 
foods.  It  is  a  yellowish-white  opaque  fluid,  denser  than  water,  contain- 
ing in  complete  solution  the  sugar,  soluble  albumin,  and  mineral  content, 
and,  in  less  complete  solution,  the  casein,  while  the  fat-globules  are  held  in 
suspension  in  the  serum,  forming  an  emulsion. 

The  specific  gravity  of  pure  milk  ranges  from  1.027  to  1.035. 

Milk  from  various  animals  has  the  same  general  physical  properties 
and  the  same  ingredients,  differing,  however,  in  percentage  composition. 
Of  all  the  varieties,  the  milk  of  the  cow  is  by  far  the  most  important  from 
its  universal  use,  and,  unless  otherwise  qualified,  the  term  milk  wherever 
it  occurs  in  this  volume  will  be  understood  to  mean  cow's  milk. 

Acidity. — When  perfectly  fresh,  milk  of  carnivorous  mammals  is, 
as  a  rule,  acid  in  reaction,  while  human  milk  and  that  of  the  herbivora  is 
alkaline.  Cow's  milk,  when  freshly  drawn,  is  more  often  amphoteric  in 
reaction,  i.e.,  it  reacts  acid  with  blue  and  alkaline  with  red  litmus.  It  soon 
becomes  distinctly  acid,  and  the  acidity  increases  as  the  milk  sugar  grad- 
ually becomes  converted  into  lactic  acid. 

Microscopical  Appearance. — Under  the  microscope  pure  milk  shows 
a  tonglomcTHiion  (;f  various-sized  fat  globules  having  a  pearly  lustre. 
These  globules  vary  from  0.00 1  to  0.0 1  mm.  in  diameter,  averaging  about 
0.005  ^^-  When  examincfl  under  very  high  powers,  it  is  possible  to 
distinguish  bacteria  in  the  milk,  the  number  to  be  seen  depending  greatly 
on  the  time  that  has  elapsed  since  the  milk  wa.s  drawn  from  its  source, 

as  well  as  on  the  surroundings,  the  conditions  of  handling,  exposure,  etc. 

124 


MILK.  125 

Color. — ^Thc  yellow  color  of  milk  is  imparled  to  it  by  the  fat  globules, 
and  varies  greatly  in  milk,  from  dilTcrcnt  breeds  of  cattle,  as  well  as  in 
milk  from  the  same  cow  at  different  seasons,  being,  as  a  rule,  paler  during 
the  winter  or  stall-fed  months,  and  having  its  greatest  intensity  soon  after 
the  cow  is  put  out  to  pasture. 

Milk  Sugar,  the  carbohydrate  of  milk,  is  normally  present  in  amounts 
var^ang  from  3  to  5  per  cent.    For  the  properties  of  milk  sugar  see  page  577. 

The  Proteins  of  Milk. — Casein  constitutes  about  80^'f  of  the  entire 
])roteins  of  milk,  being  present  in  an  average  sample  to  the  extent  of  about 
3^^.  It  exists  in  combination  with  calcium  phosphate,  and  probably 
does  not  form  a  perfect  solution  in  the  milk,  but  is  rather  diffused  therein 
in  a  somewhat  colloidal  form,  being  so  finely  divided,  however,  as  to  be 
incapable  of  separation  by  filtration  while  the  milk  is  fresh. 

Pure  casein  is  a  white,  odorless,  and  tasteless  solid,  sparingly  soluble 
in  water,  and  insoluble  in  ether  and  alcohol.  It  is  readily  soluble  in  dilute 
alkalies.  Strong  acids  also  dissolve  it,  but  its  character  is  changed.  From 
alkaline  solution  it  is  precipitated  without  change  by  neutralizing  with 
acid.     Its  solutions  are  laevo-rotary. 

Lacl-alhumin  is  the  soluble  albumin  of  milk,  existing  therein  to  the 
extent  of  about  o.()^~{.  and  forming  about  15%  or  more  of  the  milk  proteins. 
It  much  resembles  the  albumin  of  eggs,  being  coagulated  at  70°  to  75°  C. 
It  is  readily  soluble  in  water.  Its  specific  rotary  power  according  to 
Bechamp  is  [a]D=  "67.5. 

Lactoglohiilin  has  been  discovered  by  Emmerling  as  a  constituent  in 
milk,  but  exists  in  traces  only.  According  to  Babcock,  it  may  be  separated 
from  milk  whey  by  carefully  neutralizing  with  sodium  hydroxide,  and 
afterwards  saturating  with  magnesium  sulphate.  It  much  resembles  the 
globulin  of  blood  serum,  being  coagulated  at  67°  to  76°  C. 

Fibrin. — Babcock  has  discovered  in  milk  very  minute  traces  of  a 
substance  analogous  to  the  fibrin  of  blood.  This  substance,  it  is  claimed, 
forms  a  part  of  the  slime  found  in  the  separator-bowl  of  a  centrifugal 
skimmer. 

Other  Nitrogenous  Substances. — Besides  the  above  nornial  constituents 
of  milk,  certain  bodies  may  be  formed  by  proteolytic  action  during  fer- 
mentation, such,  for  example,  as  caseoses  and  peptones,  formed  for  the 
most  part  by  the  decomposition  of  a  part  of  the  casein.  Galactin  is  a 
gelatin-Hke  body  of  the  nature  of  peptone,  occurring  in  traces  in  milk. 
Besides  these,  minute  traces  of  amido-bodies,  such  as  creatin  and  urea, 
are  sometimes  present,  and  also  ammonia. 


125 


FOOD  INSPECTION  ^ND  ^N^ LYSIS. 


>.     J       C       ^  >,     3     J3 

z:    -^  o  -u    -  -  -^ 


4  d 


'.1    c  ■"  'n  .-   c   h 


'-   -  .S 


s    c    o    <-"  .S 


■5     rt 


t--   -r:     R   .n: 


hJ  O  P-i  <.  o 


10   o    o 
t--.  t~-.  ^ 

«      O      w 


r^  w  »-..  O  O 
HH  o  f^  f~^  O 
O     O     O      w     M 


OOOOOOOO 


s  rs  -s 


s  . 


S     O 


.2     C     O    ^    ^ 


5  -S  .5 


Ch   c;<   U   ^,   1^    or,    P-,   U       ?: 


a 


MILK. 


127 


Milk  Fat. — Fat  forms  the  most  variable  constituent  of  milk,  being 
found  in  proportions  ranging  from  2.5  to  7  per  cent.  For  the  chemical 
composition  and  characteristics  of  milk  fats  see  Butter  (p.  529). 

The  fat  globules  are  held  in  suspension  in  the  milk  and  have  long 
been  thought  to  be  surrounded  each  by  a  thin  nitrogenous  membrane, 
known  as  StorcKs  mucoid  protein,  which  becomes  broken  on  churning. 
This  theory,  while  rendered  probable  by  many  of  the  phenomena 
connected  v^ith  the  dairy,  is  by  no  means  universally  held  at   i)resent. 

Citric  Acid  has  been  found  to  exist  in  milk,  probably  in  combina- 
tion with  certain  of  the  mineral  constituents,  being  present  to  the  extent 
of  about  0.1%. 

The  table  on  page  126  arranged  by  Babcock  shows  quite  clearly  the 
percentage  composition  of  an  average  cow's  milk. 

For  comparison  of  milk  from  different  animals  the  following  table  * 
is  inserted,  showing  in  most  cases  minimum,  maximum,  and  mean  deter- 
minations from  a  large  number  of  actual  analyses: 


N°- "f    Specific 
"^"^^      Gravity. 


Water. 


Casein. 


Albu- 
min. 


Total 
Pro- 
teids. 

Fat. 

2.07 
6.40 

3-55 

1.67 
6-47 
3-64 

0.69 
4-70 
2.29 

1-43 
6.83 

3-78 

4.29 

3.10 

7-55 
4-78 

6.52 

2.81 
9.80 
6.86 

1-99 

1. 21 

2.22 

1.64 

Milk 
Sugar. 


Ash. 


Cow's  milk. 

Minimum. 

Maximum 

Mean.  . 

Human  milk 

Minimum. 

Maximum 

Mean.  . 

Goat's  milk. 

Minimum. 

Maximum 

Mean.  . 

Ewe's  milk.  . 

Minimum. 

Maximum 

Mean.  . 

Mare's  milk 

Mean. 
Ass's  milk  . . 
Mean.  . 


800 


32 

47 
5 


I .0264 
1.0370 
1-0315 

1.027 
1.032 


1.0280 
1.0360 

1-0305 

1.0298 

1-0385 
I. 0341 

1-0347 
1 .  036 


So.  32 
90.32 
87.27 

81.09 
91.40 
87.41 

82.02 
90.16 


74-47 
87.02 
80.82 

90.78 

89.64 


1-79 
6.29 
3.02 

0.18 
1.96 
1-03 

2.44 

3-94 
3.20 

3-59 
5-69 

4-97 

1 .24 
0.67 


0.25 
1-44 
0-53 

0.32 
2.36 
1.26 


2.01 
1.09 

0.83 
1.77 
1-55 

0.75 

1-55 


2. II 
6.12 
4.88 

3-88 
8.34 
6.21 

3.26 

5-77 
4.46 

2.76 

7-95 
4.91 

5-67 
5-99 


0.35 

I. 21 
0.71 

0.12 
1.90 
0.31 

0-39 
1.06 
0.76 

0.13 

I  .72 


0.35 
0.51 


Composition  of  the  Ash  of  Milk. — The  ash  of  milk  does  not  truly 
represent  the  mineral  content,  since,  in  the  process  of  incineration,  the 
character  of  some  of  the  constituents  is  altered  by  oxidation  and  otherwise. 

Expressed  in  parts  per  100,  the  ash  of  the  typical  milk  sample  whose 
full  analysis  is  given  on  page  126  would  be  about  as  follows: 


*  Compiled  from  Konig's  Chemie  der  mens,  Nahr.  u.  Genuss. 


128 


FOOD  INSrt'CTJON  .-IND  ^N.^ LYSIS. 


Potassium  oxide 25 . 02 

Sodium  "      10.01 

Calcium         "      20.01 

Magnesium  "      2.42 

Iron  " 0.13 

Sulphur  Irioxide 0-84 

Phosphoric  i^entoxide 24. 29 

Chlorine 14.28 


100.00 

Soldner  regards  the  following  as  more  nearly  representing  the  propor- 
tion in  which  the  mineral  salts  exist  in  milk: 

Per  Cent. 

Sodium  chloride,  NaCl 10.62 

Potassium  chloride,  KCl 9.16 

I^Iono-potassium  phosphate,  KHoPO^ 12.77 

Di-potassium  phosphate,  KjHPO^ 9.22 

Potassium  cilrate,  K3(C„H50.)2 5-47 

Di-magnesiuni  phosphate^  MgHPO^ 3.71 

Magnesium  citrate,  Mg.j(CyH30.). 4.05 

Di-calcium  phosphate,  CaHPO^ 7 .42 

Tri-calcium  phosphate,  Ca3(PO^)2 8.90 

Calcium  citrate,  Ca^iC^^H-JJ^)-, 23.55 

Lime,  combined  with  proteins 5-i3 


100.00 

Fore  Milk  and  Strippings. — Unless  a  portion  drawn  from  the  well- 
mixed  or  whole  complete  milking  of  an  animal  is  taken  for  analysis,  one 
f'.ocs  not  get  a  fair  representative  sami)le  of  the  milk,  for  it  is  a  well-known 
fact  that  the  first  portion  of  milk  drawn  from  the  udder,  termed  the  "fore 
milk,"  is  ver\'  low  in  fat,  while  the  last  portions  or  "strij)pings"  con- 
tain a  very  high  fat  content,  sometimes  exceeding  10%  fat.  The  following 
analyses  show  the  diflcrencc  between  fore  milk  and  strippings  in  two 
cases : 


(i)  Fore  milk. 

Stp'ppinRs. 

(2)   VoTv.  milk. 

Strippings. 


Per  Cent 
Water. 


88.17 
80.82 
8H.73 

80-37 


I'er  Cent 
Solids. 


11.83 
19.18 
I  I  .27 
19.63 


Per  Cent 
Fat. 


1.32 

9-63 

1.07 

10.36 


MILK. 


129 


The  per  cent  of  albuminoids,  sugar,  and  ash  is  nearly  the  same  in 
both  fore  milk  and  strippings. 

Colostrum. — The  milk  given  by  cows  and  other  mammals  for  two  or 
three  days  after  the  birth  of  young  is  termed  colostrum,  and  ditTers  ma- 
terially in  composition  from  normal  milk.  It  is  yellow  in  color,  of  an 
oily  consistency,  and  has  a  pungent  taste.  It  acts  as  a  purge  upon  the 
young.  Examined  under  the  microscope,  it  is  found  to  contain  large 
circular  cells  larger  than  fat  globules  and  somewhat  similar  to  blood 
corpuscles.  It  is  very  high  in  albumin,  which  seems  to  be  similar  to 
blood  albumin.  The  foHowing  analyses  were  made  by  Engling,  showing 
the  composition  of  colostrum  from  a  cow  eight  years  old: 


Time  after  Calving. 


Specific 
Gravity. 


Fat. 


Casein. 


Albu- 
min. 


Sugar. 


Ash. 


Total 
Solids. 


Immediately.  . 

After  10  hours. 

"     24       "    . 

"     48       "    • 
"     72        "    • 


1.068 
1 .046 
1.043 
1 .042 
1-035 


3-54 
4.66 

4-75 
4.21 

4.08 


2.6c; 
4-28 
4-50 
3-25 
3-3i 


16.56 

9-32 
6.25 
2.31 
1-03 


3.00 
1.42 
2.85 
3-46 
4.10 


1. 18 

1-55 
1.02 
0.96 
0.82 


26.93 
21.23 

19-37 
14.19 


The  average  of  twenty-two  analyses  of  colostrum  from  diflferent  cows 
by  Enghng  showed  total  solids  28.31,  fat  3.37,  casein  4.83,  albumin  15.85, 
sugar  2.48,  ash  1.78. 

Frozen  Milk. — Since  it  is  the  water  in  milk  that  freezes,  it  follows 
that  in  partially  frozen  milk  the  unfrozen  portion  of  the  milk,  or  that 
part  which  remains  still  liquid,  becomes  concentrated  by  the  process  of 
freezing.     This  is  borne  out  by  the  following  figures  of  Richmond:  * 

Frozen  Portion,    Unfrozen  Portion, 
Per  Cent.  Per  Cent. 

Water 96-23  85.62 

Fat :-23  4.73 

Sugar 1 .42  4-95 

Proteins 91  3.90 

Ash 21  .80 

Specific  gravity i  .0090  i .  0345 

Fermentations  of  Milk. — These  are  due  to  the  action  of  bacteria 
of  various  kinds,  the  most  common  being  the  lactic  fermentation. 

The  Souring  0]  Ulilk  is  caused  by  the  action  of  a  large  number  of 
species  of  acid-forming  bacteria,  chief  among  which  is  the  Bacillus  acidi 
lactici,  which  multiplies  faster  than  other  bacteria  in  raw  milk  under 

*  .Analyst,  XVIII.  p.  53. 


-I30  FOOD  INSPECTION  AND  ANALYSIS. 

favorable  conditions  of  temperature.  Part  of  the  milk  sugar  is  acted 
on  and  transformed,  I'lrst  into  dextrose  and  galactose,  the  latter  sugar 
subsequently  forming  lactic  acid,  as  follows: 

(i)      C,3H,,0,„H,0  =  C«H,,0«+  QH,A 

Lactose  Dextrose  Galactose 

(2)      QH.A  =  2C3H„03 

Galactose         Lactic  acid 

More  and  more  acid  is  formed  until  the  casein  can  no  longer  be  held 
up,  curdling  ensues,  and  the  casein  is  precipitated.  Finally,  after  a 
certain  degree  of  acidity  is  reached,  the  ferment  is  killed  and  the  action 
stops.  Other  acids  than  lactic  are  also  undoubtedly  produced,  since  a 
small  part  of  the  acid  in  sour  milk  is  found  to  be  volatile.  According 
to  Conn  *  the  volatile  acids  are  acetic  and  formic. 

Abnormal  Fermentation. — Through  the  agency  of  micro-organisms 
that  may  develop  under  certain  conditions,  various  changes  are  produced 
in  milk  that  to  some  extent  alter  its  character.  Thus  hitter  milk  is  some- 
times produced  as  the  result  of  some  organism  as  yet  l:)ut  little  understood. 

Occasionally  milk  is  found  possessing  a  peculiarly  thick  and  slimy 
consistency,  whereby  it  may  be  drawn  out  in  threads,  by  dipping  a  spoon 
into  the  milk  and  withdrawing  it  therefrom.  This  is  termed  ropy  milk, 
and  is  more  often  met  with  in  warm  weather.  It  is  undoubtedly  produced 
as  a  result  of  bacterial  action. 

Enzyme-jorming  Bacteria  are  not  uncommonly  developed  in  milk, 
causing  various  proteolytic  changes,  whereby  the  casein  is  partially  trans- 
formed into  peptones,  caseoses,  etc. 

Chromogenic  Bacteria  are  the  agencies  that  produce  peculiar  pigments 
in  milk.  Thus  red  milk  is  due  to  Bacillus  crythrogenes;  yellow  milk  to 
Bacillus  xynxanthus;  blue  milk  to  Bacillus  cyanagenes.  The  latter  is 
quite  common,  appearing  ordinarily  in  patches  in  the  milk. 

CHEMICAL   ANALYSIS   OF   MILK. 

Ordinarily,  in  ascertaining  the  nutritive  value  of  milk,  one  determines 
its  specific  gravity,  total  solids,  fat,  protein,  milk  sugar,  and  ash.  Occa- 
sionally it  is  thought  desirable  to  make  a  distinction  in  the  case  of  ];rotein 
between  the  casein  and  the  albumin.  Rarely  is  it  necessary  to  further 
subdivide  the  nitrogenous  bodies  in  milk,  unless  in  connection  with  a 
special  study  of  the  proteolytic  changes  which  it  undergoes. 

The  total  solids,  fat,  and  ash  are  usually  all  determined  directly,  and, 
*  U.  S.  Dept.  of  Agric,  Off.  of  Exp.  Stations,  BuL  25,  p.  21. 


MILK. 


^31 


^jnij, 


in  the  case  of  the  milk  sugar  and  the  proteins,  a  determination  of  cither 
one  may  be  directly  made  (whichever  is  most  convenient),  the  other  being 
calculated  by  difference. 

When  foreign  ingredients  or  adulterants  arc  present  in  milk,  special 
methods  are  employed  to  detect  them. 

Preparation  of  the  Sample. — In  procuring  a  sample  for  analysis, 
the  greatest  care  is  necessary  to  insure  a  homogeneous  sample.  By  far 
the  best  method  in  ever)-  case,  where  possible,  is  to  pour  the  milk  back 
and  forth  from  one  vessel  to  another  (i.e.,  pour  from  the  original  container 
into  an  empty  vessel  and  back  at  least  once).  Where 
this  is  impossible  from  the  size  of  the  container  or  for 
any  other  reason,  the  milk  should  be  thoroughly  mixed 
with  a  dipper.  A  "  sampler,"  of  which  the  Scovell  samp- 
ling-tube iFig.  43,  A)  is  a  convenient  form,  also  aids  in 
securing  a  representative  sample,  and  is  invaluable  when 
it  is  desirable  to  secure  a  definite  fraction  of  the  whole 
for  a  composite  sample. 

This  instrument  consists  of  a  brass  or  copper  tube 
made  in  two  parts  which  telescope  accurately  together  as 
shown  in  Fig.  43,  A,  the  lower  part  being  closed  at  the 
bottom,  but  provided  with  three  or  more  lateral  slits. 
The  sampler,  drawn  out  to  its  full  length,  is  carefully 
inserted  in  the  tank  containing  the  milk  and  lowered 
to  the  bottom,  after  which  the  upper  part  is  pressed 
down  over  the  lower  so  as  to  close  the  slits,  and  the 
tube  is  then  hfted  out  of  the  tank,  containing  a  fairly 
representative  sample  of  the  milk. 

In  all  operations  to  which  a  milk  sample  is  submitted 
during  the  process  of  analysis,  it  should  invariably  be 
poured  into  a  clean  empty  vessel  and  back,  whenever  it 
has  been  at  rest  for  an  appreciable  time,  in  order  to 
insure  a  homogeneous  mixture. 

Determination  of  Specific  Gravity. — This  is  most 
readily  obtained  with  the  aid  of  a  hydrometer,  accurately 
graduated  within  the  limits  of  the  widest  possible  varia- 
tion in  the  specific  gravity  of  milk.  Hydrometers  for 
special  use  with  milk  are  known  as  lactometers,  and  are 
graduated  variously.  One  of  the  most  convenient  forms 
of  this  instrument  is  the  Quevenne  lactometer,  graduated 
from  15°  to  40°,  corresponding  to  specific  gravity  1.015  to  1.040.      This 


A  B 

Fig.  43. 

A,  Scoveli    Milk- 
sampling  Tube. 

B,  Quevenne  Lac- 
tometer. 


132 


FOOD   INSPECTION   AND   ANALYSIS. 


instrument,  shown  in  Fig.  43.  B.  has  a  thcrniomctcr  combined  with  !t,  the 
stem  containing  a  double  scale,  on  the  lower  part  of  which  the  specific 
gravity  is  read,  while  the  temperature  is  read  from  the  upper  part. 

Another  form  of  instrument  is  termed  the  New  York  Board  of  Health 
lactometer,  which  is  not  graduated  to  read  the  specific  gravity  directly,  but 
has  an  arbitrary  scale  divided  into  120  equal  parts,  the  zero  being  equal 
to  the  specific  gravity  of  water,  while  100  corresponds  to  a  specific  gravity 
of  1.029.  To  convert  readings  on  the  New  York  Board  of  Health  scale 
to  Qucvenne  degrees  they  must  be  multiplied  by  .29. 


QUEVENNE  LACTOMETER  DEGREES  CORRESPONDING  TO  NEW  YORK 
BO.\RD  OF  HEALTH  LACTOMETER  DEGREES. 


Board  of 
Health 
Degrees. 

Quevenne 
Scale. 

Board  of 
Health 
Degrees. 

Quevenne 
Scale. 

Board  of 
Health 
Degrees. 

Quevenne 
Scale. 

60 

17.4 

81 

23-5 

lOI 

29-3 

61 

17.7 

82 

23.8 

102 

29 

6 

62 

18.0 

83 

24.1 

103 

29 

9 

63 

18.3 

84 

24.4 

104 

30 

2 

64 

18.6 

85 

24.6 

105 

30 

5 

65 

18.8 

86 

24-9 

106 

30 

7 

66 

19. 1 

87 

25.2 

107 

31 

0 

67 

19.4 

88 

25-5 

108 

31 

3 

68 

19.7 

89 

25.8 

109 

31 

6 

69 

20.0 

90 

26.1 

no 

31 

9 

70 

20.3 

91 

26.4 

III 

32 

2 

71 

20.6 

92 

26.7 

112 

32 

5 

7- 

20.9 

93 

27.0 

"3 

32 

8 

73 

21.2 

94 

27-3 

114 

32, 

I 

74 

21-5 

95 

27.6 

"5 

2,2, 

4 

75 

21.7 

96 

27.8 

116 

i3 

6 

76 

22.0 

97 

28.1 

117 

32, 

9 

77 

22.3 

98 

28.4 

iiS 

34 

2 

78 

22.6 

99 

28.7 

119 

34 

5 

79 

22.9 

100 

29.0 

120 

34 

8 

80 

23.2 

If  extreme  accuracy  is  desired,  the  Westphal  balance  or  the  pycnometer 
should  be  used  for  the  determination  of  specific  gravity.  For  ordinary 
cases,  however,  the  lactometer,  if  carefully  made,  is  sufficiently  accurate. 

With  any  other  form  of  lactometer  than  the  Quevenne,  a  separate 
thermometer  is  necessary  in  order  to  determine  the  temperature,  the 
common  practice  being  to  standardize  all  such  instruments  at  60°  F. 
(15.6°  C). 

Readings  at  temperatures  other  than  60°  may  be  corrected  to  that 
temperature  by  the  aid  of  the  table  on  page  \t,7,. 

Determination  of  Total  Solids.  -Dish  Method.— For  ])urposes 
of  milk  analy.sis,  platinum  dishes  are  by  far  the  mo.st  desirable.  These, 
if  made  for  the  purpose,  .should  be  of  the  shape  shown  in  Fig   51,  measur- 


MILK. 


133 


FOR    CORRECTING    THE   SPECIFIC    GRAVITY    OF   MILK   ACCORDING   TO 
TEMPERATURE  (BY  DR.  PAUL  VIETH). 


Degrees 

Degrees  of  Thermometer  (Fahrenheit). 

Lactom- 

eter. 

45 

46 

47 

48 

49 

SO 

51 

52 

Si 

54 

55 

56 

57 

S8 

59 

60 

20 

19.0 

19.0 

19. 1 

19. I  19.2 

i9-2'i9-3 

19.4 

19.4 

19-5 

19.619.7 

19.8 

19.9 

19.9 

— 

21 

IQ.O 

20.0 

20.0 

20.1  20.2 

20.2|20.3 

20.3 

20.4 

20.5 

20.6  20.7 

20.8 

20.9  20.9 

— 

22 

'20.9 

21  .0 

21  .0 

21. 1  21 .2 

21.2 

21.3 

21-3 

21.4 

21-5 

21  .621 .7 

21.8 

21.9  21.9 

— 

2^ 

.  21 .9 

22.0 

22.0 

22.1  22.2 

22.2 

22.3 

22.3 

22.4 

22.5 

22.6  22.7 

22.8 

22.8  22.9 

— 

24 

.  22.9 

22.9 

23.0 

23.1  23.2 

23-2 

23-3 

23-3 

23-4 

23-5 

23.6J23.6 

23-7 

23.823.9 

— 

25 

■|23-« 

23-9 

24.0 

24.0 

24.1 

24.1 

24.2 

24-3 

24.4 

24-5 

24.6 

24.6 

24-7 

24.8  24.9 

— 

2fl 

.24.8 

24-9 

24.9 

25.0 

25-1 

25-1 

25.2 

25.2 

25-3 

25-4 

25-5 

25.6 

25-7 

25.8,25.9 

— 

27 

.|2c;.8 

2=?. 9 

25 -Q 

26.0 

26.1 

26.1 

26.2 

26.2 

26.3 

26.4 

26.5 

26.6 

26.7 

26.8 

26.9 

— 

28 

.'26.7 

26.8 

26.8 

26.9 

27.0 

27.0 

27.1 

27.2 

27-3 

27-4 

27-5 

27.6 

27.7 

27-8 

27-9 

— 

20 

•  ,27.7 

27.8 

27.8 

27.9 

28.0 

28.0 

28.1 

28.2 

28.3 

28.4 

28.5 

28.6 

28.7 

28.8 

28.9 

— 

.^0 

.'28.6 

28.7 

28.7 

28.8 

28.9 

29.0 

29.1 

29.1 

29.2 

29-3 

29-4 

29.6 

29-7 

29.8 

29-9 

— 

31 

■  29-5 

29.6 

29.6 

29-7 

29.8 

29.9 

30.0 

30.1 

30.2 

30.3 

30-4 

30-5 

30.6 

30.8 

30-9 

— 

32 

•  30-4 

30-5 

30-5 

30.6|30.7 

30-931-0 

31-1 

31-2 

i^-2, 

31.431-531-6 

31-7 

31-9 

— 

.13 

-  31-3 

31-4 

31-4 

31-5  31-6 

31. 831. 9 

32-0 

32.1 

32-3 

32-432-5  32-6 

32-7 

32-9 

— 

.34 

32.2 

32-3 

32-3 

34-4'32.5 

32-7 

32.9 

33-0 

2,3,--^^ 

33-2 

2,2.-?,i3,-Si3-(> 

33-7 

33-9 

— 

35 

.33-0 

33-1 

33-2 

33-4  33-5 

iZ-^ 

iZ-^ 

33-9 

34-0 

34-2 

34-3  34-5  34-6 

34-7 

34-9 

61 

62 

63 

64 

6s 

66 

67 

68 

69 

70 

71 

72 

73 

74 

75 

20 

20.l'20.2 

20.2 

20.3 

20.4  20.5 

20.6 

20.7 

20.9 

21.0  2 1. 1 

21.2  21.3 

21.5I21.6 

21 

21. I  21.2 

21.3 

21.4 

21.5 

21.6 

21.7 

21.8 

22.0 

22.1  22.2 

22.3  22.4 

22.5I22.6 

22 

22.1  22.2 

22.3 

22.4 

22.5 

22.6 

22.7 

22.8 

23.0 

23.1,23.2 

23.323.4 

23-5  23-7 

23 

23.123.2 

23-3 

23-4 

23.5 

23.6 

23.7 

23.8 

24.0 

24.1  24.2 

24.3  24-4 

24.6 

24.7 

24 

24.  I '24.  2 

24-3 

24-4 

24-5 

24.6 

24.7 

24.9 

25.0 

25-l'25-2 

25-3 

25-5 

25.6 

25-7 

2^ 

25.1 

25.2 

25-3 

25-4 

25-5 

25.6 

25-7 

25-9 

26.0  26.1  26.2 

26.4 

26.5 

26.6 

26.8 

26 

26.1 

26.2 

26.3 

26.5 

26.6  26.7 

26.8 

27.0 

27.1  27.227.3 

27-4 

27-5 

27.7 

27.8 

27 

27.1 

27-3 

27.4 

27-5 

27.6  27.7 

27.8 

28.0 

28.1  28.2  28.3 

28.4 

28.6:28.7 

28.9 

28 

28.1 

28.3 

28.4 

28.5J28.628.7 

28.8 

29.0 

29.1  29.2  29.4 

29-5 

29.7  29.8 

29.9 

29 

29.1 

29-3 

29.4 

29-5 

29.6  29.8 

29-930-1 

30.230.3 

30.4 

30.5 

30-7 

30.9 

31-0 

30 

30-1 

i<^-3 

30.4 

30-5 

30.730.8 

3O.9I3I.I 

31. 231. 3 

31-5 

31.6 

31.8 

31.9 

32.1 

31 

31.2 

Z-^-i 

31-4 

31-5 

31-7:31.7 

31-8132.0 

32.2  32.4 

32.5 

32.6 

32.8 

33.0 

ZZ-"^ 

32 

32.2 

32-3 

32-5 

32.6,32.732.9 

33-Oi33-2 

33-3  33-4 

ZZ-^ 

33-7 

33-934-0 

34.2 

7,7, 

33-2 

ZZ-Z 

33-5 

33-6[33-8  33-9 

34.o;34.2 

34.334.5 

34.  t> 

34-7 

34.9 

35.1 

35.2 

34 

34-2 

34-3 

34.5 

34.6'34.8  34.9  35.035.2 

35.335.5 

35.6 

35 -« 

36.0 

36.1 

36.3 

35 

•• 

35-2 

35-3 

35-5 

35-6|35-8  35-9  36.1,36.2 

36.436.5 

I 

36.7 

36.8 

37-0 

37-2 

37.3 

ing  about  2f  inches  in  diameter  at  the  top,  and  2  J  inches  in  diameter 
at  the  bottom,  having  carefully  rounded  rather  than  square  edges,  and 
being  h  inch  deep.  The  bottom  is  not  perfectly  flat,  but  slightly  crowned 
outward.     Such  a  dish  will  hold  about  35  cc. 

For  ])urpo.ses  of  economy  it  is  best  to  have  these  dishes  spun  out  with 
a  thick  bottom,  but  with  thin  sides,  not  so  thin,  however,  as  to  be  too 
readily  bent. 

If  j)latinum  dishes  cannot  be  afforded,  dishes  of  porcelain,  glass, 
aluminum,  nickel,  or  even  tin  may  be  used,  but  in  all  cases  should  be 
as  thin  as  practicable. 

About  5  cc.  of  the  thoroughly  mixed  sample  of  milk  are  carefully 
transferred  by  means  of  a  pipette  to  a  tared  dish  on  the  scale-pan,  and  its 


Ij4  FOOD   INSPECTION   AND   ANALYSIS. 

weight  accurately  determined.  The  dish  with  its  contents  is  then  trans- 
ferred to  a  water-balh,  being  phiced  over  an  opening  preferably  but  little 
smaller  than  the  diameter  of  the  bottom  of  the  dish,  so  that  as  large  a 
surface  as  possible  is  in  contact  with  the  live  steam  of  the  bath.  Here 
it  is  kept  for  at  least  two  hours,  after  which  the  dish  is  wiped  dry  while 
still  hot,  transferred  to  a  desiccator,  cooled,  and  weighed.* 

Babcock  Asbestos  Method. f — Provide  a  hollow  cylinder  of  perforated 
sheet  metal.  Oo  mm.  long  and  20  mm.  in  diameter,  closed  5  mm.  from 
one  end  by  a  disk  of  the  same  material.  The  perforations  should  be 
about  0.;  mm.  in  diameter  and  about  0.7  mm.  apart.  Fill  loosely  with 
from  1.5  to  2.5  grams  of  freshly  ignited,  woolly  asbestos,  free  from  fine 
and  brittle  material,  cool  in  a  desiccator,  and  weigh.  Introduce  a 
weighed  (piantity  of  milk  (between  3  and  5  grams),  and  dry  in  a  water- 
oven  to  constant  weight,  which  is  usually  reached  after  four  hours'  heating. 

DETERMINATION  OF  ASH.— The  platinum  dish  containing  the  milk 
residue,  obtained  in  the  determination  of  total  solids  by  the  dish  method 
described  above,  is  next  placed  upon  a  suitable  support  above  a  Bunsen 
flame  (a  platinum  triangle  or  a  ring  stand  is  convenient  for  this),  and 
the  residue  is  ignited  at  a  dull-red  heat  to  a  perfectly  white  ash,  after 
which  it  is  cooled  and  weighed. 

DETERMINATION  OF  FAT.— The  Adams  Method. —  Without  doubt 
the  most  accurate  method  of  fat  determination  is  by  extraction  with 
ether.  For  this  purpose  a  strip  of  fat-free  filter-paper  about  2h  inches 
wide  and  22  inches  long  is  rolled  into  a  coil  and  held  in  place  by  a  wire 
as  shown  in  Fig.  44. 

Schleicher  andSchiill  furnish  fat-free  strips  especially  for  this  work,  but  it 
is  very  easy  to  prepare  the  strips  and  extract  them  with  theSoxhlet  apparatus. 

About  5  grams  of  milk  arc  run  into  a  beaker  with  a  pipette,  and  the 
weight  of  the  beaker  and  milk  are  determined.  The  coil  is  then  intro- 
duced   into  the  beaker,  holding  it  by  the  wire  in  such  a  manner  that  as 

*  It  is  a  common  practice  to  transfer  the  milk  residue,  after  a  preliminary  drying  on  the 
water-bath,  to  an  air-oven,  kept  at  a  temperature  of  from  100°  to  105°,  where  it  is  dried  to 
a  constant  weight;  but  after  an  experience  in  analyzing  over  30,000  samples  of  milk,  the 
author  is  prepared  to  state  that  in  his  opinion  the  results  obtained  by  the  above  method  of 
procedure,  using  the  water-bath  alone,  are  more  satisfactory.  It  is  impossible  to  keep  a 
milk  residue  at  a  temperature  above  100°  for  any  length  of  time  without  its  undergoing 
decomposition,  especially  as  to  its  sugar  content,  as  is  shown  by  the  darkening  in  color.  A 
milk  residue  should  be  nearly  pure  white,  a  brownish  color  showing  incipient  decomposi- 
tion.  Hence,  by  continued  heating,  especially  at  the  temperature  of  105°,  the  residue  would 
continue  to  lose  weight  almost  indefmitely.  If  it  is  thought  best  to  give  a  final  drying  in 
the  air-oven,  the  time  should  be  short  and  the  temperature  emjjloycd  should  not  in  any  case 
exceed  100°. 

t  A.  O.  A.  C.  method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  ii7-        ^ 


MILK. 


135 


much  as  possible  of  the  milk  is  absorbed  by  the  paper.  It  is  often  possible 
to  lake  up  almost  the  last  drop  of  the  milk.  By  then  weighing  the  beaker, 
the  amount  of  milk  absorbed  by  the  coil  is  determined  by  difference,  and 
the  paper  coil  is  hung  up  and  dried,  first  in  the  air  and  then  in  the  oven, 
at  a  temperature  not  exceeding  100°.  Another  method  of  charging 
the  paper  coil  consists  in  suspending  it  by  the  wire  and  gradually  deliver- 
ing upon  it  5  cc.  of  the  milk  from  a  pipette,  the  density  of  (f^ 
the  milk  being  know^n. 

The  coil  containing  the  dried  residue  is  then  transferred 
to  the  Soxhlct  extraction  apparatus  (see  p.  64)  and  sub- 
jected to  continuous  extraction  with  anhydrous  ether  for  at 
least  two  hours,  the  receiving-flask  being  first  accurately 
weighed.  The  tared  flask  with  its  contents  is  freed  from 
all  remaining  ether,  first  on  the  water-bath  and  finally  in 
the  air-oven.  It  is  then  cooled  and  weighed,  the  increase 
in  weight  representing  the  fat  in  the  amount  of  milk  ab- 
sorbed by  the  coil.  If  there  is  any  doubt  about  all  the 
fat  having  been  extracted  at  first,  the  process  of  extraction 
may  be  continued  till  there  is  no  longer  a  gain  in  weight 
of  the  flask.  Experience  soon  shows  the  length  of  time 
necessary  for  the  complete  extraction,  which  of  course 
depends  on  the  degree  of  heat  employed,  and  the  fre- 
quency with  which  the  extracting-tube  overflows.  Two  hours  is  ample 
for  most  cases,  in  which  the  conditions  are  such  that  the  ether  siphons 
over  from  the  extraction-tube  ten  times  per  hour. 

Babcock  Asbestos  Method.* — Extract  the  residue  from  the  deter- 
mination of  water  by  the  Babcock  asbestos  method  with  anhydrous  ether 
in  a  continuous  extraction  apparatus,  until  all  the  fat  is  removed,  which 
usually  requires  two  hours.  Evaporate  the  ether,  dry  the  fat  in  the  extrac- 
tion flask  at  the  temperature  of  boiling  water,  and  weigh.  The  fat  may 
also  be  determined  by  difference,  drying  the  extracted  cylinders  at  the 
temperature  of  boiling  water. 

Fat  Methods  Based  on  Centrifugal  Separation.  —  These 
methods  are  the  most  practicable  for  commercial  work  and  for  use  by 
the  public  analyst,  since  they  are  much  more  rapid,  and,  if  carefully 
carried  out,  practically  as  accurate  as  the  Adams  method.  They  all 
depend  upon  the  use  of  a  centrifugal  machine,  having  hinged  pockets 
in  which  are  carried  graduated  bottles,  into  each  of  which  a  measured 
quantity  of  milk  is  introduced.  The  milk  is  then  subjected  to  the  action 
of  a  suitable  reagent,  which  dissolves  the  casein  and  liberates  the  fat  in 


FiG.  44- — The 
Adams  Milk- 
fat  Coil. 


*  A.  O.  A.  C.  method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  119. 


136 


FOOD  INSPECTION  AND   /IN /I LYSIS. 


a  pure  slate,  after  which,  l)y  whirling  at  a  liigh  speed,  the  pockets  are 
thro\Mi  out  horizontally  and  the  milk  fat  driven  into  the  neck  of  each 
bottle,  where  the  amount  is  directly  read. 

Various  processes  of  this  kind,  each  having  its  own  special  adherents, 
are  in  extensive  use,  among  which  the  best  known  are  the  Babcock,  the 
LefiFman  and  Beam,  the  Gerber,  and  the  Stokes. 

A  resume  of  these  processes,  showing  the  reagents  employed  and  other 
comparative  data,  is  thus  tabulated  by  Allen.* 


Milk 

Sulphuric  acid,  volume 

specific  gravity 

Hydrochloric  acid 

Amvl  alcohol 


Babcock. 


17-S  cc. 

17-5  cc. 

1. 831  to  1.834 

None 

None 


Leffman- 
Beam. 

15 

cc. 

9 

I 

cc. 

85 

I 

5  cc. 

I 

5  cc. 

Gerber. 


Stokes. 


II  cc. 

10  cc. 
-82  to  1.825 
None 
i-o  cc. 


15  cc. 

I3i  cc. 

1.82  to  1-83 

None 

1-5  cc. 


The  Babcock  Process,  devised  originally  for  the  use  of  creameries 
and  dair)'men,  is  now  extensively  employed  for  fat  determination  in 
the  laborator}'. 

It  has  stood  the  test  of  over  ten  years'  successful  use  in  the  writer's 
hands.  During  this  time  on  various  occasions  results  as  determined 
have  been  compared  with  those  obtained  by  the  Adams  process,  and  the 
agreement  has  been  as  close  as  could  be  expected.  The  following  figures 
show  the  results  of  such  comparative  determinations  made  in  duplicate 
on  three  samples  of  milk,  viz.,  a  whole  pure  milk,  (i)  and  (2);  a  watered 
milk,  (3)  and  (4),  and  a  milk  centrifugally  skimmed,  (5)  and  (6). 

COMP.\R.\TIVE   FAT  DETERMINATION   BY  ADAMS-SOXHLET  AND   BY 
BABCOCK  PROCESSES. 


Per  Cent  of 

Fat  by  the 

Adams-Soxh- 

let  Process. 

Per  Cent  of 

Fat  by  the 

Babcock 

Process. 

A  whole  milk         (i) 

4-27 
4-28 
2.70 

2-74 
0-16 
0.14 

4-30 

4-35 
2.70 
2.80 
0.15 
0-15 

.  _ 

(2) 

A  watered  milk     (3) 

(4) 

A  skimmed  milk   ( ') 

(6) 

TJie  Centrifuge. — Various  styles  of  centrifuge,  carrying  from  2  to 
40  Ixjttlcs,  arc  in  use  for  this  process. 

Two  forms  of  hand  machine  are  shown  in  Fig.  45,  one  (D),  for  two 
bottles,  arranged  to  screw  on  the  edge  of  a  table,  the  other  for  twelve  bottles 
inclosed  in  a  cast-iron  case. 


•  Commercial  Organic  .\nalysis,  3  Ed.,  Vol.  IV,  p.  150. 


MILK. 


137 


"^11^,^ 


Fig.  45. — Apparatus  for  Babcock  Test. 
A,  Burrell's  electric  centrifuge;    B.  Burrell's  steam   turbine   centrifuge;    C  and  D.  Burrcll's 
hand  centrifuges;  E,  milk  bottle;  F,  Wagner's  skim-milk  bottle;   G,  Swedish  or  combined 
acid  bottle. 


13S  FOOD  INSPECTION  AND  ANALYSIS. 

The  Steam  turbine  machines  (Fig.  45,  B)  are  simple  in  construction 
and  the  steam  sen'cs  to  keep  the  bottles  warm  as  well  as  to  furnish  power. 
The  steam  impinges  against  a  series  of  paddles  on  the  outer  periphery  of 
the  revolving  frame,  driving  it  like  a  horizontal  water-wheel.  A  reverse 
steam  jet,  steam  gauge,  and  hot-water  tank  for  filling  the  bottles  are  also 
provided. 

Fig.  45,  A  shows  an  electric  machine  for  24  to  36  bottles.  Laboratory 
centrifuges  are  also  provided  with  frames  for  Babcock  bottles. 

Glassware. — The  ordinary  test  bottle  for  milk  is  shown  in  Fig.  45,  E. 
It  has  graduations  corresponding  to  from  o  to  10%  of  fat,  using  17.6  cc. 
of  milk.  One  of  various  forms  of  skim  milk  bottle  is  also  shown  {F), 
The  graduated  tube  has  a  capacity  corresponding  to  only  0.25%  for  its 
entire  length,  hence  the  need  of  a  second  tube  of  larger  bore  for  filling. 

The  pipettes  are  graduated  to  hold  17.6  cc,  which  for  average  milk 
weighs  18  grams.  The  lower  tube  should  be  of  such  a  size' as  to  enter  the 
neck  of  the  test  bottle. 

A  17.5  cc.  cylinder  is  provided  for  measuring  the  acid,  but  where 
considerable  numbers  of  tests  are  made  some  special  measuring  device 
is  desirable.  Fig.  45,  G  shows  a  combined  acid  bottle  and  pipette,  the 
latter  being  filled  by  tipping  up  the  bottle. 

Manipulation. — Pipette  17.6  cc.  (corresponding  to  18  grams)  of  the 
milk  into  the  test  bottle  and  add  17.5  cc.  of  commercial  sulphuric  acid. 
(sp.gr.  1. 82-1. 84),  Mix  thoroughly  by  a  vigorous  rotatory  movement 
holding  the  neck  of  the  bottle  between  the  fingers  and  at  a  slight  angle 
away  from  the  body.  The  lumps  of  curd  which  at  first  form  disappear 
upon  shaking;  much  heat  is  developed  during  the  mixing  and  the  color 
changes  to  deep  brown. 

Place  the  test  bottles  in  the  pockets  of  the  centrifuge  (symmetrically 
arranged  to  keep  the  revolving  frame  in  balance)  and  whirl  at  the  rate  of  800 
to  I  GOO  revolutions  per  minute,  according  to  the  diameter  of  the  frame,  for 
5  minutes.  Stop  the  machine,  fill  each  bottle  up  to  the  neck  with  boiling 
water  and  whirl  for  two  minutes  longer.  Add  boiling  water  up  to  near 
the  top  of  the  graduation  and  whirl  finally  for  two  minutes. 

Remove  the  bottles  from  the  machine  and  take  the  readings  of  the 
bottom  and  the  very  top  of  the  fat  column,  the  difiference  being  the  per  cent 
of  fat.  If  desired,  the  percentage  may  be  obtained  directly  by  means  of 
calipers.  To  avoid  danger  of  cooling  it  is  well  to  immerse  the  bottles  nearly 
to  the  top  of  the  neck  in  water  at  60''  C,  removing  one  at  a  time  for 
reading. 


MILK.  139 

The  Werner-Schmidt  Method.— Ten  cc.  of  milk  are  introduced  by 
means  of  a  pipette  into  a  large  test-tube  of  50  cc.  capacity,  and  10  cc.  of 
concentrated  hydrochloric  acid  are  added.  The  mixture  is  shaken  and 
heated  till  the  liquid  turns  a  dark  brown,  cither  by  direct  boiling  for  a 
minute  or  two,  or  by  immersing  the  tube  in  boiling  water  for  from  five  to 
ten  minutes.  The  tube  is  then  cooled  by  im- 
mersion in  cold  water,  and  30  cc.  of  washed  ether 
is  added.  The  tube  is  closed  by  a  cork  provided 
with  tubes  similar  to  a  wash-bottle,  the  larger 
tube  being  adapted  to  slide  up  and  down  in  the 
cork,  and  preferably  being  .urned  up  shghtly  at 
the  bottom.  The  contents  of  the  tube  are 
shaken,  the  ether  layer  allowed  to  separate,  and 
the  sliding-tube  arranged  so  that  it  terminates 
slightly  above  the  junction  of  the  two  layers. 
The  ether  is  then  blown  out  into  a  weighed 
flask.  A  second  and  a  third  portion  of  ether 
of  10  cc.  each  are  successively  shaken  with  the 
acid  liquid  and  added  to  the  contents  of  the 
w'eighed  flask,  from  which  the  ether  is  subse- 
quently  evaporated  and   the  weight    of  the   fat 

easily  obtained.  FlG.46.^TheWerner-Schmidt 

,      .  .  1  -n    •  1  •  Fat  Apparatus. 

Instead  of  measurmg  the  milk  into  the  testmg- 
tube,  a  known  weight  of  milk  may  be  operated  on*    A  sour  milk  may  be 
readily  tested  in  this  way,  provided  it  is  previously  well  mixed. 

Determination  of  Fat  by  the  Wollny  Milk-fat  Refractometer.'^' — This 
instrument  presents  the  same  appearance  as  the  butyro-refractometer. 
Fig.  38,  wnth  an  arbitrary  scale  reading  from  o  to  100,  the  equivalent 
readings  in  indices  of  refraction  of  ihe  Wollny  instrument  varying  from 
1.3332  to  1.4220.  Exactly  30  cc.  of  the  milk  to  be  tested  are  measured 
into  the  stoppered  flask  A,  Fig.  47.  This  may  be  done  by  the  use  of 
the  automatic  pipette,  which  holds  exactly  7^  cc,  removing  four  pipettes 
full  of  the  milk.  ^  is  a  numbered  tin  sampling-tube  in  which  the  milk 
sample  is  kept  for  convenience,  and  into  which  the  automatic  pipette 
readily  fits.  Having  measured  30  cc.  of  the  milk  into  the  flask  A,  12 
drops  of  a  solution  of  70  grams  potassium  bichromate  and  312.5  cc.  of 
stronger  ammonia  in  one  liter  of  water  may  be  added  as  a  preservati\-e, 


*  Milch  Zeit.,  1900,  pp.  50-53. 


I40 


FOOD  INSPECTION  AND  ANALYSIS. 


if  the  sample  is  to  be  kept  for  some  lime  b^'fore  finishing  the  test.  Twelve 
drops  of  glacial  acetic  acid  are  added  to  curdle  the  milk.  The  flask  is 
then  corked  and  shaken  for  one  to  two  minutes  in  a  mechanical  shaker, 
after  which  3  cc.  of  a  standard  alkaline  solution  are  added,  and  the  flask 
corked  and  shaken  for  ten  minutes  in  the  mechanical  shaker,  the  tempera- 
ture being  kept  at  I  7.5°  C.    The  standard  alkaline  solution  is  prepared 


Yu:.  47. — Accessories  for  Carrying  Out  the  Woilny  Milk-fat  Process. 


by  dissr»lving  800  cc.  of  potassium  hydroxide  in  a  liter  of  water,  adding 
600  cc.  of  glycerin  and  200  grams  ])ulverized  copper  hydrate,  the  mixture 
being  allowed  to  stand  for  several  days  before  using,  shaking  at  intervals. 
Finally  6  cc.  of  water-saturated  ether  are  added  to  the  mixture  in  the 
flask,  using  for  convenience  the  automatic  pipette  fitted  in  the  corked 
bottle  as  shown.  The  flask  is  again  shaken  for  fifteen  minutes  in  the 
mechanical  shaker,  and  whirk-d  for  three  minutes  in  the  centrifuge,  after 
which  a  few  drops  of  the  ether  solution  are  transferred  to  the  rcfractometer, 
and  the  reading  taken.  The  percentage  of  fat  is  obtained  by  means  of 
the  fr)llowing  table: 


MILK 


141 


PERCENTAGES  OF  FAT  CORRESPONDING  TO   SCALE  READINGS  ON  THE 
WOLLNY  REFRACTOMETER. 


Scale 

Per 

Scale 

Per 

Scale 

Per 

Scale 

Per 

Scale 

Per 

Scale 

Per 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

ing. 

Fat. 

ing. 

Fat. 

ing. 

Fat. 

ing. 

Fat. 

ing. 

Fat. 

ing. 

Fat. 

20.0 

24-S 

0.41 

29.0 

0.87 

33-5 

1-34 

38.0 

1-85 

42.5 

2.41 

I 

6 

0.42 

I 

0.88 

6 

1-35 

I 

1.87 

6 

2-43 

2 

7 

0-43 

2 

0.89 

7 

1.36 

2 

1.88 

7 

2-44 

3 

8 

0.44 

3 

0.90 

8 

1-37 

3 

1.89 

8 

2.46 

4 

9 

0-45 

4 

0.91 

9 

1-38 

4 

1.90 

9 

2.47 

5 

25.0 

0.46 

5 

0.92 

34-0 

1-39 

5 

1. 91 

43-0 

2.49 

6 

0.00 

I 

0.47 

6 

0-93 

I 

1.40 

6 

1.92 

I 

2.50 

7 

O.OI 

2 

0.48 

7 

0.94 

2 

1.42 

7 

1-93 

2 

2-51 

8 

0.02 

3 

0.49 

8 

0-95 

3 

1-43 

8 

1-94 

3 

2.52 

9 

0.03 

4 

0.50 

9 

0.96 

4 

1-44 

9 

1-95 

4 

2-54 

21.0 

0.04 

5 

0-5I 

30.0 

0.97 

5 

1-45 

39-0 

1.96 

5 

2-55 

I 

0.05 

6 

0.52 

I 

0.98 

6 

1.46 

I 

1.98 

6 

2.56 

2 

0.06 

7 

0-53 

2 

0.99 

7 

1-47 

2 

1-99 

7 

2.58 

3 

0.08 

8 

0-54 

3 

1. 00 

8 

1.48 

3 

2.00 

8 

2.60 

4 

0.09 

9 

0-55 

4 

1. 01 

9 

1.49 

4 

2.02 

9 

2.61 

5 

O.IO 

26.0 

0-57 

5 

1.02 

35-0 

i-5« 

5 

2.03 

44.0 

2.63 

6 

O.II 

I 

0.58 

6 

1.03 

I 

1-51 

6 

2.04 

I 

2.64 

7 

0.12 

2 

0-59 

7 

1.04 

2 

1.52 

7 

2.05 

2 

2.65 

8 

0.13 

3 

0.60 

8 

1.05 

3 

1.54 

8 

2.07 

3 

2.67 

9 

0.14 

4 

0.61 

9 

1.06 

4 

1-55 

9 

2.08 

4 

2.68 

22.0 

0-15 

5 

0.62 

31.0 

1.07 

5 

1-56 

40.0 

2.09 

5 

2.70 

I 

0.16 

6 

0.63 

I 

1.08 

6 

1-57 

I 

2.10 

6 

2.71 

2 

0.17 

7 

0.64 

2 

1.09 

7 

1.58 

2 

2.12 

7 

2.72 

3 

0.18 

8 

0.65 

3 

1. 10 

8 

1-59 

3 

2.13 

8 

2.74 

4 

0.19 

9 

0.66 

4 

I. II 

9 

1.60 

4 

2.14 

9 

2-75 

5 

0.20 

27.0 

0.67 

5 

1. 12 

36.0 

1. 61 

5 

2-15 

45 -o 

2-77 

6 

0.21 

I 

0.68 

6 

1-13 

I 

1.62 

6 

2.16 

I 

2.78 

7 

0.22 

2 

0.69 

7 

1. 14 

2 

1.64 

7 

2.18 

2 

2-79 

8 

0.23 

3 

0.70 

8 

I-I5 

3 

1.65 

8 

2.20 

3 

2.80 

9 

0.24 

4 

0.71 

9 

1. 16 

4 

1.66 

9 

2.21 

4 

2.82 

23.0 

0.25 

5 

0.72 

32.0 

1. 17 

5 

1.67 

41.0 

2.23 

5 

2.84 

1 

0.26 

6 

0-73 

I 

1. 18 

6 

1.68 

I 

2.24 

6 

2.85 

2 

0.27 

7 

0.74 

2 

1. 19 

7 

1.69 

2 

2.25 

7 

2.87 

3 

0.28 

8 

0-7S 

3 

1.20 

8 

1.70 

3 

2.26 

8 

2.88 

4 

0.29 

9 

0.76 

4 

1.22 

9 

1. 71 

4 

2.27 

9 

2.89 

5 

0.30 

28.0 

0.77 

5 

1-23 

37-0 

1-72 

•    5 

2.28 

46.0 

2.90 

6 

0.31 

I 

0.78 

6 

1.24 

I 

1-73 

6 

2.30 

I 

2.92 

7 

0.32 

2 

0.79 

7 

1-^5 

2 

1-75 

7 

2.32 

2 

2-93 

8 

°-3i 

3 

0.80 

8 

1.26 

3 

1.76 

8 

2-33 

3 

2.94 

9 

0-34 

4 

0.81 

9 

1.27 

4 

1.78 

9 

2-34 

4 

2.96 

24.0 

0.36 

5 

0.82 

33-0 

1.28 

5 

1-79 

42.0 

2-35 

5 

2.98 

I 

0-37 

6 

0.83 

I 

1.29 

6 

1.80 

I 

2-37 

6 

3.00 

2 

0.38 

7 

0.84 

2 

1.30 

7 

1. 81 

2 

2.38 

7 

3.01 

3 

0.39 

8 

0.8s 

3 

1-31 

8 

1.82 

3 

2-39 

8 

3.02 

4 

0.40 

9 

0.86 

4 

1.32 

9 

1.84 

4 

2.40 

9 

3-03 

5 

0.41 

29.0 

0.87 

5 

1.34 

38.0 

1.85 

5 

2.41 

47.0 

3-05 

143 


FOOD  INSPECTION  AND  ANALYSIS. 


PERCENTAGES   OF  FAT   CORRESPONDING  TO  SCALE  READINGS  ON  THE 
WOLLNY     REFRACTOMETER  —{Continued). 


Scale 

Per     . 

Scale 

Per 

Scale 

Per 

Scale 

Per 

Scale 

Per 

Scale 

Per 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

Read- 

Cent 

ing. 

Fat. 

ing. 

Fat. 

ing. 

Fat. 

ing. 

Fat. 

ing. 

Fat. 

ing. 

P'at. 

47.0 

3-05 

50-5 

3-59 

54-0 

4.18 

57-5 

4-78 

61.0 

5-44 

64-5 

6. 14 

I 

3.06 

6 

3-60 

I 

4.20 

6 

4-80   , 

I 

5 -46 

6 

6.16 

2 

3-08 

7 

3.61 

2 

4-22 

7 

4-82  : 

2 

5-48 

7 

6.18 

3 

3-IO 

8 

3-63 

3 

4-23 

8 

4.84  ! 

3 

5-50 

8 

6.20 

4 

3" 

Q 

3-64 

4 

4-25 

9 

4-86  1 

4 

5-52 

9 

6.22 

5 

3-14 

51-0 

3-66 

5 

4.26 

58.0 

4.88  j 

5 

5-54 

65.0 

6.24 

6 

3-15 

I 

3-67 

6 

4.28 

I 

4.90 

6 

5-56 

I 

6.27 

7 

3-i6 

2 

3-68 

7 

4-29 

2 

4.92 

7 

5-58 

2 

6.29 

8 

3-17 

3 

3-70 

8 

4-31 

3 

4-94 

8 

5-60 

3 

6.31 

9 

3-18 

4 

3-72 

9 

4-33 

4 

4-95  1 

9 

5-61 

4 

6.34 

48.0 

3.20 

5 

3-74 

55.0 

4-35 

5 

4-97  , 

62.0 

5-63 

5 

6.36 

I 

3-21 

6 

3-76 

I 

4-37 

6 

4.98 

I 

5-65 

6 

6.38 

2 

3-23 

7 

3-78 

2 

4-38 

7 

5.00 

2 

5.66 

7 

6.40 

3 

3-25 

8 

3-80 

3 

4.40 

8 

5-02 

3 

5-68 

8 

6.42 

4 

3-27 

9 

3-82 

4 

4.42 

9 

5-04 

4 

5-70 

9 

6-44 

5 

3-28 

52-0 

3-84 

5 

4-43 

59-0 

5.06 

5 

5-72 

66.0 

6.46 

6 

3-30 

I 

3-85 

6 

4-44 

I 

5-08 

6 

5-74 

7 

3-32 

2 

3-87 

7 

4-46 

2 

5-10 

7 

5-76 

8 

3-iZ 

3 

3-89 

8 

4-48 

3 

5-" 

8 

5-78 

9 

3-34 

4 

3-90 

9 

4-49 

4 

5-13 

9 

5.80 

490 

3-36 

5 

3-92 

56.0 

4-51 

5 

5-15 

1  63.0 

5-82 

I 

3-38 

6 

3-93 

I 

4-53 

6 

5-17 

i         1 

5-84 

2 

3-40 

7 

3-95 

2 

4-55 

7 

5-19 

2 

5.86 

3 

3-42 

8 

3-97 

3 

4.57 

8 

5.20 

3 

5-88 

4 

3-43 

9 

3-99 

4 

4-59 

9 

5-22 

4 

5-90 

5 

3-44 

53-0 

4.01 

5 

4.60 

60.0 

5-24 

5 

5-92 

6 

3-45 

I 

4-03 

6 

4.61 

I 

5.26 

6 

5-94 

7 

3-46 

2 

4-04 

7 

4-63 

2 

5-28 

7 

5-96 

8 

3-48 

3 

4.06 

8 

4-65 

3 

5-30 

8 

5-98 

9 

3-50 

4 

4.07 

9 

4.67 

4 

5-32 

9 

6.00 

50.0 

3-51 

5 

4.09 

S7-0 

4.69 

5 

5-34 

64.0 

6.02 

I 

3-53 

6 

4.10 

1 

4.71 

6 

5-36 

I 

6.04 

2 

3-55 

7 

4.12 

2 

4.73 

7 

5-38 

2 

6.07 

3 

3-56 

8 

4.14 

3 

4-75 

8 

5-40 

3 

6.09 

4 

3-57 

9 

4. 16 

4 

4.76 

9 

5-42 

4 

6.12 

S 

3-50 

=;4.o 

4,18 

5 

4.78 

61.0 

5-44 

5 

6.14 

The  following  table  is  of  use  for  those  who  wish  to  employ  the 
Wollny  meihf.d,  but  have  the  Abb6  refractometer  instead  of  the  milk-fa*; 
refractometer. 


MILK. 


143 


INDICES  OF  REFRACTION  (h/,)  CORRESPONDING  TO   SCALE  READINGS  OP 
THE   WOLLNY  MILK-FAT  REFRACTOMETER. 


Refrac- 

Fourth Decimal  of  n  n- 

tive 

Index, 

I 

np. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

Scale  Readings, 

1-333 
1-334 

0.0 

0. 1 

0. 2 

0-3 
1 .2 

0.4 
1-3 

0.5 
1-4 

0.5 
1-5 

0.6 

0.7 

""  o.b' 

0.9 

I.O 

I.I 

1.6 

1-335 

1-7 

1.8 

1.9 

2.0 

2.1 

2.1 

2.2 

2-3 

2-4 

2.5 

1.336 

2.8 

2.7 

2.8 

2-9 

3-0 

3-1 

3-2 

3-3 

3-4 

3-5 

1-337 

3-6 

3-7 

3-7 

3-8 

3-9 

4.0 

4-1 

4-2 

4-3 

4-4 

1-338 

4-5 

4-6 

4-7 

4-8 

4-9 

5-0 

5-1 

5-2 

5-3 

5-4 

1-339 

5.5 

5-6 

5-7 

5-8 

5-9 

6.0 

6.1 

6.2 

6.3 

6.4 

1-340 

6.5 

6.6 

6.7 

6.8 

6.9 

6.9 

7.0 

7-1 

7-2 

7-3 

1-341 

7-4 

7-5 

7-6 

7-7 

7-8 

7-9 

8.0 

8.1 

8.2 

8.3 

1.342 

8.4 

8.5 

8.6 

8.7 

8.8 

8.9 

9.0 

9.1 

9.2 

9.3 

1-343 

9.4 

9-5 

9.6 

9-7 

9.8 

9-9 

10. 0 

10. 1 

10.2 

10.3 

1-344 

10.4 

10.5 

10.6 

10.7 

10.8 

10.9 

II. 0 

II. I 

II. 2 

11-3 

1-345 

II. 4 

ii-S 

11-5 

II. 6 

II. 7 

II. 8 

II. 9 

12.0 

12. I 

12.2 

1-346 

12.3 

12.4 

12.5 

12.6 

12.7 

12.8 

12.9 

13.0 

13-1 

13-2 

1-347 

^?,-?, 

13-4 

13-5 

13.6 

13-7 

13.8 

13-9 

14.0 

14. 1 

14.2 

1.348 

14-3 

14.4 

14-5 

14.6 

14-7 

14.8 

14.9 

15-0 

15. I 

15.2 

1.349 

15-3 

15.4 

15.5 

15.6 

15-7 

15.8 

15-9 

16.0 

16. I 

16.2 

1-350 

16.3 

16.4 

16.5 

16.6 

16.7 

16.8 

16.9 

17.0 

17. I 

17.2 

1-351 

17.3 

17.4 

17-5 

17.6 

17.7 

17.8 

17.9 

18.0 

18. I 

18.2 

1.352 

18.3 

18.4 

18.5 

18.6 

18.7 

18.8 

18.9 

19.0 

19. I 

19.2 

1-353 

19-3 

19.4 

19-5 

19.6 

19.7 

19.8 

19.9 

20.0 

20.1 

20.2 

1-354 

20.3 

20.4 

20.5 

20.6 

20.7 

20.8 

20.9 

21.0 

21. I 

21.2 

1-355 

21.3 

21.4 

21-5 

21.6 

21.7 

21.8 

21.9 

22.0 

22.1 

22.2 

1-356 

22.3 

•  22.4 

22.5 

22.6 

22.7 

22.8 

22.9 

23.0 

23.1 

23.2 

1.357 

23.3 

23.4 

23-5 

23.6 

23-7 

23.8 

23-9 

24.0 

24.1 

24. i 

1-358 

24-3 

24.4 

24.5 

24.6 

24.7 

24.8 

24-9 

25-0 

25.1 

25.2 

1.359 

25-3 

25.4 

25-5 

25.6 

25-7 

25.8 

25-9 

26.0 

26.1 

26.2 

1.360 

26.3 

26.4 

26.5 

26.6 

26.7 

26.8 

26.9 

27.0 

27.1 

27.3 

1. 361 

27.4 

27-5 

27.6 

27.7 

27.8 

27-9 

28.0 

28.1 

28.2 

28.3 

1.362 

28.4 

28.5 

28.6 

28.7 

28.8 

28.9 

29.0 

29.1 

29.2 

29.3 

1.363 

29.4 

29-5 

29.6 

29.7 

29.8 

29.9 

30.0 

,  30-1 
31.2 

30.2 

30.3 

1.364 

30-4 

30-5 

30.6 

30-7 

30.8 

31.0 

31. 1 

^-^■i 

31.4 

1-365 

31-5 

31.6 

31-7 

31-8 

31-9 

32.0 

32.1 

32-2 

32.3 

32.4 

1.366 

32.5 

32.7 

32.8 

32-9 

33-0 

33-1 

55-^ 

ii-3, 

33.4 

33.5 

1-367 

33.6 

33.7 

33-8 

33-9 

34-0 

34-2 

34-3 

34.4 

34-5 

34-6 

1.368 

34-7 

34.8 

34-9 

35-0 

35-1 

35-2 

35.3 

35.4 

35.5 

35-6 

1.369 

35-7 

35-8 

36.0 

36.1 

36.2 

36.3 

36.4 

36.S 

36.6 

36.7 

1.370 

36.8 

36.9 

37-0 

37-1 

37-2 

37.3 

37.4 

37.6 

37-7 

37-8 

1-371 

37.9 

38.0 

38.1 

38.2 

38.3 

38-4 

38.5 

38.6 

38.7 

38.8 

1-372 

38.9 

39-0 

39-2 

39-3 

39-4 

39-5 

39-6 

39-7 

39.8 

39.9 

1-373 

40.0 

40.1 

40.2 

40-3 

40.4 

40.5 

40.7 

40.8 

40.9 

41.0 

1-374 

41. 1 

41.2 

41-3 

41.4 

41-5 

41.6 

41.8 

41.9 

42.0 

42.1 

1-375 

42.2 

42.3 

42.4 

42.5 

42.6 

42.7 

42.8 

42-9 

43-0 

43.1 

1.376 

43.2 

43-3 

43-4 

43.6 

43-7 

43-8 

43-9 

44.0 

44-1 

44-2 

1-377 

44-3 

44-4 

44.6 

44-7 

44-8 

44-9 

45-0 

45-1 

45-2 

45-3 

1.378 

45-4 

45.6 

45-7 

45-8 

45-9 

46.0 

46.1 

46.2 

46.3 

46.4 

1.379 

46.6 

46.7 

46.8 

46.9 

47.0 

47-1 

47.2 

47.3 

47-4 

47.6 

144 


FOOD  INSPECTION  AND  ANALYSIS. 


INDICES  OF  REFRACTION  (>/d)  CORRESPONDING  TO  SCALE  READINGS  OI 
THE    WOLLNV   MILK-FAT  REFRACTOMETER— (Co«//««f^). 


Refrac- 

uve 
Index. 


Fourth  Decimal  of  "/). 


Scale  Readings. 


V<5o 
38 1 
3S2 
383 
384 
385 
386 

387 
388 

389 

390 
391 
392 
393 
394 
395 
396 
397 
398 
399 

400 
401 
402 
403 
404 
405 
406 
407 
408 
409 

410 
411 
412 

413 
414 

415 
416 

417 
418 
419 

420 
421 
422 


47-7 
48. 8 

49-9 
51-0 
52-1 
53-2 
54-3 
55-4 
^6.6 
57-8 

58.9 
60.1 
61.3 
62.4 
63.6 
64.8 
66.0 
67.2 
68.4 
69.6 

70.9 
72.1 

73-4 
74.6 

75-9 
77.1 

78-5 
79-8 
81.0 

82.3 

83.6 

84.9 
86.2 

87-5 
88.9 
90.2 
91 .6 
92.9 
94-3 
95-7 

97.1 
98-5 


47-8 

47-9 

48.0 

48.1 

48.2 

48-9 

49.0 

49-1 

49.2 

49-3 

50.0 

50-1 

50.2 

50-3 

50-4 

SI -I 

51-2 

51-3 

51-4 

51-6 

52-2 

52-3 

52-4 

52-6 

52.7 

53-3 

53-4 

53-6 

53-7 

53-8 

54-4 

54-6 

54-7 

54-8 

54-9 

55-6 

55-7 

55-8 

55-9 

56.0 

56-7 

56.8 

56-9 

57-1 

57-2 

57-9 

58.0 

58.1 

58-2 

58-3 

59-0 

59-1 

59-2 

59-4 

59-5 

60.2 

60.3 

60.4 

60.6 

60.7 

61.4 

61-5 

61.6 

6r.8 

61.9 

62.6 

62.7 

62.8 

62.9 

63.0 

63-8 

63-9 

64.0 

64.1 

64.2 

65.0 

65-1 

65.2 

65-3 

65-4 

66.2 

66.3 

66.4 

66.5 

66.6 

67.4 

67-5 

67.6 

67.7 

67.8 

68.6 

68.7 

68.8 

68.9 

69.0 

69.8 

69.9 

70.0 

70.1 

70.2 

71.0 

71. 1 

71.2 

71.4 

71-5 

72.2 

72.4 

72-5 

72.6 

72.8 

73-5 

73-6 

73-8 

73-9 

74.0 

74-8 

74-9 

75-0 

75-1 

75-2 

76.0 

76.1 

76.2 

76.4 

76.5    1 

77-2 

77-4 

77-5 

77-7 

77-8    1 

78.6 

78.7 

78.8 

79.0 

79-1    i 

79-9 

80.0 

80.1 

80.2 

80.4    ! 

81. 1 

81.2 

81.4 

8r.5 

81.6 

82.4 

82-5 

82.6 

82.8 

82.9 

83-7* 

83-8 

84.0 

84.1 

84.2      ' 

8s. 0 

85-2 

85-3 

85-4 

85-5      I 

86.3 

86.5 

86.6 

86.7 

86.9 

87.7 

87.8 

87.9 

88.1 

88.2    ' 

89.0 

89.1 

89-3 

89-4 

89.6 

90.4 

90-5 

90.6 

90.8 

90.9 

91.7 

91.9 

92.0 

92.1 

92-3 

93-1 

93-2 

93-3 

93-5 

93-6 

94-4 

94-6 

94-7 

94-8 

95-0 

95-8 

96.0 

96.1 

96-3 

96.4 

97-3 

97-4 

97-6 

97-7 

97-8 

98.7 
1 

98.8 

99.0 

99.1 

99-3 

48.3 

49-4 
50.6 

51-7 
52.8 

53-9 

55-0 
56-1 
57-3 
58-4 


59-6 
60.8 
62.0 
63-2 
64.4 
65.6 
6(5.8 
67.9 
6g.  I 
70.4 


71.6 
72-9 
74-1 
75-4 
76.6 

77-9 
79-2 
80.5 
81.7 
83.0 

84.4 
85.6 
87.0 
88.3 

89.7 
91.0 

92-4 
93-8 
95-1 
96.6 


99-4 


49- 

50- 

5^ 

52- 

54- 

55- 

56- 

57- 

58. 

59- 
60. 
62. 

63- 
64. 

65- 
66. 
68. 
69. 
70. 

71. 
73- 
74- 
75- 
76. 
78. 

79- 
80. 
81. 
83- 


85- 
87. 


91. 
92. 
93- 
95- 
96. 


99- 


-4 

48.6 

.6 

49-7 

-7 

50.8 

.8 

51-9 

-9 

53 -o 

.0 

54-1 

.1 

55-2 

.2 

56-3 

-4 

57-6 

.6 

58-7 

.8 

59-9 

-9 

61.0 

.1 

62.2 

-3 

63-4 

-5 

64.6 

-7 

65.8 

-9 

67.0 

.1 

68.2 

-3 

69.4 

-5 

70.6 

.8 

71.9 

.0 

73-1 

.2 

74-4 

■5 

75-6 

.8 

76.9 

.1 

7C.2 

-4 

79-5 

.6 

80.8 

-9 

82.0 

.2 

83-3 

-5 

84.6 

-7 

85-9 

.1 

87-3 

-5 

88.6 

-9 

90.0 

.2 

91-3 

-5 

92.7 

-9 

94.0 

-3 

95-4 

-7 

96.8 

.1 

98-3 

-5 

99-7 

48.7 

49-8 

50.9 
52.0 

53-1 
54-2 

55-3 
56.5 
57-7 
58.8 


60.0 
61. 1 
62.3 
63-5 
64-7 
65-9 
67.1 
68.3 

69-5 
70.8 

72.0 
73-2 
74-5 
75-8 
77.0 

78-3 
79-6 
80.9 
82.1 
83-4 

84.8 
86.1 

87-4 
88.7 
90.1 

91-5 
92.8 

94-2 
95-6 
97.0 

98.4 
99-9 


MILK.  145 

Determination  of  Proteins. — For  determination  of  the  total  nitro- 
gen in  milk,  5  cc.  arc  measured  direct  into  a  Kjcldahl  digest  ion- flask, 
or  a  known  weight  from  a  weighing-bottle  may  be  used,  and  the  regular 
Gunning  method  is  employed  as  described  on  page  69,  proceeding  with 
the  digestion  at  once  without  evaporation. 

The  total  nitrogen,  multipHed  by  6.38,  gives  the  total  proteins.  By 
many  the  old  factor  of  6.25  is  still  employed,  but  in  view  of  the  fact  that 
both  casein  and  albumin  have  been  found  to  contain  15.7%  of  nitrogen, 
there  would  seem  to  be  the  best  reasons  for  employing  6.38  as  a  factor 
100 


15-7. 
Ritthausen's  Method. — Ten  grams  of  milk  are  measured  into  a  beaker 

and  diluted  with  water  to  about  100  cc.  Five  cc.  of  a  solution  of  copper 
sulphate  (strength  of  Fehhng's  copper  solution,  34.64  grams  CuSO^  in  500  cc. 
of  water)  are  added  and  the  mixture  stirred.  A  solution  of  sodium  hydrox- 
ide (25  grams  to  the  liter)  is  added  cautiously  a  httle  at  a  time,  till  the 
liquid  is  nearly,  but  not  quite  neutral,  avoiding  an  excess  of  alkah,  as 
this  would  prevent  the  complete  precipitation  of  the  proteins.  Allow  the 
precipitate  to  settle,  and  pour  off  the  supernatant  Hquid  through  a  weighed 
filter,  previously  dried  at  130°  C.  Wash  a  number  of  times  by  decantation, 
and  transfer  the  precipitate  to  the  filter,  being  careful  to  remove  the  por- 
tions adhering  to  the  sides  of  the  beaker  with  a  rubber-tipped  rod.  Wash 
thoroughly  with  water,  and  drain  dry,  after  which  the  precipitate  is  washed 
with  strong  alcohol,  dried,  extracted  with  ether,  preferably  in  a  Soxhlet 
extractor,  and  then  transferred  on  the  filter  to  the  oven,  dried  at  130°  C, 
and  weighed.  The  filter  and  precipitate  are  then  burnt  to  an  asli  in  a 
porcelain  crucible,  and  the  weight  of  the  residue  subtracted  from  the  first 
weight  gives  that  of  the  proteins. 

Richmond  *  recommends  modifying  this  process  to  the  extent  of 
neutralizing  the  milk,  using  phenolphthalein  as  an  indicator,  before  adding 
the  copper  sulphate  solution,  and  using  only  2.5  cc.  of  the  latter. 

Determination  of  Casein. — Official  Method  of  the  A.  O.  A.  C. — Ten 
grams  of  the  milk  are  placed  in  a  beaker,  and  made  up  with  water  to  about 
100  cc.  at  40°  to  42°  C.  One  and  one-half  cc.  of  a  10%  solution  (by  weight) 
of  acetic  acid  are  added,  the  mixture  stirred,  warmed  to  the  above  tem- 
perature, and  allowed  to  stand  for  from  three  to  five  minutes,  till  a  floccu- 
lent  precipitate  separates,   leaving  a  clear  supernatant  liquid.     Decant 

*  Dairy  C'hem.,  p.  107. 


146  FOOD  INSPECTION  AND  /iN A  LYSIS. 

upon  a  filter,  wash  with  cold  water  two  or  three  times  by  dccantation, 
and  finally  transfer  the  v/hole  of  the  precipitate  to  the  filter,  and,  after 
filtering,  wash  two  or  three  times.  The  filtrate  should  be  clear  or  nearly 
so.  If  not,  it  can  generally  be  made  so  by  repealed  fiUralions,  and  the 
washing  done  afterwards.  The  filter  containing  the  washed  precipitate 
is  transferred  to  the  Kjeldahl  digestion-flask  and  the  nitrogen  obtained 
by  the  Gunning  process.     Nx 6.38  =  casein. 

Determination  of  Albumin. — Optional  Methods  of  the  A.O.  A.  C. — To 
the  filtrate  from  the  direct  determination  of  casein  by  the  acetic  acid 
method  as  described  in  the  j)receding  section,  exactly  neutralized  with 
.sodium  hydroxide,  0.3  cc.  of  a  lo^t  solution  of  acetic  acid  is  added, 
and  the  mixture  is  boiled  till  the  albumin  is  completely  precipitated. 
The  ]jrecii)itate  is  collected  on  a  filter  and  washed,  the  nitrogen  being 
determined  in  the  precipitate,  and  the  factor  6.38  used  in  calculating 
the  albumin  therefrom. 

Lefjman  and  Beam's  Modified  Method  for  Albumin  and  Casein. — Owing 
to  the  tedious  processes  of  washing  and  filtering  incidental  to  the  above 
methods  for  determining  casein,  the  following  is  suggested.  Twenty  cc.  of 
the  milk  are  mixed  with  saturated  magnesium  sulphate  solution,  and 
the  mixture  saturated  with  the  powdered  salt.  The  whole  is  then  washed 
into  a  graduate  with  a  little  of  the  saturated  solution,  and  the  precipitate 
allowed  to  settle,  leaving  a  clear  supernatant  layer.  The  volume  of 
the  mixture  in  the  graduate  is  read,  and  as  much  as  possible  of  the  clear 
portion  is  withdrawn  by  a  pipette  and  filtered. 

An  aliquot  part  of  the  filtrate  is  then  taken,  and  the  albumin  is  precip- 
itated from  it  by  a  solution  of  tannin,  after  which  the  precipitate  is  washed 
in  a  filter  and  the  nitrogen  determined  therein.     Nx  6.38  =  albumin. 

The  casein  is  calculated  by  difference  between  the  total  proteins  and 
the    albumin. 

Determination  of  Nitrogen  as  Caseoses,  Amido-compounds,  Peptones, 
and  Ammonia. — \'an  Slyke  *  proceeds  as  follows:  The  filtrate  from 
the  determination  of  the  albumin,  as  above,  is  heated  to  70°  C,  i  cc.  of 
50^^^'  sulphuric  acid  is  first  added,  and  aften\'ards  chemically  pure  zinc 
sulphate  to  saturation.  The  mixture  is  allowed  to  stand  at  70°  until  the 
caseoses  separate  out  and  settle.  Cool,  filter,  wash  with  a  saturated  zinc 
sulphate  solution  slightly  acidified  with  sulphuric  acid,  and  determine 
the  nitrogen  of  the  caseoses  in  the  j^recipitale. 

♦  N.  Y.  Kxp.  Station,  Bui    215,  p.   102, 


MILK. 


147 


For  Amido- com  pounds  and  Ammonia  treat  50  grams  of  the  milk  in  a 
250-cc.  graduated  flask  with  i  gram  sodium  chloride  and  a  12%  solution 
of  tannin,  added  drop  by  drop  till  no  further  precipitate  is  formed.  Dilute 
to.  the  250-cc.  mark,  shake,  and  filter.  Determine  the  nitrogen  in  50  cc. 
of  the  filtrate,  the  result  being  the  combined  nitrogen  of  the  amido-com- 
pounds  and  ammonia. 

Distil  with  magnesium  oxide  100  cc.  of  the  hltrate  from  the  tannin  salt 
solution,  receiving  the  distillate  in  a  standardized  acid,  and  titrating  in 
the  usual  way  for  the  ammonia. 

Calculate  the  nitrogen  of  the  peptones  by  subtracting  from  the  total 
nitrogen  that  due  to  all  other  forms. 

Van  Slyke  has  furnished  the  following  unpublished  analysis  of  a 
sample  of  milk  three  months  old,  kept  under  antiseptic  concUlions  by 
chloroform. 


Per  Cent 

Total  N. 

Per  Cent 
Sol.  Nitrogen. 

Per  Cent 

N  as  Paranuclein, 

Caseoses,  and 

Peptones. 

Per  Cent 
N  as  Amides. 

0.561 

0.099 

0.074 

0.025 

Determination  of  Milk  Sugar.— if  a  polariscope  is  available,  the 
sugar  of  milk  can  most  readily  and  conveniently  be  determined  by 
optical  methods.  In  the  absence  of  a  polariscope,  the  reducing  power  of 
milk  sugar  on  copper  salts  may  be  utilized  quite  accurately  in  deter- 
mining the  sugar,  using  either  volumetric  or  gravimetric  methods  as 
desired. 

Determination  by  Optical  Methods. — i.  Reagoils. — Acid  Nitrate  of 
Mercury. — This  solution  is  prepared  by  dissolving  metallic  mercury 
in  twice  its  weight  of  nitric  acid  of  specific  gravity  1.42,  and  adding  to 
the  solution  an  equal  volume  of  water.  One  cc.  of  this  reagent  will  be 
found  sufficient  to  precipitate  the  proteins  and  fat  completely  from  65  grams 
of  milk,  but  if  more  is  employed  the  result  of  the  analysis  is  not  affected. 

Mercuric  Iodide  Solution. — 33.2  grams  of  potassium  iodide  are  mixed 
with  13.5  grams  of  mercuric  chloride,  20  cc.  of  acetic  acid,  and  6-1.0  cc^ 
of  water. 

Suhaceiaie  0}  Lead  Solution,  U.  S.  P.     See  p.  586. 

Notes. — For  the  Laurent  polariscope,  in  which  the  normal  weight 
for  sucrose  is  16.19  grams,  the  corresponding  normal  weight  for  lac- 
tose is  20.496,  while  for  the  Soleil-Ventzke  instrument,  in  which  the  su- 


148 


FOOD   IWSTFCTION  /1ND   ylhlALYSIS. 


crose  normal  weight  is  26.04S  grams,  Ihc  corresponding  lactose  normal 
weight  is  32.975  * 

It  is  customar)'  to  employ  three  limes  the  normal  weight  of  milk 
in  the  case  of  the  Laurent  instrument  (viz.,  61.48  grams)  and  twice  the 
normal  weight  in  the  case  of  the  Soleil-Ventzke  (viz.,  65.95  gi'ams). 

As  it  is  more  convenient  to  measure  the  milk  than  to  weigh  it,  and 
as  the  volume  varies  with  the  specific  gravity,  the  following  table  is  use- 
ful, showing  the  quantity  to  be  measured  in  any  case,  having  first  deter- 
mined the  specific  gravity. 


Specific  Gravity. 

Volume  of  Milk  to  be  Used. 

For  Polariscopes  of 

which  the  Sucrose 

Normal  Weight  is 

16.19  Grains. 

For  Polariscopes  of 

which  the  Sucrose 

Normal  Weight  is 

26.048  Grams. 

1.024 
1.026 
1.028 
1.030 
1.032 
1-034 
I -035 

60.0     CC. 
59-9    cc. 
59.8    cc. 
59-7    cc. 
59.6    cc. 
59-5    cc. 
59-35  cc. 

64.4    cc. 
64.3    cc. 
64.15  cc. 
64 . 0    cc. 
63-9    cc. 
63.8    cc. 
63.7    cc. 

For  ordinar)-  work  it  is  sufficiently  close  to  have  a  pipette  gradu- 
ated to  deliver  59.7  cc.  if  the  Laurent  instrument  is  used,  and  64  cc.  for 
the  Soleil-Ventzke. 

2.  Process.  —  Measure  as  above,  the  e(|uivalent  of  61.48  grams  of 
the  milk  for  the  Laurent,  or  65.95  grams  for  the  Soleil-Ventzke,  instru- 
ment into  a  loo-cc.  graduated  flask,  add,  in  order  to  clarify,  2  cc.  of  acid 
nitrate  of  mercur)'  .solution,  or  30  cc.  of  mercuric  iodide  solution,  or  10  cc. 
of  lead  subacetate  solution.  Shake  gently  and  liU  to  the  mark  with 
water.  Then  add  from  a  pipette  enough  water  to  make  up  for  the  volume 
of  the  precipitated  proteins  and  fat,  insuring  100  cc.  of  sugar  solution. 
If  the  Laurent  instrument  is  used,  the  amount  added  as  prescribed  by 
the  A.  O.  .\.  C.  is  2.4  cc,  and  with  the  Soleil-Ventzke  2.6  cc.  The  con- 
tents of  the  flask  are  then  shaken  and  poured  upon  a  dr)^  filter.  The 
filtrate,  which  should  be  i)erfectly  clear,  is  polarized  in  a  200-mm.  tube, 
and  the  reading,  divided  by  3  for  the  Laurent  and  by  2  for  the  Soleil- 
Ventzke,  gives  the  percentage  of  lactose  directly. 

Allowance  jor  the   Volume  oj  the  PrecipU'ale. — This  of  course  varies 

♦  {a\t)  for  lactosc=  52.53,    [a]o   for  sucrose=66.5,  hence    for   the    Laurent   instrument 

52.53  :  66.5  .:  16.19  :  20.496, 
anfl  for  the  Solcil  \'ent7.kc  instrument  52.53  :  66.5  ;;  26.048  :  32.975. 


MILK.  149 

with  the  content  in  ])r()tcins,  and  fat,  and  while  the  above  allowance  gives 
in  most  cases  sufficiently  close  results,  it  is  not  exact.  Leffman  and 
Beam  *  advise  that  the  amount  of  water  to  be  added  above  100  cc.  be 
calculated  in  each  case  from  the  percentage  of  proteins  and  fat  previously 
found  by  analysis,  multiplying  the  actual  weight  of  the  fat  in  grams  in 
the  sample  taken  by  1.075,  and  the  weight  of  proteins,  by  0.8,  the  sum 
of  the  two  results  being  the  volume  in  cubic  centimeters  occupied  by 
the  precipitate. 

All  the  calculations  are  avoided  by  employing  the  double-dilution 
method,  which  is  to  be  recommended  when  very  particular  results  are 
required. 

Wiley  and  Ewell's  Double-dilution  Method. f — Two  flasks  are  em- 
ployed graduated  at  100  and  200  cc.  respectively,  into  each  of  which 
are  introduced  65.95  grams  of  milk,  if  the  Soleil-Ventzke  instrument  is 
used  (or  61.48  grams  in  case  the  Laurent  is  used)  and  4  cc.  of  the  mer- 
curic nitrate  solution  are  added,  both  flasks  being  fllled  to  the  mark  and 
shaken.  The  contents  are  filtered  and  the  polarization  is  made  in  each 
case  in  a  400-mm.  tube. 

The  second  reading  (that  of  the  more  dilute  solution)  is  multiplied 
by  2,  and  the  product  subtracted  from  the  first  reading;  the  remainder 
is  then  multiplied  by  2,  and  the  product  subtracted  from  the  first  read- 
ing (that  of  the  stronger  or  100  cc.  solution).  The  result  is  the  cor- 
rected reading,  which,  divided  by  4,  gives  the  exact  per  cent  of  milk  sugar 
in  the  sample.  This  method  depends  on  the  fact  that  within  ordinary 
limits  the  polarizations  of  two  solutions  of  the  same  substance  are 
inversely  proportional  to  their  volumes. 

Determination  of  Milk  Sugar  by  Feeling's  Solution.— Twenty- 
five  grams  of  the  milk  (24.2  cc.)  are  transferred  to  a  250-cc.  flask,  0.5  cc.  of 
a  30%  solution  of  acetic  acid  are  added  and  the  contents  well  shaken. 
After  standing  for  a  few  minutes,  about  100  cc.  of  boiling  water  are  run 
in,  the  contents  again  shaken,  25  cc.  of  alumina  cream  are  next  added, 
the  flask  shaken  once  more,  and  set  aside  for  at  least  ten  minutes.  The 
supernatant  liquid  is  then  poured  upon  a  previously  wetted  ribbed  filter, 
and  finally  the  whole  contents  of  the  flask  are  brought  thereon,  and  the 
filtrate  and  washings  made  up  to  250  cc.  The  filtrate  must  be  perfectly 
clear.  The  milk  sugar  in  a  solution  thus  precipitated  would  ordinarily 
not  exceed  ^  of  i  per  cent. 

*  Milk  and  Milk  Products,  p.  38. 

f  Wiley's  Agricultural  Analysis,  p.  278;  Analyst,  21,  1896,  p.  182. 


I50  FOOD    IXSPFCTION   AND   ANALYSIS. 

Volumetric  Fehling  Process. — From  a  burette  containing  the  clear 
milk  sugar  solution  above  prepared,  run  a  measured  volume  into  the 
boiling  Fehling  liquor  containing  5  cc.  each  of  copper  and  alkali  solution 
till  sulYicient  has  been  introduced  to  completely  reduce  the  copper,  con- 
ducting the  operation  in  the  manner  described  in  detail  on  page  591, 

As  0.067  gram  of  milk  sugar  will  reduce  10  cc.  of  Fehling  solution 

(sec  p.  593),   it  follows  that  the  number  of  cubic  centimeters  of  sugar 

containing  solution  required   for  making  the  test  (using    preferably  the 

average    of    several   determinations)   will    contain    0.067    gram  of    milk 

sugar,  from  which  the  percentage  is  readily  computed.      Thus  if  16  cc. 

of  the  milk  sugar  solution  are  necessary  to  reduce  the  copper,  then  16 

cc.  contain  0.067  gram  milk  sugar. 

250  cc.  of  solution  contain  25  grams  milk, 

ICC.  "        "  "       0.1      " 

i6cc.  ''       "  "       1.6     "         " 

and   1.6   grams   milk   contain    0.067   gram  milk  sugar.      Therefore  the 

,              .       .067X100  „ 

sample  contams =  4.19%. 

Gravimetric  Fehling  Processes. — O^Sullivan-Dejren  Method. — Twenty- 
five  cc.  of  the  above  milk  sugar  solution  are  added  to  the  hot  mixture  of 
15  cc.  each  of  Fehling  copper  and  alkali  solutions  and  50  cc.  water,  pre- 
pared as  directed  on  page  591.  and  the  test  carried  out  in  accordance  with 
the  details  there  described.  The  weight  of  the  cupric  oxide,  CuO,  as 
formed,  may  be  roughly  calculated  to  anhydrous  milk  sugar  by  multiply- 
ing by  0.6024. 

For  more  accurate  results,  however,  the  Defren  table,  page  595,  should 
be   used. 

SoxhleCs  Method.^ — Twenty-five  cc.  of  milk  are  diluted  with  400  cc. 
of  water  in  a  halfditer  graduated  flask  and  10  cc.  of  Fehling's  copper  solu- 
tion are  added.  Then  8.8  cc.  of  half-normal  sodium  hydroxide  are  run  in, 
or  a  sufi'icient  quantity  to  nearly  but  not  quite  neutrahze,  the  solution 
being  still  slightly  acid.  The  flask  is  fflled  to  the  mark,  shaken,  and  the 
contents  fjltered,  using  a  dry  Alter. 

One  hunflred  cc.  of  the  flltrate  are  added  to  50  cc.  of  the  mixed  Fehhng 
solution,  which  is  boiled  briskly  in  a  beaker  (using  25  cc.  each  of  the 
copper  and  alkali  solution).  After  boiling  for  six  minutes,  filter  rapidly 
through  a  Gooch  crucible  provided  with  a  layer  of  asbestos  as  described  on 
page  594,  and  wash  with  boiling  water  till  free  from  alkali.     The  asbestos 

*  U.  .S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bull.  46,  p.  41;    Bui.  107  (rev.),  p.  119. 


MILK.  15' 

film  with  the  adhering  cuprous  oxide  is  washed  into  a  beaker  by  hot  dilute 
nitric  acid,  and  after  complete  solution  of  the  co{)per  is  assured,  it  is  again 
filtered  and  washed  with  hot  water  till  a  clean  solution  containing  all  the 
copper  is  obtained.  Add  lo  cc.  of  dilute  suljjhuric  acid  (containing  200  cc. 
of  sulphuric  acid,  specific  gravity  1.84  per  liter)  and  evaporate  on  the  steam- 
bath  till  the  copper  has  largely  crystallized,  then  carefully  continue  the 
heating  over  a  hot  plate  till  the  nitric  acid  is  driven  out,  as  evidenced  by 
the  white  fumes  of  sulphuric.  Add  8  or  10  drops  nitric  acid  (specific 
gravitv  1.42)  and  rinse  into  a  very  clean  tared  platinum  dish  of  about 
100  cc.  capacity,  in  which  the  copper  is  deposited  by  electrolysis.  See 
page  608, 

The  weight  of  milk  sugar  is  determined  from  that  of  coppei  found, 
from  the  table  on  page  152. 

If  the  apparatus  for  the  determination  of  the  copper  by  the  elec- 
trolytic method  is  not  at  hand,  the  cuprous  oxide  may  be  weighed 
directly  in  the  Gooch  crucible.  In  order  to  facilitate  drying,  it  should 
be  washed  successively  with  10  cc.  of  alcohol,  and  10  cc.  of  ether,  after 
which  it  is  dried  thirty  minutes  in  a  water-oven  at  100°  C,  cooled,  and 
v^-eighed.  The  weight  of  copper  is  obtained  from  the  weight  of  the 
cuprous  oxide  by  the  use  of  the  factor  0.8883. 

Munson  and  Walker  Method. — The  milk  sugar  solution  is  prepared  as 
in  Soxhlet's  method.  For  details  as  to  the  copper  reduction  process  see 
pzg2  598. 

Relation  between  Specific  Gravity,  Fat,  and  Total  Solids  of  Milk.— 
The  close  relationship  existing  between  these  factors  has  long  been 
known,  and  many  formulae  have  been  devised,  whereby,  if  two  of  them 
are  known,  the  third  may  be  computed  with  considerable  approach  to 
accuracy.  The  specific  gravity  and  the  fat  are  very  readily  determined 
by  any  dairyman,  by  the  aid  of  a  lactometer  and  the  Babcock  apparatus. 
The  total  solids  are  ascertained  with  more  difficulty,  since  the  use  of  more 
involved  and  costly  apparatus  is  necessar}',  besides  considerable  tech- 
nical skill.  It  is  therefore  common  for  producers  to  calculate  the  total 
solids  from  the  fat  and  specific  gravity,  using  one  of  the  many  tables  pre- 
pared for  the  j)urpose,  based  on  some  one  of  the  best  accepted  formulae. 
The  total  solids  can  thus  be  calculated  to  within  two  or  three  tenths  of 
a  per  cent. 

The  two  most  commonly  used  formulae  for  this  purpose  are  those  of 
Hehner  and  Richmond  in  England,  and  Babcock  in  the  United  States. 
Hehner  and  Richmond's  formula  is 

r  =  o.255'-|-  1.2F+0.14, 


FOOD  INSPECTION  AND  ANALYSIS. 


SOXHLETS   TABLE    FOR 

THE   DETERMINATION    OF   LACTOSE.* 

MUli- 

Milli- 

Milli- 

Milli- 

Milli- 

Milli- 

Milli- 

Milli- 

Milli- 

Milli- 

(Cains 

grams 

KHun;^ 

grain.s 

Krams 
of  Cop- 

grams 

grams 

grams 

grams 

grams 

of  Cop- 

of Lac- 

of Cup- 

of  Lac- 

of  Lac- 

of Cop- 

of Lac- 

of Cop- 

of Lac- 

per. 

tose. 

j>er. 

to.se. 

per. 

tose. 

per. 

tose. 

per. 

tose. 

lOO 

71.6 

161 

117. 1 

221 

162.7 

281 

209. 1 

341 

256. s 

lOI      1 

72.4 

162 

"7-0 

222 

163.4 

282 

209.9 

342 

257-4 

102 

73-' 

'63 

118. 6 

223 

164.2 

283 

210.7 

343 

258.2 

103 

73-8 

164 

119.4 

224 

164.9 

284 

211.5 

344 

259.0 

104 

74.6 

'65 

120.2 

225 

165.7 

285 

212.3 

345 

259.8 

J  05 

75-3 

166 

120.9 

226 

166.4 

286 

213.1 

346 

260.6 

106 

76.1    ' 

167 

121. 7 

227 

167.2     1 

287 

213.9 

347 

261.4 

107 

76.8    ! 

168 

122.4 

228 

167.9    , 

288 

214.7 

348 

262.3 

108 

77-6 

169 

123.2 

229 

168.6    1 

289 

215-5 

349 

263.1 

loq 

78.3    1 

170 

123-9 

230 

169.4    1 

290 

216.3 

350 

263.9 

no 

79.0 

171 

124.7 

231 

170. I     1 

291 

217. 1 

351 

264.7 

1 1 1 

79-8 

172 

'25-5 

232 

170.9    1 

292 

217.9 

352 

265-5 

112 

?°-5 

'73 

126.2 

233 

171. 6 

293 

218.7 

353 

266.3 

"3 

81-3 

'74 

127.0 

234 

172.4 

294 

219-5 

354 

267.2 

114 

82.0    1 

'75 

127.8 

235 

I73-I    i 

295 

220.3 

355 

268.0 

"5 

82.7  ! 

176 

128.5 

236 

'73-9    ' 

296 

221.1 

356 

268.8 

1x6 

83-5 

'77 

129.3 

237 

174.6    [ 

297 

221 .9 

357 

269.6 

117 

84.2 

178 

130. 1 

238 

175-4    1 

298 

222.7 

358 

270.4 

118 

85.0 

179 

130.8 

239 

176.2 

299 

223-5 

359 

271.2 

119 

85-7 

180 

131. 6 

240 

176.9   ; 

300 

224-4 

360 

272. 1 

120 

86.4 

181 

132-4 

241 

177-7 

301 

225.2 

361 

272.9 

121 

87.2 

182 

'33-1 

242 

178.5 

302 

225.9 

362 

273-7 

122 

87-9 

'83 

'33-9 

243 

179-3 

303 

226.7 

363 

274-5 

123 

88.7 

184 

134-7 

244 

180. 1 

304 

227.5 

364 

275-3 

124 

89.4 

'85 

'35-4 

245 

180.8 

305 

228.3 

365 

276.2 

I2S 

90.1 

186 

136.2 

246 

181. 6 

306 

229.1 

366 

277.1 

126 

90.9 

187 

'37-0 

247 

182.4 

307 

229.8 

367 

277.9 

127 

91.6  1 

188 

'37-7 

248 

183.2 

308 

230.6 

368 

278.8 

128 

92.4  i 

189 

138.5 

249 

184.0 

309 

231-4 

369 

279.6 

J  29 

93-1 

190 

139-3 

250 

184.8 

310 

232.2 

370 

280.5 

130 

93-8 

191 

140.0 

251 

'85-5 

311 

232.9 

371 

281.4 

131 

94.6 

192 

140.8 

252 

186.3 

312 

233-7 

372 

282.2 

132 

95-3 

'93 

141. 6 

253 

187.1 

313 

234-5 

373 

283.1 

■133 

96.1 

'94 

142.3 

254 

187.9 

314 

235-3 

374 

283.9 

>34 

96.9 

'95 

143- 1 

255 

188.7 

315 

236.1 

375 

284.8 

135 

97.6 

196 

'43-9 

256 

189.4 

316 

236.8 

376 

285.7 

'36 

98.3 

'97 

144.6 

257 

190.2 

317 

237.6 

377 

286.5 

137 

99.1 

198 

145-4 

258 

191. 0 

318 

238.4 

378 

287.4 

138 

99-8 

'99 

146.2 

259 

191. 8 

319 

239.2 

379 

288.2 

139 

100.5 

200 

146.9 

260 

'92-5 

320 

240.0 

380 

289.1 

140 

101.3 

201 

'47-7 

261 

193-3 

321 

240.7 

381 

289.9 

141 

102.0 

202 

'48.5 

262 

194. 1 

322 

241-5 

382 

290.8 

142 

102.8 

203 

149.2 

263 

194.9 

323 

242.3 

383 

291.7 

143 

'03-5 

204 

150.0 

264 

'95-7 

324 

243-1 

384 

292.5 

144 

»04-3 

205 

'50-7 

265 

196.4 

325 

243-9 

385 

293-4 

'45 

105.1 

206 

'Si-5 

266 

197.2 

326 

244.6 

386 

294.2 

146 

105.8 

207 

152.2 

267 

198.0 

327 

245-4 

387 

295-1 

'47 

106.6 

208 

153-0 

268 

198.8 

328 

246.2 

388 

296.0 

148 

'07-3 

209 

153-7 

269 

'99-5 

329 

247.0 

389 

296.8 

149 

108. 1 

210 

154-5 

270 

200.3 

330 

247-7 

390 

297.7 

'5° 

108.8 

211 

155-2 

271 

201. 1 

33^ 

248.5 

391 

298.5 

>5' 

109.6 

212 

156.0 

272 

201.9 

332 

249.2 

392 

299.4 

'52 

110-3 

213 

'5('-7 

273 

202.7 

333 

250.0 

393 

300.3 

»53 

iil.i 

214 

'57-5 

274 

203-5 

334 

250.8 

394 

301.1 

'54 

III. 9 

2'5 

158.2 

275 

204.3 

335 

251.6 

395 

302.0 

'5> 

112.6 

216 

159.0 

276 

205.1 

336 

252-5 

396 

302.8 

'5f> 

"3-4 

217 

'59-7 

277 

205.9 

337 

253-3 

397 

303.7 

'57 

114. 1 

218 

160.4 

278 

206.7 

338 

254-' 

398 

304.6 

'58 

114.9 

219 

j6i  .2 

279 

207.5 

339 

254.9 

399 

305-4 

'59 

115.6 

220 

161. 9 

280 

208.3 

340 

255-7 

400 

306.3 

160 

116.4 

1 

*  Wiley.  Principles  and  Practice  of  Agricultural  Analysis,  Vol.  III.  pp.  163-165. 


MILK. 


wheie  T  is  the  per  cent  of  total  solids,  S  the  lactometer 
reading,  and  F  the  fat.  An  ingenious  instrument  known 
as  Richmond's  milk-scale  (Fig.  48)  is  useful  in  making 
the  calculation,  instead  of  employing  either  the  formula  or 
a  table.  This  is  constructed  on  the  princij;le  of  the  slide 
rule,  and  by  its  use  the  specific  gravity  may  be  corrected 
to  the  proper  temperature,  and  the  solids  calculated  from 
the  fat  and  specific  gravity. 

Babcock's  formula  for  solids  not  fat  is  as  follows: 


Solids  not  fat 


1006* -^5 


-I  l(ioo-F)2.5, 


100  — 1. 07537*^6' 

5  being  the  specific  gravity,  and  F  the  percentage  of 
fat.  On  this  formula  he  has  prepared  a  table  *  by  means 
of  which  one  may  calculate  solids  not  fat  agreeing  quite 
closely  mth  results  obtained  by  gravimetric  analysis-! 
The  tabic  on  page  154  has  been  recomputed  and  enlarged 
from  that  of  Babcock,  so  as  to  express  results  in  total 
solids  rather  than  solids  not  fat. 

Calculation   of   Proteins.— Van  Slyke's  %  formula  for 
calculating  proteins  (P)  from  the  fat  (F)  is: 
P=(F-3)Xo.4+2.8. 

Olsen  §  has  devised  the  following  formula  for  calcu- 
lating proteins  from  total  solids  {TS): 

TS 


P=TS- 


•34 


Approximately  0.8  X  proteins  =  casein. 

The  proteins  being  thus  calculated,  the  sugar  may  be 
computed  by  difference.  These  calculations,  while  only 
approximate,  give  quite  satisfactory  results  for  normal, 
healthy  milk,  especially  from  herds. 

Determination  of  Acidity.— While  milk  is  still  fresh, 
i.e.,  before  it  has  begun  to  undergo  lactic  fermentation, 
it  will  show  an  acid  reaction,  which  is  sometimes  expressed 
in    terms    of    lactic    acid.      In    view    of    the    fact    that 

*  U.  S.  Dcpt.of  Agric,  Div.  of  Chem.,  Bui.  47,  p.  123;  Bui.  107  (rev.) 
p.  225. 

t  For  approximate  work  Babcock  has  suggested  the  following  simpli- 
fied formula;:  Solids  not  fat  =  o.25G-|-o.2F  and  total  solids  =  0.2 5^+ 
1.2F,  C  being  the  lactometer  reading  and  F  the  fat. 

t  Jour.  Am.  Chem.  Soc.  30,  1908,  p    1182. 

§  Jour.  Ind.  and  Eng.  Chem.,  i,  1909,  p.  253. 


CO' 


!■<}■■ 


10 


CD- 


CO 


10 


1>4 


FOOD  INSPECTION  ^ND  AN /I  LYSIS. 


TABLE  SHOWING  PER  CENT  OF  TOTAL  SOLIDS  IN  MILK  CORRESPONDING 
TO  QUEVENNE  LACTOMETER  READINGS*  AND  PER  CENT  OF  FAT.f 


Per 
Cent 

Lactometer  Reading  at  i 

s.s°C 

, 

of  Fat. 

33 

23 

24 

25 

36 

27 

38 

39 

30 

31 

32 

33 

34 

35 

36 

o.o 

5.  SO 

5-75 

6.00 

6.3'; 

6.  so 

6.75 

7.00 

7.2s 

7 -SO 

7.75 

8.00 

8.25 

8.50 

8. 75 

9.00 

O.  I 

S.63 

5-87 

6.12 

6.37 

6.63 

6.87 

7-12 

7-37 

7.62 

7.87 

8.12 

8.37 

8.62 

8.87 

9.  1 

O.  3 

5-74 

S-90 

6.34 

6.491    6.74 

6-99 

7-24 

7-49 

7-74 

7-90 

8.24 

8.49 

8.74 

8.99 

9-  24 

0.3 

5-86 

6.11 

6.36 

6.61 

6.86 

7-11 

7-36 

7-61 

7.86 

8.11 

8.36 

8.61 

8.86 

9.11 

9.  36 

0.4 

S-08 

6.33 

6.48 

6.73 

6.98 

7.23 

7.48 

7-73 

7-98 

8.23 

8.48 

8.73 

8.99 

9-23 

9.48 

o-S 

6. 10 

6.35 

6.60 

6.8s 

7.10 

7-35 

7.60 

7.85 

8.10 

8.35 

8.60 

8.85 

9. 10 

9-35 

9.60 

0.6 

6.33 

6.47 

6.72 

6.97 

7.32 

7.47 

7-72 

7.97 

8.22 

8.47 

8.72 

8.97 

9.22 

9-47 

9.72 

0.7 

6.34 

6-59 

6.84 

7.09 

7-34 

7-59 

7.84 

8.09 

8.34 

8.50 

8.84 

9.00 

9.34 

959 

9.84 

0.8 

6.46 

6.71 

6.96 

7-21 

7-46 

7-71 

7.96 

8.21 

8.46 

8.71 

8.96 

9.21 

9.46 

9-71 

9.96 

0-0 

6.58 

6.83 

7.08 

7-33 

7-58 

7-83 

8.08 

8-33 

8.58 

8.83 

9.08 

9-33 

9.58 

983 

10.08 

1 .0 

6.70 

6.95 

7. 30 

7-45 

7-70 

7-95 

8.20 

8-45 

8.70 

8. 95 

9.  20 

9.45 

9.70 

9-95 

10.  20 

I .  I 

6.83 

7.07 

7-32 

7.57 

7-82 

8.07 

8.32 

8.57 

8.82 

9.07 

9-32 

9-57 

9.82 

10. O7!io. 32 

1.7 

6.Q4 

7.19 

7.44 

7-60 

7.94 

8.19 

8.44 

8.69 

8.94 

9.19 

9.44 

9.69 

9.94 

10. 19  10.44 

1-3 

7.06 

7-31 

7.56 

7.81 

8.06 

8.3. 

8.56 

8.81 

9.06 

9-31 

9    56 

9.8. 

10.06 

10. 31  10. 56 

1-4 

7.18 

7.43 

7.68 

7-93 

8.18 

8.43 

8.68 

8.93 

9.18 

9-43 

9.68 

9-93 

10.18 

10.43  10.68 

».5 

7.30 

7-55 

7.80 

8.0s 

8.30 

8.55 

8.80 

9.05 

930 

9-55 

9 -So 

10.05 

10.30 

10.55,10.80 

1.6 

7-42 

7-67 

7.92 

8-17 

8.42 

8.67 

8.92 

9.17 

9.42 

9.67 

9.82 

10.17 

10.42 

to.67j10.92 

1-7 

7-54 

7.79 

8.04 

8.29 

8.54 

8.79 

9.04 

9.29 

9-54 

9-79 

10.04 

10.  29 

10.54 

10.  79  II  .04 

1.8 

7.66 

7.91 

8.16 

8.41 

8.66 

8.91 

9.16 

9.41 

9.66 

9-91 

10.16 

10.41 

10. 66;  10. 91  1 1 .  17 

X-9 

7.78 

8.03 

8.28 

8.53 

8.78 

9.03 

9.28 

9.53 

9.78 

10.03 

10.28 

10. 55 

10.78 

II .04  II .  29 

a.o 

7.90 

8. IS 

8.40 

8.6s 

8.90 

9-15 

9.40 

9.6s 

9.90 

10.15 

10.40 

10.66 

10.91 

II. 16 11.41 

a.  I 

8. 03 

8.37 

8.S2 

8.77 

9.02 

9.27 

9-52 

9-77 

10.02 

10.27 

10.52 

10.78 

11.03 

II  .28  11.53 

3.3 

8.14 

8.39 

8.64 

8.89 

9.14 

9-39 

9 .  64    9-89 

10.  14 

10.39 

10.64 

10.90 

II. 15 

II  .40  II  .65 

a. 3 

8.26 

8. SI 

8.76 

9.01 

9.  26 

951 

9.  7610.01 

10.  26 

10.51 

10.76 

11.02 

11.27  11.52  11.77 

a. 4 

8.38 

8.63 

8.88 

9-13 

9-38 

9.63 

9.88  10.  13 

10.38 

10.63 

10.88 

II .  14 

II  .39  II .  64III  .89 

a-S 

8.50 

8.75 

9.00 

9-2S 

9.50 

9.75 

10.00  10.  25 

10.50 

10.75 

1 1  .00 

11.26 

II. 51 

1 1 . 76  I  2.01 

a. 6 

8.60 

8.87 

9.12 

9-37 

9.62 

9.87 

10.  12    10.37 

10.62 

10.87 

II. 12 

11.38 

11.63 

11.88  12.13 

3.7 

8-74 

8.99 

9.24 

9-49 

9.74 

9.99 

10.  24   10.49 

10.74 

10.99 

11.24 

11.50 

11.75 

12.00I12.  25 

3.8 

8.86 

9. II 

9-36 

9.61 

9-86 

10.  II 

10.36  10.61 

10.86 

II .  II 

11.37 

1 1  .62 

11.87 

12.12:12.37 

3.9 

8.98 

9-23 

9.48 

9-73 

9.98 

10.33 

10.48   10.73 

10.98 

11.23 

11.49 

11.74 

11.99 

12.24  12.49 

30 

9. 10 

9-35 

9.60 

985 

10. 10 

10. 35 

10.60  10.85 

II. 10 

11.36 

11.61 

11.86 

12.  II 

12.36  12. 6r 

3-1 

9-22 

9-47 

9.72 

9-97 

10.22 

10.4- 

10. 72   10.  97 

11.23 

11.48 

11.73 

11.98 

12.23 

12.48,12.74 

3a 

9-34 

9-59 

9-84 

10.09 

10.34 

10. 59 

10.84    I  I   .OQ 

11-35 

1 1 .60 

11.85 

12.10 

12.35 

I2.6i|i2.86 

3-3 

9-46 

971 

9-96 

10.  21 

10.46 

10.71 

10.96    11.22 

11.47 

11.72 

11.97 

12.22 

12.48 

12.73  12.98 

3    4 

9-58 

9.R3 

10.08 

10.33 

10. s8 

10.83 

II .09  1 1 .  34 

11-59 

11.84 

12.09 

12.34 

12.60 

12.85  13.10 

3-S 

9.70 

9-05 

10.  20 

10.45 

10.  70 

10.95 

II . 21 1 1 1  .46 

1 1  .  71 

II  .96 

12.21 

12  .46 

12.72 

12.97:13.23 

3.6 

9.82 

10.07 

10.32 

10. S7 

10.82 

11.08 

11.33  ii-S8 

11.83 

12.08 

12.33 

12.58 

12.84 

13-09J13-34 

3-7 

9.94 

10.  20 

10.44 

10.79 

10.94 

II .  20 

II .45  II .  70 

11-95 

12.  20 

12.45  »2.70 

12.96 

13- 21,13.46 

3-8 

10.06 

10.31 

10.56 

10.81 

11 .06 

11.32 

II. 57  11.82 

I  2.07 

12.32 

12.57  12.82 

13.08 

13-33  13.58 

3.9 

10.18 

10.43 

10.68 

10.93 

II. 18 

11.44 

1 1 . 69  1 1 .  94 

12.19 

12.44 

12.69  12.94 

13.20  13-45J13.70 

4.0 

10.30 

10. 55 

10.80 

II. OS 

11.30 

11.56 

II .81  12.06 

12.31 

12.56 

12.81  1306 

13.32  i3-57'i3-83 

4-1 

10.42 

10.67 

10.92 

11.17 

11.42 

11.68 

11.93  12.18 

12.43 

12.68 

12.93  13.18 

13.44  13   69  13.95 

4-2 

10.  i;4 

10.  79 

1 1  .04 

II .  29 

11.54 

11.80 

12.05  12.30 

12.55 

12.80 

13.05  13.31 

13-56  13-82  14.07 

4-3 

I  0 .  O'J 

10.91 

11.16 

11.41 

11.66 

11.92 

12.17  12.42 

12.67 

12.92 

13.18  13.43 

13.68, 13  .94  14. 19 

4.4 

10.78 

11.03 

II .  28 

11.53 

11.78 

12.04 

12. 29  12.  54 

12.79 

13-04 

13.30  13-SS 

13-80  14.06  14.31 

4-5 

1 0 .  go 

H.IS 

II  .40 

11. 6s 

11.90 

12.16 

12.41   12.66 

I  2.91 

13-  16 

13.42  13.67 

13.92  14.18  14.43 

4.6 

I  I  .C2 

11.27 

II  .  >2 

11.78 

12.03 

12.28 

12.53  12.78 

1303 

13-28 

13.54  13.79 

14.04  14.30  14. 55 

4-7 

....4 

II  .40 

11.6s 

1 1 .90 

12.15 

12.40 

12.65  1  2.90 

13.15 

13-40 

13.66  13-9' 

14.16 

14-42  14.67 

4-8 

11.27 

11-52 

11.77 

I  2.02 

12.  27 

12.52 

13.77I13.02 

13.27 

13-52 

13.78  14-03 

14.28 

14- 54  14-79 

4-9 

II.3<> 

II  .64 

1 1  .  89 

13.14 

12.39 

12.64 

12.89  13-14 

13-39 

13.64 

13-90  14. IS 

1 

14.40 

14.66  14.91 

S-o 

u.Si 

IX.  76 

13. 01 

12.36 

12.51 

,3.76 

13-OI   13. 26 

13-51 

13.76 

1 
14.02  14. 27 

14.52 

14-78  15.03 

S.x 

IX  .63 

11.88 

13.13 

13.38 

12.63 

12.88 

13-13  13-38 

13-63 

13-89 

14.14  14.39 

14.64 

14.90  15.15 

S-S 

11-75 

I  3.00 

13.35 

I  2.  so 

12.75 

1300 

13.25  13-50 

13-75 

14.01 

14.26  14.51 

14.76  15.0215.27 

5.3 

11.87 

13.13 

12.37 

1  2  .62 

12.87 

1312 

13-37  13-62 

13-87 

14-13 

14.38  14-6.3 

14.88  is-i4!i5.39 

5-4 

11.99 

1  3.  34 

13.49 

12.74 

12.99 

13-24 

13-49  13-71 

14.00 

14-25 

14.50  14. 7'i 

15.01  15.26  15.51 

S-i 

13.11 

12.36 

12.61 

12.86 

13-H 

1  3 .  36 

13.6113.86 

14.  12 

14-37 

14.62  14.88 

15.13  15.38115.63 

56 

13.33 

13.48 

12.73 

12.98 

13-23 

13.48 

13 -73  13-99 

14.24 

14.49 

14.7515.00 

15.25  15.50  15.75 

'•2 

12. 3S 

1  2.60 

12.8s 

13.10 

13-35 

13-60 

13-85,14.1' 

14.36 

14.61 

14.87  15.12 

15.37  15.62  15.87 

5-8 

12.47 

12.73 

12.97 

13.22 

13.47 

13.72 

13.97  14.22 

14.48 

14-74 

14.99  15.24 

iS.49'15.74 

15-99 

5-9 

13.59 

13.84 

13.09 

13.34 

13.59 

13.84 

14.10  14.35 

14.60 

14.86 

15.11  IS. 36 

15.61  15.86 

16.  13 

6.0 

,3.7. 

13.96 

13.21 

13. 4<' 

13.71 

13.96 

14.22  14.47 

14.72 

14.98 

iS-23  15-48 

15.73  15.98 

16.  34 

•The  lactometer  reading  is  exxjr'.-ssed  in  whole  numbers  for  convenience.  The  true  specific  gravity 
correspK.»nding  to  a  given  lactomct'  r  reading  is  obtained  by  writing  i.o  before  the  lactometer  reading. 
Thu«,  1.026  is  the  specific  gravity  c/rresjxjnding  to  lactometer  reading  26,  etc. 

tAn.  Rep.  Mass.  State  Board  of  Health,  1901,  p.  445-     ^Analyst's  Reprint,  p.  25.) 


MILK.  155 

the  acidity  of  "sweet"  milk  is  due  partly  to  the  presence  of  acid  phos- 
phates and  partly  to  dissolved  carbonic  acid  in  the  milk,  and  not  to  lactic 
acid,  which  is  probably  absent,  a  better  plan  is  to  express  the  acidity  in 
terms  of  the  number  of  cubic  centimeters  of  tenth-normal  alkali  necessary 
to  neutralize  a  given  cjuantity  of  the  milk,  either  25  or  50  cc,  using  phenol- 
phthalein  as  an  indicator. 

If  it  is  desired  to  calculate  the  acidity  in  terms  of  lactic  acid,  multiply 
the  number  of  cubic  centimeters  ^i  tenth-normal  alkali  used  by  0.897,  and 
divide  by  the  number  of  cubic  centimeters  of  milk  titrated,  the  result 
being  the  percentage  of  lactic  acid. 

Detection  of  Boiled  Milk. — Starch's  MetJwd.* — Shake  5  cc.  of  the 
milk  in  a  test-tube  with  one  drop  of  a  2%  solution  of  hydrogen  peroxide 
and  two  drops  of  a  2%  solution  of  paraphenylencdiamin.  If  the  milk 
has  not  been  heated  beyond  80°  C,  a  dark  violet  color  appears  at  once, 
but  if  it  has  been  pasteurized  or  boiled,  no  color  appears.  Siegfeld  and 
Samson  t  find  that  addition  of  two  drops  of  formalin  (i :  i)  to  each  100 
cc.  of  milk  previous  to  boiling  causes  it  to  react  similar  to  raw  milk. 

MODIFIED    MILK. 

A  comparison  of  the  composition  of  cow's  milk  and  human  milk,  as 
in  the  following  table  by  Dr.  Emmett  Holt,|  shows  very  marked  differ- 
ences. 

Woman's  Milk,  Cow's  Milk, 

Average.  Average. 

Fat.. 4-00  3-50 

Sugar 7.00  4.30 

Proteins 1.50  4.00 

Ash 0.20  0.70 

Water 87.30  87.50 

The  per  cent  of  fat  in  the  two  kinds  of  milk  is  nearly  the  same.  There 
is,  however,  too  little  sugar  and  an  excess  of  proteins  and  ash  in  the  milk 
of  the  cow,  assuming  human  milk  as  the  ideal  infant  food,  so  that  in 
basing  a  diet  for  infants  on  the  basis  of  human  milk  considerable  modi- 
fication is  necessary.  Moreover,  aside  from  the  actual  variation  in  the 
amount  of  ingredients,  there  are  certain  inherent  differences  in  the 
character  of  the  same  ingredient,  as  found  in  the  milk  of  the  cow  and  in 

*  Copenhagen  Expt.  Sta.,  40th  Rep.  t  Molk.  Ztg.,  21,  1907,  p.  103. 

X  "Infancy  and  Childhood." 


15'  FOOD   INSPECTION  AND  ANALYSIS. 

human  milk.  The  proteins  of  cow's  milk  are,  for  instance,  found  to  be 
much  more  difficult  of  digestion  than  those  of  woman's  milk,  and  the 
same  is  jirobably  true  of  the  fat.  Aside  from  the  mere  statement  of  a 
few  of  these  dilTerences,  it  is  obviously  beyond  the  scope  of  this  work  to 
discuss  this  phase  of  the  subject  in  detail,  reference  being  made,  how- 
ever, to  such  books  as  Dr.  T.  j\I.  Rotch's  "Pediatrics,"  and  "Infancy 
and  Childhood"  by  Dr.  Emmett  Holt,  for  full  particulars.  So  great 
has  been  the  demand  by  physicians  for  "modified  milk"  for  infant 
feeding,  that  laboratories  for  this  exclusive  puqwse  have  been  established 
in  many  of  the  larger  cities,  in  which  not  only  is  milk  prepared  in 
accordance  with  certain  fixed  formulcc  supposed  to  be  adapted  to  average 
infants  of  varying  age,  but  milk  of  any  desired  composition  is  prepared, 
in  accordance  with  special  prescriptions  of  physicians  to  apply  to  indi- 
vidual cases. 

Methods  and  Ingredients. — The  proteins  and  the  ash  in  cow's  milk 
are  much  higher  than  in  human  milk,  and  both  arc  brought  to  the  proper 
degree  of  reduction  by  diluting  the  milk  with  water.  Milk  sugar  is 
increased  by  the  addition  of  lactose,  and  the  fat  is  increased  or  diminished 
by  addition  of  cream  or  by  skimming. 

The  dilution  of  cow's  milk  with  a  measured  amount  of  water  shows 
the  following  results  on  the  proteins  and  ash: 


Cow's  Milk. 

Diluted 
Once. 

Diluted 
Twice. 

Diluted 
Three  Times. 

Diluted 
Four  Times. 

Proteins 

Ash 

Per  cent. 
4.0c 

-  _      _                  O-VO 

Per  cent. 
2.00 

0-35 

Per  cent. 

1-33 
0.23 

Per  cent. 
1 .00 
0.18 

Per  cent. 
0.80 
0.14 

1 

The  ingredients  commonly  employed  for  modifying  milk  are  (i)  cream, 
containing  16%  of  fat,  (2)  centrifugally  skimmed  milk,  otherwise  known 
as  "separator  milk"  from  which  the  fat  has  been  removed,  (3)  milk 
sugar,  or  a  standard  solution  of  milk  sugar  of,  say,  20%  strength,  and 
(4)  lime  water.  Unusual  care  should  be  taken  in  the  selection  of  the 
milk  supply  to  insure  cleanness,  purity,  and  freshness,  as  well  as  in  the 
care  of  utensils,  etc.,  used  in  the  laboratory,  which  should  in  all  cases 
be  scrupulously  clean.  Samples  prepared  in  accordance  with  a  given 
formula  or  formula;  are  pasteurized  in  separate  bottles,  or,  if  desired, 
sterilized,  and  after  stoppering  with  cotton  arc  kept  on  ice. 

Formulcc. — It  is  obviously  impossible  to  establish  formukc  univer- 
sally applicable  even  to  healthy  infants,  but  the  following  may  be 
regarded  as  typical  formula;,  representing  the  composition  of  modified 
milk  to  suit  the  needs  of  an  average  growing  infant  during  its  first  year: 


MILK. 


157 


Periud. 

Fat. 

Proteins. 

Sugar. 

Per  cent. 

Per  cent. 

Per  cent. 

Third  to  fourteenth  day 

Second  to  sixth  week 

Sixth  to  eleventh  week 

Eleventh  week  to  fifth  month. . 

Fifth  to  ninth  month 

Ninth  to  twelfth  month 

2 

2-5 

3 

3-5 

4 

3-5 

C.6 
c.8 
1.0 

1-5 
2 

2-5 

6 
6 
6 
7 
7 
3-5 

Milk  according  to  the  above  formulae  can 
be  ver\'  simply  prepared  by  the  aid  of  a  spe- 
cially made  graduate  known  as  the  "Matema" 
and  shown  in  Fig.  49. 


PREPARED   MILK   FOODS. 

Milk  Powder. — There  are  numerous  brands 
of  desiccated  milk  or  milk  powder  on  the 
market,  sold  in  bulk  and  by  the  can,  and  largely 
used  by  bakers  and  manufacturers  of  milk 
chocolate.  Many  of  these,  purporting  to  con- 
tain all  the  ingredients  of  milk  excepting  water, 
have  been  found  by  the  author  to  be  ])ulverizcd 
dried  skimmed  milk.  The  following  are  analyses 
of  whole  milk,  half-skim  milk,  and  skim  milk 
powders : 

Whole  Milk,  Half-skim  Milk, 

Powder.*  Powder.* 

Moisture 3-62  5.01 

Fat 26.75  15-26 

Proteins  (NX 6.25) 32.06  38.39 

Milk  sugar 31 -9°  34-67 

Ash 5.67  6.67 


Fig.  49. — The  "Materna" 
Graduate  for  Modifying 
Milk. 


Skim  Milk, 

Powder. t 

8.16 


100.00 


100.00 


99-95 


The  fat  in  the  skim  milk  powder  corresponds  to  about  0.16%  fat 
in  the  original  milk. 

Jensen  %  states  that  the  casein  of  dried  milk  no  longer  has  the  power 

*  C.  Huyge,  Rev.  gen.  du  Lait,  3,  1904,  p.  400. 

t  Analysis  by  the  author. 

%  Molkerei  Ztg.,  Berlin,  15,  1905,  p.  565. 


15S  FOOD   INSPECTION  /1ND   ANALYSIS. 

of  swelling  when  mixed  with  water.  To  obviate  this  dilTiculty,  Hatmaker 
adds  to  the  milk  i  to  3 '7  of  sodium  bicarboiiate,  and  Elkenberg  2%  of 
cane-sugar.  A  Swiss  milk  powder  examined  by  Jensen  contained  an 
excess  of  sodium  and  a  low  acidity,  indicating  the  addition  of  an  alkaline 
sodium  salt. 

Artificial  Albuminous  Foods. — The  albumin  and  cascM'n  of  milk  have 
furnished  the  basis  of  a  variety  of  food  prej)arations,  some  of  which  arc 
intended  for  the  use  of  invalids  and  people  of  weak  digestion,  and  others, 
from  their  compactness,  for  travellers  and  campers.  Among  these  foods 
are  the  following: 

Xiitrosc. — This  is  a  caseinate  of  sodium  formed  by  the  action  of  the 
alkali  upon  dried  casein.     It  is  soluble  in  water. 

Eucasin  is  a  caseinate  of  ammonium,  a  soluble  powder  somewhat 
similar  to  nutrose. 

Plasmon. — This  is  a  yellowish  powder,  prepared  by  treatment  with 
sodium  bicarbonate  of  the  curd  precipitated  from  skimmed  milk.  The 
compound  is  kneaded  in  an  atmosphere  of  carbon  dioxide,  and  reduced 
to  a  soluble  powder. 

The  following  analysis  of  plasmon  was  made  by  Woods  and  Merrill:* 


Water.                  Proteids. 

Fat.             \    Carbohydrates. 

Ash.                  Fuel  Value. 

8-5 

75-0 

0.2             '               8.9 

7-4 

2044 

Sanose. — This  is  also  a  powder,  containing  80*^^  of  purc  casein  and 
20%  of  albumose,  obtained  from  the  white  of  egg.  The  j)0wdcr  possesses 
a  slight  taste  and  an  odor  suggestive  of  milk.  By  briskly  stirring  the  powder 
with  water,  an  emulsion  may  be  made  much  resembling  milk,  but  on 
standing  it  soon  breaks  up. 

Sanatogen  is  a  grayish-white,  tasteless  powder,  containing  95%  of 
casein  and  ^%  sodium  glyccro-phosphate.  When  treated  with  cold 
"water  it  swells,  forming  on  heating  a  milk-like  emulsion. 

Koumis  is  a  stimulating  beverage,  prepared  by  .allowing  milk  to  undergo 
alcoholic,  lactic,  and  proteolytic  fermentations.  The  original  koumis 
was  made  by  the  Tartar  tribes  of  Asia  from  mare's  milk,  which  contains 
more  lactose  than  cow's  milk,  and  apparently  lends  itself  more  readily 
to  fermentation.  Only  a  limited  amount  of  koumis  is  now  made  from 
mare's  milk,  the  milk  chiefly  used  for  this  preparation  being  that  of  the 
cow,  treated  with  yeast  and  sometimes  added  sugar.  Koumis  is  a 
beverage  much  more  commonly  used  in  Europe  than  in  America. 

♦Maine  Exp.  .Station,  Bulletin  178,  p.  loi. 


MILK. 


159 


The  following  analyses  were  made  by  Vielh:* 


Water. 

hoi.         Fat. 

„      .       Albu- 
Casein.|    „,;„, 

1 

Albu- 
min- 
oses. 

Lactic 

Acid. 

Sugar. 

Ash. 

Mare's  milk 

Cow's  milk 

Skimmed  milk 

92.07 

90-57 
92.52 

2.98       1.30      0.83       0.24 
1.04       1.38       1.88       0.20 
0-57      0.33  j  2.03      0.07 

0.77 
0.77 
0.63 

1.27 
1.40 
0.56 

0.23 
2.18 
2-45 

0-35 
0.58 
0.84 

Kephir. — This  is  a  fermented  milk  product  similar  to  koumis,  excepting 
that  the  fermentation  is  induced  by  a  fungus  known  as  kephir  grains. 
The  proteolytic  fermentation  is  less  pronounced  in  kephir  than  in  koumis. 
Konig  gives  the  following  table  as  the  mean  of  twenty-eight  analyses: 


Water. 

N  tro- 
gen. 

1                1 
AIh„      1    Acid 
Casein.'  ^^-  1  Albu- 
"""■    :    min. 

Hemi-         Pep- 
albumin,      tone. 

Fat. 

Lac-    1  Lactic 
tose.       Acid. 

Alco- 
hol. 

Ash. 

91.21 

3-49 

2-53      0-36      0.21 

0.21 

0.039       1.44 

2.41       1.02 

0.75 

0.68 

ADULTERATION   OF   MILK. 

Systems  of  Milk  Inspection. — A  typical  method  of  general  food  inspec- 
tion has  already  been  outlined  (see  pp.  6  and  8) ,  which  may  easily  be  modi- 
fied to  include  the  inspection  of  milk  in  connection  with  other  foods,  or  to 
provide  for  a  system  of  milk  inspection  exclusively.  In  the  examination 
of  such  a  perishable  food  as  milk,  it  has  not  been  found  practicable  for 
the  analyst  to  reserve  for  the  benefit  of  the  defendant  a  sealed  sample, 
as  in  the  case  of  other  foods,  but  experience  has  shown  it  had  best  be  made 
the  duty  of  the  collector  or  inspector  to  give  a  sealed  sample  of  milk  to 
the  dealer,  when  the  latter  requests  it  at  the  time  of  taking  the  sample. 
For  this  purpose  the  collector  is  provided  with  small  bottles  and  sealing 
pharaphernalia,  in  addition  to  the  tagged  sample  bottles  or  cans  in  which 
he  collects  the  milk.  The  collector  should  use  the  same  precautions 
for  obtaining  a  perfectly  fair  representative  sample  as  does  the  chemist 
in  making  the  analysis,  i.e.,  he  should  carefully  pour  the  milk  from  the 
original  container  into  an  empty  can  or  vessel  and  back  again,  before 
taking  his  sample. 

Each  sample  is  properly  numbered  by  the  collector  in  presence  of  the 
dealer,  and  the  data  as  to  the  taking  of  the  sample  entered  at  once  under 
the  proper  number  in  the  collector's  book.     If  a  sealed  sample  is  given, 

*  Richmond  Dairy  Chemistry,  p.  241  et  seq. 


l6o  FOOD  INSPECTION  AND  ANALYSIS. 

it  should  bear  the  same  number  as  the  sample  reser\'ed  for  analysis,  and 
a  receipt  should  invariably  be  required  from  the  dealer,  as  evidence  that 
his  request   for  a  scaled  sam])le  has  been  complied  with. 

Milk  Standards  Fixed  by  Law. — In  localities  where  a  systematic  form 
of  milk  ins])eciicni  prevails,  there  is  usually  in  force  a  statute  fixing  the 
legal  standard  for  the  total  solids,  and  in  many  cases  for  the  fat  or  for 
the  solids  exclusive  of  fat.  In  some  states  the  statute  is  so  drawn  that 
any  deviation  from  the  legal  standard  constitutes  an  adulteration  in  the 
eye  of  the  law,  and  hence  the  offender,  who  has  such  milk  in  his  possession 
with  intent  to  sell,  is  liable  to  the  same  fine  as  if  he  actually  added  water 
or  a  foreign  substance  to  the   milk. 

In  other  states  a  distinction  is  made  by  the  statute  between  milk  that 
is  >"mply  below  the  legal  standard  of  total  solids,  and  milk  containing 
actually  added  ingredients  (water  or  otherwise),  a  much  lighter  fine  being 
imposed  for  the  former  than  for  the  latter  offense.  Where  such  a  dis- 
tinction prevails,  it  often  becomes  incumbent  upon  the  analyst  to  show 
to  the  satisfaction  of  the  court,  in  case  of  milk  low  in  sohds,  whether  or 
not  the  milk  has  been  fraudulently  watered  after  being  drawn  from  the 
cow,  it  being  well  understood  that  cows  may  give  milk  below  the  standard. 

Pure  milk  that  is  low  in  solids  may  owe  its  deficiency  either  to  poor 
feeding,  or  to  an  inherent  tendency  on  the  part  of  the  cow  to  give  milk 
always  of  poor  quality.  Thus  the  Holstein  cow,  more  than  any  other 
breed,  is  open  to  the  charge  of  sometimes  giving  milk  below  the  standard.* 
That  the  Holstein  cow  is  a  favorite  with  the  producer  is  by  no  means 
strange,  from  the  fact  that  no  other  breed  can  with  moderate  feeding 
be  made  to  give  so  large  a  quantity  of  milk. 

Wherever  there  is  a  statute  fixing  the  standard  for  milk,  it  commonly 
provides  also  that  the  addition  of  any  foreign  substance  whatsoever  con- 
.slitules  an  arhilteration. 

U.  S.  SidiXiAdiX As.]— Standard  milk  is  the  fresh,  clean,  lacteal  secre- 
tion obtaineri  by  the  complete  milking  of  one  or  more  ])erfectly  healthy 

*  This  statement  should  not  be  taken  as  condemning  the  Holstein,  for  it  is  true  that  cows 
of  this  breed  often  give  milk  far  above  the  standard.  A  large  number  of  samples  of  milk 
of  known  purity  from  Holstcins  analyzed  by  the  writer  have  been  found  to  be  of  excellent 
quality.  It  is  a  curious  fa<  t  that  among  the  samples  of  known  purity  analyzed  by  the  Massa- 
chusetts Board  of  Health,  both  the  lowest  and  highest  total  solids  on  record  came  from  a 
Holstein  cow;  the  lowest  recorded  total  solids  in  a  "known  jmrity"  milk  being  9.96  per 
cent,  (seventh  annual  report  of  Massachusetts  State  Board  of  Health,  Lunacy,  and  Charity, 
O,  160),  and  the  highest  being  17.06  per  cent,  (twenty-second  annual  report  of  the  Massa. 
chusetts  State  Board  of  Health,  p.  405). 

fU.  S.  Dept.  of  Agric,  OfT.  of  .Sec,  Circ.  19. 


MILK.  i6r 

COWS,  properly  fed  and  ke])t,  excluding  that  obtained  within  fifteen  days 
before  and  ten  days  after  calving,  and  contains  not  less  than  8.5%  of 
solids  not  fat,  nor  less  than  3.25^/0  of  milk-fat. 

Standard  Skim-milk  is  skim-milk  containing  not  less  than  9.25%  of 
milk  solids. 

Forms  of  Adulteration. — Milk  is  ordinarily  aduhcraled  (i)  by 
watering,  (2)  by  skimming,  (3)  by  both  watering  and  skimming,  and 
(4)  by  the  addition  of  one  or  more  foreign  ingredients. 

"Watering  and  Skimming. — The  fact  that  milk  is  found  below  the 
standard  of  total  solids,  while  more  often  due  to  an  excess  of  water,  may 
also  be  due  to  a  deficiency  in  fat.  In  one  case  the  milk  is  commonly 
termed  watered,  and  in  the  other  skimmed,  using  the  terms  broadly  and 
not  necessarily  meaning  actual  and  fraudulent  tampering  with  the  milk. 
In  a  third  case,  and  almost  invariably  fraudulently,  both  watering  and 
skimming  may  be  found  to  have  been  practiced  on  the  same  sample. 
The  analyst  judges  w-hich  of  these  causes  have  produced  a  milk  low  in 
solids,  by  a  careful  study  of  the  relation  between  the  percentages  of  total 
solids,  fat,  and  solids  not  fat. 

If  both  the  total  solids  and  solids  not  fat  are  abnormally  low,  and 
the  proportion  of  fat  to  solids  not  fat  about  the  same  as,  or  higher  than^ 
in  a  normal  milk,  it  is  generally  safe  to  assume  that  the  sample  has  been 
watered;  if  both  the  total  solids  and  the  fat  are  well  below  the  standard, 
and  the  solids  not  fat  nearly  normal,  then  the  milk  has  undoubtedly  been 
skimmed;  if,  in  the  third  place,  the  total  solids  and  the  soHds  not  fat  are 
proportionally  reduced  below  the  standard,  while  the  ratio  of  fat  to  solids 
not  fat  is  abnormally  small,  it  is  safe  to  adjudge  the  milk  to  be  low  by 
reason  of  both  skimming  and  watering. 

Milk  of  Known  Purity, — It  is  difficult  to  place  the  minimum  figure 
for  total  solids,  below  which  a  milk  sample  may  safely  be  pronounced 
by  the  analyst  as  fraudulently  watered  after  having  been  drawn  from 
the  cow.  Nearly  nine  hundred  s::mples  of  milk  of  known  purity  from 
various  breeds  of  cow,  milked  in  the  presence  of  an  inspector,  have  been 
analyzed  in  the  Department  of  Food  and  Drug  Inspection  of  the  Massa- 
chusetts State  Board  of  Health,  extending  over  a  period  of  fifteen  years, 
and  among  these  are  many  samples  from  Holstein  cows.  It  is  extremely 
rare  that  any  of  these  known  purity  samples  have  been  found  with  total 
solids  as  low  as  11%,  though  there  are  instances  where  total  solids  have 
run  as  low  as  10%.   . 


I  52  FOOD  INSPECTION  AND  ANALYSIS. 

It  is  safe  to  assume  that  in  the  few  cases  on  record  showing  less  than 
10.75'J^  of  total  solids,  cither  there  was  something  decidedly  abnormal 
about  the  health  of  the  cow,  or,  through  some  accident,  the  cow  was  only 
partially  milked,  it  being  a  well-known  fact  tnat  the  last  fraction  of  the 
milking  includes  the  larger  percentage  of  fat.     (See  page  128.) 

It  is  therefore  nearly  always  safe  to  condemn  a  milk  standing  below 
10.75  ^^  fraudulently  watered,  if  at  the  same  time  it  has  a  proportionately 
high  per  cent  of  fat. 

The  average  total  solids  of  See  samples  of  milk  of  known  purity  analyzed 
by  the  Massachusetts  Board  up  to  and  including  the  year  1890  amounted 
to  about  i2>Y^0' 

It  is  rare  indeed  to  fmd  a  herd  of  ten  or  more  well-fed  cows  of  mixed 
breeds  in  which  the  average  milk  of  tlic  herd  falls  below  I2j%  of 
solids. 

The  milk  of  forty-seven  Holstcin  cows,  examined  in  1885,  was 
found  to  contain  an  average  of  12.51%  of  total  solids,  while  the 
milk  of  eleven  Jerseys  examined  in  the  same  year  averaged  14.02% 
of  solids.  These  examples  re{)resent  the  two  extremes  commonly  met 
with. 

Varialion  in  Standard. — In  Massachusetts  the  law  fixes  a  different 
standard  for  total  solids  in  milk  during  the  summer,  or  pasture-fed  season, 
from  that  in  force  during  the  winter,  or  stall-fed  period.  From  April 
to  September  inclusive  the  legal  standard  is  1 2%  of  total  solids,  of  which 
9%  are  solids  not  fat,  and  from  Octol:>er  to  March  inclusive  it  is  13%,  of 
which  9.3%  are  solids  not  fat.  Bearing  on  the  question  of  difference  in 
normal  quality  of  milk  during  the  two  periods,  averages  were  taken  of  the 
milks  collected  by  the  corps  of  inspectors  of  the  Massachusetts  Board  of 
Health  during  a  month  in  each  period,  December  and  June  being  selected 
as  most  typical,  and  during  these  months  all  the  samples  were  analyzed 
both  for  total  solids  and  fat.  The  samples  were  taken  from  stores,  milkmen, 
and  producers,  and  represented  as  nearly  as  possible  the  milk  as  actually 
solfl  to  the  consumers.  In  making  the  averages,  all  samples  of  skimmed 
milk,  as  well  as  all  ssimples  standing  above  17%  of  total  solids,  or  under 
10.75%,  were  deducted.     The  results  are  summarized  as  follows: 


MILK. 


163 


QUALITY  OF   MILK   SOLD    IN   MASSACHUSETTS   CITIi:S    AND   TOWNS   Ui 

WINTER  AND  SUMMER. 


December. 

Number 

of 
Samples. 

Total  Solids. 

Fat. 

Solids 
not  Fat. 
Average 
Per  Cent. 

Highest 
Per  Cent. 

Lowest 
Per  Cent. 

Average 
Per  Cent. 

Highest 
Per  Cent. 

Lowest 
Per  Cent. 

Average 
Per  Cent. 

Cities 

Towns 

Summary,  .. . 

403 
99 

502 

16.86 

15.48 
16. 86 

10.88 
12.02 
10.88 

13.21 
13-44 
13-32 

8.50 
6.65 

8.50 

2.40 

3-5° 
2.40 

4-37 
4.48 
4-42 

8.74 
8.96 
8.85 

June. 

Number 

of 
Samples. 

Total  Solids. 

Fat. 

Solids 
not  Fat. 
A\-crage 
Per  Cent. 

Highest 
Per  Cent. 

Lowest 
Per  Cent. 

Average 
Per  Cent. 

Highest 
Per  Cent. 

Lowest 
Per  Cent. 

Average 
Per  Cent. 

Cities 

Towns 

Summary .... 

311 
76 

387 

16.90 

15-71 
16.90 

IO-75 
10.99 

IO-75 

12.67 
12.63 
12.65 

8.80 
7.10 
8.80 

2.10 
3.00 
2.10 

4-03 
4.09 
4.06 

8-54 
8.54 
8.54 

It  is  interesting  to  note  that  the  average  for  total  solids  of  the  88g 
samples  examined  for  both  months  stands  at  just  13%,  of  which  4.24%  is 
fat  and  8.76  is  solids  not  fat. 

Rapid  Approximate  Methods  of  Determining  the  Quality  of  Milk. — 
The  Lactometer. — A  rough  idea  of  the  quality  of  milk  can  be  gained  by  the 
use  of  the  lactometer  (page  131), but,  in  view  of  the  fact  that  a  low  specific 
gravity  may  be  the  result  either  of  a  watered  milk  or  of  a  milk  high  in  fat, 
good  judgment  is  necessary  in  connection  with  its  use.  A  milk  of  good 
standard  quality  should  have  a  specific  gravity  between  the  limits  of 
1.027  and  1.033.  ^  watered  milk  would  run  below  the  former  and  a 
skimmed  milk  above  the  latter  figure,  though  a  milk  unusually  rich  in  fat 
would  also  run  low.  It  should  easily  be  apparent  from  the  taste  and  appear- 
ance of  the  milk,  whether  a  low  specific  gravity  is  due  to  watering  or 
unusual  richness  in  fat.  The  fact  should  also  be  recognized,  that  a  milk 
sample  may  be  far  below  the  standard,  and  still  show  a  specific  gravity 
within  the  limits  of  pure  milk,  by  skillfully  subjecting  the  milk  to  both 
skimming  and  watering. 

The  Lactoscope. — Feser's  lactoscope  (Fig.  50)  gives  an  approximation  to 
the  amount  of  fat  in  milk,  and  its  use,  especially  in  connection  with  the 
lactometer,  is  of  some  value.  This  instrument  consists  of  a  graduated  glass 
barrel,  a,  into  the  bottom  of  which  is  accurately  fitted  the  stopper,  bearing 


1 64  FOOD  INSPECTION  AND   ANALYSIS. 

a  white  glass  cylinder,  haviiv^  bkick  lines  thereon.  Four  cc.  of  milk  are 
introduced  into  the  ])arr(.'l  by  means  of  a  pipette,  c,  and  water  is  added 
with  thorough  mixing  till  the  translucence  of  the  mixture  is  sufficient  to 
allow  the  black  lines  to  be  perceptible  through  it.  The  height  of  the  level 
of  milk  and  water  in  the  barrel  a  is  then  read  ofT,  the  number  indicating 
roughly  the  percentage  of  fat  in  the  sample. 

As  in  the  case  of  the  lactometer,  the  purity  of  a  milk  sample  cannot 
be  positively  established  by  the  lactoscope  alone.  For  instance,  a  wa'.ered 
milk  abnormally  high  in  fat  would  often  Ijc  found  to  read  within  the  limits 
of  pure  milk,  when  as  a  matter  of  fact  its  total  solids  would  be  below  stand- 
ard. By  a  careful  comparison  of  the  readings  of  both  the  lactoscope  and 
lactometer,  however,  it  is  rare  that  a  skimmed  or  watered  sample  could 
escape  detection. 

Thus,  if  the  specific  gravity  by  the  lactometer  is  well  within  the  limits 
of  pure  milk,  and  the  fat,  as  shown  by  the  lactoscope,  is  above  2,\  psr 
cent.,  the  sample  may  be  safely  passed  as  pure,  or  as  conforming  to  the 
standard. 

A  normal  lactometer  reading  in  connection  with  an  abnormally  low 
lactoscope  reading  shows  both  watering  and  skimming,  and  with  an 
abnormally  high  lactoscope  reading  shows  a  milk  high  in  fat,  or  a  cream. 
AVith  the  lactoscope  reach'ng  btlow  three,  and  a  low  lactometer  reading, 
watering  is  indicated.  A  lactometer  reading  above  thirty-three,  and  a 
low  lactoscope  reading,  indicate  skimming. 

Jleereii's  Pioscope. — This  instrument  consists  of  a  hard-rubber  disk, 
having  in  the  center  a  shallow  receptacle,  the  circular  rim  of  which  is  raised 
above  the  level  of  the  disk.  Into  this  receptacle  are  introduced  a  few 
drops  of  the  milk  to  be  tested,  and  a  circular  cover-glass  containing  a 
number  of  variously  tinted  segments  is  placed  over  the  receptacle,  which 
spreads  the  milk  out  into  a  thin  layer,  and  causes  it  to  assume  a  tint  against 
the  black  background  that  can  be  matched  with  one  of  the  colors  on  the 
glass,  the  various  tints  indicating  milks  of  various  grades  from  the  very 
poorest  to  rich  cream.     This  test  is  at  best  a  very  rough  one. 

Examination  of  the  Milk  Serum. — Detection  of  Added  Water. — 
This  may  often  be  detected  by  determining  the  specific  gravity  or  the 
degree  of  refraction  of  the  milk  serum,  since  it  has  been  found  that  under 
fixed  conditions  the  comjjosition  of  the  milk  serum,  or  clear  "  whey,'' 
is  more  constant  than  that  of  the  milk  itself.  Hence  any  considerable 
amount  of  watering  is  manifest  from  the  physical  constants  of  the  serum. 
In  using  this  method  the  analyst  should  carefully  work  out  his  own 


MILK. 


165 


Standards  for  comparison,  by  personal  experiment  on  milk  of  known 
composition  to  which  varying  amounts  of  water  have  been  added,  using 


%w 


m^  Mill 


Fig.  so. — Feser's  Lactoscope. 

the  same  conditions  for  obtaining  the  scrum  in  all  cases.  Woodman's 
method  *  is  as  follows:  To  100  cc.  of  the  milk  at  a  temperature  of  about 
20°  C.  are  added  2  cc.  of  25%  acetic  acid,  specific  gravity  1.0350,  in  a 


Jour.  Am.  Chem.  Soc,  21,  1899,  p.  503. 


i66 


FOOD   INSPECTION   ^ND  .^N.-l LYSIS. 


beakcT,  and  the  beaker,  covered  with  a  watch-glass,  is  heated  in  a  water- 
bath  for  20  minute.s  at  a  temperature  of  70°  C.  After  tliis  the  beaker  is 
placed  in  ice  water  for  10  minutes  and  the  solution  filtered. 

Specific  Gravity. — The  sjiecific  gravity  of  the  clear  filtrate,  obtained 
bv  the  method  described  above,  is  taken  at  15°  C.  with  the  Westphal 
balance. 

Immersion  Rcfractomctcr  Reading. — The  instrument  used  is  the  Zeiss 
immersion  or  dipping  refractometer  described  on  pages  iii  to  121.  The 
serum,  prepared  as  directed  in  a  preceding  ])aragraph,  is  examined  in 
one  of  the  small  beakers  accompanying  the  apparatus  at  a  temperature 
of  20°  C. 

Constants  of  the  Serum. — The  three  tables  which  follow  .show  the 
variation  of  specific  gravity  and  immersion  refractometer  reading  on  milk 
of  diiTcrent  composition. 

Analyses  of  whole  milk  submitted  by  the  author  to  varying  degrees 
of  watering,  up  to  50*^^  of  added  water,  are  given  in  the  following  table : 

CONSTANTS    OF    MILK    AND    MILK    SERUM.      A    WHOLE    MILK 
SYSTEMATICALLY    WATERED. 


Determinations  or 

Milk. 

On  Millc  Serum. 

Added 

Water. 

Per  Cent. 

Total 

SoUds, 

Per  Cent. 

Water, 
Per  Cent. 

Fat. 
Per  Cent. 

Solids 
not  Fat, 
Per  Cent. 

Ash, 
Per  Cent. 

Specific 
Gravity 
at  I  5°  C. 

Specific 
Gravity 
at  15°  C. 

Immersion 
Refrac- 
tometer 
Reading 
at  20°  C. 

0 
10 

12.65 

87-35 
88.67 

4.00 
3-50 

8.65 
783 

0.65 
0.60 

I -0315 
1.0278 

1.0287 
1.0260 

42.40 

39-75 

20 

10.10 

89.90 

3.10 

7.00 

0-53 

I .0252 

1.0230 

36.90 

30 

8-95 

91.05 

2.80 

6.15 

0.48 

1. 02 1 1 

I .0200 

34-10 

40 

7.67 

92-33 

2.40 

5-27 

0.40 

I. 0192 

I .0167 

31.10 

50 

6-43 

93-57 

2.00 

4-43 

0.38 

1-0154 

I. 0140 

28.45 

The  first  table  on  p.  167  .shows  a  centrifugally  skimmed  milk,  .systemat- 
ically watered  ujj  to  50%  of  added  water,  as  in  the  preceding  table.  It 
will  be  ob.served  that  both  the  specific  gravity  and  immersicm  refractom- 
eter readings  of  the  .serum  of  the  whole  milk,  agree  very  clo.sely  with 
those  of  the  .skimmed  milk  in  cases  having  a  corresponding  amount  of 
added  water. 

The  second  table  on  \).  167  .shows  analyses  of  milk  .selected  from  a 
wide  range  of  .samples  regularly  collected  and  e.xaminefl  in  the  routine 
of  food  inspection  by  the  Massachusetts  State  Board  of  Health. 


MILK. 


167 


CONSTANTS    OF    MILK    AND    MILK    SERUM.      A    SKIMMED    MILK 
SYSTEMATICALLY    WATERED. 


Determinations  on  Milk. 

On  Milk  Serum. 

Added 

Water, 

Per  Cent. 

Total 

Solids, 

Per  Cent. 

Water, 
Per  Cent. 

Fat, 
Per  Cent. 

Solids 
not  Fat, 
Per  Cent. 

Ash, 
Per  Cent. 

Specific 
Gravity 
at  15°  C. 

Specific 
Gravity 
at  15°  C. 

Immersion 
Refrac- 
tometer 
Reading 
at  20°  C. 

0 
10 

905 
8.14 

90-95 
91.85 

0.03 
0.03 

9.02 
8. II 

0.64 
0.60 

1-0350 
I. 0317 

I .0296 
1.0260 

42.85 
39.60 

20 

7.27 

92-73 

0.02 

7-25 

0.56 

1.0278 

1.0230 

36.85 

30 

6.41 

93  -  59 

0.02 

6-39 

0.4S 

1.0247 

I .0200 

34-00 

40 

5  ■  50 

94-50 

O.OI 

5-49 

0.44 

1.0209 

I .0170 

31-20 

50 

4.61 

95-39 

O.OI 

4.60 

0-39 

I .0172 

I .0140 

28.50 

CONSTANTS    OF    MILK    AND    MILK    SERUM.       LABORATORY    SAMPLES 


Determinations  on  Milk 

On  Milk  Serum. 

Total  Solids, 

Water, 

Fat, 

Solids 
not  Fat, 

Ash, 

Specific 
Gravity 

Specific 
Gravity 
at  15°  C. 

Immersion 
Refractom- 

Per  Cent. 

Per  Cent. 

Per  Cent. 

Per  Cent. 

Per  Cent. 

at  15°  C. 

eter  Read- 

ing at  20°  C. 

16.45 
15-90 

8^.t:c 

8.20 

8-2; 

I . o^cc 

1.0274 
1.0285 

40.95 
42.00 

^0 
84 

10 

7 

00 

8 

90 

0.69 

0277 

14-37 

85 

63 

5 

50 

8 

88 

0.58 

0282 

1.0280 

42.40 

14.17 

85 

83 

4 

85 

9 

32 

0.62 

0313 

I. 0281 

44.20 

14.04 

85 

96 

4 

95 

9 

09 

0.60 

0303 

1.0274 

42.70 

13.80 

86 

20 

5 

00 

8 

80 

0.65 

0302 

1.0289 

42.75 

13-59 

86 

41 

4 

30 

9 

29 

0.64 

0321 

1.0285 

44-50 

13-39 

86 

61 

4 

40 

8 

99 

0.50 

0324 

1.0285 

43-7° 

13.28 

86 

72 

4 

40 

8 

88 

0.60 

0299 

1.0289 

42.65 

13.12 

86 

88 

4 

00 

9 

12 

0-59 

0317 

1.0280 

43-75 

13.00 

87 

00 

4 

30 

8 

70 

0.56 

0310 

1.0266 

42.60 

12.90 

87 

10 

3 

85 

9 

05 

o.6r 

0318 

1.0289 

43-40 

12.80 

87 

20 

4 

30 

8 

50 

0.46 

0304 

1.0277 

42.70 

12.70 

87 

30 

3 

80 

8 

90 

0.53 

0314 

1 . 0280 

43.10 

12.63 

87 

37 

3 

50 

9 

13 

0.65 

0323 

1.0277 

43-65 

12.62 

87 

38 

4 

10 

8 

52 

0.52 

0298 

1.0272 

42.40 

12.57 

87 

43 

3 

70 

8 

87 

0.68 

0317 

1.0278 

43-45 

12.47 

87 

53 

3 

60 

8 

87 

0.65 

0303 

1.0282 

43-15 

12.36 

87 

64 

3 

20 

9 

16 

0.55 

0327 

1.0282 

43-25 

12.30 

87 

70 

3 

20 

9 

10 

0.62 

0327 

1.0283 

44.00 

12.16 

87 

84 

4 

35 

7 

81 

0.49 

0275 

I   0265 

41.10 

12.00 

88 

00 

3 

40 

8 

60 

0.62 

0275 

1.0280 

41-75 

11.86 

88 

14 

3 

60 

8 

26 

0.49 

0306 

1.0266 

42.40 

11.67 

88 

33 

3 

95 

7 

77 

0.48 

0265 

1 . 0240 

39-30 

11.60 

88 

40 

2 

75 

8 

85 

0.65 

0320 

1.0282 

43-55 

11.50 

88 

50 

3 

45 

8 

05 

0.51 

0290 

1.0269 

41.40 

11.40 

88 

60 

3 

10 

8 

30 

0.60 

0297 

1.0278 

42.00 

11.25 

88 

75 

2 

80 

8 

45 

0.58 

0280 

1.0274 

40.90 

11.07 

88 

93 

3 

00 

8 

07 

0.62 

0290 

1.0270 

40.75 

10.69 

89 

31 

75 

2 

95 
20 

7 
6 

74 
95 

0288 

I .0262 

39-85 
36.40 

10.25 

89 

3 

0.55 

0230 

1.0223 

8.34 

91.66 

2.20 

6.14 

0.38 

0224 

1.0207 

34-70 

1 68  FOOD   INSPFCTION   AND   ANALYSIS. 

A  comparison  of  the  immersion  refractomctci  readings  of  the  serum 
of  milk  of  varying  quality  sht)\vs  at  once  that  the  refraction  of  the  serum 
is  a  general  "ndex  to  watering.  A  reading  below  40  with  the  above 
conditions  carefully  observed  would  be  suspicious  of  added  water,  though 
39  might  more  safely  be  placed  as  a  limit,  below  whicli  milk  could  be 
declared  fraudulently  watered.  The  analyst  need  not  hesitate  in  testify- 
ing to  the  presence  of  added  water,  when  the  refraction  is  lower  than 
39  under  the  above  conditions  and  the  solids  not  fat  below  7.3^. 

The  tables  on  page  169  give  a  sinum;!ry  of  refractometric  and  analytical 
results  of  a  large  number  of  milk  samples  from  three  widely  separated 
localities,  namely,  Massachusetts,  New  Jersey,  and  Great  Britain: 

Xitrales. — Pure  milk,  free  from  contamination  with  stable  filth,  con- 
tains no  nitrates;  well  water,  however,  often  contains  a  sufficient  amount 
to  enable  the  detection  of  a  10%  admixture  in  milk. 

The  diphenylamin  test,  first  employed  by  Soxhlet  to  detect  nitrates 
in  milk,  has  since  been  modified  by  Moslinger,*  Richmond, f  Hefel- 
mann.J  Rcisz,§  Patrick,  and  others. |j 

Place  in  a  small  porcelain  crucible  one  cc.  of  a  solution  of  o.i  gram 
of  diphenylamin  in  1000  cc.  of  concentrated  sulphuric  acid  and  allow 
a  few  drops  of  the  milk  serum  to  flow  over  the  surface.  A  blue  color 
appearing  within  10  minutes  indicates  the  presence  of  nitrates.  On 
longer  standing,  a  brown  color  forms,  whether  or  not  nitrates  are 
present. 

The  delicacy  of  the  test  is  increased  by  adding  to  the  reagent  a  small 
amount  of  powdered  sodium  chloride  shortly  before  using. 

Systematic  Examination  of  Milk  for  Adulteration.— If  a 
large  number  of  samj)les  of  milk  have  to  be  examined  daily  for  adul- 
teration, it  may  be  an  advantage  to  submit  all  to  a  preliminary  test  with 
the  lacto.scope  and  lactometer,  excluding  from  further  analysis,  as  above 
the  standard,  such  samples  as  pass  certain  ])rcscribc'd  limits  wliich  experi- 
ence has  proved  the.sc  tests  to  be  capable  of  showing  to  an  experienced 
ob.servcr,  and  submitting  the  remainder  to  a  chemical  analysis.  In 
u.sing  such  an  instrument  as  the  lacto.scope  for  this  purpo.se,  the  individual 
clement  is  a  most  important  consideration,  and  the  u.sc  of  this  in.strument 


*  Bcr.  iiber  die  7  Versammlung  bayerischer  Chemiker.     Berlin,  i{ 

t  Analyst,  18,  1893,  P-  272. 

X  ZfiLs.  ofTentl.  Chem.,  7,  1901,  p.  200. 

{  Pharm.  Zcit.,  49,  1904,  p.  608. 

jj  See  Tillmans:  Zcits.  Untcrs.  Nahr.  (It-nuss.,  20,  1910,  ji.  676. 


MILK. 


169 


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New  Jersey  State  Laboratory  of  Hygiene. 

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Massachusetts  State  Board  of  Health. 

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3  S  J  E  hJ  S  J  K  ^J  S  H 

3 

Classification 

according  to 

Total  Solids, 

Per  cent. 

1 
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1  ;o  FOOD   INSTECTION  ^ND   ANAL  YSIS. 

in  the  milk  laboratory  shouUl  be  limited  only  to  a  skillful  operator, 
accustomed  to  interpret  its  results. 

The  method  used  in  the  writer's  laboratory  has  been  to  submit  all 
sami)les  to  the  regular  test  for  solids,  and  such  samples  as  fall  below 
the  legal  standard  for  solids,  are  further  examined  for  fat. 

Total  Solids,  Ash,  and  Fat. — It  is  presupposed  tliat  the  analyst  is 
equij)[)ed  with  a  sulTicient  number  of  platinum  dishes  for  the  number 
of  milk  samples  daily  analyzed.  It  is  a  convenience  to  have  these  dishes 
numbered,  and  instead  of  weighing  each  dish,  to  have  a  system  of  num- 
bered counterweights  (Fig.  51,  .4)  corresponding  to  the  dishes.  The 
counterweights  in  use  by  the  author  for  this  purpose  are  easily  made 
from  half-inch  lead  pipe,  cut  to  the  appropriate  length  and  flattened. 
Each  weight  is  then  carefully  adjusted  to  its  appropriate  dish,  by  trim- 
ming off  the  weight  with  a  knife,  or  by  adding  bits  of  lead  scraps,  if 
necessary,  by  simply  prying  open  in  the  center,  inserting  the  required 
amount  of  scrap,  and  then  closing  by  a  blow  of  the  hammer,  the  weight 
being  plainly  numbered  before  final  adjustment.  A  rack  is  provided 
bv  the  side  of  the  balance-case  (Fig.  51)  with  slits  for  liolding  the  weights 
in  their  appropriate  places.  Such  a  set  of  counterweights  is  not  diflicult 
to  make,  requires  very  little  care  to  keep  in  adjustment,  and  is  an 
immense  labor-saving  device. 

Details  of  Manipulation. — The  following  method  of  examining  large 
numbers  of  milk  samples  is  the  one  in  use  in  the  laborator}'  of  the  Massa- 
chusetts State  Board  of  Health  and  is  given  in  st)me  detail,  as  long  exper- 
ience has  proved  it  to  be  rapid,  easy,  and  accurate. 

From  12  to  20  samples  of  milk  are  conveniently  weighed  out  at  a 
sitting,  the  unopened  sample  cans  or  bottles  being  contained  in  a  tray 
at  the  left  of  the  operator  on  a  low  stand,  another  low  Ltand  and  tray 
being  at  his  right  hand  for  the  cans,  after  removmg  the  weighed  portions, 
and  a  third  tray  on  the  table  at  the  right  of  the  balance  for  the  platinum 
dishes  with  the  weighed  samples.  The  analyst  enters  the  number  of 
the  i)latinum  dish  in  his  note-book,  or  on  a  card,*  in  hne  with  the  number 
of  the  milk  sample,  verifies  the  correctness  of  the  counterweight,  and 
weighs  out  exactly  5  grams  of  the  milk  with  the  aid  of  a  pipette,  after 
first  having  thoroughly  mixed  the  sample.  This  operation  is  repeated 
with  all  the  samples,  the  platinum  dishes  containing  the  weighed  amounts 

*  Specially  ruled  library  cards,  as  shown  on  page  172,  are  useful  for  this  purpose. 


MILK. 


171 


of  each  being  placed  in  succession  on  the  tray,  which  is  finally  carried  to 
the  water-bath  and  the  dishes  transferred  thereto.  The  time  required 
for  weighing  out  1 2  samples  of  milk  in  this  manner  is  about  fifteen  minutes. 
The  water-bath  is  inclosed  in  a  hood,  and  the  sliding  front  is  so  arranged 
that  it  can  be  shut  down  and  locked,  so  that  if  the  analyst  has  to  leave 


Fig.  51. — Set  of  Counterweights  for  Numbered  Platinum  Dishes,    in  a  Convenient  Rack. 

A.  One  of  the  Counterweights. 

B.  Platinum  Dishes. 

the  laboratory'  during  the  three  hours  required  for  the  evaporation,  he 
can  swear  in  court  that  the  samples  could  not  be  tampered  with  during 
his  absence  (see  page  21). 

WTien  ready  to  make  the  second  weighings  for  the  total  solids,  each 
dish  is  taken  from  contact  with  the  steam,  and,  while  still  hot,  is  wiped 
dry  with  a  soft  towel,  till  tv/elve  of  the  dishes  are  placed  on  the  tray, 
which  is  then  taken  to  the  balance.  Experience  has  shown  that  with 
ordinary  rapidity  in  weighing,  twelve  of  the  residues  may  be  thus  dealt 
with  at  a  time  without  the  need  of  a  desiccator,  the  gathering  of  moisture 
during  that  time  being  inappreciable,  excepting  in  very  damp  weather, 
when  a  less  number  of  dishes  should  be  removed  at  a  time  from  the  bath. 
In  making  the   second  weighing,  and  employing  the   counterweight   as 


.^7- 

FOOD 

INSPECTION  AND  ANALYSIS. 

1 

Date . . 

7    ' 

/fO<^. 

Inspector  s 
Nurnbi-r. 

No  of 
J)Uh 

3"  Gra»n^. 

Total 

Solids. 

Uo  of 
Bottle 

Fat. 

Sols-ds   not 
Tat 

"Rema-rHS 

ZG^Z^ 

/ 

.6^6-? 

/Z.9I 

Xi>^^ 

i,6-3  0 

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3.  Z6' 

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26  dt) 

sf 

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2. SO 

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2.6.r^ 

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.  6301 

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2.6. ^-6" 

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9./9 

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1664 

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9.j'9 

6 

(LBf 

6.S^ 

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65-30 

J3.0(> 

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7.1.90 

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2t7Z 

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7393 

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.TzTVtA. 

267^ 

/? 

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1^1.7.0 

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f^ 

GOlO 

)1.02 

267^ 

/9 

.  ^.<ro  1 

9.00 

7 

I.ZO 

7.80 

'       2,65^^ 

^C) 

.  G6-3f 

I3.0G 

1 

■     ' 

Specimen  Card  for  Analyst's  Records  of  Milk  Analyses.     To  be  filed  in  a  cabinet. 


MILK. 


173 


before,  the  exact  net  weight  of  the  residue  is  at  once  ascertained  and 
entered  in  the  appropriate  cohinin  in  the  note-book.  Multiphed  by 
20  it  gives  at  once  the  percentage  of  total  soHds. 

It  is  a  great  saving  of  time  to  weigh  out  exactly  5  grams  as  above 
described.  The  knack  of  quickly  measuring  out  the  exact  amount  is  easily 
acquired  with  practice,  the  5 -gram  weight  is  the  only  one  required  for 
the  operation  with  the  counterweight  of  the  dish,  and  the  laborious  figuring 
of  percentage  due  to  using  a  fraction  above  or  below  the  5  grams  of  milk 
is  avoided. 

Such  samples  as  are  found  to  stand  below  the  standard  of  total  solids 
are  further  examined  for  fat  by  the  Babcock  process  (p.  136),  entering 
the  number  of  the  fat  bottle  in  the  note-book  in  the  appropriate  column, 
and  subsequently  the  percentage  of  fat. 

Ordinarily  the  specific  gravity  is  not  determined,  excepting  in  some 
cases  of  badly  watered  milk,  when,  for  purposes  of  a  check,  it  is  customary 
to  take  the  specific  gravity,  and  calculate  the  solids  from  the  gravity  and 
the  fat  by  Babcock's  formula  (p.  153),  or  the  Richmond  sliding  scale,  and 
compare  the  result  with  the  figure  directly  determined. 

The  ash  is  rarely  weighed  except  in  special  cases. 

The  dishes  containing  the  dry  residues  are  easily  cleaned  by  first 
burning  to  an  ash  and  cooling,  after  w^hich  they  are  treated  successively 
with  strong  nitric  acid,  which  is  poured  from  one  to  another,  the  dishes 
being  rinsed  thoroughly  with  w'ater  and  finally  heated  to  redness. 

A  convenient  device  for  ashing  a  large  number  of  residues  for  purposes 
of  cleaning  the  platinum  dishes  and  for  final  heating  is  the  incinerator 
shown  in  Fig.  52,  made  of  Russia  iron. 


Fig.  52.     A  Sheet-metal  Incinerator,  Specially  Used  for  Ashing  Milk  Residue. 


Added  FOREIGN  Ingredients. —  Passing  over  such  mythical 
adulterants  as  chalk  and  such  rarely  used  substances  as  calves'  brains, 
starch,   glycerin,    sugar,    etc.,    often    discussed    in    manuals  on  milk,  but 


174  FOOD    INSPECTION   AND    ANALYSIS. 

with  few  authentic  instances  of  their  actual  occurrence,  the  commonly 
found  adulterants  may  be  divided  into  two  classes:  coloring  matters  and 
prcscfN'atives. 

The  coloring  matters  almost  exclusively  used  are  annatto,  azo-colors, 
and  caramel.  The  preservatives  commonly  met  with  are  formaldehyde, 
boric  acid,  borax,  and  sodium  bicarbonate.  Rarely  salicylic  and  benzoic 
acids  arc  found. 

Coloring  Matters. — While  it  is  more  often  true  that  an  artificially 
colored  milk  is  also  found  to  be  watered,  the  coloring  being  added  to 
cover  up  evidence  of  the  watering,  it  is  not  uncommon  to  find  added 
coloring  matter  in  milk  above  the  standard.* 

About  95%  of  the  milks  found  colored  in  Massachusetts  show  on 
analysis  the  fraudulent  addition  of  water. 

Statistics  of  the  Massachusetts  State  Board  of  Health  show  that  out 
of  48,000  samples  of  milk  collected  throughout  the  state  and  analyzed 
during  nine  years  (from  1894  to  1902  inclusive)  342  samples  or  0.7% 
were  found  to  contain  foreign  coloring  matter.  Of  these  samples,  about 
67%  contained  annatto,  approximately  30%  were  found  with  an  azo- 
dye,  and  about  3%  with  caramel. 

Until  comparatively  recently  annatto  was  employed  almost  exclu- 
sively for  this  purpose.  Caramel  is  least  desirable  of  all  the  above  colors 
from  the  point  of  view  of  the  milk-dealer,  in  that  it  is  difficult  to  imitate 
with  it  the  natural  color  of  milk,  by  reason  of  the  fact  that  the  caramel 
color  has  too  much  of  the  brown  and  too  little  of  the  yellow  in  its  com- 
position. Annatto,  on  the  other  hand,  when  judiciously  used  and  with 
the  right  dilution,  gives  a  very  rich,  creamy  appearance  to  the  milk,  even 
when  watered,  which  accounts  for  its  popularity  as  a  milk  adulterant. 
Of  late,  however,  the  use  of  one  or  more  of  the  azo-dyes  has  been  on 
the  increase,  and  so  far  as  a  close  imitation  of  the  cream  color  is  con- 
cerned, these  colors  arc  quite  as  efficient  as  annatto. 

Appearance  of  Artificially  Colored  Milk. — The  natural  yellow  color 
of  milk  confines  itself  largely  to  the  cream.  An  artificial  color,  on  the 
contrar)',  is  dissipated  through  the  whole  body  of  the  milk,  so  that  when 
the  cream  has  risen  in  a  milk  thus  colored,  the  underlying  layers,  instead 
of  showing  the  familiar  bluish  tint  of  skimmed  milk,  are  still  distinctly 
tinged  below  the  layer  of  the  fat,  especially  if  any  considerable  quantity 
of  the  color  has  been  used.     This  distinctive  appearance  is  in  itself  often 

*  In  one  instance  an  azo-dye  was  found  by  the  writer  in  a  milk  that  contained  over 
17%  of  total  solids. 


MILK.  175 

sufficient  to  direct  the  attention  of  the  analyst  to  an  artificially  colored 
milk,  in  the  course  of  handling  a  large  number  of  samples. 

Nature  of  Annatto. — Annatto,  arnatto,  or  annotto  is  a  reddish-yellow 
coloring  matter,  derived  from  the  pulp  inclosing  the  seeds  of  the  Bixa 
orellana,  a  shrub  indigenous  to  South  America  and  the  West  Indies. 

A  solution  of  the  coloring  matter  in  weak  alkali  is  the  form  usually 
employed  in  milk. 

Nature  of  "Anilin  Orange." — Of  the  coal-tar  colors  employed  for 
coloring  milk,  the  azo-dyes  are  best  adapted  for  this  purpose  and  arc 
most  used.  A  few  samples  of  these  commercial  "milk  improvers"  have 
fallen  into  the  hands  of  the  Department  of  Food  and  Drug  Inspection 
of  the  Massachusetts  Board  of  Health,  and  have  proved,  on  examination, 
to  be  mixtures  of  two  or  more  members  of  the  diazo-compounds  of  anilin. 
A  mixture  of  what  is  known  to  the  trade  as  "Orange  G"  and  "Fast  Yel- 
low" gives  a  color  which  is  practically  identical  with  one  of  these  prep- 
arations, secured  from  a  milk-dealer  and  formerly  used  by  him. 

For  purposes  of  prosecution  or  otherwise,  it  is  obviously  best  in  our 
present  knowledge  of  the  subject  to  adopt  a  generic  name  such  as  "a 
coal-tar  dye"  or  "anilin  orange"*  to  designate  this  class  of  coloring 
matters  in  milk,  rather  than  to  particularize. 

Systematic  Examination  of  Milk  for  Color. — The  general  scheme 
employed  by  the  writer  for  the  examination  of  milk  samples  suspected 
of  being  colored  is  as  follows:!  About  150  cc.  of  the  milk  are  curdled  by 
the  aid  of  heat  and  acetic  acid,  preferably  in  a  porcelain  casserole  over 
a  Bunsen  flame.  By  the  aid  of  a  stirring-rod,  the  curd  can  nearly  always 
be  gathered  into  one  mass,  w^hich  is  much  the  easiest  method  of  separa- 
tion, the  whey  being  simply  poured  off.  If,  however,  the  curd  is  too 
finely  divided  in  the  whey,  the  separation  is  effected  by  straining  through 
a  sieve  or  colander.  All  of  the  annatto,  or  of  the  coal-tar  dye  present 
in  the  milk  treated  would  be  found  in  the  curd,  and  part  of  the  caramel. 
The  curd,  pressed  free  from  adhering  liquid,  is  picked  apart,  if  necessary, 
and  shaken  with  ether  in  a  corked  flask,  in  which  it  is  allowed  to  soak 
for  several  hours,  or  until  the  fat  has  been  extracted,  and  with  it  the 
annatto.  If  the  milk  is  uncolored,  or  has  been  colored  with  annatto, 
on  pouring  off  the  ether  the  curd  should  be  left  perfectly  white.     If,  on 

*  The  term  "anilin  orange"  has  been  so  commonly  applied  during  the  last  eight  years 
to  any  color  or  mixture  of  colors  of  this  class  in  complaints  in  the  Massachusetts  courts,  as 
to  have  acquired  a  special  meaning  perfectly  well  understood. 

t  Jour.  Am.  Chem.  Soc,  22,  1900,  p.  207. 


176  FOOD  INSPECTION  AND   .ANALYSIS. 

ihe  other  kind,  anilin  orange  or  caramel  has  been  used,  after  pouring 
oflF  the  ether  the  curd  will  be  colored  more  or  less  deeply,  depending  on 
the  amount  of  color  employed.  In  other  words,  of  the  three  colors, 
annatto,  caramel,  and  anilin  orange,  the  annatto  only  is  extracted  by 
ether.  If  caramel  has  been  used,  the  curd  will  h.ave  a  brown  color  at 
this  stage;  if  anilin  orange,  the  color  of  the  curd  will  be  a  more  or  less 
bright  orange. 

Tests  for  Annatto. — The  ether  extract,  containing  the  fat  and  the 
annatto,  if  present,  is  eva])orated  on  the  waterd^ath,  the  residue  is  made 
alkaline  with  sodium  hydroxide,  ami  poured  upon  a  small,  wet  filler, 
which  will  hold  back  the  fat,  and,  as  the  filtrate  passes  through,  will  allow 
the  annatto,  if  present,  to  permeate  the  pores  of  the  filter.  On  washing 
off  the  fat  gently  under  the  w^ater-tap,  all  the  annatto  of  the  milk  used 
for  the  test  will  be  found  to  have  ])een  concentrated  on  the  fdter,  giving 
it  an  orange  color,  tolerably  permanent  and  varying  in  depth  with  the 
amount  of  annatto  present.  As  a  conhrmatory  test  for  annatto,  stan- 
nous chloride  may  after\vard  be  applied  to  the  colored  fiUer,  producing 
the  characteristic  i)ink  color. 

Tests  for  Caramel. — The  fat-freed  curd,  if  colored  after  the  ether 
has  been  poured  off,  is  examined  further  for  caramel  or  anihn  orange, 
by  placing  a  portion  of  the  curd  in  a  test-tul)c,  and  shaking  vigorously 
with  concentrated  hydrochloric  acid.  If  the  color  is  caramel,  the  acid 
solution  of  the  colored  curd  will  gradually  turn  a  deep  blue  on  shaking, 
as  would  also  the  white  fat-free  curd  of  an  uncolored  milk,  the  blue  colora- 
tion being  formed  in  a  very  few  minutes,  if  the  fat  has  been  thoroughly 
extracted  from  the  curd;  indeed,  it  seems  to  be  absolutely  essential  for 
the  prompt  formation  of  the  blue  color  in  the  acid  solution  that  the  curd 
be  free  from  fat.  Gentle-  heat  will  hasten  the  reaction.  It  should  be  noted 
that  it  is  only  when  the  blue  coloration  of  the  acid  occurs  in  connection 
with  a  colored  curd  that  caramel  is  to  be  suspected,  and  if  much  caramel 
be  present,  the  coloration  of  the  acid  solution  will  be  a  brownish  blue.  If 
the  above  treatment  indicates  caramel,  it  would  be  well  to  confirm  its 
presence,  by  testing  a  separate  portion  of  the  milk  in  the  following  manner.* 

About  a  gill  of  the  milk  is  curdled  by  adding  to  it  as  much  strong 
alcohol.  The  whey  is  filtered  off,  and  a  small  quantity  of  subacetale  of 
lead  is  added  to  it.  The  precipitate  thus  produced  is  collected  uj-on  a 
small  filter,  which  is  then  dried  in  a  place  free  from  hydrogen  sulphide. 
A  pure  milk  thus  treated  yields  upon  the  filter-paper  a  residue  which  is 

♦See  Nineteenth  Annual  Rejxjrl  of  the  Mass.  State  Board  of  Health  (1887),  p.  183. 


MILK. 


177 


either  wholly  white,  or  at  most  of  a  pale  straw  color,  while  in  the  presence 
of  caramel,  the  residue  is  a  more  or  less  dark-brown  color,  according  to  the 
amount  of  caramel  used. 

Tests  for  Coal-tar  Dye. — H  tlie  milk  has  been  colored  with  an  azo-dye, 
the  colored  curd,  on  applying  the  strong  hydrochloric  acid  in  the  test-tube, 
will  immediately  turn  pink.  If  a  large  amount  of  the  anilin  dye  has  been 
used  in  the  milk,  the  curd  will  sometimes  show  the  pink  coloration  when 
hydrochloric  acid  is  applied  directly  to  it,  before  treatment  with  ether, 
but  the  color  reaction  with  the  fat-free  curd  is  very  delicate  and  unmistak- 
able.* 

Lythgocf  has  shown  that  the  amount  of  anilin  orange  ordinarily 
present  in  a  milk  for  the  purposes  of  coloring  can  be  detected  by  adding 
directly  to  say  10  cc.  of  the  sample  an  equal  quantity  of  strong  hydro- 
chloric acid  and  mixing,  whereupon  the  pink  coloration  is  produced,  if 
the  dye  is  present  in  more  than  minute  traces.  The  test  is  more  deli- 
cate if  carried  out  in  a  white  porcelain  dish.  It  had  best  be  used  as  a 
preliminary  test  only,  and  confirmed  by  a  subsequent  test  on  the  fat-free 
curd  as  above. 

SUMMARY  OP^  SCHEME  FOR  COLOR  ANALYSIS. 

Curdle  150  cc.  milk  in  casserole  with  heat  and  acetic  acid.  Gather  curd  in  one  mass. 
Pour  off  whey,  or  strain,  if  curd  is  finely  divided.  Macerate  curd  with  ether  in  corked  flask. 
Pour  off  etheV. 


Ether  Extract. 

I^vaporate  off  ether,  treat  residue  with 
NaOH  and  pour  on  wetted  filter.  After 
the  solution  has  passed  through,  wash  off 
fat  and  dry  filter,  which  if  colored  orange, 
indicates  presence  of  annatto.  (Confirm 
by  SnCl,.) 


Extracted  Curd. 

(i)  7/  Colorless. — Indicates  presence  of 
no  foreign  color  other  than  in  ether  extract. 

(2)  //  Orange  or  Brownish. — Indicates 
presence  of  anilin  orange  or  caramel. 
Shake  curd  in  test-tube  with  concentrated 
hydrochloric  acid. 


If  solution  gradu- 
ally turns  blue,  in- 
dicative of  caramel. 
(Confirm  by  testing 
for  caramel  in  whey 
of   original    milk.) 


If  orange  curd  im- 
medialely  turns  pink, 
indicative  of  anilin 
orange. 


PRESERVATIVES.— In  most  states  and  municipahties  where  pure  food 
laws    are    in    force    preservatives    in    milk    are  regarded  as  adulterants 

*  Occasional  samples  of  milk  colored  with  a  coal-tar  dye  of  a  different  class  from  those 
already  described  have  recently  been  found  in  Massachusetts.  In  these  cases  the  color 
of  the  separated  fat-free  curd  does  not  change  when  treated  with  hydrochloric  acid.  The 
color  of  the  curd  is,  however,  very  marked,  being  deep  orange,  bordering  on  the  pink. 

t  Jour.  Am.  Chem.  Soc,  22,  1900,  p.  813. 


i/S  FOOD  INSPECTION  AND  ANALYSIS. 

Their  use,  however,  seems  to  be  on  the  decrease.  Of  6,i86  samples  of  milk 
examined  by  the  Massachusetts  Stale  Bt)ar(l  of  Health  during  one  year 
(1S99)  71  samples,  or  1.2%,  were  found  to  contain  a  preservative.  Of 
these  55  were  found  with  formaldehyde,  13  containing  boric  acid,  borax, 
or  a  mixture  of  the  two,  and  3  contained  carbonate  of  soda. 

Comparative  tests  have  been  made  in  the  writer's  laboratory  of  the 
keeping  qualities  of  these  cc)mmt)nly  used  milk  preservatives,  when  present 
in  varying  strength,  the  milk  being  kept  during  the  experiment  at  the  tem- 
perature of  the  room,  which  at  that  season  of  the  year  (February)  was  about 
20°  C*  The  preservatives  were  added  about  five  hours  after  milking. 
The  samples  were  titrated  for  acidity  each  morning,  the  acidity  being 
expressed  by  the  number  of  cubic  centimeters  of  decinormal  sodium 
hydroxide  necessary  to  neutralize  5  cc.  of  the  milk. 

The  proportions  of  preservatives  used  in  this  experiment,  as  shown  in 
the  table  on  page  179,  were  intended  to  cover  a  wide  range,  from  the 
weakest  that  could  aid  in  preserving  the  milk  up  to  a  strength  limited 
only  by  being  perceptible  to  the  taste.  The  tal)le  opposite  shows  the 
results. 

Formaldehyde,  the  most  commonly  used  preservative  for  milk,  is  sold  to 
the  trade  under  various  names,  such  as  "Preservaline,"  "Freezine,"  "Ice- 
line,"  etc.,  all  being  dilute  aqueous  solutions  of  formaldehyde,  containing 
from  2  to  6  per  cent  of  the  gas,  being  nearly  always  diluted  from  the  40% 
solution  known  as  formahn.  These  preparations  are  usually  accompanied 
by  directions,  which  specify  the  amount  to  be  used,  varying  from  a  table- 
spoonful  of  the  solution  in  5  to  10  gallons  of  the  milk.  It  is  commonly 
used  in  the  strength  of  i  part  of  the  gas  in  20,000,  and  rarely  less  than 
I  part  in  50,000.  The  antiseptic  power  of  formaldehyde  increases  in  a 
marked  degree  as  the  strength  of  the  preservative  is  increased.  Milk 
treated  with  i  .part  in  10,000,  for  instance,  according  to  the  table  was 
found  to  keep  sweet  5  J  days.  In  the  strength  of  1  part  to  5000,  the  milk 
did  not  curdle  for  \o\  days,  while  i  part  of  formaldehyde  to  2500  parts  of 
milk  kept  the  milk  from  curdling  for  55  days,  the  acidity  uj)  to  that  time 
being  nearly  normal. 

Formaldehyde  is  thus  shown  to  be  decidedly  the  most  efficient  of  all 
milk  preservatives,  besides  being  inexpensive  and  convenient  to  use. 

Whether  the  growth  of  other  bacteria  than  those  that  produce  lactic 
fermentation  is  inhibited  by  formaldehyde  in  milk  is  not  definitely  settled. 
The  ( laim  has  been  made  that  pathogenic  varieties  are  destroyed  by  its  use. 
♦Thirty-first  Annual  Rcix)rt  Mass.  State  Board  of  Health,  1899,  p.  611. 


MILK. 


179 


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I  So  FOOD  INSPECTION  AND  ANALYSIS. 

Whether  or  not  formaldehyde  in  milk  is  harmful  to  processes  of  diges- 
tion, when  present  in  the  amount  commonly  used,  is  still  an  open  question.* 

Carbonate  and  Bicarbonate  of  Soda. — These  substances  are  occasion- 
ally used  in  milk,  though,  as  the  above  table  shows,  they  possess  little 
or  no  value  as  milk  preservatives.  They  do,  however,  serve  to  neutralize 
the  acidity  of  slightly  soured  milk  and  to  postpone  the  time  of  actual 
curdling. 

Salicylic  and  Benzoic  Acids,  in  view  of  the  much  more  efhcient  anti- 
septics at  hand,  are  now  rarely  used  as  milk  preservatives,  though  the 
analyst  should  be  on  the  outlook  for  them.  Salicylic  acid  is  a  poor  milk 
prescrv'ative,  in  view  of  the  fact  that  it  affects  the  taste  of  the  milk,  when 
present  in  sufficient  quantity,  to  be  of  service. 

Detection  of  Formaldehyde. — Hydrochloric  Acid  Test.-\ — Commercial 
hydrochloric  acid  (specific  gravity  1.2)  containing  2  cc.  of  10%  ferric 
chloride  per  liter  is  used  as  a  reagent.  Add  10  cc.  of  the  acid  reagent  to  an 
equal  volume  of  milk  in  a  porcelain  casserole,  and  heat  slowly  over  the 
free  flame  nearly  to  boiling,  holding  the  casserole  by  the  handle,  and  giving 
it  a  rotar}'  motion  while  heating  to  break  up  the  curd.  The  presence  of 
formaldehyde  is  indicated  by  a  violet  coloration,  varying  in  depth  with 
the  amount  present.  In  the  absence  of  formaldehyde,  the  solution  slowly 
turns  brown.  By  this  test  i  part  of  formaldehyde  in  250,000  parts  of 
milk  is  readily  detected  before  the  milk  sours.  After  souring,  the  limit 
of  delicacy  proves  to  be  about  i  part  in  50,000. 

Various  aldehydes,  when  introduced  into  milk,  give  color  reactions 
under  the  above  treatment,  but  formaldehyde  alone  gives  the  violet  colora- 
tion, which  is  perfectly  distinguishable  and  unmistakable. 

Hehncr^s  Sulphuric  Acid  Test. — To  5  to  10  cc.  of  milk  in  a  wide  test- 
tube  add  about  half  the  volume  of  concentrated  commercial  sulphuric 
acidjj  pouring  the  acid  carefully  down  the  side  of  the  tube,  so  that  it  forms 
a  layer  at  the  bottom  without  mixing  with  the  milk.     A  violet  zone  at 


*  Milk -dealers  are  led  to  believe,  by  artful  dealers  in  preservative  preparations,  that  the 
chemist  cannot  detect  them.  The  manufacturer  of  a  widely  used  preservative,  a  weak  solu- 
tion of  formaldehyde,  issues  an  attractive  pamphlet  in  which  he  makes  the  following  remark- 
able claims: 

"It  is  not  an  adulterant.  It  immediately  evaporates,  so  that  no  trace  of  it  can  be  found 
as  soon  as  it  has  rendered  all  the  bacteria  inert.  No  chemical  analysis  can  prove  its  pres- 
ence in  milk,  quantitatively  or  otherwise." 

t  .\nnual  Report  Mass.  .State  Board  of  Health,  1897,  p.  558;  also  1899,  p.  699. 

X  The  coloration  produced  seems  to  depend  on  the  presence  of  iron  salts  in  the  acid, 
hence  the  use  of  commercial  acid  is  recommended.  If  only  pure  acid  is  available,  a  little 
ferric  chloride  should  be  added 


MILK.  iSl 

the  junction  of  ihc  two  liquids  indicates  formaldehyde.  This  test  may 
be  combined  with  the  Babcock  test  for  fat,  noting  whether  a  violet 
color  forms  on  addition  of  the  commercial  sulphuric  acid  to  the  milk 
in  the  test  bottle. 

Confirmatory  Tests  with  Distilled  Milk. — If  it  is  desired  to  confirm 
the  above  tests  by  further  evidence,  loo  to  200  cc.  of  the  milk  sample 
are  subjected  to  distillation,  anv^  the  first  20  cc.  of  the  distillate  are  used 
for  testing. 

(i)  To  a  few  drops  of  this  distillate  in  a  test-tube  add  a  drop  of  Schiff's 
reagent.*  In  presence  of  any  aldehyde,  a  pink  coloration  will  soon  be 
perceptible,  deepening  in  intensity  on  standing. 

(2)  Add  to  5  cc.  of  the  milk  distillate  a  few  drops  of  a  1%  aqueous 
solution  of  resorcin  or  phenol,  and  proceed  as  directed  on  page  826  (pre- 
servatives). The  crimson  color  indicates  formaldehyde,  and  not  other 
aldehydes. 

(3)  Use  I  or  2  cc.  of  the  milk  distillate  and  apply  the  phenylhydrazine 
test,  page  826. 

(4)  A  small  amount  of  the  distillate  from  milk  (which  prior  to  distilling 
is  acidified  slightly  with  sulphuric  acil  to  fix  any  free  ammonia)  is  treated 
with  a  few  drops  of  Nessler's  reagent. f  Traces  of  formaldehyde  produce 
a  yellow  coloration,  while  if  considerable  formaldehyde  be  present,  the 
color  darkens  on  standing  and  a  grayish  precipitate  may  be  formed. 

Determination  of  Formaldehyde  in  Milk.| — To  ico  cc.  of  milk  add 
I  cc.  of  1:3  sulphuric  acid  and  subject  to  distillation  in  a  500-cc.  Kjeldahl 
nitrogen-flask,  using  a  low  circular  evaporating  burner  to  avoid  frothing. 
According  to  Smith,  the  first  20  cc.  of  the  distillate,  or  one-fifth  the 
original  volume,  contain  ver}^  nearly  one-third  of  the  total  formaldehyde. 
Collect  20  cc.  of  the  distillate  and  determine  the  formaldehyde  therein 
by  the  potassium  cyanide  method,  as  follows :  § 

Treat  10  cc.  of  tenth-normal  silver  nitrate  with  6  drops  of  50%  nitric 
acid  m  a  50-cc.  flask,  add  10  cc.  of  a  solution  of  potassium  cyanide  con- 
taining 3.1  grams  of  KCN  in  500  cc.  of  w'ater,  and  make  up  to  the  50-cc. 
mark.  Shake,  filter,  and  titrate  25  cc.  of  the  filtrate  with  tenth-normal 
ammonium  sulphocyanate,||  using  ferric  chloride  as  an  indicator. 

*  Table  of  reagents,  No.  226. 

t  Table  of  reagents,  No.  187. 

J  Smith,  Jour.  Am.  Chem.  Soc.,  25,  1903,  pp.  1032  and  1037. 

§  Zeits.  anal.  Chem.,  36,  pp.  18-24. 

(I  Theoretically  7.6  grams  per  liter.  On  account  of  the  deliquescent  nature  of  the  salt 
weigh  out  8  grams,  make  up  to  a  liter,  and  titrate  against  tenth-normal  sihcr  nitrate  fo: 
its  exact  value,  using  ferric  chloride  as  an  indicator.  Sutton,  Volumetric  Analysis,  8th  Ed, 
P-  155- 


iS2  FOOD  INSPECTION  AND  ANALYSIS. 

Acidify  another  portion  of  lo  cc.  of  tenth-normal  silver  nitrate  with 
nitric  acid,  add  lo  cc.  of  the  potassium  cyanide  sohition  to  which  the 
above  20  cc.  of  the  formaldehyde  distillate  has  been  added.  Make  up 
the  whole  to  50  cc,  filter  and  titrate  as  before  25  cc.  of  the  filtrate  with 
tenth-nc^rmal  ammonium  sulphocyanate  for  the  excess  of  silver. 

The  amount  of  potassium  cyanide  used  up  by  the  formaldehyde,  in 
terms  of  tenth-normal  ammonium  sulphocyanate,  i^  found  by  multiplying 
by  two  the  dilTerence  between  the  two  results,  and  the  total  formal- 
dehyde is  calculated  by  mulliplying  by  3  the  aniount  found  in  ihe  20  cc. 
of  distillate. 

The  reaction  that  takes  place  between  the  formaldehyde  and  the 
potassium  cyanide  probably  results  in  the  formation  of  an  addition 
product  as  follows: 

CH2O+ KCN  =  KO.CHXN. 

Detection  of  Boric  Acid. — This  is  best  accomplished  by  the  turmeric- 
paper  test  applied  either  directly  to  the  milk  or  to  the  ash  (page  823).  In 
the  former  case  10  cc.  of  milk  are  thoroughly  mixerl  with  6  drops  of 
concentrated  hydrochloric  acid,  after  which  the  tumeric  paper  is  mois- 
tened witli  the  mixture  and  dried. 

Determination  of  Boric  Acid. — Use  the  method  of  Thompson.*  Add 
10  cc.  of  a  1:1  solution  of  sodium  hydroxide  to  100  cc.  of  the  milk,  evaporate 
to  dryness  in  a  platinum  dish,  and  proceed  as  described  on  page  829. 

Detection  of  Carbonate  and  Bicarbonate  of  Soda.  —  The  addition 
of  carbonates  is  manifest  by  the  effervescence  caused  by  treating  the 
milk-ash  with  acid.  EfTer\'escence  in  the  milk-ash  is  quite  perceptible, 
when  as  much  as  0.05%  of  sodium  carbonate  is  present. 

Schmidt's  method  of  detecting  sodium  carbonate  or  bicarbonate, 
when  i^rescnt  to  the  extent  of  0.1%  or  more,  is  as  follows:  Ten  cc.  of 
milk  are  mixed  with  an  equal  volume  of  alcohol,  and  a  few  drops  of  a 
1%  solution  of  rosolic  acid  are  added.  If  carbonate  is  present,  a  rose- 
red  color  will  be  produced,  while  pure  milk  shows  a  brownish-yellow 
coloration.  The  susfK-cted  sample  thus  treated  should  be  compared 
with  a  similarly  treated  sample  of  pure  milk  at  the  same  time. 

Detection  of  Benzoic  Acid. — Shake  5  cc.  of  hydrochloric  acid  with 
50  cc.  of  the  milk  in  a  llask.  Then  add  150  cc.  of  ether,  cork  the  flask 
and  shake  well.  Break  up  the  emulsion  which  forms  by  the  aid  of  a 
centrifuge,  or,  in  the  absence  of  a  centrifuge,  extract  the  curdled  milk 
by  gently  shaking  with  successive  portions  of  ether,  avoiding  the  forma- 

*  Jour.  Soc.  Chem.  Ind.,  12,  p.  432. 


MILK. 


183 


\ 


tion  of  an  emulsion.  A  volume  of  elher  largely  in  excess  over  that  of 
the  curdled  milk  has  been  found  to  be  less  apt  to  emulsionize.*  Transfer 
the  ether  extract  to  a  separatory  funnel,  and  separate  the  benzoic  acid 
from  the  fat  by  shaking  out  with  dilute  ammonia,  which  takes  out  the 
former  as  ammonium  ])enz()ate.  Evaporate  the  ammonia  solution  in 
a  dish  over  the  water-bath  till  all  free  ammonia  has  disappeared,  but 
before  getting  to  dryness,  add  a  few  drops  of  ferric  chloride  reagent. 

The  characteristic  flesh-colored  precipitate  indicates  benzoic  acid. 
Care  should  be  taken  not  to  add  the  ferric  chloride  till  all  the  ammonia 
has  been  driven  off,  otherwise  a  precipitate  of  ferric  hydrate  is  formed. 

Detection  of  Salicylic  Acid. — (i)  To  50  cc.  of  the  milk  add  i  cc.  of 
acid  nitrate  of  mercury  reagent  (p.  147),  shake  and  filter.  The  filtrate, 
which  should  be  perfectly  clear,  is  then  shaken  with  ether  in  a  separatory 
funnel,  the  ether  extract  evaporated  to  dryness,  and  a  drop  of  ferric  chloride 
reagent  applied.  If  salicylic  acid  be  present,  a  violet  color  will  be  pro- 
duced. In  carrying  out  the  test  it  should  be  noted  that  a  small  portion 
only  of  the  salicylic  acid  is  in  the  filtered  whey,  the  larger  part  being  left 
in  the  curd.  The  color  test  is,  however,  so  delicate  as  to  show  its  presence, 
when  an  appreciable  amount  is  used. 

(2)  Proceed  exactly  as  directed  for  benzoic  acid  (p.  182).  On  apply- 
ing the  ferric  chloride  to  the  final  solution,  after  evaporation  of  the 
ammonia,  a  violet  color  shows  the  presence  of  salicylic  acid. 

Routine  Inspection  of  Milk  for  Preservatives. — It  was  the  writer's 
custom  in  Alassachusetts  to  examine  all  the  samples  of  milk  collected 
during  the  months  of  June,  July,  August,  and  September  for  the  com- 
monly used  preservatives,  in  addition  to  the  regular  analysis  for  total 
solids  and  fat.  The  number  of  samples  thus  examined  amounted  to 
upwards  of  500  per  month,  varying  from  10  to  60  per  day.  The  results 
of  such  an  examination  during  four  years  are  thus  shown:  f 
PRESERVATIVES  IN  MILK. 


Year. 

Samples 
Examined. 

Number 
containing 

Form- 
aldehyde. 

Per  Cent 
containing 

Form- 
aldehyde. 

Number 

containing 

Boric 

Acid. 

Per  Cent 

containing 

Boric 

Acid. 

Number 
containing 
Carbonate. 

Total 
containing 
Preserva- 
tive. 

1898 

1046 
210^ 
2018 
2154 
1934 

26 

55 
61 
42 
29 

2-5 
2.6 

3-0 
1.9 

1-5 

II 

13 

6 

12 

14 

1.0 
0.6 
o"3 
0-5 
0.7 

4 
3 

41 
71 
67 
54 
43 

1800 

1000 

IQOI 

1002 

Totals.  .  .  . 

9257 

213 

2-3 

56 

0.6 

7 

376 

*  When  this  process  is  used  the  ether  may  readily  be  recovered  by  distillation, 
t  An.  Rep.  Mass.  State  Board  of  Health,  1902,  p.  474;  Analyst's  Reprint,  p.  22. 


lS4  hOOD  INSPECTION  yIND  y4NALYSlS. 

Such  a  system  by  no  means  involves  a  large  amount  of  time  or  labor, 
and  is  really  essential  before  passing  judgment  upon  the  purity  cf  the 
milk,  since,  unlike  added  color,  there  is  nothing  in  the  physical  appear- 
ance of  the  milk  to  suggest  the  presence  of  preservatives,  nor  are  they 
rendered  apparent  by  the  taste,  if  skilfully  used. 

The  methods  employed  are  carried  out  as  follows:  * 

(i)  Formaldehyde. — After  having  been  examined  for  total  sohds 
and  fat,  the  milk  samples  are  arranged  in  order  in  their  original  con- 
tainers, and  about  lo  cc.  of  each  sample  arc  poured  into  a  casserole  and 
tested  in  succession  by  means  of  the  hydrochloric  acid  and  ferric  chloride 
test  (p.  i8o).  A  large  stock  bottle,  which  may  be  fitted  with  a  siphon 
if  desired,  is  kept  on  hand  containing  the  hydrochloric  acid  reagent. 
Less  than  one  minute  is  required  in  making  the  formaldehyde  test  for 
each  sample. 

2.  Carbonate  and  Boric  Acid. — These  tests  have  been  so  simplified 
as  to  be,  as  it  were,  a  side  issue  in  the  process  of  cleaning  the  platinum 
dishes  used  for  the  determination  of  total  sohds.  The  various  residues 
from  the  total  solids  are  burnt  to  an  ash  in  the  original  numbered  dishes 
in  succession,  these  dishes,  after  incineration,  being  arranged  side  by  side 
on  a  fiat  tray.  By  means  of  a  pipette,  one  or  two  drops  of  dilute  hydro- 
chloric acid  are  introduced  into  each  dish  in  succession,  noting  at  the 
time  any  eflervescence  that  may  ensue,  which  is  in  itself  an  indication 
of  sodium  carbonate.  After  every  milk  ash  has  been  acidulated,  a  few 
cubic  centimeters  of  water  are  added  to  each  dish  by  means  of  a  wash- 
bottle,  the  dissolving  of  the  ash  being  hastened  by  giving  a  rotar}'  motion 
to  the  tray  containing  the  dishes.  A  strip  of  turmeric-paper  is  then  allowed 
to  soak  for  a  minute  or  so  in  each  dish,  after  which  it  is  withdrawn  from 
contact  with  the  solution  and  allowed  to  adhere  to  the  side  of  the  dish 
above  the  liquid,  where  it  remains  until  dry.  If  the  paper  when  dry 
is  of  a  deep  cherry-red  color,  turning  a  dark  olive  when  treated  with 
dilute  alkali,  the  presence  of  boric  acid  is  assured.  These  methods 
are,  of  course,  preliminary  tests  for  quickly  singling  out  the  preserved 
samples.  Such  confirmatory  tests  as  are  desired  may  in  all  cases  be 
employed. 

Another  method  of  dr)'ing  the  strips  outside  the  dishes  is  as  follows: 

In  a  part  of  the  laboratory  free  from  dust,  two  long  sections  of  glass 
rod  or  tubing    are  placed   in   jjarallcl  lines  over  a  strip  of  filter-paper, 

*  Lcarh,  Analyst,  XXVI,  p.  289.  An.  Rep.  Mass.  State  Board  of  Health,  1901,  p.  447 
Food  and  Drug  Reprint,  p.  27. 


MILK.  185 

with  numbers  marked  on  the  paper  at  close  intervals  corresponding  to 
the  numbers  of  the  ])latinum  dishes.  The  strips  of  turmeric-paper,  after 
soaking,  are  removed  from  the  dishes  and  placed  across  the  glass  tubes, 
over  the  numbers  corresponding  to  those  of  the  dishes  from  which  they 
were  taken.  Here  they  are  rJlowed  to  stand  till  dry,  being  kept  in  posi- 
tion by  a  third  section  of  tube  or  rod  placed  over  them.  When  dry,  the 
color  of  the  turmeric  strips  will  indicate  whether  or  not  boric  acid  is  present, 
and  also  the  position  will  show  in  what  sample  to  look  for  it' 

VARIOUS  ADULTERANTS. — Cane  Sugar  is  said  to  be  used  to  increase 
the  total  sohds  of  milk,  but  if  present  to  any  marked  degree,  it  could 
hardly  fail  of  detection  by  reason  of  the  sweet  taste  imparted  to  the  milk. 
Cane  sugar  in  milk  may  be  detected  *  by  boiling  5  to  10  cc.  of  the  sample 
with  about  o.i  gram  of  resorcin  and  a  few  drops  of  hydrochloric  acid  for 
a  few  minutes.  In  the  presence  of  cane  sugar,  a  rose-red  color  is  pro- 
duced. 

According  to  Richmond,  cane  sugar  may  be  estimated  by  first  ascer- 
taining the  total  polarization  of  the  sample  as  in  the  estimation  of  milk 
sugar  (p.  147).  The  milk  sugar  is  then  determined  by  Fehling's  solution 
(pp.  149  to  150)  either  volumetrically  or  gravimetrically.  The  difference 
between  the  anhydrous  milk  sugar  found  by  the  latter,  or  Fehling  method, 
and  that  calculated  by  dividing  the  polarization  by  1.217  will  give  the 
percentage  of  cane  sugar  present. 

Cotton's  t  method  of  detecting  cane  sugar,  when  present  to  the  extent 
of  0.1%,  consists  in  mixing  in  a  test-tube  10  cc.  of  the  suspected  milk 
with  0.5  gram  of  powdered  ammonium  molybdate,  and  adding  to  the 
mixture  10  cc.  of  dilute  hydrochloric  acid  (i  to  10).  Ten  cc.  of  milk  of 
known  purity,  or  10  cc.  of  a  6%  solution  of  milk  sugar  are  similarly  treated 
by  way  of  comparison.  Both  tubes  are  placed  in  a  water-bath  and 
the  temperature  gradually  raised  to  80°  C.  If  cane  sugar  is  present,  an 
intense  blue  coloration  is  produced,  while  the  genuine  milk  or  the  solution 
of  milk  sugar  remains  unchanged  at  the  temperature  of  80°.  If  the  tem- 
perature is  raised  to  the  boiling-point,  however,  the  pure  milk  or  milk 
sugar  solution  may  also  turn  blue. 

Detection  of  Starch  in  Milk. — A  small  quantity  of  milk  is  heated  in 
a  test-tube  to  boiling,  cooled,  and  a  drop  of  iodine  in  potassium  iodide 
added.    A  blue  coloration  indicates  starch. 

*  Richards  and  Woodman,  Air,  Water,  and  Food,  p.  166. 
t  Abs.  Analyst,  1898,  p.  37. 


lS6  FOOD  ISSPHCTION  AND  ANALYSIS. 

Condensed  Skimmed  Milk  as  an  Adulterant. — The  use  of  condensed 
unsweetened  skimmed  milk  \o  mise  the  solids  of  a  skimmed  or  watered 
milk  above  the  standard  has  been  noted  in  ^Fassachusetts.  This  sophis- 
tication is  rendered  apparent  by  the  abnormally  high  solids  not  fat  of 
the  sample,  which  in  some  instances  have  exceeded  ii%.  A  solid  not  fat 
in  excess  of  io%  is  suspicious  of  this  form  of  adulteration.  By  fixing  a 
legal  standard  for  both  fat  and  solids  not  fat,  such  tampering  with  milk 
may  readily  be  checked. 

Analysis  of  Sour  Milk. — It  occasionally  becomes  necessary  for  the 
analyst  to  deal  with  samples  of  sour  milk,  especially  in  the  summer-time, 
when  the  milk  has  been  brought  from  a  long  distance.  While  the  process 
of  lactic  fermentation  results  in  the  formation  of  traces  of  volatile  acids, 
unless  the  sample  has  become  so  badly  curdled  as  to  render  an  even  homo- 
geneous mixture  of  the  various  parts  impossible,  a  fair  determination  of 
the  solids  and  fat  can  readily  be  made.  Experience  has  proved  that, 
excepting  in  instances  of  milk  so  badly  soured  as  to  have  become  actually 
putrid,  the  analysis  of  sour  milk,  if  carefully  made,  should  not  differ 
materially  from  that  of  the  same  milk  before  souring. 

Care  must  be  taken  to  secure  an  even  emulsion  of  the  curd  and  whey. 
This  may  sometimes  be  accomplished  by  repeatedly  pouring  the  sample 
back  and  forth  from  one  container  to  another.  Again,  it  is  sometimes 
necessar)'  to  use  an  egg-beater  of  the  spiral  wire  pattern,  which  preferably 
should  easily  fit  the  can  or  milk-container.  Unless  a  fine,  even  emulsion 
can  be  secured,  it  is  impossible  to  make  a  satisfactory  analysis  of  sour 
milk.     With  such  an  emulsion  results  can  be  relied  on. 

In  measuring  portions  of  the  thoroughly  mixed  sample  of  sour  milk 
for  analysis,  a  pipette  should  be  used  having  a  large  opening.* 


CONDENSED   MILK. 

Canned  condensed  milk  has  become  a  very  important  article  of  food, 
its  use  having  increased  considerably  during  the  last  few  years.  The 
universally  accepted  meaning  of  the  term  "condensed  milk"  in  this  country 
is  milk  both  condensed  and  preserved  with  cane  sugar,  being  what  is  com- 
monly known  in  England  as  "preserved  milk."  The  unsweetened  variety 
is  more  often  termed  '  *  evaporated  cream  "  and  sold  as  such.     It  is,  however, 

*  A  pipette  open  to  the  full  size  of  the  tube  is  convenient  for  this  work. 


MILK. 


187 


as  found  on  the  market  usually  nothing  better  than  condensed  ordinary 
milk,  having  no  added  sugar,  and  has  generally  no  resemblance  in  com- 
position to  cream  other  than  in  consistency. 

Condensed  milk  is  usually  prepared  by  boihng  milk  in  vacuum-pans 
under  diminished  ])rcssure  to  the  proper  degree  of  concentration.  Up- 
wards of  350  samj)les  of  sweetened  condensed  milk  have  been  analyzed 
in  full  in  the  laboratory  of  the  Massachusetts  State  Board  of  Health  in  the 
course  of  eight  years,  representing  no  less  than  no  brands,  together  with 
about  30  samples  (representing  8  brands)  of  the  unsweetened  variety. 

In  view  of  the  fact  that  a  considerable  number  of  the  condensed-milk 
samples  are  shown  by  their  analysis  to  have  been  produced  from  skimmed 
milk,  the  fat  content  in  the  samples  analyzed  varying  from  a  mere  trace 
to  12%,  it  is  obvious  that  the  typical  composition  of  condensed  milk  could 
not  fairly  be  shown  by  giving  maximum,  minimum,  and  mean  results 
from  the  entire  tabulated  series,  nor  would  it  be  possible  to  draw  a  hard- 
and-fast  line  excluding  certain  samples  known  to  be  adulterated  in  making 
up  the  averages.  It  has  therefore  been  thought  best  to  select  a  few  typical 
brands  and  give  their  analyses  in  full. 


COMPOSITION  OF  SWEETENED  CONDENSED  MILK. 


Points  to  be  Noted. 


Total 

Solids, 

Per 

Cent. 


Water 
Per 
Cent. 


Milk 

Solids, 

Per 

Cent. 


Cane 

Sugar, 

Per 

Cent. 


Milk 

Sugar, 

Per 

Cent. 


Pro- 
teins, 

Per 
Cent. 


Fat, 

Per 

Cent. 


I  Fat  in 

Ash,    I  0"gJ- 
Per        nal 
Cent.     Milk, 
I     Per 
Cent. 


High  in   fat,  much   added 

sugar 

High  fat,  low  milk  sugar.  .  . 
Low  fat,  high  milk  sugar; 

low  proteins 

Normal    constituents 

throughout* 

Condensed   from   skimmed 

milk 

Condensed    from    centrifu- 

gally  skimmed  milk 


7P.I7 
68.70 

69.30 

74.29 

69.30 

69.06 


20.83 
32-30 

30.70 

25.71 

30.70 

30.94 


31-32 
30.27 

31.83 

32.37 
29- IS 
25.88 


47.8s 
38.43 

37-47 

41  .92 

40.15 

43-18 


9-S7 
6.38 


16.7s 
11.97 


7-95 
10.70 

6.34 
8.46 

12.15 

11.78 


12  .00 
II  .46 


7.  20 


1.80 
1-73 


I.S4 


10.65  1.29 
3.06  2.05 
0.09      2.46 


4.60 
S.63 

2.77 

4.56 

t.ll 

Trace 


COMPOSITION  OF  UNSWEETENED  CONDENSED  MILK. 


Points  to  be  Noted. 


Total 

Solids, 

Per 

Cent. 


Water, 

Per 

Cent. 


Milk 
Sugar, 

Per 
Cent. 


Pro- 
teins, 

Per 
Cent. 


Fat, 

Per 

Cent. 


Ash, 

Per 

Cent. 


Fat  in 

Original 

Milk, 

Per 

Cent. 


No.  of 
Times 
Con- 
densed. 


High  in  fat 

Low  in  proteins 

Normal  constituents., throughout* 
Condensed  from  skirrimed  milk.  . 


36.00 
31-25 
28.16 
3S-I7 


64.0c 
86.75 
69.24 
64.83 


10.65 

13-4° 

9-8s 

13.90 


11.63 
7.02 
8.66 

iS-37 


1 2 .00 
9.60 
8.10 
4.  20 


1.72 
1-23 
1.55 
1 .70 


4.61 
4.18 
3.68 
1.28 


*  Can  be  taken   as  being  very  near  the  average  for  all  constituents  in  honest  condensed  milk  of 
fair  quality. 


iSS  FOOD   IXSPECTION  AND  ANALYSIS. 

In  the  case  of  sweetened  condensed  milk  it  will  be  observed  that 
the  proteins  as  a  rule  run  cinisiderably  lower  than  the  sugar,  whereas 
in  ordinar)'  cow's  milk  the  percentage  of  proteins  and  milk  sugar  are 
more  nearly  alike.  In  making  the  above  analyses  all  the  reducing  sugar 
was  reckoned  as  milk  sugar,  whereas  it  is  possible  that  a  small  amount 
of  the  cane  sugar  is  inverted  in  the  process  of  manufacture,  and  thus 
increases  the  anicv/.nt  of  reducing  sugar. 

U.  S.  Standards,* — Standard  Condensed  Milk  and  Standard  Sweetened 
Condensed  Milk  are  condensed  milk  and  sweetened  condensed  milk  re- 
spectively, containing  not  less  than  28%  of  milk  solids,  of  which  not  less 
than  27.5'^  is  milk  fat.  Standard  condensed  skim-milk  is  skim- 
milk  from  which  a  considerable  portion  of  water  has  been  evaporated. 

The  standard  for  evaporated  or  condensed  milk  (unsweetened)  has 
been  amended  by  the  Board  of  Food  and  Drug  Inspection  as  follows:! 

(i)  It  should  be  prepared  by  evaporating  the  fresh,  pure,  whole 
milk  of  healthy  cows,  obtained  by  complete  milking  and  excluding  all 
milkings  within  15  days  before  calving  and  7  days  after  calving,  pro- 
vided at  the  end  of  this  7-day  period  the  animals  are  in  a  perfectly  nor- 
mal condition. 

(2)  It  should  contain  such  percentages  of  total  solids  and  of  fat  that 
the  sum  of  the  two  shall  be  not  less  than  34.3  and  the  percentage  of  fat 
shall  be  not  less  than  7.8%.  This  allows  a  small  reduction  in  total  solids 
with  increasing  richness  of  the  milk  in  fat. 

(3)  It  should  contain  no  added  1)utter  or  butter  oil  incorporated 
either  with  whole  milk  or  skimmed  milk  or  with  tiie  evaporated  milk  at 
any  stage  of  manufacture. 

ANALYSIS  OF  CONDENSED  MILK. 

Preparation  of  the  Sample. — Mix  the  sample  thoroughly,  best  by 
transferring  the  entire  contents  of  the  can  to  a  large  evaporating-dish, 
and  working  it  thoroughly  with  a  pestle  till  homogeneous  throughout. 
Weigh  40  grams  of  the  mixed  sample,  preferably  in  a  tared  weighing-tray 
for  sugar  analysis,  transfer  by  washing  to  a  graduated  loo-cc.  sugar- 
flask  and  make  up  to  the  mark  with  water. 

Total  Solids. — Dilute  an  aliquot  part  of  the  mixed  solution  further 
with  an  equal  amount  of  water,  and  pipette  5  cc.  of  the  diluted  mixture, 
corresponding  to  i  gram  of  the  condensed  milk,  into  a  tared  platinum 
dish,  such  as  is  used  for  ordinary  milk,  and  rinse   the    pipette   into   the 

•  U.  .S.  Dcpt.  of  Agric,  Off.  of  Sec,  Circ.  19.  t  Food  Inspection  Decision,  131. 


MILK.  189 

dish  by  means  of  a  wash-bottle.  Evaporate,  dry  at  the  temperature  of 
boiling  water  and  weigh  as  in  the  case  of  milk  (p.  132). 

The  character  of  the  residue  should  be  noted.  It  should  not,  excepting 
in  the  case  of  a  skimmed  milk,  be  caked  down  hard  and  glossy  on  the 
bottom  of  the  dish,  but,  if  the  ojjeration  is  properly  carried  out,  should 
have  a  well-separated  fat  layer  at  the  top,  and  the  residue  should  resemble 
in  appearance  that  from  ordinary  milk.  This  result  is  accomplished  by 
the  extreme  dilution  of  the  sample. 

Ash. — Burn  carefully  the  residue  from  the  total  solids  as  above  obtained, 
cool,  and  weigh  as  in  the  case  of  ordinary  milk  (p.  134). 

When  the  total  solids  are  not  to  be  determined,  as  in  cases  where 
the  quality  of  the  milk  used  in  preparation  of  the  sample  is  decided  by 
the  fat  and  ash  alone  (see  p.  192),  12.5  cc.  of  the  above  40%  solution,  corre- 
sponding to  5  grams  of  the  sample,  may  be  evaporated  and  burned  directly. 

Fat. — The  Author's  Method* — Fifteen  cc.  of  the  40%  solution  pre- 
pared as  above  described,  corresponding  to  6  grams  of  the  original  con- 
densed milk,  are  measured  into  an  ordinary  test-bottle  of  the  Babcock 
centrifuge.  This  is  filled  nearly  to  the  neck  with  water,  and  4  cc.  of  a 
solution  of  copper  sulphate  of  the  strength  of  Fehling's  copper  solution 
are  added.  The  contents  arc  thoroughly  shaken,  and  the  precipitated 
proteins,  carr}'ing  with  them  the  fat  are  rapidly  separated  out  by  whirl- 
ing the  fat  bottle  in  the  centrifuge,  preferably  without  heating.  The 
writer  prefers  an  electric  centrifuge  of  the  Robinson  type  (p.  137)  for 
this  purpose,  as  the  heat  of  the  steam-driven  machine  cakes  the  precipitate 
down,  so  that  it  is  harder  to  wash.  If  desired,  the  precipitate  may  be 
allowed  to  settle  out  of  itself,  which  it  does  more  quickly  in  the  cold. 

The  supernatant  liquid  containing  the  sugar  is  drawn  off  by  means  of 
a  pipette  of  large  capacity,  having  a  stem  sufficiently  small  to  pass  easily 
into  the  neck  of  the  milk-bottle,  a  small  wisp  of  absorbent  cotton  being 
first  twisted  over  the  bottom  of  the  pipette  to  serve  as  a  filter.  On  with- 
drawing the  pipette  with  the  sugar  solution,  the  cotton  is  wiped  off  into 
the  bottle  by  rubbing  against  the  inner  side. 

The  precipitated  proteins  and  fat  are  given  two  additional  washings, 
as  above,  by  shaking  thoroughly  with  water  introduced  nearly  to  the 
neck  of  the. bottle,  separating  out  in  each  case  by  centrifuge  or  by  settling, 
and  finally  removing  the  washings  with  the  pipette,  two  of  such  extra 
washings  being  found  nearly  always  sufficient  to  remove  all  the  sugar. 
If  the  precipitate  is  caked  down  hard  after  treatment  with  the  centrifuge, 

*  28th  An.  Rep.  ]Mass.  State  Board  of  Health,  1896,  p  630,  and  Jour.  Am.  Chem.  See, 
22,  1900,  p.  589. 


igo  FOOD   IXSPFCTION  /IND  ANALYSIS. 

it  may  be  necessary  to  employ  a  stilT  {platinum  wire  as  a  stirrer  to  aid  in 
mixing  with  the  wash-water.  Finally  the  volume  of  17.6  is  completed 
by  addition  of  water,  17.5  cc.  of  sulphuric  acid  arc  added,  and  the  test 
continued,  as  in  the  ordinary  Babcock  process  (p.  136),  multiplying  the 
reading  obtained  by  three. 

For  unsweetened  condensed  milk,  these  precautions  are,  of  course, 
unnecessary. 

Roese-Goltlich  Method. — This  method  (p.  199)  is  recommended  when 
the  accuracy  of  a  gravimetric  process  is  desired. 

'Proteins.— Calculation  from  the  Nitrogen. — Determine  nitrogen  by 
the  Kjeldahl  or  Gunning  method  in  5  cc.  of  the  4o9(  solution,  corre- 
sponding to  2  grams  of  the  condensed  milk,  and  multiply  the  result 
by  6.38. 

Precipitation  Method. — Dilute  5  cc.  of  the  4o'^'(;  solution  further  to 
about  40  cc.  and  add  sufficient  Fehling  copper  solution,  drop  by  drop, 
to  precipitate  the  proteins,  avoiding  a  large  excess.  As  a  rule,  0.6  cc. 
of  copper  solution  is  ample  for  this.  Nearly  neutralize  with  sodium 
hydroxide,  leaving  the  solution  still  slightly  acid.  An  excess  of  alkali 
tends  to  dissolve  the  casein  and  cause  turbidity  in  the  filtrate.  Pass 
through  a  weighed  filter-paper,  wash,  dry  in  an  air-oven  at  too°  C,  and 
weigh.  The  filter  with  the  dry  precipitate  is  then  carefully  burnt  m  a 
porcelain  crucible,  and  the  difference  between  the  weight  of  the  dry 
precipitate  and  the  weight  of  the  ash  is  the  weight  of  the  proteins  and  fat. 
Expressing  this  in  percentage,  and  deducting  from  it  the  per  cent  of  fat 
previously  obtained,  the  result  is  the  per  cent  of  proteins. 

Milk  Sugar, — Volumetric  Process. — The  filtrate  and  the  washings 
from  the  preceding  oi)eration  are  made  u])  to  100  cc.  with  water,  and  the 
amount  of  reducing  .sugar,  obtained  volumt'lrically  by  Fehling's  solution, 
is  reckoned  as  milk  sugar.  The  titration  is  conducted  in  the  manner 
described  on  p.  591. 

Assuming  the  solution  to  be  exactly  of  the  strength  above  described, 

100X0.067       r        u  T    ■       ] 

the  milk  sugar  is  calculated  as  follows:       SX002    ^ A  where  L  is  the 

per  cent  of  lactose  or  milk  sugar,  and  .V  llie  number  of  cc.  of  milk 
soluti<jn,  prepared  as  above  reciuired  to  reduce  10  cc.  of  Fehhng's 
solution.  Calculation  may  be  avoirled  by  the  use  of  the  following 
table,  which  may  be  employed  when  the  above  details  are  minutely 
tarried  out: 


MILK. 


igr 


PER  CENT  MILK  SUGAR  CORRESPONDING    TO   NUMBER    OF   CUBIC 
CENTIMETERS    USED. 

Strength  of  solution  2  grams  in  ico  cc. 


Cu.  Cm. 

Percent. 

Cii.  Cm. 

Per  Cent. 

Cu.  Cm. 

Per  Cent. 

Cu.  Cm. 

Per  Cent. 

18.0 

18.61 

25.0 

13.40 

32-0 

10.47 

39-0 

8.59 

18.5 

18.10 

25-5 

13-14 

32 

5 

10.31 

39-5 

8.49 

19.0 

17-63 

26.0 

12.89 

33 

0 

10.15 

40.0 

8.37 

19-5 

17,18 

26.5 

12.64 

!     33 

5 

10.00 

40-5 

8.27 

ro.o 

16.75 

27.0 

12.41 

1     34 

0 

9-85 

41.0 

8.17 

20.5 

16.34 

27.5 

12.18 

34 

5 

9.71 

41-5 

8.07 

21.0 

15-95 

28.0 

11.97 

35 

0 

9-57 

42.0 

7-98 

21-5 

15-58 

28.5 

II-7S 

35 

5 

9-43 

42.5 

7.88 

22.0 

15.22 

29.0 

"■55 

36 

0 

9-3° 

43-0 

7.78 

22.5 

14.89 

29-5 

'1-35 

36 

5 

9.17 

43-5 

7.70 

23.0 

14.56 

30.0 

11.16 

37 

0 

9-05 

44-0 

7.61 

23-5 

14-25 

3°-S 

10.89 

37 

5 

8.93 

44-5 

7-53 

24.0 

13-95 

31.0 

10.80 

3« 

0 

8.81 

24-5 

13.67 

31-5 

10.63 

3« 

5 

8.70 

Gravimetric  Methods.  — Lactose  may  be  determined  in  the  40% 
solution  of  the  condensed  milk  by  the  O'SuUivan-Defren  method  (page 
15c),  the  Soxhlet  method  (page  150),  or  the  Munson  and  Walker  method 
(page  151),  the  solution  being  treated   exactly  as  if  it  were  milk. 

Cane  Sugar. — This  is  obtained  by  difference,  deducting  the  milk 
solids  (the  sum  of  the  milk  sugar,  proteins,  fat,  and  ash)  from  the  total 
solids  first  obtained. 

Detection  of  Foreign  Fats  and  Oils. — The  invention  of  the  homogenizer 
has  led  to  the  preparation  of  emulsions  of  oleo,  cotton  seed  and  other  oils, 
as  well  as  of  butter  fat,  with  skim  milk  and  milk  in  imitation  of  whole  milk 
and  cream  and  the  use  of  such  homogenized  products  in  condensed  milk 
and  ice  cream.  This  substitution  is  detected  by  the  separation  and  examina- 
tion of  the  fat  as  follows : 

Paurs  Method.^ — Dilute  100  grams  of  the  material  with  300  cc.  of 
water,  heat  to  boiling  and  add  slowly,  while  boiling,  25  cc.  of  Fehling's 
copper  sulphate  solution  (p.  28). 

Filter  through  a  filter  paper  on  a  Biichner  funnel,  wash  three  times 
with  hot  water  and  allow  to  suck  dry.  Remove  filter  and  precipitate  from 
the  funnel,  break  into  small  pieces,  dry  over  night  at  room  temperature 
and  grind  with  about  25  grams  of  anhydrous  copper  sulphate. 

Place  a  layer  of  anhydrous  copper  sulphate  in  the  bottom  of  the  inner 
tube  of  a  Johnson  extractor  (p.  65),  then  add  the  powdered  mixture  and 
place  a  loose  plug  of  cotton  on  the  top.  Connect  the  extractor  with  a 
flask,  pour  50  cc.  of  ether  through  the  mixture  and  proceed  as  usual  with 
the  extraction. 


'  U.  S.  Dept.,  Bur.  of  Chem.,  Circ.  90,  p.  10. 


iq2  FOOD  INSPECT/ON  /1ND  ANALYSIS. 

Dry  the  fat  as  quickly  as  possible  and  weigh.  Determine  the  refractive 
index,  volatile  fatty  acids  and  such  other  constants  as  seem  desirable 
(Chapter  XIII). 

Calculation  of  Fat  in  Original  Milk. — The  "fat  in  the  original  milk," 
as  e.xprossotl  in  the  tables  on  page  187,  was  calculated  by  assuming  a 
percentage  of  solids  not  fat  of  9.3  in  the  original  milk,  this  being  the  standard 
fixed  by  the  Massachusetts  law.  Calculate  first  the  fat  and  the  m.ilk 
solids  to  tlic  basis  of  the  cane-sugar-free  sample.  This  is  done  by  divid- 
ing the  per  cent  of  each  as,  found  in  the  sample  by  100  less  the  percentage 
of  c  ;nc  sugar,  and  multiplying  the  result  by  100.  Ascertain  the  dif- 
ference between  the  milk  solids  and  the  fat  thus  obtained  in  the  canc- 
sugar-frec  sample,  and  divide  this  perceniage  of  milk  solids  not  fat  by 
9.3.  The  result  is  the  ''number  of  times  condensed  "  (if  cane  sugar  were 
not  present  as  a  diluent). 

'1  he  per  cent  of  fat  in  the  cane-sugar-free  sample,  divided  by  the 
number  of  times  condensed,  as  above  obtained,  gives  the  percentage  of 
fat  in  the  original  milk. 

The  above  calculation  from  the  solids  not  fat  of  the  factor  desig- 
nated as  "the  number  of  times  condensed,"  necessitates  determinations  of 
fat,  ash,  proteins,  and  milk  sugar,  in  fact,  a  complete  analysis  of  the  sample. 

A  simjjler  method  of  calculating  the  "  number  of  times  condensed," 
involving  determinations  of  fat  and  ash  only  in  the  samjjlc,  consists  in 
dividing  the  per  cent  of  ash  found  in  the  condensed  milk  by  0.7,  this 
figure  being  the  assumed  ash  of  normal,  standard  milk.  Tlien,  by  divid- 
ing the  fat  in  the  sample  by  the  "  number  of  times  condensed  "  as  last 
calculated,  the  result  is  the  fat  in  the  original  milk.  If  this  is  found 
to  be  well  below  39o  there  is  reason  to  suspect  that  skimmed  milk  was 
used  in  its  preparation. 

The  "  fat  in  the  original  milk  "  as  thus  calculated  is,  of  course,  an 
arbitrary  factor  and  is  useful  only  in  deciding  whether  or  not  skimmed 
milk  ha.s  been  used  in  j^reparing  the  sample.  By  assuming  the  above 
very  reasonable  figures  for  the  solids  not  fat,  or  for  the  ash  of  natural 
milk  (according  to  which  method  is  used  for  calculation),  it  is  readily 
.seen  that  the  highest  result  is  obtained  for  the  "  fat  in  the  original  milk  " 
and  hence  the  benefit  of  the  floubt  as  to  the  use  of  skimmed  milk  is 
^iven  to  the  manufacturer. 

Bigelow  and  McElroy's  Polarimetric  Method  for  Cane  Sugar.*  26.048 
grams  of  the  mixed  sample  of  c  ondenaed  milk  are  transferred  to  a  loo-cc. 

*  Jour.  Am.  Chem.  Soc,  15,  p.  668. 


MILK.  193 

graduated  sugar-flask  and  dissolved  in  water,  which  is  boiled  to  make 
sure  of  nonnal  rotation.  The  solution  is  then  clarified  by  the  addition 
of  an  acetic  acid  solution  of  mercuric  iodide  ■''  and,  if  necessary,  alumina 
cream,  the  volume  is  made  up  to  100  cc,  shaken,  and  filtered  through 
a  dry  filter.  Rejecting  the  first  part  of  the  filtrate,  a  further  portion  is 
polarized.  For  inversion,  another  sample  of  26.048  grams  is  weighed 
out  as  before  and  dissolved,  but  before  clarifying,  is  heated  to  55°  C. 
and  treated  with  half  a  cake  of  compressed  yeast,  the  heating  with  the 
yeast  being  continued  at  55°  for  five  hours.  The  clarifying  solution 
is  added  before  cooHng,  and,  after  cooling,  making  up  to  100  cc,  and 
filtering  as  before,  the  invert  reading  is  obtained  with  the  polariscope. 
By  this  process  of  yeast  inversion  the  cane  sugar  only  is  inverted,  the 
lactose  remaining  unchanged.  It  is  best  to  work  with  several  samples 
and  use  the  mean  of  the  readings  both  for  direct  and  invert  figures.  It  is 
also  best  to  use  the  double  dilution  method  (p.  149)  to  compensate  for 
the  volume  of  the  precipitated  fat  and  proteins. 

The  per  cent  of  cane  sugar  is  calculated  by  the  formula  of  Clerget, 

c.  «-^ 

142.66 

2 

5  being  the  per  cent  of  cane  sugar, 
a  the  direct  reading, 

h  the  invert  reading  and  /  the  temperature  at    which  the  observation  is 
made. 
The  above  process  presupposes  the  absence  of  invert  sugar  in  the 
sample,  .a  supposition  which  Wiley  claims  it  is  fair  as  a  rule  to  assume. 

CREAM. 

Composition. — Cream  varies  in  composition  according  to  the  method  by 
which  it  is  obtained,  i.e.,  whether  (i)  by  allowing  it  to  separate  from  the 
milk  set  in  shallow  pans,  whence  it  is  removed  by  hand-skimming,  (2)  by- 
setting  in  deep  vessels  surrounded  by  cold  water  (as  for  example  in  the 
"Cooley"  creamer)  the  skimmed  milk  being  commonly  drawn  off  from 
below,  or  (3)  by  the  centrifugal  separator.  Most  of  the  heaxy  cream 
found  in  the  market  at  the  present  time  is  the  product  of  the  third  or 
separator  process.     Analyses  of  different  kinds  of  cream  follow: 

*  Prepared  by   dissolving  53  grams  of  potassium  iodide,    22  'grams  mercuric  chloride, 

and  32  cc.  of  strong  acetic  acid  in  wafer  and  making  up  to  1  liter. 


194 


FOOn  INSPECTION  ^ND  ANALYSIS. 


COMPOSITION  OF  CREAM. 


Character  of  Cream. 

It 

•c 

0 
3 
< 

u 

(LI 

nl 

c 
'S 

2 
a. 

al 
03 

< 

•a 
H 

0 

c  . 

■J3&4 

1 

By  natural  separation 

By       centrifugal      separator, 
"Heavv"   cream 

46 
iS 

Konig 

Mean 

Maximum 

Minimum 

Mean 

Maximum 

Minimum 

Mean 

68.82 

54.80 
46.76 

SI. 68 
83.29 
70.50 
77.89 

3-7^' 

22.664.23 

0-53 

31.18 

53-24 
45.20 
48.32 
29.50 
16.71 

22.11 

8.42 
8.50 

4.20 

6.30 

0-30 
7.22 

8.25 

"Light"  cream 

iS     T.pnrli 

3S-10 
42.02 
21.60 
8.60 
13.86 

.... 

U.  S.  Standards.='^'— 5/t277(/(zn/  Cream  is  cream  containing  not  less  than 
18*  t  ot  milk  fal.  Standard  Evaporated  Cream  is  cream  from  which  a 
considerable  portion  of  water  has  been  evaporated. 

Adulteration  of  Cream. — In  some  localities  fat  standards  are  fixed 
for  cream  both  "  heavy  "  and  "  light,"  those  falling  below  such  standards 
being  deemed  adulterated. 

Foreign  Fats. — Oleo    oil,    possibly  other    fats,    "  homogenized  "    or 
emulsified  with  milk  or  skim  milk,  is  now  being  substituted  for  true  cream- 
A  product  known  as  ''  Syntho  "  l^elongs  in  this  class  but 
is  sold  by  its  manufacturers  under  its  true  name. 


C^K 


Vu..  53. — A  Balxock  Cream-test  Scale. 

Preservatives. — The  same  preservatives  are  empUjyed  in  cream  as  in 


milk. 


*  U.  S.  Dept.  of  Agri(  .,  ()n.  of  Sec,  Circ.  19. 


MILK.  195 

Gelatin. — The  author  has  detected  this  substance  in  cream  sold  in 
Massachusetts.  It  serves  as  a  thickener  and  is  sometimes  sold  in  powder 
form  mixed  with  boric  acid. 

Sucrate  of  Lime  in  Milk  and  Cream. — Pasteurizing  reduces  the  con- 
sistency of  cream  so  that  its  apparent  richness  and  its  value  for  certain 
culinaiy  preparations  is  impaired.  Babcock  and  Russell  *  have  shown 
that  sucrate  of  lime  ("viscogen")  may  be  used  to  thicken  such  cream, 
but  insist  that  the  treated  product  be  sold  under  a  distinctive  name,  such 
as  " visco-cream "  or  "pasteurized  visco-cream." 

To  prepare  "viscogen"  dissolve  2\  parts  by  weight  of  cane-sugar  in 
5  parts  o-f  water,  add,  after  straining,  i  part  of  (quicklime  slaked  in  3  parts 
of  water;  shake,  allow  to  settle,  siphon  off  the  supernatant  liquid,  and 
bottle.  For  thickening  cream  use  two-thirds  of  the  amount  required  to 
neutralize  its  acidity.     It  will  also  thicken  milk  and  condensed  milk. 

ANALYSIS  OF  CREAM. 

Total  solids,  ash,  sugar,  proteins,  and  fat  (gravimetric)  are  deter- 
mined by  the  methods  used  in  milk  analysis  (pp.  130-155). 

Determination  of  Fat. — Babcock  Process. — Owing  to  the  viscosity  of 
cream  and  its  variation  in  density  strictly  accurate  results  can  be  secured 
only  by  weighing  the  sample.  Fig.  53  shows  a  cream  scale  provided  with 
a  sliding  poise  for  balancing  the  bottle  and  a  second  for  weighing  the 
cream.  If  a  large  number  of  tests  are  to  be  made,  a  balance  for  weighing 
several  samples  on  each  pan  or  the  Wisconsin  hydrostatic  cream  balance 
will  be  found  convenient. f  The  latter,  devised  by  Babcock  and  Farring- 
ton,{  is  constructed  on  the  principle  of  the  lactometer.  It  is  provided 
with  a  pan  on  the  top  of  the  stem  for  holding  the  test  bottle  and  weights. 

Two  forms  of  test  bottles  are  shown  in  Fig.  54.  Others  with  grad- 
uations up  to  50%  are  also  obtainable. 

The  process  is  as  follows:  Weigh  9  or  18  grams  of  the  well-mixed 
sample  into  the  tared  test  bottle,  using  a  pipette  with  a  wide  delivery  tube. 
If  9  grams  are  used  dilute  with  9  cc.  of  water.  Add  17.5  cc.  of  sulphuric 
acid  of  proper  strength  and  proceed  as  in  the  case  of  milk  (p.  138). 

The  error  due  to  the  curved  meniscus  of  the  fat  column  in  the  test 


*  Wisconsin  Exp.  Station,  Bull.  54. 

I  Farrington  and  Woil,  Testing  Milk  and  its  Products,  20th  ed.,  pp.  81-83. 

J  Wisconsin  Exp.  Station  Bui.  195. 


iq6 


FOOD   IKSPFCTJON  ^ND    ANALYSIS. 


bottle  may  be  overcome  by  addin;^  a  few  drops  of  fat-saturated  alcohol 
(Babcock  and  Farrington  *)  or  of  glymol  (Hunzikerf). 

To  prepare  fat-saturated  alcohol    place  a  teaspoonful  of  butter  m  a 
bottle  with  200  cc.  of    denatured    or  wood    alcohol,  warm  slightly  and 

shake  until  saturated.  Coloring  matter  mz.y  be 
added  to  further  facilitate  the  reading.  Glymol 
may  be  colored  with  alkanet  root. 

Detection  of  Foreign  Fats. — Determine 
the  refractive  index  and  the  volatile  fatty 
acids  of  the  fat  obtained  by  the  Babcock 
method. 

Detection  of^  Preservatives. — See  pp.  180- 
183. 

In  testing  for  formaldehyde,  using  ferric 
chloride  and  hydrochloric  acid,  the  sample 
should  be  diluted  with  an  equal  volume  of 
water,  heated  with  the  reagents  in  a  casserole 
but  fmally  poured  into  a  test  tube  to  observe 
the  color. 

Detection  of  Gelatin. — Stokes  Method.X — 
The  reagents  are  as  follows:  (i)  Acid  nitrate 
of  mercury,  prepared  by  dissolving  metallic 
mercury  in  twice  its  weight  of  concentrated 
nitric    acid    (sp.  gr.    1.42)   and    diluting    with 


Pig.  $a  ■ — \'arietks  of  Babcock 
Test  Bottle  for  Cream. 


A,  Bartlett  Bottle;  B,  Winton  twenty-five  times  its  bulk  of  water,  and  (2)  a 

saturated  aqueous  solution  of  picric  acid. 
To  about  10  cc.  of  the  cream  add  the  same  amount  of  the  acid  nitrate 
of  mercury  solution  and  20  cc.  of  cold  water.  Shake  the  mixture  vigor- 
ously and  allow  to  rest  for  five  minutes,  after  which  filter.  If  much 
gelatin  is  present,  the  filtrate  will  not  be  clear,  but  opalescent.  To  the 
whole  or  a  part  of  the  filtrate  add  a  few  drops  of  the  picric  acid  solution. 
If  gelatin  be  present  in  any  considerable  amount,  a  yellow  precipitate 
is  fonri'd.  Avoid  an  excess  of  acid  nitrate  of  mercury,  as  this  would 
cause  a  jjrecipitatc  with  picric  acid. 

If  gelatin  is  present  in  small  amount  only,  a  cloudiness  is  produced, 
best  S'-*en  against  a  dark  background.  The  reaction  is  delicate  to  1  part 
of  gelatin  in  io,oc»o  parts  of  milk  or  cream. 


*  Wisconsin  Exp.  Station,  Bull.  195,  p.  6. 

t  Purdue,  Ind.  Kxp.  Sution,  Bui.  145,  XV,  p.  593. 


X  Analyst,  22,  p.  320. 


MILK.  197 

Detection  of  Sucrate  of  Lime. — This  is  indicated  by  the  presence  of 
sucrose,  in  connection  with  an  abnormally  hi^h  alkalinity  of  ash  and 
excessive  calcium  oxide.     The  tests  are  as  follows: 

Lythgoe's  Modification  of  Baier  and  Neuman's  Test  for  Detecting 
Sucrose.* — To  25  cc.  of  milk  or  cream,  add  lo  cc.  of  a  5%  solution  of 
uranium  acetate,  shake  well,  allow  to  stand  for  5  minutes,  and  filter. 
To  TO  cc.  of  the  clear  filtrate  (in  the  case  of  cream  use  the  total  filtrate, 
which  will  be  less  than  10  cc.)  add  a  mixture  of  2  cc.  saturated  ammo- 
nium molybdate  and  8  cc.  dilute  hydrochloric  acid  (i  part  25%  acid 
and  7  parts  water),  and  heat  in  a  water-bath  at  80°  C.  for  5  minutes.  If 
the  sample  contains  sugar,  the  solution  will  be  of  a  Prussian  blue  color, 
which  should  be  compared  in  a  colorimeter  with  standard  Prussian  blue 
solution,  prepared  by  adding  a  few  drops  of  potassium  ferrocyanide  to 
a  solution  of  i  cc.  of  1%  ferric  chloride  in  20  cc.  of  water. 

Occasional  samples  of  pure  milk  will  give  a  pale  blue  color,  but  this 
can  be  entirely  removed  by  filtration,  the  iiltrate  being  green,  while  the 
color  due  to  sugar  will  pass  through  the  filter,  giving  the  usual  blue  solution. 
This  color,  due  to  a  reduction  of  molybdic  acid,  is  also  produced  by  levulose 
and  dextrose.  Solutions  of  i  gram  of  lactose,  levulose,  dextrose,  and 
sucrose  in  35  cc.  of  water  heated  with  molybdenum  reagent  for  5  minutes 
reacted  as  follows:  lactose  no  color,  levulose  a  heavy  blue,  sucrose  a  weaker 
blue,  and  dextrose  the  weakest  blue,  the  intensity  of  the  last  three  being 
as  10  :3  : 1. 

Stannous  chloride,  ferrous  sulphate,  and  hydrogen  sulphide  give  this 
blue  color  in  the  cold,  but  it  disappears  on  heating  except  in  case  the 
stannous  or  ferrous  salt  is  present  to  the  extent  of  at  least  t%  (calculated 
as  the  metal)  which  amount  would  coagulate  the  cream  and  impart  a  very 
disagreeable  taste. 

As  a  confirmatory  test  for  sugar,  the  resorcine  test  may  be  applied 
to  the  serum  prepared  with  uranium  as  described  above.  This  test  is 
given  by  sucrose  and  levulose,  but  not  by  dextrose  or  lactose. 

Determination  of  Alkalinity  of  Ash  and  Calcium  Oxide. — Weigh 
25  grams  of  cream  into  a  platinum  dish,  place  in  an  oven  at  about 
125-150°  C.  over  night,  and  1)urn  to  an  ash  in  a  mufile  at  a  low-red 
heat.     Dissolve   the   ash   in   20  cc.    N/io  sulphuric  acid,  boil  to  expel 

*  Zcits.  Unters.  Nahr.  Genussm.,  16,  1908,  p.  51 


iqS  FOOD  INSPECTION  AND  ANALYSIS. 

the  carbon  dioxide,  and  titrate  back  with  N/io  sodium  hydroxide,' 
using  phenolphthalein  as  the  indicator.  Express  results  as  cc.  N/io 
acid  required  to  neutralize  the  ash  of  loo  grams  of  cream. 

Make  the  Imal  solution  of  the  above  determination  acid  with  acetic 
acid,  heat  to  boiling,  add  i  gram  of  sodium  acetate,  and  to  the  clear 
solution  add  an  excess  of  ammonium  oxalate,  boil  for  a  few  minutes, 
lilter,  and  wash  with  water.  Dissolve  the  calcium  oxalate  in  hot  dilute 
sulphuric  acid,  and  titrate  hot  with  N/io  potassium  permanganate. 
The  number  of  cubic  centimeters  of  N/io  permanganate,  multiplied  by 
O.OII2  (4X0.0028),  gives  the  percentage  of  CaO  in  the  sample. 

Cream  samples  treated  with  calcium  sucrate,  having  a  fat  content 
from  26  to  ^^'^^c^  show  as  a  rule  an  alkalinity  of  ash  of  from  14  to  18,  and  a 
CaO  content  of  from  0.15  to  0.175%  while  the  same  untreated  show  in 
general  alkalinity  of  ash  not  exceeding  12.5  and  a  CaO  content  not  exceed- 
ing 0.135.  With  higher  fat  contents  both  constants  drop.  For  example, 
a  cream  of  45%  fat  containing  calcium  sucrate  had  an  alkalinity  of  ash 
of  10.2  and  a  CaO  content  of  0.12%.  Cream  of  about  45%  fat  untreated 
had  an  ash  alkalinity  of  6.5  and  a  CaO  content  of  0.103%. 

ICE  CREAM. 

For  many  years  a  wide  variety  of  iced  foods  have  been  made  and 
sold  under  the  general  name  of  ice  cream,  many  of  which  are  largely 
composed  of  ingredients  other  than  milk  or  cream.  In  the  study  and 
classification  of  foods  of  such  a  miscellaneous  nature  as  ice  cream,  in  its 
popularly  accepted  meaning,  it  is  not  ah^ays  easy  to  satisfactorily  define 
and  fix  standards.  Whether,  for  example,  the  product  should  consist 
excltisively  of  frozen  cream,  sugar  and  flavoring,  or  whether  eggs  and 
other  materials  should  be  allowed  under  the  unqualified  name  of  ice 
cream,  is  a  subject  of  some  controversy. 

Proj)erly  speaking,  many  mixtures  sold  under  the  name  should  be 
otherwise  designated,  as,  for  examyile,  "  frozen  custard,"  to  specify  more 
aptly  their  nature  and  comj^osilion.  The  following  standards  show 
the  attitude  of  the  government  in  this  regard: 

U.  S.  Standards.* — Ice  cream  is  a  frozen  product  made  from  cream 
and  sugar  with  or  without  a  natural  flavoring,  and  contains  not  less  than 
14%  of  milk  fat. 

*  U.  S.  Dept.  of  Agric,  Ofl&ce  of  Secretary,  Circ.  19. 


MILK.  199 

Fruit  ice  cream  is  a  frozen  product  made  from  cream,  sugar,  and 
sound,  clean,  mature  fruits,  and  contains  not  less  than  12%  of  milk  fat. 

Nut  ice  cream  is  a  frozen  product  made  from  cream,  sugar,  and  sound, 
non-rancid  nuts,  and  contains  not  less  than  12%  of  milk  fat. 

Fillers  or  Stiffeners. — In  the  manufacture  of  commercial  "  ice 
cream  "  substances  are  frequently  added  to  cause  the  product  to  hold 
stiff  and  keep  its  consistency  for  many  hours  after  freezing.  The 
thickeners  or  fillers  most  commonly  thus  used  are  starch,  gelatin,  and 
gums  such  as  gum  tragacanth.  Agar-agar  and  commercial  casein  are 
also  said  to  be  employed  for  this  purpose. 

Preparations  are  on  the  market  sold  for  thickening  ice  cream,  con- 
sisting, as  a  rule,  of  one  or  more  of  the  above-named  substances. 

Homogenized  Products.  — Unsalted  butter  emulsitied  with  milk  or 
skim  milk  is  now  extensively  substituted  for  true  cream  in  the  manufacture 
of  so-called  ice  cream.  Oleo  oil  and  cotton  seed  oil  are  also  used  in  such 
emulsions.  None  of  these  emulsions  are  allowable  in  the  product  sold 
as  ice  cream. 

Ice  Cream  Cones. — These  are  cornucopias  made  of  a  kind  of  dry  crust 
used  to  serve  ice  cream  without  a  spoon,  the  cones  as  well  as  the  ice  cream 
being  eaten  from  the  hand.  In  addition  to  flour,  sugar,  and  eggs  or  gelatin, 
which  are  proper  constitutents,  they  frequently  contain  saccharin,  artificial 
color  and  borax,  the  latter  being  used  to  prevent  sticking  to  the  mold 
during  baking. 

ANALYSIS  OF  ICE  CREAM. 

Fat. — Roese-Gottlieh  Method."^ — Prepare  a  40%  water  solution,  as 
described  for  condensed  milk  (p.  188).  Of  this  solution  measure  10  cc. 
into  a  Rohrig  tubef  (Fig.  55),  or  a  glass  cylinder  2  cm.  in  diameter  and 
40  cm.  high,  to  which  a  narrow  siphon  can  be  fitted;  dilute  with  0.5  cc.  of 
water,  add  1.25  cc.  of  concentrated  ammonium  hydroxide  (2cc.  if  the 
sample  is  sour)  and  mix  thoroughly.  Add  10  cc.  of  95%  alcohol  and 
shake  well.  Then  add  25  cc.  of  washed  ethyl  ether,  shake  vigorously 
for  half  a  minute,  add  25  cc.  of  petroleum  ether  (p.  66),  preferably  re- 
distilled below  60°  C,  and  shake  again  for  half  a  minute.     Let  stand 

*  Roese,  Zeits.  Angew.  Chem.,  1889,  p.  100;  Gottlieb,  Landw.  Versuchs-Stat.,  40,  1892, 
p.  I ;  Patrick,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  66;  A.  O.  A.  C.  Method, 
f  Zeits.  Unters.  Nahr.  Genussm.,  9,  1905,  p.  531. 


200  FOOD  INSPECTION  .4ND   ANALYSIS. 

twcntv  minutes  or  until   the  upper  liquid   is  clear  and   its  lower  level 
constant. 

Draw  oil  as  much  as  possible  of  the  ethereal  liquid — usually  0.5  to 
o.S  cc.  is  left — through  a  diminutive  filter  into  a  weighed  flask.     Extract 
the  liquid  remaining  in  the  tube  in  the  same  manner  as 
j^  before    except    that  only    15   cc.   each   of  the   ethers  are 

U  used,  draw  otT  through  the  same  paper  into  the  flask  and 

wash  with  a  few  cc.  of  the  mixed  ethers  ( i :  i ).  Evaporate 
the  drawn  off  and  filtered  liquid  slowly  and  dry  in  a 
boiling-water  oven,  one  hour  at  a  time,  to  constant 
weight.  The  ether  used  must  be  tested  for  residue 
upon  evaporation  and  a  correction  introduced  if  neces- 
sary. 

The  dried  and  weighed  fats  should  be  dissolved  in  a 
little  petroleum  ether;  if  a  residue  be  found  (due  to  a 
trace  of  the  aqueous  liquid  which  may  have  passed  the 
filter)  it  must  be  washed  in  the  flask,  dried,  and  its 
weight  deducted  from  that  of  the  crude  fat. 

This  method   is  also   applicable   to    condensed   milk, 

cream,   milk,    skim  milk,    buttermilk,    and   whey.     With 

substances  of  low  fat  content  the  second  extraction  may 

be  omitted,    the   weight   of   the    fat   being    increased    to 

Fig.  55.— Rcihrig    correspond    to    the    entire     volume    of    ethereal    liquid 

tubcforRoese-   ^le^sured  in  the  tube. 

GottliebMeth-  ,   ^       .         ^  ,     ^•,         ^ 

oj  Detection  of  Foreign  Fats   and   Oils. — Separate    and 

examine  the  fat  as  described  on  page  191. 
Detection  of  Thickeners.  — Patrick's  Method.^- — Add  25  cc.  of  water 
to  50  cc.  of  the  sample,  and  boil  till  any  thickener  present  is  dissolved. 
Add  2  cc.  of  a  10%  solution  of  acetic  acid,  heat  to  boiling,  add  3  heap- 
ing tcaspoonfuls  of  kieselguhr,  and  after  shaking  pass  at  once  through 
a  plaited  filter.  To  3  cc.  of  the  clear  filtrate  add  12  cc.  of  95%  alcohol 
and  mix  thoroughly,  thus  precipitating  the  milk  proteins  not  already 
removed,  and  also  the  gums  and  some  of  the  gelatin,  if  much  is  present. 
Add  3  cc.  of  a  mixture  of  95  cc.  of  95%  alcohol  and  5  cc.  of  concen- 
trated hydrochloric  acid.  This  acidified  alcohol  dissolves  completely  the 
milk  proteins,  and,  if  a  clear  solution  then  remains,  no  gums  or  vegetable 
jellies   have    been    used   as    thickeners.     Turbidity  does   not,    however, 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chtm.,  Bui.  116,  p.  26. 


MILK.  20 1 

ncccssaril}'  indicate  presence  of  a  tliickencr,  as  it  may  be  causecl  by  a 
large  amount  of  eggs,  or  by  the  souring  of  tlie  ice  cream.  Dilute  the 
mixture,  if  turbid,  by  adding  3  cc.  of  water.  .\ny  jjrecipitate  due  to 
gelatin  or  eggs  will  be  dissolved  at  tliis  dilution,  but  not  that  due  to 
vegetable  gums.  If  gum  tragacanth  be  present,  tlie  precipitate  will  be 
stringy  and  cohesive,  especially  after  shaking,  while  agar-agar  or  other 
vegetable  thickeners  will  cause  a  fine  flocculent  j)recipitate. 

Souring  of  the  ice  cream  sometimes  produces  a  turbidity  or  precip- 
itate under  the  above  conditions,  which  is  not  always  dissolved  after 
diluting  with  water.  Formation  of  such  a  precipitate  (due  to  sourness) 
may,  however,  apparently  be  prevented  by  the  previous  addition  of 
formaldehyde  to  the  sample. 

HowanVs  Test  for  Gums. — Precipitate  10  cc.  of  the  melted  sample 
with  acetone,  and  wash  with  2  or  3  portions  of  dilute  alcohol,  using 
the  centrifuge.  Boil  the  washed  residue  with  6  to  8  cc.  of  water  and 
I  cc.  of  io9c  sodium  hydroxide  solution  for  half  a  minute.  Cool,  let 
stand  a  few  minutes,  filter,  and  heat  the  filtrate  to  boiling.  Add  one 
and  one-half  volumes  of  warm  alcohol  and  shake.  If  agar-agar  or  gum 
tragacanth  be  present,  a  flocculent  precipitate  will  immediately  sepa- 
rate. Disregard  a  mere  turbidity.  To  prove  the  absence  of  any  con- 
siderable quantity  of  milk  proteins  in  the  precipitate,  dissolve  in  cold 
water  and  saturate  the  solution  with  ammonium  sulphate. 

Gelatin. — Use  the  method  of  Stokes  (p.  196)  on  10  to  15  cc.  of  the 
sample,  disregarding  a  faint  cloudiness  at  the  end. 

Starch  is  detected  by  the  usual  iodine  test. 

Detection  of  Preservatives. — Formaldehyde  and  boric  acid  are  tested 
for  as  in  milk. 

Detection  of  Colors. — See  Chapter  XVH.  The  colors  used  are  not 
merely  yellows  and  oranges  such  as  are  added  to  milk,  but  include  also 
reds,  greens,  and  even  blues,  coal-tar  dyes  being  most  commonly  employed. 

BUTTER. 

The  value  of  butter  as  a  food  depends  almost  entirely  on  its  fat  con- 
tent, although  minute  (quantities  of  protein  and  milk  sugar  are  also  in- 
cluded in  its  composition. 

Hence  butter  is  more  logically  treated  in  detail  under  the  heading  of 
fats,  page  529. 


202  FOOD  INSPECTION  JND   AN /I  LYSIS. 


CHEESE. 


Nature  and  Composition. — Cheese  consists  principally  of  the  curd 
and  fat  removed  in  a  mass  from  milk,  which  has  been  curdled  by  the 
natural  souring  of  the  milk,  or  by  the  action  of  rennet.  The  separated 
mass  of  curd  and  fat,  after  being  compressed,  is  allowed  to  undergo  certain 
changes,  which  constitute  the  ripening  or  curing,  due  to  the  action  of 
micro-organisms  and  enzymes.  Sometimes  cream  is  used  as  the  source 
of  cheese  and  sometimes  skimmed  milk.  During  the  ripening  process, 
which  requires  from  a  few  weeks  to  several  months,  the  characteristic 
flavor  is  developed  by  the  changes  which  the  proteins  undergo,  and  the 
digestibility  of  the  cheese  is  improved.  The  nature  of  the  proteolytic 
changes  that  take  place  during  ripening  are  very  little  understood,  but  a 
variety  of  complex  nitrogenous  products  are  formed,  which  Van  Slyke 
divides  as  follows:  paracasein,  unsaturated  paracasein  lactate,  para- 
nuclein,  caseoses  (albumoses),  peptones,  amides,  and  ammonia.  Besides 
nitrogenous  bodies  and  fat,  which  are  its  chief  constituents,  cheese  con- 
tains notable  quantities  of  water,  milk  sugar,  lactic  acid,  and  mineral 
matter. 

In  some  kinds  of  cheese  salt  and  coloring  matter  are  added. 

Varieties. — Well-known  cheeses  of  commerce  are  often  named  from 
districts,  towns,  or  locahties  where  they  originated  or  are  still  made. 
They  may  be  classified  as  cream,  whole-milk,  or  skimmed-milk  cheese, 
according  to  the  quality  of  the  product  from  which  they  are  made,  or 
again  as  hard,  medium,  or  soft,  according  to  whether  (i)  they  are  pressed, 
or  (2)  allowed  to  drain  for  days  and  sometimes  weeks  without  pressure 
to  a  firm  consistency,  or  (3)  are  made  in  the  space  of  a  few  hours,  being 
quickly  drained  on  a  sieve  by  hand  pressure. 

Cheddar  Cheese,  which  is  the  common  cheese  of  the  United  States 
(though  originally  made  some  250  years  ago  in  England  and  still  made 
there),  is  a  type  of  the  hard  cheese.  Stilton,  an  English,  and  Gruyere,  a 
Swiss  cheese,  belong  to  the  medium  class,  and  soft  cheeses  are  represented 
by  Brie  and  Neujchalel,  both  French  cream  chr-eses.  Other  well-known 
varieties  are  Edam,  a  rounri,  mild,  long-keeping  Dutch  cheese,  Camemberi, 
a  rich  cream  cheese,  and  Roquejort,  made  originally  from  ewe's  milk  in 
the  French  town  of  that  name,  and  ripened  in  caves  in  the  mountains. 
It  is  flavored  by  a  peculiar  mold. 


MILK. 


203 


The  following  table,  compiled  by  Woll,*  shows  the  average  composition 
of  various  cheeses  of  commerce,  both  foreign  and  domestic: 


Cheddar 

Cheshire 

Stilton 

Brie 

Neufchatel 

Roquefort 

Edam 

Swiss 

Full  cream,  mean  of  143  analyses 


Water. 

Casein. 

Fat. 

Per  cent. 

Per  cent. 

Per  cent. 

34-38 

26.38 

32.71 

32-59 

32-51 

26.06 

30-35 

28. 8^5 

35-39 

50-35 

17.18 

25.12 

44-47 

14.60 

33-70 

31.20 

27.63 

33,--^^ 

36.28 

24.06 

30.26 

35-80 

24.44 

37-40 

38.60 

25-35 

30-25 

Sugar. 


Ash. 


Per  cent. 

2-95 

4-53 
1-59 
1-94 
4.24 
2.00 
4.60 

2.03 


Per  cent. 
3-58 


Van  Slyke  has  furnished  the  following  analysis  of  the  nitrogen  com- 
pounds in  a  sample  of  normal  American  Cheddar  cheese  six  months 
old  and  cured  at  60°  F. : 


Per  Cent 

Nin 
Cheese. 

Per  Cent 
Water- 
soluble  N. 

Per  Cent 

Nas  , 

Paracasein 

Mono- 

lactate. 

Per  Cent 

N  as  Para- 

nuclein. 

Per  Cent 

N  as 
Caseoses. 

Per  Cent 

N  as 
Peptones. 

Per  Cent 

N  as 
Amides. 

Per  Cent 

N  as 
Ammonia. 

3.80 

1.46        1        0.94 

1 

0.14 

0.22 

0.18 

0-79 

0.13 

U.  S.  standards.! — Cheese  is  the  sound,  solid,  and  ripened  product 
made  from  milk  or  cream  by  coagulating  the  ca.scin  thereof  with  rennet 
or  lactic  acid,  with  or  without  the  addition  of  ripening  ferments  and 
seasoning,  and  contains,  in  the  water-free  substance,  not  less  than  50% 
of  milk  fat.  By  act  of  Congress,  approved  June  6,  1896,  cheese  may 
also  contain  added  coloring  matter. 

Skim-milk  Cheese  is  defined  the  same  as  cheese  except  that  it  is 
made  from  skim  milk,  and  no  minimum  percentage  of  fat  in  the  water- 
free  substance  is  specified. 

Adulteration. — Cheese  is  commonly  adulterated  in  two  ways:  first, 
by  the  partial  or  total  substitution  for  the  milk  fat  of  a  foreign  fat,  as 
oleomargarine  or  lard,  and,  second,  by  using  skimmed  milk  as  a  mate- 
rial for  its  manufacture. 

In  many  locahties  a  standard  percentage  for  fat  in  cheese  is  fixed  by 
law,  as  in  the  case  of  the  U.  S.  standard  noted  above,  all  samples  falling 
below  that  standard,  unless  sold  as  skim-milk  cheese,  being  deemed  adul- 
terated. 


*  Dairy  Calendar,  p.  223. 

t  U.  S.  Dept.  of  .'\gric..  Off.  of  Sec,  Circ.  19. 


204  FOOD  INSPFCTION   AND  ANALYSIS. 

Some  States  have  specific  standards  for  varying  grades  of  cheese, 
classified  as  to  their  fat  content.  Thus  under  the  Pennsylvania  law* 
cheese  is  divided  into  five  grades,  as  follows: 

Full-cream  cheese  must  contain  not  less  than  32*^,  butter  fat. 

Three-fourths  cream  cheese  must  contain  not  less  than  24%  butter 
fat. 

One-half  cream  cheese  must  contain  not  less  than  16%  butter  fat. 

One-fourth  cream  cheese  must  contain  not  less  than  8%  butter  fat. 

All  cheese  having  less  than  8%  fat  must  be  branded  "  Skimmed  Cheese." 

The  term  "filled  cheese"  is  commonly  apphed  to  a  product  in  which 
a  foreign  fat,  as  oleo  oil  or  lard,  has  been  used.  Filled  cheese  is  more 
commonly  found  in  localities  where  a  carcfull}'  enforced  fat-standard 
law  prevails,  but,  in  the  absence  of  a  standard  for  fat  in  cheese,  the  manu- 
facturer can  cheapen  his  product  much  more  readily  and  conveniently 
by  selling  a  skim-milk  cheese  in  i)lace  of  the  whole-milk  article,  though 
not  without  producing  a  sensibly  inferior  product. 

METHODS    OF   ANALYSIS. 

Obtaining  a  Representative  Sample. — Method  oj  the  A.  O.  A.C.-] — By 
means  of  a  cheese-trier  remove,  if  possible,  three  cylindrical  plugs  from 
the  cheese  perpendicular  to  the  surface  and  in  length  equal  to  about  half 
the  thickness  of  the  cheese,  one  at  the  centre,  one  near  the  circumference, 
and  one  midway  between  the  two.  About  one  inch  in  length  is  cut  off 
from  each  plug  from  the  end  having  the  rind,  and  this  is  discarded.  The 
rerrraining  portions  of  the  i)lugs  are  then  finely  divided  and  mixed  as 
intimately  as  possible. 

In  place  of  the  plugs  a  narrow,  wedge-shaped  segment  may  be  cut  from 
the  cheese,  reaching  from  the  circumference  to  the  center,  the  portions 
near  the  rind  being  removed,  and  the  remainder  of  the  i)iece  being  finely 
divided  and  mixed  as  before.  Analyses  should  immediately  be  begun 
after  obtaining  the  sample. 

Determination  of  Water. — Two  or  three  grams  of  the  sample  are 
carefully  weighed  in  a  tared  platinum  dish,  and  dried  to  constant  weight 
in  an  oven  at  lOo'"'  C.     The  loss  of  weight  i^  reckoned  as  water.J 

*  Penn.  Laws,  1901,  Act.  95,  p.  128. 
t  I'.  S.  Dcpt.  of  Agric,  Bur.  of  C'hem.,  Hul.  46,  p.  55. 

X  I'revif)usly  ignitcfl  .sanfl  or  asbestos  is  recommended  by  some  as  an  absorbent  to  be 
placed  in  the  dish,  but  the  writer  gets  better  results  in  most  cases  directly  as  above. 


I 


MILK.  205 

Determination  of  Ash. — Ignite  the  residue  from  the  moisture  determina- 
tion at  a  low,  red  heat,  cool  in  a  desiccator,  and  weigh. 

Determination  of  Fat. — Lythgoe^s  Modified  Babcock  Method. — Weigh 
accurately  about  6  grams  of  the  sample  in  a  tared  beaker.  Add  10  cc. 
of  boihng  water,  and  stir  with  a  rod  till  the  cheese  softens  and  an  even 
emulsion  is  formed,  preferably  adding  a  few  drops  of  strong  ammonia  to 
aid  in  the  softening  and  emulsionizing,  and  keeping  the  beaker  in  hot 
water  till  the  emulsion  is  tolerably  complete  and  free  from  lumps. 

If  the  sample  is  a  full-cream  cheeee,  which  is  usually  evident  from 
its  taste  and  appearance,  a  Babcock  cream-bottle  is  employed.  The 
contents  of  the  beaker,  after  cooling,  are  transferred  to  the  test-bottle 
as  follows:  Add  to  the  beaker  about  half  of  the  17.6  cc.  of  sulphuric 
acid  regularly  used  for  the  test,  stir  with  the  rod  and  pour  carefully  into 
the  bottle,  using  the  remainder  of  the  acid  in  two  portions  for  washing 
out  the  beaker.  Finally  proceed  as  in  the  regular  Babcock  test  for  milk. 
Multiply  the  fat  reading  by  18  and  divide  by  the  weight  of  the  sample 
taken  to  obtain  the  per  cent  of  fat. 

Short's  Method."^ — Grind  to  a  uniform  powder  2  to  5  grams  of  the 
sample,  and  about  twice  its  weight  of  anhydrous  copper  sulphate.  Place 
a  layer  of  anhydrous  copper  sulphate  about  2  cm.  thick  on  the  bottom 
of  the  inner  tube  of  a  Johnson  or  Knorr  extractor,  add  the  ground  mix- 
ture, and  rinse  the  mortar  first  with  a  little  anhydrous  copper  sulphate 
and  finally  with  ether.  Extract  for  16  hours,  evaporate  the  ether  from 
the  extraction-flask,  and  dry  the  fat  in  a  boiling-water  oven  to  constant 
weight. 

Werner-Schmidt  Method. — Boil  2  to  3  grams  of  the  sample  in  the 
Werner-Schmidt  tube  (p.  139)  with  5  cc.  of  water  and  10  cc.  of  con- 
centrated hydrochloric  acid  till,  with  constant  shaking,  all  but  the  fat  is 
dissolved.  Cool,  add  25  cc.  of  ether,  and  shake  the  tube  well.  Draw 
off  as  much  as  possible  of  the  ether,  after  separation,  in  the  usual  manner, 
and  extract  with  four  or  five  additional  portions  of  the  solvent. 

Distil  off  the  ether  from  the  combined  extractions,  and  weigh  the  fat. 

Determination  of  Protein. — From  i  to  2  grams  of  the  cheese  are 
treated  by  the  Gunning  or  Kjeldahl  method,  adding  after  partial  diges- 
tion a  piece  of  copper  sulphate  the  size  of  a  pea  to  aid  in  the  con- 
version.!    NX6.25  =  protein. 

*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bu'.  35,  pp.  15,  17,  225. 
t  Van  Slyke,  N.  Y.  p:xp.  Station,  Bulletin  215. 


2o6  FOOD   INSPECTION   /1ND  /IN A  LYSIS. 

Separation  and  Determination  of  Nitrogen'  Compounds. —  Methods  of 
Van  Slvkc* — Twenty-five  grams  of  the  samjile  are  mixed  in  a  porcelain 
mortar  with  an  equal  volume  of  clear  quartz  sand.  Transfer  the  mix- 
ture to  a  450-cc.  Erlenmever  llask,  add  about  100  cc.  of  water  at  50°  C, 
and  keep  the  temperature  at  50°  to  55°  C.  for  half  an  hour  with  frequent 
shaking.  Decant  the  liquid  through  an  absorbent-cotton  filter  into  a 
500-cc.  graduated  flask.  Treat  the  residue  with  repeated  portions  of 
100  cc.  each  of  water,  heating,  shaking,  and  decanting  as  above  till  the 
nitrate,  or  water  extract,  at  room  temperature  amounts  to  just  500  cc. 
exclusive  of  the  fat  floating  on  top,  and  use  aliciuot  parts  of  this  water 
extract  for  the  various  determinations. 

Water-soluble  Nitrogen. — Determine  the  nitrogen  by  the  Gunning 
method  in  50  cc.  of  the  above  water  extract,  corresponding  to  2.5  grams 
of  cheese. 

Xitrogcn  as  Paranuclei n. — Add  5  cc.  of  a  1%  solution  of  hydrochloric 
acid  to  100  cc.  of  the  above  w-ater  extract  (corresponding  to  5  grams  of 
cheese),  and  keep  the  temperature  at  50°  to  55°  till  the  separation  is  com- 
plete, as  shown  by  a  clear  supernatant  liquid.  Filter,  wash  the  precipi- 
tate with  water,  and  determine  the  nitrogen  therein  by  the  Gunning 
method. 

Xitrogcn  as  Coagulable  Protein. — Neutralize  the  filtrate  from  the 
preceding  determination  with  dilute  potassium  hydroxide,  and  heat  at 
the  temperature  of  boiling  water  till  the  coagulum,t  if  any,  settles  com-, 
pletely.     Filter,  wash  the  precipitate,  and  determine  the  nitrogen  therein. 

Nitrogen  as  Caseoses. — Treat  the  filtrate  from  the  preceding  with  i  cc. 
of  50^  sulphuric  acid  saturated  with  C.  P.  zinc  sulphate,  and  warm  to 
about  70°  C.  till  the  caseoses  settle  out  completely.  Cool,  filter,  wash 
with  a  saturated  solution  of  zinc  sulphate  acidified  with  sulphuric  acid, 
and  determine  the  nitrogen  in  the  precipitate. 

Nitrogen  as  Amides  and  Peptones. — Place  100  cc.  of  the  water  extract 
of  cheese  in  a  250-cc.  graduated  flask,  add  i  gram  of  sodium  chloride 
and  a  solution  containing  12%  of  tannin,  till  the  addition  of  a  drop  to 
the  clear  supernatant  liquid  does  not  further  precipitate.  Dilute  to  the 
250-cc.  mark,  shake,  pour  upon  a  dr)'  filter,  and  determine  the  nitrogen 
in  50  cc.  of  the  filtrate,  which  gives  the  amount  of  nitrogen  in  the 
amido-acid  and  ammonia  compounds.     Deduct  from  this  the  amount  of 

*  Van  Slykc,  N.  Y.  Exp.  Station,  Bulletin  215. 

t  According  to  Van  Slyke  a  precipitate  at  this  point  is  rare  in  (  hecse. 


MILK.  207 

nitrogen  as  ammonia  separately  determined,  and  the  difference  is  the 
amido-nitrogen. 

Nitrogen  as  peptones  is  obtained  by  subtracting  the  sum  of  the  amounts 
of  nitrogen  as  paranuclein,  coagulablc  proteins,  caseoses,  amido-bodies, 
and  ammonia  from  the  total  nitrogen  in  the  water  extract. 

Nitrogen  as  Ammonia. — Distil  100  cc.  of  the  filtrate  from  the  above 
tannin-salt  precipitation  into  standardized  acid,  and  titrate  in  the  usual 
manner. 

Nitrogen  as  Paracasein  Lactate. — Treat  the  residue  insoluljlc  in  water 
in  obtaining  the  water  extract,  with  several  portions  of  a  5%  solution 
of  sodium  chloride,  to  form  a  500-cc.  salt  extract  of  the  same,  in  an 
analogous  manner  to  that  employed  in  preparing  the  water  extract. 
Determine  the  nitrogen  in  an  aliquot  part  of  this  salt  extract. 

Determination  of  Lactic  Acid.* — Add  water  to  10  grams  of  the  cheese 
sample  at  40°  C.  till  the  volume  equals  105  cc.  Shake  and  filter.  Titrate 
i25  cc.  of  the  filtrate  (equivalent  to  2.5  grams  of  cheese)  with  tenth-normal 
sodium  hydroxide,  using  phenolphthalein  as  an  indicator. 

Each  cubic  centimeter  of  decinormal  alkali  is  equivalent  to  0.009 
gram  lactic  acid. 

Determination  of  Milk  Sugar. — Boil  25  grams  of  finely  divided  cheese 
with  two  successive  portions  of  about  100  cc.  each  of  water,  decant 
through  a  filter,  and  finally  transfer  the  residue  upon  the  filter  and  wash 
with  hot  water.  Make  up  the  entire  aqueous  extract  thus  obtained,  when 
cold,  to  250  cc,  and  determine  the  milk  sugar  by  either  Fehling  method. 

Detection  of  Foreign  Fat. — The  cheese  fat,  separated  in  the  manner 
described  below,  is  subjected  to  the  various  processes  detailed  under 
butter,  in  precisely  the  same  way,  the  fat  of  cheese  being  identical  with 
that  of  butter.  The  most  ready  means  for  judging  its  purity  consists 
in  determining  the  refraction  with  the  butyro-refractometer,  and  the 
Reichert  number. 

Separation  of  the  Fat  for  Examination. — Place  a  quantity,  say  25 
grams,  of  the  finely  divided  sample  in  a  large  Erlenmeyer  flask,  add  about 
100  cc.  of  petroleum  ether,  cork  the  flask  and  allow  it  to  stand  for  several 
hours  with  frequent  shaking.  Decant  the  petroleum  ether  through  a 
filter,  evaporate  off  the  solvent  by  the  aid  of  heat,  and  the  residue  will 
be  found  to  consist  of  nearly  pure  fat. 

Or,  wrap  a  suflacient  portion  of  the  finely  divided  sample  in  a  muslin 

*  U.  S.  Dept.  of  Agric,  Bureau  of  Chem.,  Bui.  46,  p.  56,    ' 


200  FOOn   l.\SPFCTIOIV  AND    ANALYSIS. 

cloth,  place  this  in  a  dish,  and  heat  on  the  water-bath.  The  fat  which 
runs  out  is  afterward  filtered  and  dried  at  ioo°. 

Sufficient  cheese  fat  may  usually  be  obtained  for  the  rcfractometcr 
reading  from  the  neck,  of  the  test-bottle,  after  completing  the  Babcock 
test,  anil,  usually  (except  in  the  case  of  skimmed-milk  cheesf),  for  the 
Reichcrt  number. 

Detection  of  Skimmed-milk  Cheese. — In  a  cream  cheese  the  fat 
should  greatly  e.N'ceed  the  protein;  in  a  whole-milk  cheese  the  per  cent 
of  fat  should  at  least  equal  that  of  the  protein,  and  is  generally  in  excess. 
If  the  fat  is  considerably  less  tlian  the  [jrotein,  tlic  cheese  has  undoubtedly 
been  made  from  skimnied  milk.  The  following  analyses,  made  in  the 
writer's  laboratory,  illustrate  these  grades: 


Varieties  of  Cheese- 

Full  cream  (soft) 

Whole  milk  (hard) 

Whole  milk  (soft) 

Skinmied  milk  (soft) 

Ccnlrifugally  skimmed  milk  (soft) 


Water. 


Fat. 


37-63  ' 
21.89 

55-95  1 
62.17  ' 
72.80       I 

*  By  difference. 


47.40 
38-00 
24.00 
15.20 
2.00 


Protein.* 


13.70 

37-71 
16.49 
21.36 
23-52 


Ash. 


1.27 
2.40 
3-56 
1.27 
1.68 


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MILK.  209 

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McGiLL,  A.     Condensed  Milk.     Canada  Inl.  Rev.  Dept.,  Buls.  54,  69. 
Otto,  A.     Die  Milch  und  ihre  Produkte.     Berlin,  1892. 
Pearmain,  T.  H.,  and  Moor,  C.  G.     The  Analysis  of  Food  and  Drugs.     Part  I.  Milk 

and  Milk  Proteids.     London,  1897. 
Pearson,  R.  A.     National  and  State  Dairy  Laws.     U.  S.  Dept.  of  Agric,  Bureau  of 

An.  Ind.  Bui.  26,  1900. 
Richmond,  H.  D.     Dairy  Chemistry.     London,  1889. 
Russell,  H.  L.     Dairy  Bacteriology.     Madison,  1899. 

Scherer,  R.,  trans,  by  Salter,  C.     Casein:    Its  Preparation  and  Technical  Utiliza- 
tion.    London,  1906. 
ScHOLL.     Die  Milch. 

ScHRODT,  M.     Anleitung  zur  Priifung  der  Milch  u.  s.  w.     Bremen,  1892. 
Sherman,  H.  C.     Seasonal  Variations  in  the  Composition  of  Cow's  ]Milk.     Jour.  Am. 

Chem.  Soc,  28,  1906,  p.  17 19. 

On  the  Composition  of  Cow's  Milk.     Jour.  Am.  Chem.  Soc,  25,  1903,  p.  132. 

Snyder,  H.     The  Chemistry  of  Dairying.     Easton,  1897. 

Stutzer,  a.     Die  chem.  Untersuchung  der  Kase.     Zeits.  f.  anal.  Chem.,  1886,  p.  493. 

SwiTHiNBANK,  H.     Bactcr'ology  of  Milk.     1903. 

Tourchot,  a.  L.     Milk  ;  nd  Milk  Adulteration.     Canada  Int.  Rev.  Bui.  53. 

Van  Freudenreich,  E.     Die  Bakteriologie  in  der  Milchwirthschaft.     Basel,  1893. 

Van  Slyke.     Modern  Methods  of  Testing  Milk  and  Milk  Products.     New  York,  1907. 

Woo'  MAN,  A.  G.     On  the  Determination  of  Added  Water  in  Milk.     Jour.  .\m.  Chem. 

Soc,  21,  1899,  p.  503. 
Wanklyn,  J.  A.     Milk  Analysis.     London. 

Weigmann,  H.     Die  ]Methodcn  der  Milchcunsrvirung.      Bremen,  1S93. 
Whitaker,  G.  M.     The  Milk  Supply  of  Boston  and  other  New  England  Cities.     U.  & 

Dept.  of  Agric,  Bur.  of  An.  Ind.  Bui.  26,  1900. 


2IO  FOOD   IXSPECTION  JND    ANALYSIS. 

Alabama  Exp.  Sta.  Bui.  07.     Dairy  arni  Milk  Inspection. 
Annual  Reports  of  Inspector  of  Milk  and  Vinegar,  Boston,  Mass. 

"      "     Cambridge,   Mass. 
Arkansas  Exp.  Sta.  Bui.  45.     Milk,  its  Decomposition  and  Preservation. 
Dair>-  Products.     U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bulletin  13,  part  i,  1887. 
Die  Milchzeitung.     Bremen,  1872  et  scq. 
Farmers'  Bulletin,  Xo.     2.     Bacteria  in  Milk. 


20 
29 
42 

74 
166 


Milk  Fermentation  and  its  Relations  to  Dairying. 
Souring  of  Milk. 
Facts  about  Milk. 
Milk  as  Food. 

Cheese-making  on  the  Farm. 
Kansas  Exp.  Sta.  Bui.  88.     Keeping  Milk  in  Summer. 
Maine  Exp.  Sta.  Bui.  23  (New  Series).     Cream  Preservation. 
Massachusetts  State  Board  of  Health  Reports,  1883  ct  seq. 
Michigan  Exp.  Sta.  Bui.  140.     Ropiness  in  Milk. 

Minnesota  Exp.  Sta.  Bui.  74.     Milk  and  Cheese,  Digestibility  and  Food  Value. 
New  York  (Geneva)  Exp.  Sta.  Bui.    70.     Reasons  for  Changing  Milk  Standards. 

"  "  "       "        "    215.     Estimation    of   Proteolytic    Compounds   ia 

Cheese  and  Milk. 
"       "      (Ithaca)        "       "        "    165.     Ropiness  in  Milk. 

(1  (<  (<  (I  <(  (C  ^  ((  II  H 

North  Carolina  Exp.  Sta.  Bui.  113.     Testing  of  Milk. 

Oklahoma  Exp.  Sta.  Bui.  21.     A  New  Milk  Test. 

West  Virginia  Exp.  Sta.  Bui.  58.     Effect  of  Pressure  in  the  Preservation  of  Milk. 

Wisconsin  Exp.  Sta.  Bui.  48.     Conn.  Culture  B.  41,  in  Butter-making. 

"  "       "        "    52.     Babcock  vs.  Gravimetric  Tests  for  Fat.     Acidity  in  Milk. 

"  "       "        "    54.     Restoration  of  Consistency  of  Pasteurized  Cream. 

"  "       "        "    61.     Constitution  of  M  ilk  with  Reference  to  Cheese  Produc- 

tion. 
"       "        "    62.     Tainted  or  Defective  Milks. 

"  "       "        "    70.     Cheese-cunng. 

"  "       "     Annual  Reports.     12th  et  seq. 

Zeitschrift  der  Fleisch  und  Milch  Hygiene. 


CHAPTER  Vlir. 
FLESH    FOODS. 

MEAT. 

General  Structure  and  Composition. — Meat  is  structurally  made  up 
of  muscle  fibers,  held  together  by  connective  tissue,  through  which  fat 
cells  are  usually  more  or  less  abundantly  distributed.  Each  muscle  fiber 
has  a  sheath  or  covering  known  as  sarcolemma,  formed  of  an  albuminoid 
substance  similar  to  elastin,  and  within  the  fibers  are  contained  the  meat 
juices,  which  are  solutions  in  water  of  proteins,  non-protein-nitrogenous 
extractives,  and  salts.  The  substance  of  the  connective  tissue  is  made 
up  largely  of  the  albuminoids  elastin  (insoluble)  and  collagen,  the  latter 
being  convertible  by  boiling  with  water  or  treatment  with  acids  into  gela- 
tin. The  proteins  of  the  meat  juices  consist  chiefly  of  the  globulin  myo- 
sin (by  far  the  most  abundant),  muscle  albumin,  and  the  muscle  pigment 
hcemoglohin,  or  a  substance  closely  analogous  thereto. 

In  the  living  muscle  there  are  no  peptones,  but  the  ferment  pepsin 
is  present.  After  death,  by  the  action  of  the  pepsin  in  presence  of  lactic 
acid,  a  portion  of  the  normal  proteins  of  the  muscle  undergoes,  as  it  were, 
digestion,  so  that  in  meat  both  peptones  and  proteoses  *  are  found. 

The  non-protein-nitrogenous  extractives  are  mainly  creatin,  xanthin, 
hypoxanthin,  and  carnin,  which,  from  their  basic  character,  are  known 
as  flesh  bases. 

The  approximate  proportions  in  which  the  chief  constituents  are  present 

in  meat  is  thus  shown  by  Konig : 

Water 75.0  to  77.0 

Sarcolemma  (muscle  fiber) 13-0  to  18.0 

Connective  tissue 2.0  to    5.0 

Albumin 0.6  to    4.0 

Creatin 0.07  to    0.34 

Hypoxanthin 0.61  to    0.03 

Creatinin 

Xanthin Undetermined 

Inosinic  acid 

Uric  ^cid 

Urea o.ot  to    0.03 

*  A  proteose  or  albumose  known  as  myoalbumose  normally  exists  in  the  live  muscle. 

211 


Nitrogenized  compounds. 


-J  I  2  FOOD  JNSf'ECTlON  /tND  ANALY:>IS. 


Fat - 0.5       to    3  5 

Lactic  acid o  -  05     to    o .  oj 

Butyric  acid ] 

Acetic  acid 


t-        .         -J  \    Undetermined 

r orniic  acid 


Other  nitrogen-free  compounds. . 

Inosite J 

Glycogen (0.3       to  O-O 

Salts '. (0.8      to  1.8) 

Composed  of: 

Potash 0.40    to  o.qo 

Soda 0.02     to  0.08 

Linu- o.oi     to  0.07 

Magnesia 0.02     to  0.05 

Oxide  of  iron 0.003  to  0.0 

rhos|)horir  ac  id 0.40    to  0.50 

Suli)hnric  acid 0.003  to  0.04 

Chlorine o.oi     to  0.05 

Nitrogen  compounds  constitute  by  far  the  most  abundant  and  im- 
portant portion  of  the  substance  of  lean  meat.  Carbohydrates  are  alm.ost 
entirely  lacking,  the  small  amount  of  glycogen  and  muscle  sugar  togcthci 
constituting  rarely  more  than  i  per  cent. 

Glycogen  (CeHioOs),  sometimes  called  animal  starch,  is  a  white,  amor- 
phous, tasteless,  and  odorless  substance,  when  pure,  much  resembling 
starch.  It  is  soluble  in  water,  forming  an  opalescent  solution,  and  is 
insoluble  in  ether  and  alcohol.  With  iodine  a  port-wine  color  is  pro- 
duced, which  disappears  on  heating  and  reappears  on  cooling.  Glycogen 
is  strongly  de.xtro-rotar}-.  It  is  converted  to  dextrose  by  boiling  with 
dilute  mineral  acid. 

Muscle  Sugar  is  either  entirely  absent  m  the  living  muscle,  or  exists 
in  traces  only.  After  death  it  is  formed  presumably  from  the  glycogen, 
and  cxi.^t5  in  a  very  minute  quantity,  probably  as  dextrose. 

Inosite  (C8H,,0e+  HjO)  is  found  in  traces  in  the  muscular  substance  of 
the  heart,  liver,  kidneys,  and  testicles. 

Proximate  Constituents  of  the  Commoner  Meats.- — The  chief  charac- 
tcristics  of  the  flesh  of  various  animals  are  in  the  main  very  similar,  Vv-hat- 
cvcr  the  nature  of  the  animal.  So  tme  is  this,  indee;!,  that  it  is  extremely 
difficult  from  a  chemical  analysis  to  distinguish  a  particular  kind  of  fle.-,h 
when  mixed  with  that  of  other  animals  in  finely  divided  meat  [) reparations^ 
such  as  sausages,  potted  and  deviled  meats,  and  the  like. 

The  average  composition  of  the  commoner  cuts  of  Ijeef,  veal,  niuttor, 
lamb,  and  pork,  as  well  as  of  fowl  and  game,  is  shown  in  the  following 
tables,  compilerl  from  the  work  of  Atwater  and  lir}'ant,*  the  accompanying 
diagrams  sen-ing  to  locate,  in  the  case  of  ordinan,'  meats,  the  portion  of 
the  animal  from  which  the  meat  is  taken. 

♦  U.  .S.  Dcpt.  of  Agric,  Off.  of  Exp.  Stations.  Bui.  28  (.Revised  Ed.). 


FLESH  HOODS. 


1.  Keck 

2.  Chuck 

3.  Ribs 

4.  Shoulder  clod 

5.  Foi-e  shank 
0.  Brisket 

7.  Cross  ribs 

8.  Plate 


'/iD/U- 


9.  Navel 

10.  Loin 

11.  Flank 

12.  Kump 

13.  Round 

H.  Second  cut  round 
1>.  Hind  shank 


Fig.   56.— Diagram  Showing  Cuts  of  Beef. 
COMPOSITION  OF  BEEF. 


Cut. 


Num- 
ber of 
Anal- 
yses. 


Refuse. 


Water. 


Protein. 


N  < 
6.25. 


By 

Differ- 
ence. 


Fat. 


Ash. 


Fuel 
Value 

per 
Pound. 
Cals. 


Chuck:  Lean — 
Medium- 
Fat— 

Ribs:      Lean — 
Medium- 
Fat— 

Loin:      Lean — 
Medium- 
Fat— 

Rump:    Lean — 
Medium- 
Fat— 

Round:  Lean — 
Medium- 
Fat— 


edible  portion. 

as  purchased.  . 
-edible  portion. 

as  purchased. . 

edible  portion. 

as  purchased. . 

edible  portion. 

as  purchased. . 
-edible  portion. 

as  purchased. . 

edible  portion. 

as  purchased. . 

edible  portion. 

as  purchased. . 
-edible  portion. 

as  purchased. . 

edible  ])ortion. 

as  purchased. . 

edible  portion. 

as  purchased. . 
-edible  portion. 

as  purchased. . 

edible  portion. 

as  purchased. . 

edible  portion. 

as  purchased. . 
-edible  portion. 

as  purchased . . 

edible  jxirtion . 

as  purchased. . 


19-5 


15.2 
14.7 


22.6 


20.8 


32 
32 
6 
6 
4 
3 

10 
10 
S 
5 
31 
29 
18 

14 
5 
3 


13- 1 


14.0 


20.7 


5.1 


7.2 
12.0 


71-3 

20.2 

I 

57-4 

16.3  .  I 

68., C5 

19.6  I   I 

57-9 

16.6  i   I 

62.3 

18.5 

53-3 

15-9 

66.0 

16-5 

52.6 

15-2 

55-5 

17-5 

43 -« 

13-9 

48.5 

15-0 

,S9-6 

12.7 

67.0 

19.7 

S8.2 

17. 1 

60.6 

18.5 

52-S 

16. 1 

54-7 

17-5 

49-2 

15-7 

65.7 

20.9 

56.6 

19. 1 

56-7 

17.4 

45-0 

13-8 

47-1 

16.8 

36.2 

12.9 

70.0 

21-3 

64.4 

19-5 

t>5.5 

20.3 

60.7 

19.0 

60.4  ■ 

19-5 

54-0 

17-5 

9-5 
5-7 
8.9 
6.0 
8.0 

5-4 
6.9 
4-8 
7.0 

3-5 

5-2 
2.4 

9-3 
6-7 
8.2 

5-8 
6.8 
5-0 
9.6 

7-5 
6.9 

3-4 
6.4 
2.6 
i.o 

9-2 

9.8 
8.3 

9.1 

7-1 


8.2 

6.6 

II. 9 

lO.I 

18.8 

15-9 
9.8 

9-3 
26.6 
21.2 
.35-6 
30.6 
12.7 
II. I 
20.2 

17-5 
27.6 
24.8 
13-7 

11. 0 

25-5 
20.2 

35-7 
27.6 

7-9 

7-3 

13.6 

12.8 

19-5 

16. 1 


0.8 
0.9 
0.8 
0.9 
0.7 
0.8 
0.7 
0.9 
0.7 
0.7 
0.6 
1.0 
0.9 
1 .0 
0.9 
0.9 
0.8 
1.0 
0.9 
0.9 
0.7 
0.8 
0.6 


I.I 
1.0 
1.0 
o.S 


720 
580 
865 
735 
113s 
965 
790 

675 
1450 

"55 
1780 

1525 
900 

785 
1 190 
1040 
1490 
1305 

965 

S?o 

1400 

mo 

1820 

1405 

730 

670 

950 

895 

1 185 

1005 


214 


FOOD  INSPECTION  AND  ANALYSIS. 


l.Neck 

6.  Ribs 

2.  Chuck 

T.Loin 

S.  Shoulder 

8.  Flank 

I ,  Foie  .>-bank 

9lAB 

6.  Breuit 

10.  Ilind  shank 

Fig.  57. — Diagram  Showing  Cuts  of  Veal. 


COMPOSITION  OF  VEAL. 


Cut. 


Chuck:  Lean —      edible  portion. 

as  purchased. . 

Medium — edible  [jortion. 

as  purchased. . 

Ribs:       Medium — edible  jjortion. 

as  purchased. . 

Fat —         edible  portion. 

as  purchased. . 

Loin:      Lean —      edible  jjortion. 

as  purchased. . 

Medium — edible  portion. 

as  purchased. . 

Fat —  edible  portion. 

as  purchased. . 

Leg:        Lean —      edible  jKjrtion. 

as  purchased. . 

Medium — edible  f)oriion. 

as  purchased.. 


Num- 
ber of 
Anal- 
yses. 


6 
6 
9 
9 
3 
3 
5 
5 
6 
6 
2 
2 
9 
9 
10 

9 


Refuse. 


19.0 


i».9 
25-3 


24-3 
22.0 


16.5 


9.1 
14.2 


Water. 


76.3 
61.8 

73-3 
59-5 
72.7 

54-3 
60.9 
46.2 
73-3 
57-1 
69.0 

57-6 
61.6 
50-4 
73-5 
66.8 
70.0 
60.1 


Protein. 


NX 
6.25. 


19 
16 

7 
0 

20 

7 

15 
18 

5 
7 

14 

2 

20 

4 

15 

9 

19 
16 

9 
6 

18 

7 

15 

3 

21 

3 

19 

4 

20 

2 

15 

5 

Bv 
DifTer- 
ence. 


20.6 
16.7 
19.2 
15.6 
20.1 
15-0 


14.2 
19.9 
15-6 
19.2 
16.0 
18.5 
15-I 
21  .2 

19-3 
19.8 
16.9 


Fat. 


1-9 
1.6 

6.5 

5-2 

6.1 

4.6 

19-3 

14-5 

5-6 

4-4 

10.8 

9.0 

18.9 

iS-4 

4-1 

3-7 

9.0 

7-9 


Ash. 


1.2 
0.9 


0.8 
i.o 
0.8 
1.2 
0.9 
I   o 

0.9 

1.0 

0.8 


1.2 
0.9 


Fuel 
Value  . 

per 

Pound. 

Cals. 


465 
380 
640 

515 
640 
480 

1 160 
87s 
615 
480 
825 
690 

1 145 
935 
570 
520 

755 
620 


FLESH  FOODS. 


215 


1.  Neck 

2.  Chuck 

3.  Shoulder 
i .  Flank 
6.Loia 

a.  Leg 


Fig.  58. — Diagram  Sho\\ing  Cuts  of  Mutton. 
COMPOSITION  OF  MUTTON  AND  LAMB. 


Cut. 


Num- 
ber of 
Anal- 
yses. 


Refuse. 


Water. 


Protein. 


NX 
6.25. 


By 
Differ- 
ence. 


Fat. 


Ash. 


Fuel 
Value 

per 
Pound. 

Cals. 


Mutton. 

Chuck:  Lean —      edible  portion. 

as  purchased. . 

Medium — edible  portion. 

as  purchased. . 

Fat —         edible  portion. 

as  purchased. . 

Loin:      Medium — edible  portion. 

as  purchased . . 

Fat —         edible  portion . 

as  purchased. . 

Flank:    Medium — edible  portion. 

as  purchased. . 

Leg:        Lean —      edible  portion. 

as  purchased. . 

Medium — edible  portion. 

as  purchased. . 

Lamb. 

Chuck:  edible  portion. 

as  purchased. . 

Leg:        Medium — edible  portion. 

as  purchased. . 

Fat — -         edible  portion. 

as  purchased.. 

Loin:  edible  portion. 

as  purchased. . 


■9-5 


21.3 


16.0 
II. 7 


9-9 
16.8 


1S.4 


19. 1 


17.4 

13-4 
14.8 


64.7 
52.1 
50-9 
39-9 
40.6 

33-8 
50.2 
42.0 
43-3 
38-3 
46.2 

.S9-0 
67.4 
56.1 
62.8 
51-2 

56.2 
4S-5 
63-9 
52-9 
54-6 

47-3 
53-1 
45-3 


16.3 

13-1 
33-6 
26.7 

44-9 
37-5 
33-1 
28.3 

41-7 
36.8 

38-3 
36-9 
12.4 
10.3 
18.0 
14.7 

23.6 
19. 1 
16.5 
13.6 
27.4 

23-7 
28.3 
24.1 


0.9 


0.9 
0.6 


0.7 
0.8 
0.7 
0.8 
0.7 
0.7 
0.6 
1 .1 
0.9 
i.o 


0.8 


0.9 
0.9 


0.8 


1020 
820 
1700 
1350 
2155 
1800 

1695 

1445 

203s 

1795 

1900 

1815 

890 

740 

1 105 

900 

1350 
1090 

1055 
870 

1495 
1295 
1540 
1315 


i6 


hOOD  INSPECTION  AND  ANALYSIS. 


._       x<i"\'^'''""i" 
''III  v/.'-Js." '''/;!'*///'«"/'/ 


].  Head. 
2   Shoulder. 

3.  Back. 

4.  Middle  cut. 

5.  Belly. 

6.  Ham. 

7.  Ribs. 

8.  Loin. 


Fig.  59- — Diagram  Showing  Cuts  of  Pork. 
COMPOSITION  OF  PORK,  POULTRY,  AND  GAME. 


Num- 
ber of 
.\nal- 
yses. 

Refuse. 

Water. 

Protein. 

Fat. 

Ash. 

Fuel 

Cut. 

NX 
6.25. 

By 

Differ- 
ence. 

Value 

per 
Pound 
Cals. 

POPK. 

Shoulder:                  edible  portion. . 

as  purchased.. . 
Loin:      Lean —      edible  portion. . 

as  purchased 

Fat —         edible  portion. . 

as  purchased . . . 
Ham:      Lean —      edible  portion. . 

as  purchased.. . 
Fat —         edible  [X)rtion.. 

as  purchased 

Poultry  and  Gamt:. 
Chicken:                   edible  portion. . 

as  7jurcha.sed 

Fowl:                         edible  portion. . 

as  purchased... 
Goose:                       edible  portion. . 

as  purchased. .. 
Turkey:                     edible  portion. . 

as  purt  based 

Quail:                         as  purchased 

19 
19 

I 
I 
4 
4 

2 

2 

5 
5 

3 
3 

26 
26 
I 
I 
3 
3 
I 

12.4 

23-5 

'^6:5' 

0.9 

13-2 

41.6 
25-9 

"I'i.e 
22.7 

51.2 

44-9 
60.3 
46.1 
41.8 
.U-8 
60.0 
59-4 
.38.7 

74.8 
43-7 
63-7 
47-1 
46.7 

38-5 
55-5 
42.4 
66.9 

^3-3 
12.0 
20.3 
15-5 
14-5 
II. 9 
25.0 
24.8 
12.4 
,0.7 

21-5 
12.8 

19-3 
13-7 
.,6.3 

13-4 
21. 1 
16. 1 
21.8 

13.8 
12.2 
19.7 
I5-I 
I3-I 
10.9 

24-3 

24.2 

10.6 

9.2 

21  .6 
12.6 

19.0 
14.0 

16.3 

13-4 

20.6 

15-7 

34.2. 
29.8 
19.0 

14-5 
44-4 
37-2 
14.4 
14.2 
50.0 
43-5 

2-5 

1-4 
16.3 
12.3 
36.2 
29.8 
22.9 
18.4 

8.0 

0.8 
0.7 
1.0 
0.8 
0.7 
0.6 
1-3 
1-3 
0.1 

0-5 

I.I 

0.7 
1.0 

0.7 
0.8 
0.7 
1.0 
0.8 
1-7 

1690 

1480 

1 180 

900 

2145 
1790 

1075 
1060 

2345 
2035 

.-05 

295 

1 045 

775 
1830 

1505 
1360 

107s 

775 

FLHSH  FOODS.  217 

Characteristics  of  Sound  Meat. — The  reaction  of  meat  should  be  acid. 
If  neutral  or  alkaline,  decomposition  is  indicated,  except  that  alkalinity 
may  be  due  to  the  use  of  alkaline  salts  as  prcser\^atives. 

Lethcby  *  gives  the  following  characteristics  of  sound,  fresh  meat.  In 
color  it  is  neither  pale  pink  nor  deep  purple,  the  former  indicating  that 
the  animal  was  affected  with  some  disease,  and  the  latter  that  it  died  a 
natural  death,  and  was  not  slaughtered.  In  appearance  it  is  marbled, 
due  to  the  presence  of  small  veins  of  fat  distributed  among  the  muscles. 
In  consistency  it  is  firm  and  elastic  to  the  touch,  and  should  hardly  moisten 
the  finger;  a  wet,  sodden,  or  flabby  consistency  with  a  jelly-like  fat  is 
indicative  of  bad  meat.  As  to  odor,  it  is  practically  free  ;  whatever  odor 
there  is  should  not  be  disagreeable;  a  sickly  or  cada^•erous  smell  is  indica- 
tive of  diseased  meat.  After  standing  for  a  day  or  so,  it  should  not  become 
wet,  but  on  the  contrary  should  grow  drier.  When  dried  at  100°  C.  it 
should  not  lose  more  than  70  to  74  per  cent  in  weight;  unsound  meat 
frequently  loses  80%  or  more.     It  should  shrink  vcr\'  little  in  cooling. 

Inspection  of  Meat. — While  carefully  drawn  laws  exist  almost  every- 
where relating  to  the  sale  of  meat,  and  government  inspectors  are  ap- 
pointed to  carry  out  the  requirements  of  the  laws,  yet  in  this  country  there 
is  undoubtedly  some  meat  unfit  for  food  on  the  market,  owing  to  the 
small  number  of  inspectors,  and  the  consequent  comparative  safety  with 
which  unscrupulous  dealers  may  sell  meats  forbidden  by  law  and  escape 
detection.  The  insp"Ction  of  meats  and  lish  under  municipal  ordinances 
is  not  always  carried  out  as  thoroughly  as  might  be  desired. 

Unwhole sameness  of  Meat  may  be  due  to  a  diseased  condition  of  the 
animal  w^hile  ahve,  or  to  poisonous  or  injurious  toxins  developed  by 
the  action  of  bacteria  after  death.  In  the  first  case,  the  diseased  conditions 
may  be- due  to  temporary  causes  only,  or  to  the  presence  of  animal  parasites, 
such  as  trichinae  in  pork,  or  as  the  result  of  pathogenic  bacteria,  causing 
such  serious  diseases  as  tuberculosis,  anthrax,  glanders,  etc.  It  thus 
requires  much  skill  and  judgment  on  the  part  of  the  meat-inspector 
to  correctly  pass  upon  the  suitability  for  food  of  the  various  meals  as 
they  appear  on  the  market.  Coplin  and  Bevan  f  give  in  detail  useful 
data  regarding  the  inspection  of  meat,  as  well  as  of  the  animal  before 
slaughtering,  showing  the  requisite  size,  weight,  age,  conditions  of  health 
etc.,  that  should  obtain,  Tlie  detailed  physical  and  microscopical  exami- 
nation involved  in  such  inspection  is,  however,  rarely  germane  to  the 
work  of  the  public  food  analyst,  and  will  not  be  treated  of  in  this  manual. 

*  Lectures  on  Food,  p.  210.  f  Practical  Hygiene,  pp.  130-157. 


2lS  FOOD  INSPECTION  AND  ANALYSIS. 

It  is  also  beyond  the  scope  of  the  present  work  to  treat  of  the  harmful 
toxins  developed  by  bacterial  action  in  meat  and  fish,  causing  what  is 
kno\Mi  as  ptomaine  poisoning.  The  work  of  detecting  and  isolating 
such  poisons  comes  within  the  province  of  the  bacteriologist  and  biolo- 
gist, rather  than  that  of  the  chemist,  involving  many  experiments  upon 
guinea-pigs,  rabbits,  or  other  aninials  not  usually  found  in  the  chemist's 
laboratory-.  It  has  furthermore  been  recently  shown  by  Vaughn  and 
Novy  *  that  even  when  these  toxins  are  present  in  foods  in  sufficient 
quantity  to  produce  serious  results,  very  considerable  amounts  of  the 
food  must  be  taken  in  order  to  isolate  them  by  chemical  means,  more, 
in  fact,  than  is  usually  available  for  analysis. 

For  the  general  inspection  of  meats  for  animal  parasites,  poisonous 
toxins,  etc.,  the  reader  is  referred  to  such  works  as  those  of  Vaughn  and 
Novy,  Fischoder,  Walley,  Andrews,  Cobbold,  and  Salmon  as  cited  in  the 
references  on  jiages  258  to  260. 

U.  S.  Standards.! — Standard  Meat  is  any  sound,  dressed,  and  properly 
prepared  edible  part  of  animals  in  good  health  at  the  time  of  slaughter. 
The  term  "animals"  as  herein  used  includes  not  only  mammals,  but 
fish,  fowl,  crustaceans,  mollusks,  and    all  other  animals  used  as  food. 

Standard  Fresh  Meat  is  meat  from  animals  recently  slaughtered,  or 
preserved  only  by  refrigeration. 

Standard  Salted,  Pickled,  and  Smoked  Meats  are  unmixed  meats  pre- 
served by  salt,  sugar,  vinegar,  spices,  or  smoke,  singly  or  in  combination, 
whether  in  bulk  or  in  jjackages. 

Standard  Manujacturcd  Meats  are  meats  not  included  in  the  above 
divisions,  whether  simple  or  mixed,  whole  or  comminuted,  with  or  without 
the  addition  of  salt,  sugar,  vinegar,  spices,  smoke,  oils,  or  rendered  fat, 
if  they  bear  names  descriptive  of  their  composition,  and  when  bearing  such 
descriptive  names,  if  force  or  flavoring  meats  are  used,  the  kind  and 
quantity   thereof  are   made   known. 

Preservation  of  Meat. — Ravv  meat  soon  begins  to  decompose,  unless 
precautions  are  taken  to  destroy,  or  at  least  check  the  growth  of  putrefying 
bacteria.  From  earliest  times  the  subjection  of  meat  to  extreme  cold 
has-been  practiced  in  order  to  enhance  its  keeping  qualities.  Bacterial 
growth  is  inhibited  to  a  greater  or  less  extent  ])y  refrigeration,  by  sub- 
jecting the  meat  to  the  vari(;us  [processes  of  curing,  by  the  use  of  high 
temperatures  and  the  exclusion  of  air  as  in  canning,  and  by  the  employ- 
ment of  antiseptics. 

*  CeUuIar  Toxines.  f  U.  S.  Dept.  of  Agric,  Off.  of  Sec,  Circ.  No.  19. 


I 


FLESH  FOODS.  219 

Refrigeration  may  consist  (i)  in  actually  freezing  the  meat, 
in  which  condition  it  may  be  kept  without  decomposition  almost 
indefinitely,  until  finally  thawed  for  use,  or  (2)  in  keeping  the  meat 
at  or  near  the  temperature  of  freezing  without  actually  congealing 
it,  as  is  done  by  tlie  use  of  the  ordinary  refrigerator.  The  second 
method,  while  much  less  efficacious  than  the  first,  serves  to  jjrevent 
decomposition  for  a  considerable  time  and  is  preferred  for  beef, 
mutton,  and  pork.  The  lower  temperatures  are  employed  with  poultry 
and  game. 

Curing  consists  in  subjecting  the  meat  to  various  processes  of  drying, 
smoking,  pickling,  corning,  etc.,  or  to  a  combination  of  these  processes. 
In  simple  drying,  the  meat  is  subjected  to  the  heat  of  the  sun  or  to  artificial 
heat.  In  smoking,  which  is  commonly  practiced  on  beef  and  ham,  the  meat, 
which  may  or  may  not  be  first  salted  or  otherwise  treated,  is  exposed  to  the 
smoke  of  the  burning  beech  or  hickory  wood,  thus  becoming  impregnated 
with  the  antiseptic  properties  of  the  creasote  and  pyroligenous  acid,  at  the 
same  time  being  dried  by  the  heat.  Treatment  with  crude  pyroligenous 
acid,  instead  of  smoking,  is  also  commonly  practiced.  In  some  cases  best 
results  are  obtained  by  a  slow  smoking  at  a  comparatively  low  temperature, 
while  in  others  quick,  hot  smoking  is  found  most  efficacious.  The  character 
of  the  meat  is  decidedly  changed  by  smoking,  and,  according  to  Utescher, 
smoked  meat  is  always  alkaline  in  reaction.  In  pickling,  the  meat  may  be 
treated  with  dry  salt  and  subjected  to  pressure,  so  that  the  meat  juice  forms 
the  liquid  for  the  brine,  in  which  it  is  allowed  to  remain  for  some  time;  or,  as 
in  the  ordinary  process  of  corning,  the  beef  is  soaked  for  some  days  in  a 
strong  solution  of  salt  to  which  a  little  saltpetre  (KNO3)  has  been  added. 
In  the  process  of  pickling,  the  salts  from  the  brine  slowly  diffuse  into 
the  interior  of  the  meat  by  osmosis,  a  part  of  the  soluble  albumin  passing 
out  into  the  brine.  The  effect  of  the  saltpetre  is  to  preserve  the  natural 
red  color  of  the  meat,  which  by  the  action  of  salt  alone  becomes  destroyed, 
or  at  least  impaired. 

Bacon  and  ham  are  frequently  cured  by  pickling  in  brine  containing 
salt,  saltpetre,  and  cane  sugar,  and  sometimes  also  such  antiseptics  as 
boric  acid  and  calcium  bisulphite.  ' 

The  curing  of  bacon  is  sometimes  effected  by  injecting  the  pickling 
fluid  into  the  tissues  with  a  "  pickle-pump,"  capable  of  exerting  a  pressure 
of  40  lbs.  to  the  square  inch,  and  provided  with  a  hollow,  perforated 
need' -^-nozzle,  which  penetrates  the  flesh.    After  pickling,  the  bacon  or  ham 


2  20  FOOD   INSPECTION  AND    ANALYSIS. 

mav  be  simply  dried,  or,  if  desired,  smoked.  Oak  sawdust  is  frequently 
burned  for  the  smoking  of  ham. 

The  Use  of  Antiseptics  in  Meat. — Most  of  what  might  be  termed 
the  modern  preservatives  are  to  be  looked  for  in  one  or  another  of  the 
various  meat  j)rei)arations.  thougli  some  are  better  afhi])ted  than  others 
for  use  in  particular  cases,  as  will  be  seen  by  reference  to  the  composition 
of  tvpical  commercial  preservative  mixtures  given  on  jxige  823. 

Borax  and  boric  acid,  usually  in  mixture,  have  been  used  more  com- 
monlv  than  any  other  preservatives  for  the  preservation  of  meat.  Like 
salt,  they  are  used  commonly  in  surface  application,  in  the  case  of  large 
cuts  of  meat,  or  by  mixing,  in  the  ca.se  of  sausage  meal.  A  more  recent 
method  of  a])])licaiion  consists  in  impregnating  the  tissue  of  the  meat 
with  a  solution  of  the  boric  mixture,  by  means  of  the  above-de.scribcd 
pickle-jnmip.  The  use  of  boric  acid  and  its  compounds,  however,  is  not 
permitted  under  the  regulations  of  the  Federal  meat  inspection  law  of 
the  United  States  and  Germany. 

Sulphurous  Acid.—\s  much  as  1%  of  a  solution  of  sulphurous  acid  may 
oe  added  to  meat  without  being  apparent  to  the  taste  or  smell.  Mitchell 
quotes  Fischer  as  having  found  that  50%  of  the  preserved  meat  products 
(sausages,  etc.)  sold  in  Breslau  in  1895  contained  sulphites,  varying  in 
amount  from  o.oi  to  0.34  per  cent  of  sulphur  dioxide.  Calcium  bisulphite 
is  a  salt  commonly  employed.  In  Hamburg  steak  it  serves  partly  as  a 
preservative,  but  chiefly  as  a  deodorizer  and  a  restorer  of  the  bright  red 
color  of  fre-sh  meat. 

Salicylic  Acid  is  not  of  such  common  occurrence  in  meat  j)roducts  as 
the  other  antiseptics  mentioned.  The  writer  has  found  it  in  prepared 
mince-meat. 

Among  other  preservative  substances  sometimes  used  with  meat  are 
solutions  containing  pho.sphoric  acid  and  aluminum  salts. 

The  toxic  effects  of  these  and  other  antiscfjlic  chemicals  in  meats,  and 
the  mo.st  practical  means  of  controlling  their  u.se  are  questions  in  con- 
troversy, presenting  no  new  pha.ses  that  have  not  been  elsewhere  dis- 
cussed in  treating  of  the  general  question  of  preservatives  in  food. 
Methods  of  detecting  preservatives  in  meats  arc  given  elsewhere. 

Effect  of  Cooking  on  Meat. — The  general  result  of  cooking  is  to  render 
the  meat  less  tough,  to  develojj  an  agreeable  flavor,  and  to  coagulate  more 
or  less  of  the  proteins.  When  .subjected  to  moist  heat,  such  as  boil- 
ing and  .steaming,  .some  of  the  soluble  materials  arc  dissolved,  so  that 
when  the  liquor  in  which  the  meat  is  boiled  is  thrown  away,  .some  of  the 


FLESH  FOODS.  22 r 

valuable  substances  arc  lost.  This  is  especially  true  when  meat  is  placed 
in  cold  water  which  is  afterwards  brought  to  boiling,  a  method  to  be 
recommended  when  the  liquor  with  the  dissolved  extractives  is  to  be  used 
for  broth.  When  the  meat  to  be  boiled  is  ])laced  at  once  in  boiling 
water,  there  is  less  loss  of  soluble  mailer  by  reason  of  the  formation  of  a 
more  or  less  impenetra])le  coaling  on  the  outside,  by  the  coagulation  of 
the  proteins.  Meat  that  is  boiled  becomes  softer,  owing  to  a  partial 
dissolving  of  the  gelatin  formed.  In  the  dry  cooking  of  meat,  as  by 
broiling  or  roasting,  there  is  usually  a  hardening  of  the  tissues,  and  a 
driving  out  of  some  of  the  meat  juices,  which  are,  however,  often  recovered 
in  the  form  of  gravies. 

Canning  of  Meat. — By  far  the  most  effective  method  of  preserving 
meat  and  meat  preparations  of  all  kinds  for  long  periods  of  time,  consists 
in  the  application  of  the  principle  of  sterilizing  by  heat,  and  sealing  in 
air-tight  cans.  The  process  of  canning  cooked  meat  and  its  products 
does  not  differ  materially  from  that  employed  in  the  similar  preparation 
of  vegetables.  (See  Chapter  XXL)  Previous  to  canning,  the  meats 
are  usually  cooked  by  boihng,  during  which  process  the  changes  described 
in  the  preceding  paragraph  take  place. 

The  practice  of  misbranding  chopped  meat  with  respect  to  variety 
has  been  very  prevalent  in  the  past,  and  many  varieties  of  so-called  potted 
and  devilled  meats  and  game  have  frequently  consisted  wholly  or  in  large 
part  of  a  cheaper  variety  than  that  specified  on  the  label.  This  practice 
has  been  largely  corrected  in  this  country,  owing  to  the  enforcement  of 
the  regulations  of  the  Federal  meat  inspection  law. 

It  is  largely  among  the  canned  meats  and  prepared  meat  products 
that  instances  of  adulteration  are  to  be  found,  since  the  fresh  meats  in 
whole  cuts  are  rarely  subject  to  adulteration. 

Preservatives  are  sometimes  added  to  canned  meats,  especially  in 
the  case  of  dried  and  smoked  beef,  ham  and  bacon,  and  in  the  potted 
and  devilled  mixtures.  Boric  acid,  benzoic  acid,  and  sulphites  have 
been  found  in  these  preparations. 

It  is  believed,  however,  that  this  practice  has  been  largely  discontinued, 
owing  to  the  enforcement  of  ihe  Federal  regulations  mentioned  above. 

Composition  of  Canned  Meats. — The  following  table,  compiled  from 
results  published  by  Bigelow  and  others,*  shows  the  composition  of 
various   of   the   most    common   canned    and    ])reserved    meats   and   meat 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bulletin  13,  part  10. 


FOOD  INSPECTION  AND  ANALYSIS. 


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FLESH   FOODS. 


223 


y)roducts,  and  in  one  or  two  instances  fresh  meat  has  been  included  for 
comparison. 

Sausages. — Nature  and  Composition. — Sausages  arc  made  from  finely 
chopj)ed  meat,  highly  seasoned  with  various  sjjices,  and,  as  usually  sold, 
stuffed  into  casings  made  of  the  cleaned  and  prepared  intestine-skin  of 
cattle,  sheep,  or  hogs.  The  meat  most  commonly  used  is  pork.  Sau- 
sages are  frequently  home-made,  especially  in  farm  communities,  the 
chopped  and  seasoned  meat  being  stuffed  in  cloth  bags  instead  of  casings. 
Any  and  all  kinds  of  meal  are  used  in  sausages,  and  much  that  is 
undesirable  and  e\'en  unwholesome,  is  undoubtedly  most  readily  used  up 
in  this  product.  There  is  little  doubt  that  horse  meat  occasionally  gets 
into  the  hands  of  the  markctmcn  to  be  worked  uj)  in  ihe  form  of  sausages 
mixed  with  other  meat.  The  condition  in  respect  to  these  matters  has 
been  greatly  improved,  however,  by  the  increased  vigilance  of  State  and 
Federal  authorities.  Sausages  are  sometimes  artificially  colored,  and  in 
some  cases  contain  so-called  "  fillers  "  in  the  nature  of  dried  bread,  corn 
meal,  potato  starch,  crackers,  waste  biscuit,  boiled  rice,  etc. 

CHEMICAL   COMPOSITION    OF   SAUSAGES.* 


No.  of 
Analy- 
ses. 

Ref- 
use. 

Water. 

Protein. 

Fat. 

Total 
Carbo- 
hy- 
drates. 

Ash. 

Fuel 
Value. 
Cals. 

Kind. 

By 
NX 6.25    Differ- 
ence. 

Farmer:     edible  portion. . . 

as  purchased 

Pork:          as  purchased 

Bologna:   edible  portion 

as  purchased 

Frankfort :  as  purchased.  -  - 

I 

I 

II 

8 

4 
8 

3-9 

23.2 
22.2 
.39-8 
60.0 

55-2 
57-2 

29.0 
27.9 
13.0 
18.7 
18.2 
19.6 

27.2 
26.2 
12.7 
18.4 
18.0 
19.7 

42.0 
40.4 
44-2 
17.6 
19.7 
18.6 

I.I 
0-3 

I.I 

7-6 
7-3 
2.2 

3-7 
3-8 
3-4 

2310 
2225 
2125 

1095 
I170 
T170 

*  U.  S    Dept    of  Agric,  Off.  of  Exp.  Stations,   Bui.  28  (Revised  Ed.). 

Adulteration  of  Sausages  with  Starchy  Materials  and  Water. — 
Robison,  who  has  made  a  special  study  of  these  forms  of  adulteration  at 
the  Michigan  Dairy  and  Food  Department,  states  as  follows:*  "  Lean 
meat  carefully  chopped  has  an  enormous  combining  power  and  can  be 
made  to  take  up  a  great  (juantity  of  water.  Frankfurts,  bologna,  and 
pork  sausage  have  been  found  to  be  adulterated  with  from  0.5  to  59c  of 
starch,  indicating  an  addition  of  approximately  i  to  10%  of  so-called 
cereal  (chiefly  corn  flour),  and  from  5  to  40%  of  water  in  addition  to 


*  Personal  communication. 


2  24  FOOD  INSPECTION  AND  ANALYSIS. 

that  contained  in  the  meats  when  in  their  fresh  condition.  The  main 
excuse  for  the  use  of  water  is  iliai  it  renders  the  meat  of  such  a  consistency 
that  it  may  be  easily  stulTed  into  thin  cases,  such  as  are  usually  used  for 
sausages  that  are  eaten  without  removing  the  casing.  As  a  matter  of 
fact,  this  addition  is  not  necessary  where  fresh  meals  are  used,  nor  with 
those  cuts  of  meat  which  the  American  ])ublic  is  in  the  habit  of  using  in 
the  manufacture  of  sausages  in  the  home.  Without  doubt,  in  sausages 
composed  of  ox  hearts,  ears,  snouts,  lips,  etc.,  in  considerable  quantities, 
the  addition  of  water  may  facilitate  the  stuffmg  into  thin  casings. 

"  Starch  hastens  and  increases  the  absorbing  or  combining  power  of 
lean  meat.  In  many  instances  where  inferior  products,  such  as  ears,  etc., 
are  used,  virtually  it  is  the  only  absorbing  agent  present  in  the  product. 
It  then  serves  a  two-fold  purpose,  first,  giving  an  absorbing  power  to  meat 
which  it  has  not,  or  inflating  the  absorbing  power  of  a  meat  which  natur- 
ally is  deficient  in  this  respect,  and  second,  acting  as  a  skeleton  or  frame- 
work, thereby  disguising  shrinkage  during  the  process  of  cooking. 
Generally,  added  water  and  cereal  are  evidences  of  inferiority,  and  they 
are  by  no  means  infrequently  added  with  the  very  purpose  of  concealing 
such  inferiority. 

"  The  evidence  of  adulteration  with  water  is  thq  discrepancy  in  the 
ratio  of  the  water  to  the  j)rotein  in  the  sausage.  This  ratio  in  sausage 
made  from  the  fresh  carcass  varies  from  3:1  to  3.6:1,  being  on  an  average 
about  3.35:1." 

Artificial  Coloring  Matter  in  Sausages. — Owing  to  the  rapid  color 
changes  which  freshly  chopped  meat,  especially  beef  and  mutton,  natu- 
rally undergo,  it  is  a  common  practice  to  employ  powdered  niter  or  salt- 
peter. Treated  in  this  manner,  meat  remains  pink,  owing  to  the  action 
on  the  haemoglobin  of  the  oxides  of  nitrogen  resulting  from  the  nitrate. 
As  much  as  4  ounces  of  niter  to  100  lbs.  of  meat  is  sometimes  used.  A 
larger  quantity  would  result  in  a  shriveled  aj)pearance.  The  use  of 
artificial  colors  has  been  common  in  the  past,  in  order  to  permanently  dye 
the  flesh  a  bright  red,  similar  to  the  tint  which  the  oxy-hajmoglobin 
naturally  imparts  to  the  beef  when  fresh.  A  variety  of  colors  have  been 
employed  for  this  jjurpose,  such  as  red  ocher,  coal-tar  dyes,  cochineal, 
etc.  They  were  sometimes  used  in  admixture  with  preservatives.  Their 
use  has  been  largely  discontinued  in  this  country,  owing  to  the  enforcement 
of  the  regulations  under  the  Federal  meat  inspeciton  law. 


FLESH  FOODS.  225 

ANALYTICAL   METHODS. 

In  analyzing  meats  and  meat  products  due  regard  must  be  paid  to 
their  perishable  nature,  and,  for  this  reason,  immediately  after  their 
receipt  by  the  analyst  the  various  determinations  should  be  promptly 
begun  and  rapidly  carried  out.  If  delays  are  absolutely  necessary,  the 
samples,  as  well  as  some  of  the  solutions,  especially  during  the  earlier 
course  of  the  analysis,  should  be  kept  on  ice  to  jjrevent  decomposition. 
Even  at  low  temperatures,  however,  both  bacterial  and  enzymic  decom- 
position occur,  and  the  nature  of  the  proteins  is  slowly  changed.  Refuse 
material,  such  as  bones,  skin,  gristle,  tendons,  etc.,  are  separated  as 
completely  as  possible  by  means  of  a  knife  from  the  edible  portion,  and  the 
latter,  cut  first  into  small  pieces,  is  passed  repeatedly  through  a  sausage- 
machine  or  ordinary  household  meat-chopper,  in  order  to  reduce  to  a 
homogeneous,  finely  divided  mass. 

Determination  of  Water.  — From  i  to  3  grams  of  the  finely  divided 
material  are  weighed  in  a  tared  platinum  dish,  and  dried  to  minimum 
weight  at  a  temperature  of  100°  C.  in  an  air-oven,  A  slight  oxidation 
of  the  fat  may  introduce  a  trifling  error,  but,  excepting  for  the  most  exact 
work,  where  the  drying  should  be  accomplished  in  an  atmosphere  of 
hydrogen,  or  in  vacuo,  the  above  method  is  sufiicicntly  close. 

Determination  of  Water  in  Sausages. — Rohisoii's  Method. — A  large 
sample  (100  to  500  grams)  is  put  through  a  food-chopper,  weighed  on  a 
large  porcelain  plate,  and  allowed  to  dry  at  70  to  90°  C.  A  steam 
radiator  may  be  conveniently  used  for  this  purpose.  After  drying  10  to 
12  hours,  or  over  night,  it  is  reweighcd  and  finely  ground  in  a  small 
laboratory  mill.  If  the  sample  is  quite  fat,  the  preliminary  drying  of  the 
chopped  meat  may  be  carried  out  conveniently  on  a  sieve,  which  will 
permit  the  fat  to  drain  through  onto  a  plate  below,  thereby  making  more 
simple  and  accurate  the  sampling  and  mixing.  The  fat  thus  removed 
should  be  separately  weighed  and  dried.  If  the  sample  is  quite  lean,  the 
final  drying  of  2  to  5  grams  of  the  air-dried  sample  may  be  made  at  100° 
C.  in  an  ordinary  water  or  electric  oven.  If  it  is  quite  fat,  it  is  best  to 
conduct  this  drying  in  a  current  of  hydrogen. 

Determination  of  Ash. — Incinerate  the  residue  from  the  total  solids  in 
the  original  dish  at  a  low  red  heat.  It  is  usually  advantageous,  especially 
in  the  case  of  salt  meat,  to  exhaust  the  charred  sample  with  water,  collect 
the  insoluble  residue  on  a  filter  and  ignite.  The  filtrate  is  then  added, 
evaporated  to  dryness,  and  the  whole  heated  to  low  redness  and  weighed. 
A  perfectly  white  ash  is  difilcult  to  obtain. 


226  FOOD  INSPECTION  /tND  /IN A  LYSIS. 

Determination  of  Fat. — Extraction  Method. — Dry  2  grams  of  the  sample 
at  100^  and  extract  v/ith  anhydrous  ether  for  sixteen  hours  as  in  the  case 
of  cereal  products  (p.  277).  More  complete  extraction  is  obtained  by 
grinding  the  residue  in  a  mortar  and  repeating  the  process  and  still  more 
complete  by  digestion  with  pepsin  and  intermittent  treatment  with  the  fat 
solvent  but  this  latter  is  both  tedious  and  open  to  other  errors. 

Kita's  Centrifugal  Method.^ — Treat  2.5  grams  of  meat  in  a  Babcock 
milk  flask  with  8  cc.  of  i :  i  H2SO4  (or  5  grams  with  17  cc.)  and  heat  in  a 
water-bath  to  60-70°  with  occasional  agitation  till  the  proteins  dissolve. 
Add  I  cc.  of  amyl  alcohol  and  sufficient  dilute  H2SO4  to  bring  the  layer 
of  fat  within  the  neck.  Whirl  in  a  centrifuge  for  from  3  to  5  minutes  and 
read  the  amount  of  fat  on  the  scale.  Amyl  alcohol  is  usually  necessary 
for  complete  separation  and  a  clear  fat  layer. 

Examination  of  Fat.  — Shake  a  large  portion  of  tlie  original  finely 
divided  sample  in  a  corked  flask  with  petroleum  ether  boiling  below  60° 
C,  and  digest  for  some  hours.  Pour  off  the  solvent,  remove  most  of  the 
petroleum  ether  by  distillation,  and  the  last  traces  by  allowing  to  stand 
in  a  vacuum  desiccator  over  freshly  ignited  calcium  chloride.  Determine 
the  usual  constants  as  described  in  Chapter  XIII.  In  minced  prepara- 
tions these  constants  furnish  a  possible  clue  to  the  variety  of  meat  used. 

Determination  of  Acidity  of  Fat. — Pennington  and  Hepburn  Method. -\ 
Weigh  ID  grams  of  the  fat,  mechanically  separated  and  ground  in  a  meat 
chopper,  directly  into  a  250  cc.  Erlenmeyer  flask,  add  50  cc.  of  neutral 
alcohol,  and  phenolphthalein  as  indicator,  and  bring  to  a  brisk  boil. 
The  hot  alcohol  dissolves  the  fat.  Titrate  immediately  with  tenth  normal 
sodium  hydroxide,  shaking  vigorously,  until  a  pink  color  appears,  which 
persists  for  one-quarter  of  a  minute.  Calculate  the  acid  value  from  the 
amount  of  sodium  hydroxide  used,  or  the  free  oleic  acid  by  multiplying 
the  acid  value  by  0.503. 

Determination  of  Total  Nitrogenous  Substance. — Determine  nitrogen 
in  2  grams  of  the  sample  by  the  (Running  or  Kjcldahl  method  (p.  69)  and 
multiply  by  6.25. 

Ahhough  nitrogenous  substances  other  than  proteins  are  present 
and  the  factors  for  the  individual  proteins  vary,  this  result  is  a  fairly  close 
approximation  to  the  total  nitrogenous  suh)stance  present.  The  factors 
for  meat  bases  are  give  on  page  252. 

Determination  of  Ammoniacal  Nitrogen. — Folin  Method  modified  by 
Pennington  and  Greenlee.]. — The  ammonia,  set  free  by  sodium  carbonate, 
.    *  Arch.  f.  Hyg.  51,  p.  165.      f  Jour.  Amer.  Chem.  Soc,  32,  1910,  p.  568.      J  Ibid,  p.  561. 


FLESH  FOODS. 


227 


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228  FOOD  INSPECTION  AND  ANALYSIS. 

is  evolved  at  room  temperature  in  a  rapid  current  of  air.  The  ingoing 
air  is  purified  by  passing  through  sulphuric  acid  in  a  flask  provided  with 
a  safety  bulb.  It  next  passes  through  a  liter  flask  containing  25  grams  of 
the  ground  meat,  i  gram  sodium  carbonate,  250  cc.  of  water,  and  25  cc. 
of  alcohol,  tlien  tlirough  an  empty  flask  to  intercept  spray  into  a  250  cc. 
flask  containing  tenth  normal  acid  and  Imally  through  a  100  cc. 
flask,  to  catch  acid  carried  over  mechanically,  to  an  air  pump  operated 
by  an  electric  motor  and  provided  with  an  anemometer.  One  pump 
and  one  air  purifier  sulTices  for  four  series  of  flasks,  the  current  being  divided 
by  means  of  four-way  tubes.  A  volume  of  8000  cu.ft.  passed  through 
each  series  in  3  to  6  liours  suffices  to  remove  all  tlie  ammonia   liberated. 

Separation  and  Examination  of  Nitrogenous  Bodies.  It  is  rarely 
necessary  to  go  further  than  to  divide  the  nitrogenous  bodies  into  several 
main  groups,  according  to  their  solubility  in  water  or  other  solvents, 
and  their  behavior  toward  certain  reagents.  The  nitrogen  may  be  deter- 
mined separately  in  each  of  these  groups  and  by  the  approximate  factor 
the  corresponding  substance  or  class  of  substances  ascertained. 

A  portion  of  the  fat-free  sample  should  first  be  exhausted  with  cold 
water,  which  removes  the  soluble  proteins  (soluble  globulins,  proteoses, 
and  peptones)  and  meat  bases,  leaving  behind  the  insoluble  globulins, 
the  sarcolemma,  the  albuminoids  of  the  connective  tissue  (elastin,  etc., 
also  insoluble)  and  the  collagen.  By  next  exhausting  with  boiling  water 
the  collagen  is  removed  in  the  form  of  soluble  gelatin. 

By  treatment  of  the  combined  aqueous  extract  with  zinc  sulphate, 
and  with  sodium  chloride  and  tannic  acid,  as  hereafter  explained,  the 
soluble  proteins,  including  the  peptones  and  gelatin,  may  be  separated 
from  the  meat  bases. 

In  obtaining  the  results  from  which  the  table  on  page  222  was  compiled, 
but  three  divisions  of  nitrogenous  substances  were  made,  viz.,  (i)  those 
in.soluble  in  hot  water;  (2)  those  precipitated  from  the  water  extract  by 
bromine;  and  (3 J  the  flesh  bases.  Owing  to  the  incompleteness  of  the 
bromine  precipitate,  the  figures  given  there  for  nitrogen  precipitated  by 
bromine  are  somewhat  high,  and  tho.sc  for  nitrogen  as  meat  bases  are 
correspondingly  low.  This  fact  was  observed  during  the  progress  of  the 
work,  and  pointed  out  in  the  text  with  the  statement  that  "considering  the 
small  amount  of  the.se  bodies  contained  in  meat,  the  results  are  believed 
to  be  a[)proximately  correct."     See  also  page  250. 

Determination  of  Nitrogenous  Substances  Insoluble  in  Water, — The 
sample  is  thoroughly  extracted  with  cold  water,  the  filter  and  insoluble 
material  transferred  to  a  flask,  and  nitrogen  determined  by  the  Gunning 


FLESH  FOODS.  2  2r, 

or  Kjcidahl  method.  The  insoluble  nitrogen  thus  obtainerl  is  multiplied 
by  6.25  to  obtain  insoluble  proteins.  It  is  obvious  that  the  insoluble 
nitrogen  may  be  obtained  by  difference,  the  cold  water  extract  being 
diluted  to  definite  volume,  the  nitrogen  determined  in  an  aliquot  por- 
tion, and  calculated  to  percentage  of  soluble  nitrogen  in  the  weight  of 
original  sample  corresponding  to  the  alicjuot  portion  taken.  The  figure 
thus  obtained,  deducted  from  the  percentage  of  total  nitrogen,  gives  the 
percentage  of  insoluble  nitrogen. 

Trowbridge  and  Grindley*  digest  the  sample  (thoroughly  ground  in 
a  meat  chopper)  for  one  hour  in  ice  water,  in  the  proportion  of  1000  grams 
of  meat  to  1500  cc.  of  water.  The  resulting  solution  is  filtered  through 
cheese  cloth,  the  process  being  assisted  by  squeezing  the  cloth  and  its 
contents  with  the  hand.  The  residue  is  divided  into  smaller  portions, 
placed  in  beakers,  and  washed  in  series,  using  fresh  water  with  No.  i  only, 
and  filtering  through  cheese  cloth  from  one  beaker  to  another  until  the 
last  filtrate  is  colorless,  neutral  to  phenolphthalein,  and  gives  no  reaction 
for  proteins  by  the  biuret  test.  The  mixed  fihrates  and  washings  filter 
through  j)apcr  readily,  and  give  a  clear  red  filtrate. 

Penningtont  proceeds  as  follows  with  the  meat  of  chickens: 
A  portion  of  the  finely  divided  red  or  white  meat,  weighing  60  grams, 
is  put  into  a  tall,  slender  bottle  of  500  cc.  capacity,  constructed  to  fit  a 
centrifuge  capable  of  carrying  i  liter  of  material;  300  cc.  of  water  are 
added,  and  the  flask  gently  shaken  for  15  minutes.  The  movement  is 
merely  sufficient  to  keep  the  particles  of  meat  in  motion  and  the  composi- 
tion of  the  extract  homogeneous.  Forcible  shaking  causes  an  emulsion 
to  form,  as  does  the  very  fine  grinding  of  the  tissue.  After  shaking  for  the 
required  length  of  time,  the  flask  is  rotated  in  an  electric  centrifuge  for 
20  minutes,  which  causes  the  heavier  particles  to  settle  in  a  compact 
mass,  and  permits  the  decantation  of  the  supernatant  liquid,  which  is 
then  filtered  through  paper.  The  extraction,  as  outlined,  is  repeated 
with  portions  of  300  cc.  of  water  until  the  filtrate  is  practically  protein 
free,  as  indicated  by  the  biuret  reaction.  The  attainment  of  this  result 
requires  ordinarily  a  volume  of  1500  to  2500  cc.  To  guard  against 
bacterial  decomposition,  thymol  is  added  both  to  the  flesh  and  to  the 
extract,  and  to  inhibit,  so  far  as  possible,  the  action  of  the  naturallv 
occuring  enzymes  of  the  meat,  the  solution  and  the  meat  itself  are  kept 
cold,  ice  being  used  when  necessary. 

*  Jour.  Am.  Chem.  Soc,  28,  1906,  p.  472. 

t  U.  S.   Dept.  of  Agric,  Bur.  of  Chem.,   Bui.    115,  p.  64. 


230  FOOD    INSPECTION   AND  ANALYSIS. 

The  extraction  of  the  white  meat  is  a  much  simpler  operation  than 
the  extraction  of  the  dark  meat.  The  latter  does  not  settle  as  compactly 
in  centrifuging,  filters  more  slowly,  and  persists  in  showing  a  distinct 
biuret  reaction  for  a  considerable  time  after  the  white  meat  is  free  of 
water-soluble  ]>roteins.  In  fact,  certain  fowls,  more  especially  those 
which  have  been  in  cold  storage  for  long  periods  of  time,  never  show  a 
dark  meat  entirely  free  from  water-soluble  nitrogen.  In  such  cases,  the 
question  of  the  error  due  to  long  manipulation  and  enzyme  action,  involv- 
ing a  rise  in  the  actual  quantity,  has  to  be  considered.  It  has  been  found 
by  experiment  that  after  long  extraction  of  such  tissue,  a  point  is  reached 
when  a  very  faint  biuret  reaction,  which  does  not  apparently  diminish, 
persists  indefinitely.  Such  extractions  are  halted  after  about  26  hours, 
it  being  believed  that  a  greater  error  would  result  in  the  gain  of  what 
has  been  originally  insoluble  material,  than  the  loss  of  the  preformed 
water-soluble  nitrogen.  The  total  extract  of  the  muscle  is  made  up  to 
a  definite  volume,  and  neutralized  to  litmus  paper  with  tenth-normal 
sodium  hydroxide. 

Cook  weighs  200  grams  in  a  450  Erlenmeyer  flask,  adds  250  cc.  of 
water,  and  shakes  for  three  hours  in  a  shaking  machine.  The  material  is 
then  filtered  by  means  of  linen  bags,  and  extracted  with  water  repeatedly 
by  vigorous  manipulation  with  the  hands  in  successive  portions  of 
water,  pressing  out  after  each  extraction  until  negative  biuret  reaction 
is  obtained.  The  operation  ordinarily  requires  from  2200  to  2500  cc. 
of  water.  A  small  quantity  of  phenol  and  thymol  are  added  as  pre- 
servatives. 

Weber*  appfied  Cook's  method  at  room  temperature  and  with  ice 
water  to  samples  of  fresh  and  storage  meat,  as  well  as  to  samples  which  he 
had  kept  for  varying  lengths  of  time  in  the  laboratory.  He  obtained  a 
larger  amount  of  soluble  proteins  when  working  at  room  temperature. 
No  ojMuion  was  expressed  as  to  whether  this  was  due  to  the  greater 
extracting  jjower  of  water  at  room  temperature,  or  to  greater  enzymic 
action  during  the  period  of  extraction. 

Determination  of  Collagen. — The  insoluble  proteins  obtained  as 
directed  above  are  transferred  to  a  beaker,  water  added,  and  heated  to 
boiling  for  some  minutes.  They  are  then  separated  by  filtration  and 
washed  with  boiling  water.  The  nitrogen  of  the  residue  insoluble  in 
boiling  water  is  deducted  from  the  nitrogen  insoluble  in  cold  water,  and 
multiplied  by  5.55  for  the  per  cent  of  collagen.     This  method  is  of  doubt- 

♦  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  p.  42. 


FLESH  FOODS.  231 

ful  value,  owing  to  the  difficulty  of  converting  the  collagen  to  soluble 
form  on  the  one  hand,  and  to  the  tendency  to  decompose  a  portion  of 
the  protein  on  the  other. 

Determination  of  Coagulable  Proteins.— The  entire  filtrate,  or  an 
aliciuot  portion  thereof,  from  the  determination  of  nitrogenous  bodies 
insoluble  in  water  is  heated  sufficiently  to  coagulate  the  coagulable  pro- 
teins, filtered,  the  insoluble  material  washed  with  hot  water,  and  the 
filter  and  contents  transferred  to  a  Kjeldahl  flask  and  nitrogen  determined 
by  the  Gunning  method.  The  per  cent  of  nitrogen  muhiplied  by  6.25 
gives  the  per  cent  of  coagulable  proteins. 

The  amount  of  heating  necessary  to  obtain  maximum  coagulation 
varies  with  different  materials.  The  Association  of  Official  Agricultural 
Chemists  directs  that  the  solution  be  almost  neutralized,  but  left  still 
faintly  acid,  and  boiled  until  the  globulins  are  coagulated.* 

Pennington, t  working  with  chickens,  evaporates  350  cc.  to  a  volume 
of  about  100  cc.  before  filtering.  Grindley  and  EmmettJ  employ 
200  cc.  of  the  solution,  add  alkali  till  neutral  to  litmus  paper,  and 
evaporate  to  50  cc.  In  a  later  article,  Trowbridge  and  Grindley  § 
report  maximum  results  from  the  cold  water  extract  of  fresh  beef  by 
neutrahzing  one-fourth  of  the  acidity  to  phenolphthalein  before  coagu- 
lation. 

Determination  of  Proteoses,  Peptones,  and  Meat  Bases. — The 
filtrate  from  coagulated  proteins,  having  been  diluted  by  wash  water,  is 
concentrated  by  evaporation  and  made  up  to  100  cc.  Proteoses  are  then 
determined  by  Bomer's  method  (page  250),  and  meat  bases  by  Sjerning's 
method,  as  modified  by  Bigelow  and  Cook  (page  252).  Peptones  are 
determined  by  difference — the  sum  of  the  nitrogen  occurring  in  insoluble 
nitrogenous  bodies,  coagulated  proteins,  meat  bases  and  ammonia  being 
deducted  from  the  total  nitrogen. 

Determination  of  Gelatin. — Modified  Slutzer's  Meihod.\\ — A  weighed 
portion  of  the  sample,  say  10  grams,  is  thoroughly  extracted  by  boihng 
water,  the  extract  transferred  to  a  porcelain  dish  containing  about  20 
grams  of  previously  ignited  sand,  and  evaporated  to  dryness.  The 
residue  is  then  stirred  with  four  successive  portions  of  absolute  alcohol, 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  108. 

t  Ibid.,  Bui.  115.  p.  65. 

t  Jour.  Am.  Chem.  Soc,  27,  1905,  p.  665. 

§  Ibid,  28,  1906,  p.  494. 

II  U.  S.  Dept.  of  Agric,  Bui.  13,  part  10,  p.  1397. 


232  FOOD    INSPECTION  AND   AN  < LYSIS. 

using  about  50  cc.  each  time  and  pouring  it  ofT  through  a  filter  consist- 
ing of  a  layer  of  asbestos  fiber  on  a  perforated  porcelain  plate  within  a 
funnel.  This  funnel  is  surrounded  by  chopped  ice,  and  is  so  arranged 
that  gentle  suction  may  be  used  to  hasten  the  filtration.  The  residue  is 
then  repeatedly  stirred  with  successive  portions  of  about  100  cc.  each  of 
a  mixture  containing  100  cc.  of  95%  alcohol,  300  grams  of  ice,  and  600 
grams  of  cold  water,  the  portions  being  passed  through  the  asbestos  filter, 
and  tlie  washing  being  continued  till  the  solution  is  colorless  as  it  comes 
from  the  filter,  keej)ing  the  temperature  always  below  5°.  The  asbestos 
is  then  transferred  to  a  beaker  with  the  washed  residue,  and  the  whole 
thoroughly  extracted  with  boiling  water.  The  hot-water  extract  is  evap- 
orated to  small  volume,  and  washed  into  a  Kjeldahl  flask,  in  which  it  is 
then  evaporated  to  dryness,  and  the  nitrogen  determined  by  the  Gunning 
method:    Nx 5.55=  gelatin. 

Detection  of  Nitrates. — ^A  small  portion  of  the  finely  divided  mate- 
rial is  treated  in  a  ])orcclain  dish  or  on  a  tile  with  a  little  1%  solution 
of  diphcnylamine  in  concentrated  sulphuric  acid.  Presence  of  a  blue 
color  indicates  nitrate. 

Detection  of  Preservatives. — Meats  may  be  systematically  tested  for 
preservatives  in  the  same  manner  as  canned  goods.  The  })reservatives  most 
commonly  used  in  meat  and  meat  preparations  are  tested  for  as  fol- 
lows : 

Detection  of  Sulphurous  Acid. — Proceed  as  directed  on  page  840. 

Traces  should  be  ignored,  as  slight  reactions  for  sulphurous  acid  are 
obtained  with  meats  that  have  not  been  chemically  preserved.  This 
is  probably  due  to  the  decomposition  of  a  portion  of  the  proteins. 
According  to  Mentzel,*  4  milligrams  per  100  grams  may  be  due  to  this 
cause. 

Detection  of  Boric  Acid. — A  portion  of  the  finely  divided  meat,  mechan- 
ically freed  from  the  fat  as  far  as  possible,  is  warmed  with  water  acidified 
with  hydrochloric  acid,  and  turmeric-paper  is  soaked  in  the  extract.  The 
ro.se-red  color  of  the  turmeric-paper  after  drying  (turned  blue  by  weak 
alkali)  is  indicative  of  boric  acid. 

A  more  delicate  method  of  procedure  consists  in  burning  to  an  ash 
a  portion  of  the  meat,  after  treatment  with  lime  water,  and  testing  with 
turmeric  tincture  a  solution  of  the  ash  slightly  acidified  with  hydrochloric 
acid. 

*  Zeits.  Unters.  Xahr.  Genuss.,  11,  igo6,  p.  320. 


FLESH    FOODS.  233 

Detection  of  Salicylic  Acid. — The  sample,  mechanically  freed  from 
fat,  is  slightly  acidified  and  shaken  out  with  ether.  The  ether  extract 
evaporated  to  dryness  is  tested  with  a  drop  of  a  solution  of  ferric  chloride. 
A  deep-violet  coloration  indicates  salicylic  acid. 

Starch  in  Sausages,  Meat-balls,  etc,  —  Detection. — The  addition  of 
cracker  or  bread  crumbs  is  best  indicated  by  the  presence  of  considerable 
starch,  which  is  readily  recognized  by  the  iodine  test,  applied  by  boiling 
up  a  portion  of  the  sample  with  water,  cooling  and  adding  a  drop  of 
iodine  reagent  to  the  licjuid.  The  characteristic  blue  color  is  produced, 
if  starch  be  present  in  notable  quantity.  Traces  of  starch  may  be  due 
to  the  pepper  and  spices  used  in  seasoning  the  sausage.  A  small  admix- 
ture of  starch  is  rendered  apparent  when  a  thin  section  of  the  sausage 
is  treated  with  a  drop  of  iodine  reagent  and  viewed  under  the  micro- 
scope. A  microscopical  examination  will  sometimes  reveal  the  character 
of  the  starch,  whether  it  is  from  cereals  or  from  pepper,  but  in  some 
preparations  the  starch  is  thoroughly  cooked  and  its  structure 
destroyed. 

Estimation  0}  Starch. — The  regular  acid  conversion  process,  p.  283,  may 
be  applied,  but  more  accurate  results  are  obtained  by  the  method  of 
inversion  with  malt  extract.  Medicus  and  Schw^ab  *  prepare  the  malt 
extract  for  this  purpose  by  digesting  5  grams  of  ground  malt  with  50  cc. 
of  water  for  one  and  one-half  hours  at  20°  to  30°  C.  In  making  the 
starch  estimation,  they  digest  for  two  hours  at  a  temperature  of  from 
40°  to  50°  C.  20  grams  of  the  sausage  mixed  with  20  cc.  of  the  malt 
extract,  and  afterwards  for  eighteen  hours  at  room  temperature.  After 
filtering  and  w-ashing,  the  filtrate  is  boiled  to  coagulate  the  albumin  and 
again  filtered.  The  second  filtrate  is  then  made  up  to  200  cc,  20  cc.  of 
25%  hydrochloric  acid  (specific  gravity  1-125)  are  added,  and  the  starch 
determined  in  the  regular  manner. 

Mayrhojcr^s  Method.-\ — This  is  considered  the  simplest  and  most 
reliable  method  of  estimating  the  starch  in  such  substances  as  sausages. 
From  60  to  80  grams  of  the  sample  are  heated  on  the  water-bath  with 
an  8%  solution  of  alcoholic  potassium  hydroxide,  which,  in  the  case  of 
pure  sausages,  dissolves  nearly  everything  except  a  little  cellulose.  To 
prevent  gelatinization,  warm  alcohol  is  added  to  dilute  the  solution, 
which  is  then  filtered  through  paper  or  asbestos.     The  starch  is  con- 

*  Berichte  d.  chem.  Gesell.,  XII,  p.  1285. 

t  Zeits.  Nahr.  Untersuch.,  1896,  p.  331;    Abs.  Analyst,  1897,  p.  11. 


'■34 


FOOD  INSPECTION  ^ND  ANALYSIS. 


taincd  in  the  insoluble  residue,  wliich  is  washed  with  alcohol  till  the  wash- 
ings arc  no  longer  alkaline,  after  which  it  is  treated  with  an  aqueous  solu- 
tion of  potassium  hydroxide,  and  the  starch  solution  made  up  to  a  definite 
volume.  To  an  aliquot  part  of  the  solution  95^7,  alcohol  is  added,  where- 
upon the  starch  comes  down  as  a  ilocculent  precipitate.  This  is  col- 
lected on  a  weighed  filter,  washed  with  alcohol  and  ether,  dried,  and 
weighed.  The  filter  with  its  contents  is  then  burnt  to  an  ash,  the  amount 
of  which  is  deducted. 

In  order  to  avoid  the  ash  determination,  the  starch  may  be  j)recipitated 
from  a  weak,  acetic  acid  solution  instead  of  from  an  alkaline  solution,  the 
potassium  acetate  formed  being  soluble  in  the  alcohol,  and  nothing  but 
pure  starch  is  precipitated. 

Characteristics  of  Horse  Flesh. — Ahhough  certain  authorities  have 
found  distinguishing  characteristics  in  color,  consistency,  odor,  etc.,  between 
horse  llesh  on  the  one  hand,  and  beef  and  pork  on  the  other,  it  is  extremely 
difficult,  by  its  physical  properties,  to  detect  horse  flesh  when  mixed  with 
other  meat,  especially  when  the  mixture  is  chopped.  Horse  flesh  has  a 
much  coarser  texture  and  is  darker  in  color  than  beef.  The  muscle  fibers 
are,  as  a  rule,  shorter  in  horse  flesh.  On  treating  horse  flesh  with  formal- 
dehyde, Ehrlich  *  has  found  that  a  very  characteristic  odor  is  developed 
within  forty-eight  hours,  suggestive  of  roasted  goose  flesh. 

Certain  of  the  constants  of  the  fat  of  horse  meat  differ  from  those  of 
beef  and  pork,  notably  the  iodine  value  and  the  rcfractometer  readings. 
These  constants  are  compared  as  follows: 


Iodine  Value. 

B  ut  yro- refract  om- 

eler  Readings. 
Temperature  40°. 

71-86 
38-46 
50-70 

53-7 
49.0 
48.6-51.2 

Beef  fat 

Hog  fat 

The  fact  that  glycogen  usually  exists  to  a  much  larger  extent  in  horse- 
flesh than  in  other  meat,  renders  it  possible  in  some  cases  to  detect  horse- 
flesh, when  present  in  the  mixture. 

The  following  table  i)re[jared  by  Bujard  shows  the  relative  amount  of 
glycogen  in  various  kinds  of  meat  and  sausages: 


*  Zt-it.  P'leisch  u.  Milch  Hyg.,  1895,  p.  232. 


FLESH  FOODS. 


235 


Horse  flesh 

Red  sausage  (Knackwurst) 

Pork  sausage 

Veal 

Pork 


Water. 


74-44 

74.87 

76.17 

76.00 

69.26 

67.25 

74-6 

75-0 


Glycogen  Direct. 


Niebel 
Method. 


0.440 
0.600 
1.827 
0.592 


Mayrhofer 
Method. 


0.445 

0.520 

1.727 

0.610 

0.038 

0.24 

0.086 

0.186 


Glycogen  in  Dried 
Substance. 


Niebel.     ',  Mayrhofer. 


1. 721 
2.388 
7.667 
2.466 


1. 741 
2.069 

7-247 
2-542 
o.  124 

0-733 
0.342 
0.744 


In  beef  Bujard  found  0.74  and  0.073  Pcr  cent  of  glycogen  calculated  in 
terms  of  dried  substance,  and,  in  sausages  made  exclusively  from  horse 
meat,  amounts  of  glycogen  ranging  from  0.05  to  5.34,  the  sample  in  the 
latter  case  being  made  from  the  liver.  It  was  formerly  thought  possible 
to  detect  as  small  an  amount  as  5%  of  horse  flesh  in  mixture,  but  later 
investigation  showed  that  after  the  death  of  the  animal,  glycogen,  though 
present  at  first  in  considerable  quantity,  decomposes  more  or  less  rapidly, 
going  over  into  muscle  sugar  (dextrose).  Hence,  while  the  presence  of 
much  glycogen  is  suspicious,  its  absence  is  by  no  means  proof  that  horse 
flesh  was  not  used. 

Niebel  did  not  consider  the  failure  of  the  glycogen  test  as  sufficiently 
conclusive  to  estabhsh  the  absence  of  horse  flesh,  on  account  of  the  tendency 
toward  decomposition  of  the  glycogen.  In  the  absence  of  starch,  he 
regards  the  presence  of  more  than  1%  of  dextrose  in  the  fat-free  meat, 
after  conversion  of  the  carbohydrates,  to  be  proof  of  the  presence  of  horse- 
flesh. 

Detection  of  Glycogen. — From  the  well-known  color  reaction  produced 
by  iodine  on  glycogen,  horse  flesh  can  often  be  detected,  when  present  in 
sausages,  unless  obscured  by  the  presence  of  starch  or  dextrin. 

Brautigam  and  Edelmann*  proceed  as  follows:  50  grams  of  the  finely 
divided  meat  are  boiled  with  200  cc.  of  water  for  an  hour,  and,  after  cool- 
ing, dilute  nitric  acid  is  added  to  the  broth  to  precipitate  the  proteins 
and  to  decolorize.  The  broth  is  then  filtered,  and  a  portion  of  the  filtrate 
is  treated  in  a  test-tube  with  a  freshly  prepared,  saturated,  aqueous  solution 


*  Pharm.  Central.,  1898,  p.  557. 


236  FOOD  INSPECTION  AND   ANALYSIS. 

of  iodine,  or,  better,  with  a  mixture  of  2  parts  iodine  to  4  parts  j)otassium 
iodide  and  100  parts  water,  the  reagent  being  carefully  added  so  as  not 
to  mix  with  the  broth,  but  form  a  layer  above  it.  If  glycogen  be  present 
in  considerable  amount,  a  wine-colored  ring  is  observable  at  the  junction 
of  the  two  layers.  On  heating  the  test-tube,  the  coloration  disappears 
if  due  to  glycogen,  but  it  reappears  on  cooling.  This  reaction  was  found 
to  occur  with  horse  flesh  and  not  with  beef,  mutton,  veal,  or  pork.* 

If  the  color  is  not  clearly  apparent,  the  chopped  meat  is  heated  on  the 
water-bath  with  a  solution  of  potassium  hydroxide  (using  an  amount  of 
potassium  hydroxide  equivalent  to  3%  of  the  weight  of  the  flesh)  till  the 
liber  is  decomposed,  after  which  the  broth  is  concentrated  to  half  its  volume, 
treated  with  nitric  acid  to  precipitate  the  {.Toteins,  filtered,  and  treated 
with  the  iodine  solution  as  previously. 

Determination  of  Glycogen.! — NicheVs  Modification  o'j  Briicke's 
Method. — This  method  is  applicable  only  in  the  absence  of  dextrose  and 
dextrin.  If  therefore  the  presence  and  character  of  the  starch  indicates 
the  presence  to  a  considerable  extent  of  cracker  crumbs  or  other  cereal 
"filler,"  the  method  is  not  accurate. 

A  weighed  portion  of  the  flesh  is  heated  on  the  water-bath  with  3  to  4 
per  cent  of  potassium  hydroxide  and  four  volumes  of  water  for  six  hours. 
Evaporate  the  broth  to  half  its  original  bulk,  and  add,  after  cooling,  a 
solution  of  mercuric  iodide  in  potassium  iodide,J  which  precipitates  the 
protein.  Fiher,  and  to  the  clear  flhrate  add  2^  times  its  volume  of  95% 
alcohol,  collect  the  precipitated  glycogen  on  a  flker,  wash  first  with  60% 
alcohol,  then  with  95%  alcohol,  then  with  absolute  alcohol,  then  with 
ether,  and  finally  with  absolute  alcohol.     Dry  at  115°  C.  and  weigh. 

Landwehr^s  Method. — Applicable  in  presence  of  dextrose.  The  broth 
prepared  as  in  Xiclx-l's  method  is  freed  from  j)rotein  by  the  addition 
of  zinc  acetate.  Filter,  wash,  and  heat  the  entire  filtrate  on  the  water- 
bath  with  sufficient  of  a  concentrated  solution  of  ferric  chloride,  after- 
v/ards  precipitating  the  iron  with  a  few  droj^s  of  a  saturated  solution  of 
sodium  hydroxide.    Filter,  wash  the  precipitate  with  hot  water,  and  dis- 

*  The  reaction  was  found  to  occur  also  with  the  flesh  of  the  human  foetus  and  with  the 
fcettis  of  animab;  abo  with  mule  meat,  but  not  with  the  flesh  of  the  dog  or  cat. 

t  Jahresb.  Nahr.  Genuss  ,  1891,  p.  38. 

X  Th'-  reagent  known  as  Briicke's  reagent  is  prepared  by  precipitating  a  solution  of  mer- 
curic chloride  with  potassium  iodide,  washing  the  precijntatcd  mercuric  iodide  till  free  from 
chloride,  and  afterwards  saturating,  while  i)oiling,  a  10%  potassium  iodide  solution  with  the 
mercuric  iodide. 


FLESH  FOODS.  237 

solve  in  strong  acetic  acid.  Add  to  the  solution,  after  cooling,  sufficient 
hydrochloric  acid  to  produce  a  yellow  color,  then  pour  into  2\  volumes 
of  alcohol,  and  proceed  as  in  the  preceding  paragraph. 

Mayrhojer's  Method,^  on  which  the  results  in  the  table  on  page  235 
are  based,  is  as  follows:  Dissolve  a  weighed  portion  of  the  flesh  in  an 
aqueous  solution  of  ])otaBsium  hydroxide,  precipitate  the  proteins  by 
hydrochloric  acid  and  Ncssler's  reagent,  filter,  and  treat  the  clear  filtrate 
with  alcohol,  which  precipitates  the  glycogen.  This  is  collected  on  a 
tared  filter  and  washed,  first  with  dilute  alcohol,  and  finally  with  ether, 
dried  at  110°  C,  and  weighed. 

Pfliiger  and  Nerking's  Method.] — Of  the  finely  divided  sample  50  grams 
are  heated  on  the  water-bath  with  200  cc.  of  2%  potassium  hydroxide 
till  the  solution  is  practically  complete.  After  cooling,  the  solution  is 
made  up  to  200  cc.  wdth  water,  shaken,  and  filtered.  To  100  cc,  of  the 
filtrate,  10  grams  of  potassium  iodide  and  i  gram  potassium  hydroxide 
are  added,  and  the  solution  stirrred  till  clear,  after  which  50  cc.  of  95% 
alcohol  are  added  and  the  mixture  allowed  to  stand  over  night.  This 
precipitates  the  glycogen.  FiUer,  and  wash  the  precipitate  with  a  solution 
made  up  of  i  cc.  70%  potassium  hydroxide,  10  grams  potassium  iodide, 
100  cc.  water,  and  50  cc.  95%  alcohol.  After  further  washing  the  glycogen 
with  2  parts  strong  alcohol  and  i  part  water,  dissolve  in  water  and  by 
means  of  Briicke's  mercuric-iodide-in-potassium-iodide  reagent  (see  foot- 
note, p.  236)  remove  any  remaining  nitrogenous  substances.  Filter  if 
turbid,  and  to  the  solution  add  common  salt  (about  2  milligrams  per  100  cc. 
of  solution),  and  reprecipitate  the  glycogen  by  adding  2  volumes  of  95% 
alcohol.  Piker,  wash  first  with  95%  alcohol  containing  a  little  common 
sak,  then  wkh  absolute  alcohol,  and  lastly  wkh  ether.     Dry  and  weigh. 

Bigclow  suggests  that  the  glycogen  as  above  obtained  be  converted 
by  acid  hydrolysis  to  dextrose,  which  is  determined  in  the  regular  manner. 
Dextrose  X  .9  =  glycogen. 

Identification  of  Raw  Horse  Flesh  by  the  Blood  Serum  Test.|— This 
test  depends  upon  the  recent  development  of  the  principle  that  when  a 
rabbk  has  been  inoculated  with  the  blood  of  a  particular  animal,  as  for 
instance  that  of  the  horse,  the  serum  of  the  rabbit's  blood  will  react  with 

''■'■  Forsch.  Ber.,  1897,  IV,  47. 

t  Arch.  ges.  Physiol.,  1899,  76,  531-542;  Bui.  65,  Bur.  of  Chem.,  p.  13.  Recommended 
for  Provis.  Adoption  by  the  A.  O.  A.  C. 

X  Schiitze,  A.,  Ueber  weitere  Anwendungen  der  Pracipitine.  (Deuts.  med.  Wochs., 
1902,  No.  45,  p.  8od.) 

n  assernunni,   A.,   u.   Schiitze,  A.,  Ueber  die   Entwickelung  der  biologischen  Methode 


238  FOOD  INSPECTION  AND   ANALYSIS. 

ihe  blood  of  the  horse  and  with  that  of  no  other  animal.  To  prepare  the 
blood  senim  for  a  reagent,  inject  a  rabbit  with  10  cc.  of  dcfibrinated 
horse's  blood  ever}'  day  for  five  to  six  days,  cither  siibcutancously  or 
intravenously.  The  blood  afterwards  taken  from  the  rabbit  is  clotted, 
and  the  liltered  senmi  is  used  in  making  the  test,  or,  if  the  reagent  is  to 
be  kept  for  some  time,  the  rabbit's  blood  serum  is  dried  and  an  aqueous 
solution  used  for  the  reagent. 

If  the  clear  expressed  juice  from  the  suspected  flesh,  filtered  if  necessar)', 
be  treated  with  a  few  drops  of  the  rabbit's  blood  reagent,  prepared  as 
above,  a  cloudy  precipitate  will  be  produced  in  the  case  of  horse  flesh. 

By  inoculating  different  rabbits  in  like  manner  with  the  blood  of 
various  animals,  the  flesh  of  the  corresponding  animals  may  be  recognized 
from  the  reaction  of  the  blood  serum  of  the  rabbit  with  its  juices.  Only 
raw  flesh  responds  to  the  test,  as  heating  destroys  the  virtue  of  the  reagent. 

Determination  of  Muscle  Sugar  (Dextrose). — Boil  a  weighed  quantity 
of  the  finely  (li\ided  sample,  say  50  grams,  with  water,  add  an  excess  of 
normal  lead  acetate  solution,  and  make  up  with  water  to  a  given  volume, 
say  250  cc.  Filter,  and  to  an  aliquot  part  of  the  filtrate  add  enough  of 
a  saturated  solution  of  sodium  sulphate  to  precipitate  the  lead.  Again 
filter,  make  up  to  a  given  volume,  and  determine  the  dextrose  in  a  measured 
part  of  the  solution  by  either  of  the  regular  methods. 

Detection  of  Coloring  Matter. — Red  Oclier  is  indicated  by  an  excessive 
amount  of  iron  in  the  ash. 

Cochineal  is  most  readily  tested  for  by  the  method  of  Klinger  and 
Bujard.*  The  sausage,  finely  divided,  is  heated  with  two  volumes  of  a 
mixture  of  equal  parts  of  glycerin  and  water  for  several  hours  on  the 
water-bath,  the  mixture  being  slightly  acidified.  The  yellow  solution 
is  passed  through  a  wet  filter,  and  the  coloring  matter,  if  present,  is  pre- 
cipitated as  a  lake  by  adding  alum  and  ammonia,  the  j)recipitate  is  filtered 
off  and  washed,  after  which  it  is  dissolved  in  a  small  amount  of  tartaric 
acid,  and  the  concentrated  solution,  contained  in  a  test-tube,  is  examined 

zur  Unterscheidung  von  menschlichem  unci  tierischcm  Eiweissmittels  Pracipitine.     (Ibid., 

1902,  No.  27,  p.  483.) 

Wassermann,   A.,   Ucbcr  Agglutinine   und   Pracipitine.      (Zcits.   f.   Ilyg.,   etc.,    Bd.    42, 

1903,  2,  p.  267.) 

V hUnhuth,  Die  Unterscheidung  des  Fleisches  verschiedcner  Tierc  mit  Hilfe  spezifische 
Sera  und  die  praktischc  Anwendung  der  Methode  in  der  Flcischbeschau.  (Deuts.  Med. 
^Vochs.,  1901,  No.  45,  p.  780.) 

Miessner,  H .,  u.  Herbst,  Die  Serum  agglutination  und  ihre  Bedeutung  fiir  die  Fleis  h- 
untersuchung.     (Arch.  f.  wissensch.  u.  j)rakt.  Tierheilk.,  1902,  Heft  3-4,  ji.  359-} 

*  Zeit.  angcw.  Chem.,  1891,  p.  515. 


FLESH  FOODS. 


239 


through  the  spectroscope  for  the  characteristic  absorption-bands  of  carmine 
lake,  lying  between  h  and  D. 

Spaeth  *  has  shown  that  both  carmine  (cochineal)  and  anilin  red, 
which  are  the  dyes  most  commonly  used  for  coloring  sausages,  can  be 
most  readily  extracted  therefrom  by  warming  the  finely  divided  material 
a  short  time  on  the  water-bath  with  a  5%  solution  of  sodium  salicylate. 

Vegetable  and  Coal-tar  Colors. — Various  solvents  are  suggested  for 
the  removal  of  these  dyes  from  sausage  meat.  Allen  f  recommends 
extraction  with  methylated  spirit  (a  mixture  of  ethyl  alcohol  with  10% 
methyl);  Bigelow  %  recommends  heating  with  a  mixture  of  50%  glycerin 
slightly  acidified;  A.  S.  Mitchell  uses  alcohol  acidified  with  hydrochloric 
acid;  Spaeth  a  5%  solution  of  salicylate  of  soda.  Other  solvents  appli- 
cable in  some  cases  are  dilute  ammonia  and  amyl  alcohol.  The  solvent, 
after  filtering,  is  evaporated  to  small  volume,  acidified  with  hydrochloric 
acid,  and  white  wool  is  boiled  in  it.  If  the  wool  is  distinctly  dyed,  a  coal-tar 
color  is  undoubtedly  present,  and  this  can  often  be  identified  by  methods 
given  in  Chapter  XVII.  According  to  Marpmann,  pure  normal  flesh  con- 
taining natural  color  only  is  completely  decolorized  by  macerating  for 
two  hours  in  50%  alcohol,  while  artificially  colored  meat  remains  colored 
after  this  treatment. 

Marpmann' s  Microscopical  Mcthod.^—Moisten  a  thin  section  of  the 
sausage  with  50%  alcohol,  and  examine  under  the  microscope.  Some 
colors  are  readily  apparent  without  further  treatment.  If  only  traces 
of  color  are  present,  clarify  the  substance  by  treatment  with  xylol,  which 
is  removed  by  the  use  of  carbon  tetrachloride.  The  mass  rendered 
transparent  by  this  treatment  is  then  immersed  in  cedar  oil  and  examined, 
the  coloring  matters,  if  present,  being  especially  apparent.  If  the  color 
used  is  fuchsin  (magenta),  carmine,  logwood,  or  orchil,  the  substance 
of  the  cell  will  appear  stained.  If  acid  coal-tar  dyes  are  used,  the  hquid 
contents  of  the  cell  will  show  the  color. 

Detection  of  Frozen  Meat. — Maljean  ||  detects  frozen  meat  by  the 
aid  of  a  microscope.  A  drop  of  the  blood  or  meat  juice  is  pressed  out 
upon  a  slide  and  immediately  examined  before  it  soHdifies.  Fresh  meat 
juice  contains  many  red  blood  corpuscles,  floating  in  a  clear  colorless 
€erum,  and  readily  apparent.     In  blood  from  frozen  meat,  the  red  cor- 

*  Pharm.  Central.,  1897,  38,  p.  884. 

f  Commercial  Organic  Analysis,  Vol.  IV,  p.  294. 

J  U.  S.  Dept.  of  Agric,  Bureau  of  Chemistn,',  Bui.  65,  p.  16. 

§  Zeits.  angewand.  Mikrosk,  1895,  p.  12. 

II  Jour.  Pharm.  et  Chem.,  1892,  XXV,  p.  348. 


-MO  FOOD  INSPFCT/ON  /1ND  yINALYSIS. 

pusclcs  arc  nearly  always  completely  dissolved  in  the  scrum,  due  to  freez- 
ing, or.  if  not  dissohed,  are  much  dislortcd  and  entirely  decolorized,  the 
liquid  portion  being  darker  than  usual. 

I^Iegascopically,  the  fresh  meat  juice  is  more  abundant  than  that  of 
frozen  meat,  and  its  color  is  deeper.  According  to  C.  A.  Mitchell,  if  a 
small  piece  of  meat  once  frozen  be  shaken  in  a  test-tube  with  water,  color 
is  imjxirted  to  the  water  much  more  quickly  than  with  fresh  meat,  and 
the  color  is  deeper. 

MEAT    EXTRACTS. 

Character  and  Composition. — Numerous  preparations  sold  under  the 
name  of  meat  extracts  have  been  on  the  market  for  many  years.  At  the 
beginning  of  the  nineteenth  century  the  value  of  such  extracts  was  known, 
but  Liebig  was  the  first  some  fifty  years  later  to  produce  a  commercial 
extract  of  meat.  Liebig's  preparation,  as  originally  made,  consisted 
of  a  cold-water  extract  of  chopped  lean  meat,  strained  free  from  fiber, 
heated,  filtered,  and  evaporated,  thus  containing  little  of  any  gelatin  or  pro- 
teins. Later,  however,  Liebig  advocated  the  use  of  warm  and  even  boiling 
water  for  extraction,  by  which  method  of  preparation  the  amount  of 
gelatin  was  greatly  increased.     He,  however,  condemned  the  use  of  salt. 

The  best  modern  meat  extracts  consist  for  the  most  part  of  such  por- 
tions of  the  meat,  previously  freed  from  bone  and  superfluous  fat,  as 
are  soluble  in  water  the  temperature  of  which  does  not  exceed  75°  C. 
The  widest  latitude,  however,  prevails  as  to  the  temperature  employed 
for  the  extraction,  hence  the  character  of  the  various  products  is  some- 
what varied.  It  is  not  an  uncommon  practice  to  submit  the  meat  to 
actual  Ijoiling  with  water,  in  which  case  the  amount  of  gelatin  will  be 
considerable.  In  an  extract  j)repared  by  warm  water,  one  finds  verv 
little  gelatin,  more  or  less  albumin,  albumoses,  and  peptones,  and  prac- 
tically all  the  meat  bases,  phosphates,  and  chlorides  present  in  the  meat- 
also  minute  quantities  of  lactic  acid,  inosite,  and  j)ossibly  glycogen.  By 
far  the  most  imj)ortant  of  these  substances  from  the  physiological  stand- 
jxiint  are  the  meat  bases — creatin,  creatinin,  xanthin,  sarkin,  etc.  To 
the  predominance  of  these  amido-bodies  is  undoubtedly  due  the  well- 
known  stimulating  effect  of  meat  extracts.  Indeed,  a  properly  prepared 
extract  has  very  little  actual  food  value,  but  is  rather  to  be  regarded  as 
a  condiment  or  as  a  stimulant,  acting  on  the  nervous  system  in  a  some- 
what analogous  manner  to  tea  and  coffee. 

Commercial  meat  extracts  differ  much  in  consistency  according  to 


FLESH   FOODS.  241 

the  extent  to  which  evaporation  is  carried,  varying  from  the  thin  fluid 
through  the  pasty  form  to  the  semi-sohd.  Some  ])reparations  have  added 
thereto  finely  ground  dried  beef  or  beef  meal. 

Owing  partly  to  unfounded  claims  of  manufacturers,  meat  extracts 
are  commonly  confused  with  meat  juices,  and  {)roducts  belonging  to  the 
former  class  are  sold  for  the  latter.  Considering  the  widely  different 
nature  of  meat  extracts  and  meat  juices,  such  confusion  is  a  serious  matter. 
Meat  extract  is  employed  as  a  stimulant  in  the  form  of  beef  tea  or  as  a 
flavor  for  soups.  Meat  juices,  on  the  other  hand,  are  employed  in  the 
sickroom  as  a  readily  available  form  of  food. 

Standards. — -The  following  standards  for  products  of  this  class  have 
been  adopted  by  the  Association  of  Official  Agricultural  Chemists  and  the 
Association  of  State  and  National  Dairy  and  Food  Departments: 

1.  Meat  extract  is  the  product  obtained  by  extracting  fresh  meat 
with  boiling  water,  and  concentrating  the  liquid  portion  by  evaporation 
after  the  removal  of  fat,  and  contains  not  less  than  75%  of  total  solids,  of 
which  not  over  27%  is  ash,  and  not  over  12%  is  sodium  chloride 
(calculated  from  the  total  chlorine  present),  not  over  0.6%  is  fat,  and 
not  less  than  8%  is  nitrogen.  The  nitrogenous  compounds  contain 
not  less  than  40%  of  meat  bases,  and  not  less  than  10%  of  creatin  and 
creatinin. 

2.  Fluid  meat  extract  is  identical  with  meat  extract,  except  that  it 
is  concentrated  to  a  lower  degree,  and  contains  not  more  than  75,  and  not 
less  than  50%  of  total  solids. 

3.  Bone  extract  is  the  product  obtained  by  extracting  fresh  trimmed 
bones  with  boiling  water  and  concentrating  the  liquid  portion  by  evapo- 
ration after  removal  of  fat,  and  contains  not  less  than  75%  of  total  solids. 

4.  Fluid  hone  extract  is  identical  with  bone  extract,  except  that  it  is 
concentrated  to  a  lower  degree  and  contains  not  more  than  75  and  not 
less  than  50%  of  total  sohds. 

5.  Meat  juice  is  the  fluid  portion  of  muscle  fiber,  obtained  by  pressure 
or  otherwise,  and  may  be  concentrated  by  evaporation  at  a  temperature 
below  the  coagulating  point  of  the  soluble  proteins.  The  sohds  contain 
not  more  than  i'^%  of  ash,  not  more  than  2.5%  of  sodium  chloride  (calcu- 
lated from  the  total  chlorine  present),  not  more  than  4  nor  less  than  2% 
of  phosphoric  acid  (PoOr,),  and  not  less  than  12%  of  nitrogen.  The 
nitrogenous  bodies  contain  not  less  than  35%  of  coagulable  proteins,  and 
not  more  than  40%  of  meat  bases. 

6.  Peptones  are  products  prepared  by  the  digestion  of  protein  material 


2\2 


FOOD  INSPECTION  AND  ANALYSIS. 


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244  FOOD  INSPECTION  AND   ANALYSIS. 

by  means  of  enzymes  or  otherwise,  and  contain  not  less  than  90*^0  of 
proteoses  and  peptones. 

7.  Gelatin  {edible  gelatin)  is  a  purilied,  dried,  inodorous  product  of 
the  hydrolysis,  by  treatment  with  boiling  water,  of  certain  tissues,  as  skin, 
ligaments,  and  bones,  from  sound  animals,  and  contains  not  more  than 
2','  of  ash  and  not  less  than  15'  ,'  of  nitrogen. 

ANALYSES  OF  MEAT  EXTRACTS. —Largely  by  the  a])plication  of  the 
above  standards,  Bigelow  and  Cook*  have  classihed  a  number  of  ])roducts 
of  this  class  as  solid  (pasty)  meat  extracts,  tluid  meat  extracts,  and  "  mis- 
cellaneous preparations." 

Their  results  are  given  on  pages  242,  243,  247,  and  248. 

Solid  and  Fluid  Meat  Extracts. — It  will  be  noted  that  the  solid 
and  lluid  extracts  are  identical,  exce})t  that  the  latter  are  concentrated  only 
half  as  much  as  the  former.  AUenf  holds  that  the  maximum  chlorine 
content  of  meat  extract  calculated  to  sodium  chloride  is  o.oO'/,,  for  every 
unit  of  dry  solid  matter,  and  that  excess  over  that  amount  is  due  to  added 
common  salt.  This  opinion  is  based  on  the  composition  of  South  Ameri- 
can extracts  prepared  from  the  meat  of  the  entire  carcass.  StreetJ  con- 
siders that  the  maximum  standard  of  12%  is  too  high,  and  encourages 
the  manufacturer  to  add  salt  to  his  product.  In  this  country,  however, 
extracts  are  commonly  prepared  in  part  by  the  evaporation  of  the  soup 
liquor  in  which  meat  is  parboiled  before  canning, §  and  in  part  from  trim- 
mings. It  is  claimed  that  the  natural  salt  content  of  the  product  made 
in  this  manner  is  higher  than  when  the  entire  meat  of  the  carcass  is 
emj^loyed.  A  second  grade  article  is  also  made  from  bones,  trimmings, 
etc.,  and  contains  a  still  higher  percentage  of  sodium  chloride.  This 
product  is  designated  as  "bone  extract"  in  the  standards  given  on  page  241. 

The  presence  of  an  excessive  amount  of  sodium  chloride  is  usually 
due,  probably,  to  the  presence  of  the  product  last  mentioned,  or  to  the 
use  of  corned  beef  in  the  ])reparation  of  the  substance.  In  the  latter 
case  nitrates  are  generally  j)resent.  On  com[)aring  the  analyses  given 
abo've  with  the  comi)Osition  of  other  jjroducts  of  this  class,  as  contained 
in  the  following  tables,  the  value  of  the  ]KTCcntagc  of  meat  bases,  es- 
pecially of  creatin  and  creatinin,  in  distinguishing  meat  extracts  from 
meat  juices  and  manufactured  products  of  that  general  type  is  apparent. 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  114. 
t  Commercial  Organic  Analysis,  3  Ed.,  Vol.  IV,  p.  ,^07. 
X  Conn.  Expt.  Station,  Report  for  1907  and  1908,  p.  622. 

J  Bigelow  and  Cook,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.  Bui.  13,  pt.  10,  p.  1389. 
Bigelow  and  Cook,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  114,  p.  13. 


FLESH  FOODS. 


245 


Meat  Juices  Prepared  in  the  Laboratory. — For  the  purpose  of 
comparison  with  meat  extracts,  the  following  analyses  of  meat  juices 
prepared  in  the  laboratory  are  of  interest. 

MEAT   JUICES    PREPARED    IN   LABORATORY.* 


Preparation  of  Juice. 


Round  beef,  cold  pressed 

Chuck  beef,  cold  pressed 

Round  beef  pressed  at  60°  C 

Chuck  beef  pressed  at  60°  C 

Juice  from  beef  chuck  at  60°  C 

Juice  pressed  from  sirloin  steak  and  water. 
Juice  extracted  from  sirloin  steak  by  cold 

pressure  

Juice   extracted   from   beef   chuck   by  cold 

pressure  

Juice   extracted   from   beef   chuck   by   cold 

pressure  after  6  hours  at  60°- 100°  C 


Composition  of  Sample. 


Wa 

ter 

Jui 

ce. 

«5 
86 

76 

8s 

90 

f>,s 

91 
89 

90 

91 

10 

96 

'.? 

96 

58 

98 

1 1 

Ash. 


Chlorine 
as 

Sodium 

Chloride 

in  Ash. 


I  -53 
1.86 
1.36 
I  .  29 

1.27 
I  .  40 

o .  46 

0.43 

0.39 


o.iS 
0.19 
o.  16 
0.12 


0.05 
0.05 
0.0s 


Phos- 
phoric 

Acid 
(P2O5). 


0.37 
0.31 
0.36 
o.  29 
0.37 
0.18 

0.14 

o.  I  r 

0.12 


Ether 
Extract. 


o.  27 
0.30 


0.64 


Acidity 


Lactic 
Acid. 


.27 
■32 

■IS 


Composition  of  Sample. 


Preparation  of  Juice. 


Total 
Nitro- 
gen. 


Insolu- 
ble 
Nitro- 
gen. 


Coag- 

ulable 
Nitro- 
gen. 


Pro- 

Pep- 

teose 
Nitro- 

tone 
Nitro- 

Nitro- 
gen. 

gen. 

gen. 

0.06 

0. 16 

0.33 

0.07 

0. 1 1 

0.  29 

0.04 

0 .  01 

0.43 

0 .  07 

0.21 

0.27 

0.42 

0.  18 

0 .  20 

0. 18 

0.  26 

trace 

none 

0.14 

trace 

none 

0. 09 

trace 

0.12 

0.08 

Unde- 
ter- 
mined 
Matter. 


Round  beef,  cold  pressed 

Chuck  beef,  cold  pressed 

Round  beef  pressed  at  60°  C 

Chuck  beef  pressed  at  60°  C 

Juice  from  beef  chuck  at  60°  C 

Juice  pressed  from  sirloin  steak  and  water. 
Juice  extracted  from  sirloin  steak  by  cold 

pressure 

Juice   extracted   from   beef   chuck   by   cold 

pressure 

Juice  extracted   from   beef   chuck  by   cold 

pressure  after  6  hours  at  6o°-ioo°  C 


2.08 
1.74 
1. 16 
1 .09 
I  .09 
I. 18 


0.43 
o .  24 


o. 16         1.37 
0.29         o . 98 

0.68 

0.12     I    0.41 
0.49 


0.34 
0.34 
0.00 


0.47 

1  03 

1 .90 

0.40 

2  .  92 
0.94 

0.8s 

0.59 

0.25 


Preparation  of  Juice. 


Round  beef,  cold  pressed 

Chuck  beef,  cold  pressed 

Round  beef  pressed  at  60°  C.  .  . 
Chuck  beef  pressed  at  60°  C.  .  . 
Juice  from  beef  chuck  at  60°  C. 
Juice  pres.sed  from  sirloin  steak 

and  water 

Juice    extracted    from    sirloin 

steak  by  cold  pressure 

Juice     extracted     from     beef 

chuck  by  cold  pressure 

Juice     extracted     from     beef 

chuck  by  cold  pressure  after 

6  hours  at  6o°-ioo°  C 


Results  in  Terms  of  Total 
Nitrogen. 


Insol- 
uble 
Pro- 
tein. 


Coag- 
ulable 
Pro- 
tein. 


7.69    65.87 
16.66     56.32 

58.62 
II  .oi|   3761 

44-95 


Albu- 
moses 


3-45 

6 .  42 

38.53 

1695 


Pep- 
tones, 


Amido 
Bodies 


15-87 
16.66 
37-07 
24-77 
16-51 

22.03 

29.17 


Nitrogenous  Bodies. 


Insol- 
uble 
Pro- 
tein. 


Coag- 
ulable 
Pro- 
tein. 


8.56 
6.13 

4-25 
0-75I    2-56 

3.06 

3-38 
2-13 


Pro- 
teoses. 


0.38 
0.44 
0.25 
0.44 
2.63 

1-25 
trace 


Pep- 
tones. 


o.  69 
0.06 
1-31 


I-I3 

none 


Amido 
Bodies 


I  03 
0.90 
I  34 
0.84 
0.56 

0.81 

0.44 


*  Bigelow  and  Cook,  U.  S.  Dept.  of  Agric,  Bui.  114,  p.  19. 


246  FOOD   INSTECTION  AND   ANALYSIS. 

The  composition  of  these  products  is  widely  different  from  that  of 
the  so-called  meat  juices  of  commerce,  as  given  in  the  table  on  page  247. 
It  appears  to  be  impracticable  to  so  preserve  a  true  meat  juice  that  it 
can  become  an  article  of  commerce. 

Miscellaneous  Meat  Preparations, — There  is  on  the  market  a  wide 
variety  of  manufactured  products  intended  to  replace  beef  juice.  Some 
of  these  have  meat  extract  as  a  base,  and  some  have  an  addition  of  a  small 
amount  of  albumin,  or  some  form  of  soluble  protein.  Others  consist 
largely  of  albumoses  and  peptones,  and  are  formed  by  the  action  of  steam 
or  of  acid  and  pepsin  on  meat.  The  tables  on  pages  247  and  248  give 
the  composition  of  a  number  of  products  of  this  nature. 

The  preparations  given  in  the  table  on  j)age  248  are  arranged  in  four 
classes,  according  to  their  content  of  proteoses  and  peptones,  meal  bases, 
creatin.  and  insoluble  proteins. 

Yeast  Extract. — During  recent  years  a  product  closely  resembling 
meat  extract  has  been  prepared  by  the  evaporation  of  the  water  extract 
of  yeast.  This  product  has  been  sold  as  a  substitute  for  meat  extract 
and  has  been  reported  in  Germany  as  an  adulterant  therefor.  The  best 
means  of  distinguishing  yeast  extract  from  meat  extract  is  by  the  deter- 
mination of  creatin  and  creatinin,  which  are  absent  in  the  former.* 

Wintgent  has  pointed  out  that  the  filtrate  from  the  zinc  sulphate 
precipitate  obtained  in  the  determination  of  albumoses  is  clear  in  the 
case  of  meat  extracts,  but  turbid  if  a  considerable  percentage  of  yeast 
extract  be  present. 

METHODS    OF    ANALYSIS. 

Water. — Water  is  best  estimated  by  weighing  from  2  to  3  grams  of 
the  preparation  (if  of  the  dry  or  jjasty  variety),  or  from  5  to  10  grams  of 
the  fluid  extract,  into  a  large  platinum  dish,  the  dry  variety  being  dissolved 
in  a  little  hot  water.  The  powdered  preparations  are  dried  directly 
without  admixture.  To  pasty  and  fluid  preparations  are  added  sufficient 
ignited  asbestos,  pumice  stone  or  sand,  sifted  free  from  dust,  to  absorb 
the  solution.  Pasty  preparations  are  first  dissolved  in  sufficient  water  to 
make  them  distinctly  fluid.  The  sample  is  then  dried  at  100°  C.  till  it 
ceases  to  lose  weight.  Tin  or  lead  dishes  or  Hoffmeister  glass  dishes 
may  be  employed,  and  after  being  cut  or  broken,  placed  in  the  extraction 
tube  for  the  determination  of  fat. 

•  Micko,  Zeits.  Unters.  Nahr.  Genuss.,  5,  1902,  p.  193;   6,  1903,  p.  781. 
t  Arch.  Pharm.,  242,  1904,  p.  537. 


FLE^H  FOODS. 


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FLESH  FOODS.  249 

Ash. — From  2  to  3  grams  of  a  fluid  preparation,  or  a  correspondingly 
less  amount  of  a  pasty  preparation,  are  evaporated  to  dryness  in  a  flat- 
bottom  dish.  Pasty  preparations  should  flrst  be  dissolved  in  water,  in 
order  that  the  sample  may  distribute  itself  evenly  over  the  bottom  of  the 
dish.  The  substance  is  then  charred  at  the  lowest  possible  heat,  the 
charred  mass  exhausted  with  water,  the  insoluble  residue  collected  on  a 
filter  and  washed.  The  filtrate  and  residue  are  then  returned  to  the 
dish  and  completely  incinerated,  the  soluble  portion  of  the  ash  added, 
evaporated  to  dryness,  heated  to  a  low  redness  and  weighed.  Chlorine 
is  determined  volumetrically  or  gravimetrically  in  the  solution  of  the  ash. 

Fat. — This  is  best  obtained  by  extracting  a  portion  of  the  air-dried 
substance  with  petroleum  ether  in  a  Soxhlet  apparatus.  Petroleum 
ether  extracts  the  fat  only,  while  ether  extracts  other  substances  as  well. 

The  determination  is  usually  made  in  the  residue  from  the  determina- 
tion of  water,     k  properly  prepared  extract  has  very  little  fat. 

Total  Nitrogen. — The  extract  should  be  tested  for  nitrates,  and  the 
proper  modification  of  the  Gunning  method  should  be  employed,  depend- 
ing on  the  presence  or  absence  of  nitrates.  Use  from  i  to  5  grams  for  the 
determination.     Nitrates  should  be  properly  accounted  for. 

Separation  of  Nitrogenous  Compounds. — To  correctly  gauge  the  food 
value  of  a  meat  extract,  it  is  essential  to  separate  and  estimate  at  least 
roughly  its  principal  nitrogenous  components.  To  attempt  to  make  such 
a  separation  with  a  high  degree  of  accuracy  would  involve  a  long  and 
tedious  series  of  operations,  which  in  most  cases  would  be  impracticable. 
Usually  the  separation  into  three  main  groups  is  sufficient,  insoluble 
proteins,  tannin-salt  precipitate  (proteoses,  peptones  and  gelatin)  and 
meat  bases.  At  times,  however,  it  may  become  necessary,  or  at  least  desir- 
able for  specific  purposes,  to  determine  certain  of  the  nitrogenous  com- 
pounds separately. 

.  \'arious  quick  methods  have  often  been  employed  in  connection  with 
technical  operations  to  determine  the  approximate  amount  of  the  several 
nitrogenous  bodies  or  groups,  but  they  have  been  generally  discarded  as 
untrustworthy.  Among  these  may  be  mentioned  Bruylant's*  method  of 
fractional  precipitation  by  varying  strengths  of  alcohol,  and  Hehner'sf 
method  of  precipitation  by  methylated  spirits.  Another  method  that 
was  widely  used  for  a  time  was  that  of  Allen  and  Searle,|  which  is  based 

*  Jour.  Pharm.  et  Chem.,  5,  1897,  p.  515. 

t  Analyst,  10,  p.  221. 

{  Analyst,  22,  1897,  p.  259. 


250  FOOD  INSPECTION  AND  ANALYSIS. 

on  the  belief  that  proteoses  and  peptones  were  completely  precipitated 
from  aqueous  solution  by  saturating  with  bromine,  after  acidifying  with 
hydrochloric  acid.  The  experimental  evidence  on  which  this  method 
was  based  -consisted  of  the  precipitation  of  proteins  from  the  filtrate  from 
the  zinc  sulphate  precipitate,  diluted  with  an  equal  volume  of  water. 
From  the  results  so  obtained,  it  ap])cared  that  peptones  and  proteins  of 
larger  molecule  were  completely  j)recipitated  by  bromine  in  a  half  satur- 
ated solution  of  zinc  sulphate,  and  it  was  assumed  that  precipitation 
from  aqueous  solution  would  be  equally  complete.  Owing  to  a  lack  of 
methods  by  which  peptones  could  be  completely  precipitated,  this  method 
has  been  widely  used.  The  use  of  the  method  now  appears  to  have  been 
largelv  discontinued,  as  it  has  been  repeatedly  found  to  be  unreliable.* 

Complete  Separation  of  Nitrogen  Compounds  would  involve  a  discrimi- 
nation between  meat  fiber  and  insoluble  protein,  coagulable  proteins,  acid 
albumin  (syntonin),albumoses, peptones,  meat  bases,  gelatin  and  ammonia. 

(i)  Insoluble  Proteins. — About  5  grams  of  the  extract  of  the  dry,  or 
20  to  25  grams  of  the  fluid  variety  are  exhausted  with  200  to  250  cc.  water 
at  about  20°  C,  and  the  residue  collected  on  a  tared  filter.  It  is  often 
ditTicult  to  filter  such  an  extract  in  the  ordinary  way,  and  the  use  of  the 
centrifuge  is  helpful,  passing  the  clear  supernatant  liquid  through  the 
filter,  and  finally  washing  the  residue  thereon.  The  residue  is  washed, 
dried  at  100°,  and  weighed,  or  the  nitrogen  may  be  determined  by  the 
Gunning  method.  The  sample  may  also  be  placed  in  a  graduated  flask, 
digested  in  a  considerable  amount  of  cold  water  for  several  hours  with 
frequent  shaking,  and  the  nitrogen  determined  in  an  aliquot  part  of  the 
filtrate.  This  deducted  from  total  nitrogen  gives  the  nitrogen  of  insol- 
uble proteins.  Nx6.25=total  insoluble  matter,  which  includes,  besides 
the  meat  fiber,  the  insoluble  proteins. 

(2)  Coagulable  Proteins. — The  filtrate  from  (i)  is  neutralized  exactly 
to  litmus,  and  dilute  acetic  acid  added  till  acidity  is  just  apparent.  It 
is  then  boiled  for  some  minutes  to  make  insoluble  the  coagulable  ])roteins, 
which  are  collected  uj)on  a  filter  (using  to  advantage  a  centrifuge  as  in 
the  preceding  paragraph).  Determine  the  nitrogen  in  the  washed  residue, 
using  the  factor  6.25  for  coagulable  protein. 

(3)  Albumoses  or  Proteoses.^ — An  aliquot  j^art  of  the  filtrate  from  (2) 


*  Bigelow,  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  pt.  10,  p.  1396;  Bui.  81, 
p.  106.  Sjeming,  Zeits.  anal.  Chem.,  39,  1900,  p.  545.  Fraps  and  Bizzcll,  Jour.  Am. 
Chem.  Soc.,  22,  1900,  p.  709.     Van  Slyke,  Chem.  News,  88,  1903,  p.  92. 

t  Bomer,  Zeit.  anal.  Chem.  5,  1895,  p.  562. 


FLESH   FOODS.  251 

is  saturated  with  zinc  sulphate,  adding  the  powdered  salt  as  long  as  it 
continues  to  dissolve  with  stirring  and  shaking.  Proteoses  and  any 
traces  of  gelatin  or  insoluble  proteins  that  have  escaped  removal  are 
precipitated,  but  not  the  peptones  or  meat  bases.  Filter,  wash,  and 
determine  the  nitrogen  in  the  residue,  using  the  factor  6.25  for  the  proteoses. 

(4)  Peptones. — Sjerning's  Tannin-salt  Method,  modified  by  Bigelow 
and  Cook.* — An  aliquot  part  of  the  filtrate  from  (2),  concentrated  by 
evaporation  to  20  cc.  or  less,  in  case  it  is  necessary  to  take  more  than  20 
cc,  is  transferred  to  a  loo-cc.  flask. 

Then  50  cc.  of  a  solution  containing  30  grams  of  sodium  chloride  per 
100  cc.  are  added,  and  the  flask  agitated  to  insure  the  thorough  mixing 
of  its  contents  and  the  solution  of  the  sample.  The  flask  is  now  placed 
in  the  ice  box  at  approximately  12°  C.  After  the  solution  has  reached 
the  ice  box  temperature  (this  requires  an  hour  usually),  30  cc.  of  a  24% 
solution  of  tannin  (which  must  be  at  ice  box  temperature)  are  added. 
The  total  volume  is  now  100  cc.  The  contents  of  the  flask  are  thoroughly 
mixed,  and  tlie  flask  returned  to  the  ice  box,  where  it  remains  over  night. 
In  the  morning  the  solution  is  filtered  at  ice  box  temperature  into  a  50  cc. 
graduated  flask.  The  nitrogen  is  determined  in  this  filtrate,  and  also 
in  an  aliquot  portion  of  the  filtrate  from  a  blank,  in  which  the  reagents 
alone  are  employed.  The  nitrogen  found  in  the  50  cc.  portion,  multiplied 
by  two  (after  correction  for  the  nitrogen  in  the  blank),  gives  the  total 
nitrogen  in  the  filtrate,  and  is  calculated  to  per  cent  of  nitrogen  on  the 
sample  employed.  This  includes  the  nitrogen  present  as  ammonia,  and 
all  of  the  nitrogen  of  the  meat  bases,  except  that  portion  of  the  creatin 
precipitated  by  the  tannin-salt  reagent.  The  figure  thus  obtained  is  added 
to  the  per  cent  of  nitrogen  as  determined  in  (i),  (2),  and  (3).  This  sum, 
deducted  from  the  total  nitrogen,  is  ordinarily  reported  as  the  per  cent 
of  nitrogen  existing  as  peptones,  and  is  multiphed  by  6.25  for  the  per  cent 
of  peptones. 

It  is  probable  that  the  substances  so  reported  are  not  true  peptones, 
since  the  filtrate  from  (3)  commonly  gives  no  biuret  reaction.  They 
probably  consist  largely  of  peptoids,  formed  by  the  action  of  the  hot  solu- 
tion on  gelatin  and  polypeptides. 

Bigelow  and  Cook  find  that  the  tannin-salt  precipitate  is  not  contam- 
inated with  other  meat  bases  than  creatin.  They  beheve  that  about 
one-quarter   of   the   creatin   is   found   in   this   precipitate.     Accordingly, 

*  Jour.  Am.  Chem.  Soc,  28,  1906,  p.  1496. 


2S2  FOOD  INSPECTION  AND  ANALYSIS 

they  suggest  that  the  percentage  of  creatin  be  determined  before  and 
after  precipitation  with  tannin-salt  reagent,  and  correction  made  by  the 
results  so  obtained. 

Street  believes  this  correction  to  be  impr-acticable.  He  fmds  that  it 
is  very  difficult,  if  not  impossible,  to  remove  tannin  completely  from  the 
filtrate,  and  that  the  slightest  trace  of  tannin  prevents  the  color  reaction 
for  creatin. 

(5)  yieat  bases. — The  per  cent  of  nitrogen  found  in  the  filtrate  from 
the  tannin-salt  precipitate  in  (4),  after  deducting  the  per  cent  of  nitrogen 
found  as  ammonia  in  (6),  is  multiplied  by  3.12  to  obtain  the  per  cent  of 
meat  bases. 

(6)  Ammonia. — From  5  to  10  grams  of  the  original  sample  arc  dissolved 
in  a  convenient  volume  of  water,  and  distilled  after  the  addition  of  powdered 
magnesia.  The  distillate  is  titrated,  and  its  alkalinity  reported  as  per  cent 
of  XH3.  The  corresponding  percentage  of  nitrogen  is  also  calculated, 
as  it  is  necessary  for  the  calculation  of  meat  bases  in  (5). 

Determination  of  Creatin  and  Creatinin,* — This  determination  may 
be  made  in  an  aliquot  of  the  filtrate  from  the  insoluble  and  coagulable 
protein  determination.!  The  aliquot  must  contain  suftkient  total  creatinin, 
after  dehydration  of  the  creatin  to  creatinin,  to  give  a  reading  not  far 
from  8°  on  the  scale  of  the  Dubosc  colorimeter,  after  applying  the  colori- 
metric  method  as  outlined  by  FolinJ  for  the  estimation  of  creatinin  in 
the  urine.  Heat  this  aliquot  with  5  cc.  of  half-normal  hydrochloric  acid 
for  three  and  a  half  hours  on  a  steam  bath  under  a  rellux  condenser. 
Neutralize  the  hydrochloric  acid  by  the  addition  of  5  cc.  of  half-normal 
sodium  hydroxide,  then  add  15  cc,  of  a  saturated  picric  acid  solution, 
and  5  cc.  of  10%  sodium  hydroxid.  Shake  the  solution,  and  allow  it  to 
stand  for  five  minutes;  make  up  to  500  cc,  and  compare  the  color  with 
a  half-normal  solution  of  potassium  bichromate  in  the  Dubosc  colorimeter. 
The  half-normal  bichromate  solution  when  the  scale  is  set  at  8°  corresponds 
to  10  mg.  of  creatinin,  and  from  this  figure  the  amount  of  creatinin  in  the 
aliquot  is  readily  calculated. 

Hehner§  criticises  this  method  as  ajj])lied  to  meat  extracts.  He  believes 
that  more  complete  results  may  be  obtained  by  using  25  cc.  of  a  1.01%  of 
picric  acid  with  "  a  quite  small  amount  of  alkali."     He  considers  the 


*  Bigelow  and  Cook,  Jour.  Am.  Chem.  Soc,  28,  1906,  p.  1497. 

f  Aliquot  bhould  represent  approximately  0.2  gram  of  a  first  class  solid  beef  extract. 

4  Zcits.  physiol.  Chem.,  41,  1904,  p.  223. 

§  Pharm.  Jour.,   78,   1907,  p.  683. 


I 


FLESH  FOODS.  253 

precipitate  somewhat  soluble  in  excess  of  alkali.  Emmctt  and  Grindley* 
have  made  an  exhaustive  study  of  the  method  as  applied  to  meats,  meat 
extracts,  and  urines.  They  fmd  that  15  cc.  of  1.2%  picric  acid  should  be 
employed  for  the  original  creatinin  determinations,  and  30  cc.  for  the 
dehydrated  creatinin.  They  also  recommend  5  cc.  of  alkali  for  the 
original  creatinin,  and  10  cc.  for  the  dehydrated  creatinin,  though  an 
additional  5  cc.  does  not  give  lower  results. 

Determination  of  Xanthin  Bases. — -In  addition  to  creatin  and  creatinin, 
a  true  meat  extract  or  meat  juice  should  contain  small  amounts  of  xanthin 
bases,  including  xanthin,  hypo-xanthin,  guanin,  and  adcnin.  These 
bodies  are  derived  from  the  nuclei  of  the  cells,  and,  consequently,  in  an 
extract  that  is  prepared  from  fresh,  unaltered  beef  a  certain  amount  of 
these  bodies  should  be  obtained,  together  with  the  salts  and  other  extractive 
matter.  The  determination  of  the  xanthin  bases  is,  therefore,  of  value 
in  determining  the  origin  of  an  alleged  extract  of  meat. 

The  xanthin  base  figures  in  the  tables  show  a  variety  of  results,  which 
is  explained  by  the  fact  that  in  the  preparation  of  the  extract  under  certain 
conditions  of  heat  and  pressure  some  of  these  bodies  are  destroyed.  The 
following  method  was  employed  for  their  determination: 

Schittenhelm'' s  Method  modified  by  Cook.1[ — Use  an  amount  of  the  stand- 
ard solution  equivalent  to  5  grams  of  the  original  extract.  Place  in  a 
large  evaporating  dish,  and  add  500  cc.  of  1%  sulphuric  acid.  Evaporate 
to  100  cc.  within  4  to  5  hours.  Cool,  and  neutrahze  with  sodium  hydroxide. 
Add  10  cc.  of  15%  sodium  bisulphate,  and  15  cc.  of  20%  copper  sulphate; 
allow  this  to  stand  over  night,  filter,  and  wash.  The  precipitate  suspended 
in  water  is  treated  with  sodium  sulphide,  and  warmed  on  the  steam  bath. 
Add  acetic  acid  to  acidify,  and  filter  hot.  To  the  filtrate  add  10  cc.  of 
10%  hydrochloric  acid,  and  evaporate  to  a  volume  of  about  10  cc.  Filter, 
make  ammoniacal,  and  add  ammoniacal  silver  nitrate  of  3%  strength. 
After  standing  several  hours,  the  solution  is  filtered  and  the  precipitate 
washed  with  distilled  water  until  no  longer  alkaline.  The  nitrogen  in 
the  precipitate  is  that  of  the  xanthin  bases. 

Determination  of  Gelatin. — This  is  accomplished  by  the  modified 
Stutzer  method  as  given  on  page  231. 

Determination  of  Acidity. | — In  the  average  solid  or  pasty  extract  the 
lactic  acid  content  varies  from  4  to  8  per  cent,  and,  as  a  rule,  the  extract 
showing  the  highest  phosphoric  acid  content  likewise  shows  the  highest 

*  Jour.  Biol.  Chem.,  3,  1907,  p.  491. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  114,  p.  41. 

J  Ibid.,  p.  39. 


254  FOOD   INSPECTION   y4ND    /ANALYSIS. 

acidity.  This  is  iincUnibiodly  due  to  the  fact  that  some  of  the  phos- 
phoric acid  is  in  the  form  of  di-hydrogen  or  acid  ])hosphate,  ahhough 
the  character  of  the  acidity  has  not  been  defmitcly  determined. 

The  method  employed  for  determining  acidity  consisted  in  adding 
tenth-normal  sodium  h\(lro.\ide  to  a  dilute  solution  of  tlie  meat  extract  in 
water,  until  a  drop  removed  by  means  of  a  small  capillary  tube  and  tested 
on  a  piece  of  litmus  paper  gives  a  neutral  reaction.  The  results  are 
expressed  in  cubic  centimeters  of  tenth-normal  sodium  hydroxide,  also 
as  per  cent  of  lactic  acid  present.  The  acidity  is  commonly  expressed  as 
I)er  cent  of  lactic  acid,  though  it  is  probably  due  in  large  part  to  acid 
jx)tassuim  phosphates.  Lactic  acid  is  the  chief  organic  acid,  though 
succinic  acid  is  also  present  in  notable  amount.* 

Detection  of  Preservatives  in  Meat  Extracts. — Boric  acid  is  some- 
times used  as  a  preservative  in  these  preparations,  and  is  tested  for  by 
the  usual  methods  (Chapter  XVIII). 

Determination  of  Glycerin. — This  substance  is  sometimes  used  as 
a  preservative  for  tluid  preparations.  Perhaps  the  most  satisfactory 
method  that  has  been  suggested  for  its  determination  is  that  of  Bigclow 
and  Cook.t  The  dried  residue  is  extracted  with  acetone,  the  meat  bases 
removed  by  precipitation  with  silver  nitrate,  followed  by  jihosphotungstic 
acHd.     The  glycerin  is  determined  in  the  filtrate  by  Hehner's  method. | 

FISH. 
Structure  and  Composition. — Fish  resembles  meat  both  structurally 
and  in  the  nature  of  its  constituents,  but  differs  from  it  in  a  marked  degree 
in  the  relative  proportions  of  its  various  com})()nents.  Thus,  there  is 
considerably  more  refuse  matter  such  as  skin  and  bones  in  fish  than  in 
meat,  and  in  the  edible  portion  of  fish  the  amount  of  water  is  much  greater. 
Comparing  the  nitrogenous  components  of  each,  we  fmd  in  fish  more 
of  the  gelatin-yielding  matter  (collagen)  and  less  of  the  extractives  than 
in  meat.  There  is  much  less  haemoglobin  or  allied  coloring  substance 
in  the  flesh  and  blood  of  fish  than  in  meat,  which  accounts  for  the  white  color 
usuallv  characteristic  of  the  former.  Certain  fish,  however,  like  the  salmon, 
probably  owe  their  distinctive  color  to  a  pigment  belonging  to  the  hpo- 
chrorae§  class.  The  mineral  content  of  fish,  as  a  rule,  exceeds  that  ol 
meat  and  contains  more  j^hosphates.  The  various  edible  fishes  diffei 
less  among  themselves  in  composition  than  do  the  meats.  According  to 
Chafjman  the  average  composition  of  fish  is  as  follows,  in  parts  per  looo: 

*  Arb.   kais.   Gesundheitsamt,    1906,    vol.    24. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  114,  p.  42. 

J  Jour.  See.  Chem.  Ind.,  8,  1889,  p.  4. 

5  A  series  of  fatty  animal  pigments. 


FLESH  FOODS. 


255 


Water 740 .  82 

Albumin 137 .40 

Collagen 43-88 

Fal 45-97 

Extractives 16.97 

Salts 14.96 

Hutchison  classifies  fish  as  follows  with  reference  to  their  content  of  fat: 

Lean. — Fish  having  less  than  2%  fat,  such  as  cod  and  haddock. 

Medium. — Fish  having  2  to  5%  fat,  such  as  halibut  and  mackerel. 

Fat. — Fish  having  more  than  5%  of  fat,  such  as  eel,  18%;  salmon,  12%; 
turbot,  12%,  and  herring,  8%. 

According  to  At  water  and  Bryant  *  the  composition  of  different  varie- 
ties of  fish  is  as  follows: 

COMPOSITION  OF  FISH. 


Refuse. 


Water. 

Protein. 

Fat. 

Ash. 

NX 

By 

6.25. 

Differ- 
ence. 

77-7 

18.6 

18.3 

2.8 

1.2 

35-1 

8.4 

«-3 

I.I 

0-5 

7«-5 

19.4 

19.0 

1 .2 

1-3 

40.3 

10. 0 

Q.8 

0.6 

0.7 

82.6 

16.^ 

15.8 

0.4 

1.2 

38.7 

8.4 

8.0 

0.2 

0.6 

71.6 

18.6 

18.3 

9.1 

1.0 

57.2 

14.8 

14.6 

7-2 

0.8 

81.7 

17.2 

16.8 

0-3 

1.2 

40.0 

8.4 

8.2 

0.2 

0.6 

75-4 

18.6 

18.4 

5-2 

1.0 

61.9 

15-3 

15-I 

4-4 

0.9 

72-5 

19-5 

18.9 

7-1 

1-5 

41-7 

II. 2 

10.9 

3-9 

0.9 

73-4 

18.7 

18.3 

7-1 

1.2 

40.4 

10.2 

10. 0 

4-2 

0.7 

75-7 

19-3 

19. 1 

4.0 

1.2 

28.4 

7-3 

7-2 

1-5 

0.4 

79-8 

18.7 

18.6 

0-5 

I.I 

42.2 

9-9 

10.7 

0-3 

0.6 

64.6 

22.0 

21.2 

12.8 

1-4 

40.9 

15-3 

14.4 

8.9 

0.9 

70.6 

18.8 

18.6 

9-5 

1-3 

35-2 

9-4 

9-2 

4.8 

0.7 

82.2 

18.2 

15-3 

1.6 

I.I 

40.2 

8.9 

7-5 

0.7 

0.6 

79-2 

17-6 

17-3 

1.8 

1-7 

46.1 

10. 1 

10. 0 

I.O 

1.0 

77-8 

19.2 

18.9 

2.1 

1.2 

40.4 

9-9 

9.8 

I.I 

0.6 

71.4 

14.8 

12.9 

14.4 

1-3 

37-3 

7-7 

6.8 

7-5 

0.7 

69.8 

22.9 

22.1 

6-5 

1.6 

32.5 

10.6 

10.3 

3-0 

0.7 

Fuel 
Value 

per 
Pound. 


Bass — 

Bluefish— 
Cod- 
Eel— 
Haddock- 
Halibut— 
Herring  — 
Mackerel- 
Perch — 
Pickerel — 
Salmon — 
Shad- 
Skate— 
Smelt — 
Trout— 
Turbot— 
Whitefish- 


55-0 


edible  portion 

as  purchased 

edible  portion 

as  purchased '  48 . 6 

edible  [)ortion ' 


52-5 


51- 


17.7 
42.6 


as  purchased 
edible  portion 
as  purchased, 
•edible  portion 
as  purchased, 
edible  portion 
as  purchased, 
edible  portion 
as  purchased . 
-edible  portion 

as  purchased i  44 . 7 

edible  portion ! 

as  purchased |   62.5 

edible  portion, 
as  purchased. . 
edible  ])ortion. 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
-edible  portion, 
as  purchased. . 


47-1 


34-9 


50- 


51-0 


41.9 
48.1 


47-7 


53-5 


465 
200 
410 
210 

325 
165 
730 
580 

335 
165 
565 
470 
660 
375 
645 
365 
530 
200 

370 
210 

950 
660 

750 
380 
400 

195 
405 
230 

445 
230 
885 
460 
700 
325 


*  U.  S.  Dept.  of  Agric,  Off.  of  Exp.  Sta.,  Bui.  28,  p.  47  et 


seq. 


256 


FOOD   l\SPt:CTlO.\   AM)  .ANALYSIS 


Characteristics  of  Fresh  Fish. — Fish  of  all  kinds  should  be  eaten  when 
perfectly  fresh,  as  it  undergoes  decomposition  much  sooner  than  meal 
when  killed.  While  with  meat  aging  is  often  beneficial  to  bring  out 
requisite  tenderness  and  flavor,  in  the  case  of  fish  deterioration  begins 
almost  immediately  after  death.  E\en  though  certain  varieties  of  fish 
may  be  kept  firm  and  wholesome  for  some  days  on  ice,  I  lie  flavor  is  dis- 
tinctly impaired  by  k)ng  keeping.  Fish  that  is  not  j)erfectly  firm  to  the 
touch,  or  that  has  abnormally  dry  scales,  or  that  shows  blubber  at  the 
gills,  or  that  possesses  the  marked  odor  that  accompanies  incipient  decom- 
pt)sition.  shoukl  not  l)e  used  as  food. 

Crustaceans  and  Mollusks. — These  differ  from  the  meats  and  common 
fish  by  reason  of  the  presence  in  considerable  proportion  of  the  carbohydrate 
glycogen  contained  in  the  liver.  The  lobster  and  crab  arc  nearly  alike  in 
composition,  the  flesh  being  made  up  of  coarse,  dense,  thick-walled  fibers. 

Payen  gives  the  following  composition  of  the  flesh  and  body  of  lobster: 

Flesh  (contained  in      Body  (consisting 
Claws  and  Tail).       mainly  of  Liver). 

Water 76.6  84.31 

Protein 19-17  12.14 

Fat 1. 1 7  1. 14 

Clams  and  Oysters  are  low  in  solid  nutriment,  and  are  more  digestible 
(S'hen  eaten  raw  than  cooked.     Oysters  contain  3%  or  more  of  glycogen. 
The  following  analyses  are  from  At  water  and  Bryant:* 

COMPOSITION  OF  SHELL   FISH,  ETC. 


Clams — 

Crabs — 

Lobster — 

Mussels — 

Oysters — 

Scallops — 
Terra  j)in  — 

Turtlr— 


edible  jjortion. 
as  purchased. . 
edible  fjortion. 
as  pur(  hased. . 
edible  ]>ortinn. 
as  [lurchased. . 
edilile  portion, 
as  purchased . . 
edible  portion, 
as  purchased. . 
as  purchased.  . 
*diblc  portifin  . 
as  purrhas<.-d.  . 
edible  [)ortion. 
as  purchased. . 


Refuse. 


41.9 

52-4 


61.7 
46.7 
81.4 


75-4 
76.0 


Water. 


85.8 

49-9 
77.1 

36.7 
79-2 
30-7 
84.2 

44-9 
86.9 
16. 1 
80.3 
74-5 
18.3 
79-8 
19.2 


Pro- 
tein. 
NX 
6.25. 


Fat. 


8.6 

5-0 
16.6 

7-9 
16.4 

5-9 

8.7 

4.6 

6.2 

1.2 

14.8 

21.2 

5-2 

19.8 

4-7 


1.0 
0.6 
2.0 
0.9 
1.8 
0.7 
I.I 
0.6 
1 .2 
0.2 
o.  I 

3-5 
0.9 

0-5 
0.1 


Car- 
bohy- 
drates. 


I.I 
1.2 
0.6 

0.4 
0.2 

4.1 
2.2 

3-7 

0.7 

3-4 


Ash. 


2.6 
1-5 
3-1 
1-5 


1-9 
i.o 
2.0 

0.4 

1-4 
1 .0 
0.2 
1 .2 
0-3 


Fuel 
Value 

per 
Pound. 

Cals. 


240 
140 
415 
195 
390 
140 
285 
150 
235 

45 
345 
.545 
135 
390 

90 


/        *  U.  S.  Dept.  of  Agric,  Off.  of  Exp.  Sta.,  Bui.  28,  pp.  52  and  53. 


FLESH    FOODS.  Z57 

Floating  of  Shellfish, — ^Oysters  and  other  shellfish,  cither  in  the  shell 
or,  more  commonly,  after  shucking,  are  often  subjected  to  "floating'* 
or  "drinking"  in  fresh  or  brackish  water  or  else  shipped  in  direct  contact 
with  lumps  of  ice.  Both  practices  cause  the  shellfish  to  greatly  increase 
in  size,  owing  to  the  absorption  of  an  undue  amount  of  water,  and  if  not 
labelled  "floated"  the  product  is  adulterated  under  the  Federal  law  and 
the  laws  of  certain  States. 

It  is  however,  not  regarded  as  improper  to  drink  oysters  in  water  of 
a  saline  content  ecjual  to  that  in  which  they  will  grow  to  maturity  or  to 
wash  the  shucked  oysters  in  unpolluted,  cold  or  iced  water  for  the  mini- 
mum time  recjuired  for  cleaning  and  chilling.  After  washing  they  should 
be  drained  and  packed  for  shipment  in  tight  receptacles  surrounded  by 
ice  but  protected  from  the  absorption  of  the  water  resulting  from  the 
melting  of  the  ice. 

Often  shellfish  is  polluted  by  growing  or  floating  in  impure  water, 
handling  under  insanitary  conditions,  or  packing  in  unclean  receptacles.. 

Preservatives  in  Fish  and  Oysters. — Boric  acid  and  borax  in  mixture 
and  sodium  benzoate  form  the  most  common  preservatives  of  salt  dried 
fish  and  of  oysters.  Ki  the  case  of  salt  codfish,  the  preservative  is  sprinkled 
on  the  surface.  Such  surface  application  in  some  States,  as  for  example 
Massachusetts,  is  allowed  by  law.  In  opened  oysters  sold  in  casks  and 
kegs,  boric  mixture  has  been  used  commonly  in  solution  in  the  oyster 
liquor,  but  is  now  infrequent. 

Artificial  Colors  of  the  coal-tar  group  are  used  to  give  smoked  fish  a 
rich  brown  color. 

Methods  of  Analysis. — These  are  similar  to  the  methods  given  for 
meat. 

CONCENTRATED    FOODS. 

Under  the  name  of  "condensed"  or  "concentrated  foods"  or  "emer- 
gency rations"  a  number  of  canned  preparations  are  sold  for  the  use  of 
campers,  travelers,  armies  in  the  field,  etc.  These  consist  usually  of 
mixtures  of  dried  ground  meats  and  vegetables,  pressed  together  in  com- 
pact form,  and  preserved  in  tin  cans.  The  claims  made  for  the  food  value 
of  these  preparations  arc,  as  a  rule,  extravagant  and  erroneous,  as  shown 
by  Woods  and  Merrill,*  who  give  the  following  analyses  of  some  of  these 
foods : 

*  Maine  Exp.  Sta.,  Bui.  75,  p.  103. 


258 


FOOD  INSPECTIOW  AND   ANALYSIS. 


Net 
WeiRht 
Con- 
tents. 


Weight  of  Materials  in  Package. 


Water. 


Pro- 
teins 


Fat. 


Carbo- ; 

hy-     \   Ash. 
drates. 


Total 

Fuel 

Value. 

Cals. 


Ration  cartridge,  pea.  beef,  etc 

Blue  ration  campaigning  food,  a  ... 
"       />..  . 

Red  ration  campaigning  food,  a 

"6.... 
Ration  cartridge,  potatoes,  beef,  etc. 

Emergency  ration,  a 

•'       b 

Emergency  ration,  a 

"  "       b 

Nao  meat  food 

.■Krmy  rations 

Standard  emergency  ration 

"  "  ' '     u 

"     b 

Arctic  food 

Tanty  emergency  ration 

F-A  Food  Company's  stew 


Grams 

241 

169 

78 

122 

77 
283 
120 

"3 
121 
127 

437 
661 

418 
270 
49 
423 
475 
964 


Grams. 

34.2 

76.1 

I   O 

33-8 

1.2 

"7-9 
14-2 

1-9 

4-5 
5-7 

231-3 

420 

23 
17 


30- 
3^3 


638.0 


Grams. 

52-9 

37-5 

5-6 

26.2 

5-0 
62.3 

56.i 

8.2 

71.8 

8-3 

56.9 

101.2 

129.6 

50.6 

3-2 

75-1 

60.2 

149.2 


Grams, 

42.0 

9.0 

23.1 

18-5 
23.0 
12.6 

29.6 

32-7 
32.6 

15-3 
90.1 

84-3 
90-5 
54-« 
10-5 
167-3 
48.6 

114-5 


Grams. 

Grams. 

98.0 

37-9 
46.9 

13-9 
8-5 
1-4 

37-8 
46.6 

5-7 
1.2 

76.4 

13-8 

II. 9 
68.0 

7-8 
2.2 

6-7 

5-4 

94.8 
46.2 

2.9 
12.5 

47-9 
160.3 

7-4 
14.0 

137-0 

10.6 

34.0 

0.8 

119. 8 

30.1 

41.9 

10.8 

52-5 

9.8 

I07I 
432 
436 
496 
424 
772 

617 
622 

776 

S88 
1328 
1542 
2198 
1402 

254 
2430 
1482 
2460 


REFERENCES  ON   FLESH   FOODS. 

ACKERMA.N,  D.,  und  KuTSCHER,  F.     Uebcr  Krabben-Extrakt.     Zeits.  Unters.  Nahr. 

Genuss.,  13,  1907,  pp.  180,  610,  and  613. 
Andrews,  O.  \V.  Flesh  Foods.  London,  1900. 
Arnold,   C,  und  Mentzel,   C.     Zur  Untersuchung  von   Fleischextrakt  und  Hefe- 

e.xtrakt.     Pharm.  Ztg.,  49,  1904,  p.  176. 
Association  of  Official  .Agricultural   Chemists.     Methods  for  the  .'Analysis  of  Meat 

and   Meat   Products.     U.   S.   Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p. 

106. 
Baillet,  L.     Traite  de  I'inspection  des  viandes. 
Balijvnd,  a.     The  Com{iosition  of  Fish,  Crustaceans  and  Molluscs.     Compt.  rend., 

126,  1898,  p.  1721. 
Barscuall,  H.,  und  Baur,  E.     Beitrage  zur  Kenntnis  des  Fleischextraktes.     Arb. 

Kaiserl.  Gesundheitsamte,  24,  1906,  p.  552. 
BiGELOW,  \\.  D.     Prcser\cd  Meats.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  13, 

Part  X. 
Floating  of  Oysters.     .\.  O.  .\.  C.  Proc,   1908,  U.  S.  Dept.  0/  -Agric,  Bur.  of 

Chem.,  Bui.  122,  p.  215. 
Report  on  Separation  of  Meat  Proteids.     Proceedings  of  the  h.  O.  A.  C,  1903, 

1904,  1905.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  81,  jj.  104;    Bui.  90, 

p.  126;  Bui.  99,  p.  172. 
BiGELOW,  W.  D.,  and  Cook,  F.  C.     The  Separation  of  Proteoses  and  Peptones  from 

the  Simpler  .\mino  Bodies.     Jour.  Am.  Chem.  Soc,  28,  1906,  p.  1485. 
Meat  Extract.s  and  Similar  Preparations.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem., 

Bui.  114. 


FLESH  FOODS.  259 

Boos,   \V.     Chemical   Examination   of   Drawn   and   Undrawn   Poultry   Kept   in   Cold 

Storage.     Mass.  State  Board  of  Health,  39th  An.  Rep.,  1907. 
Cook,  F.  C.     Report  on  the  Separation  of  Meat  Proteids.     Proceedings  of  the  A.  O. 

A.  C,  1906,  1907.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  105,  p.  91;    Bui. 

116,  p.  44. 
D.AVIES,  H.  E.     Searl's  Test  for  Yeast  Extract.     Pharm.  Jour.,  72,  1904,  p.  86. 
Douglas's  Encyclo[)icdia  for  Bacon  Curers,  Meat  Inspectors,  Local  Authority  Officers, 

etc.     Wm.  Douglas  &  Sons,  London. 
Duff,  Jas.  C.     Manufacture  of  Sausages.     New  York,  1899. 
FiEHE,  J.     Ueber  den  Nachweis  von  Pferdefleisch  in  Fleisch-  und  Wurstwaren  mittels 

der  Pracipitatreaktion.     Zeits.  Nahr.  Unters.  Genuss.,  13,  1907,  p.  744. 
FiscHODER,  F.     Leitfaden  der  Praktischen  Fleischbeshau.     Berlin,  1899. 
Gautier,  a.     Les  Toxines.     Paris,  1896. 
Grindley,  H.  S.     Losses  in  Cooking  Meat.     U.  S.  Dept.  of  Agric,  Office  of  Exp. 

Sta.,  Bui.  102. 

The  Nitrogenous  Constituents  of  Flesh.     J.  Am.  Chem.  Soc,  26,  1904,  p.  1086. 

Grindley,  H.  S.,  and  Emmett,  A.  D.    The  Chemistry  of  Flesh.    Improved  Methods  for 

the  Analysis  of  Animal  Substances.     Jour.  Am.  Chem.  Soc,  27,  1905,  p.  658. 
The  Chemistry  of  Flesh.     A  Study  of  the  Phosphorus  Centent  of  Flesh.     Jour. 

Am.  Chem.  Soc,  28,  1906,  p.  25. 
A  Preliminary   Study  of   the   Effect  of   Cold   Storage  upon    Beef  and   Poultry. 

Jour.  Ind.  and  Eng.  Chem.,  i,  1909,  p.  413. 
Grindley,  H.  S.,  and  Mojonnier,  T.     The  Artificial  Method  for  Determining  the 

Ease  and  Rapidity  of  the  Digestion  of  Meats.     Studies  of  the  University  of 

Illinois,  I,  No.  5,  1903,  p.  185. 
Grindley,  H.  S.,  and  Trowbridge,  P.  F.    The  Chemistry  of  Flesh.    A  Study  of 

the  Proteids  of  Beef  Flesh.     Jour.  Am.  Chem.  Soc,  28,  1906,  pp.  469-505. 
Grindley,  H.  S.,  and  Woods,  H.  S.     The  Chemistry  of  Flesh.     Methods  for  the 

Determination  of  Creatinin  and  Creatin  in  Meats  and  their  Products.     J.  Biol. 

Chem.,  2,  1907,  p.  309. 
Hall,  L.  D.,  and  Emmett,  A.  D.     Relative  Economy  Composition  and  Nutritive 

Value  of  the  Various  Cuts  of  Beef.     111.  Exp.  Sta.  Bui.  158. 
EliCKTON,  A.,  und  MuRDFiELD,  R.    Ueber  den  praktischen  Wert  der  Glykogenbestim- 

mung   zum  Nachweis    von    Pferdefleisch.      Zeits.  Unters.  Nahr.  Genuss.,   14, 

1907,  p.  501. 
KiTA,  T.   Ueber  die  Fettbestimmung  im  Fleisch  und  Fleischwaren  mittels  des  Ger- 

berschen  Azid-Butyrimeters.     Arch.  f.  Hyg.,  51,  1904,  p.  165. 
Langworthy,  C.  F.     Fish  as  Food.     U.  S.  Dept.  of  Agric,  Farmer's  Bui.  85. 
Lebben,  S.     Preservation  and  Coloring  of  Meat  Produce.     Berlin,  1901. 
Leuckart.     Human  Parasites. 

McGiLL,  A.     Commercial  Beef  Extracts.     Canada  Inland  Rev.  Dept.,  Bui.  63. 
Mallet,  J.  W.     Physiological  Effect  of  Creatine  and  Creatinine,  and  their  Value 

as  Nutrients.     U.  S.  Dept.  of  Agric,  Off.  of  Exp.  Sta.,  Bui.  66. 
MiCKO,  K.     Vergleichende  Untersuchung  Fleischextrakten  und  deren  Ersatzmitteln. 

Zeits.  Unters.  Nahr.  Genuss.,  5,  1902,  p.  193. 
Untersuchung  von  Fleisch-,  Hefen-  und  anderen  Extrakten  auf  Xanthinkorper. 

Ibid.,  6,  1903,  p.  781;    7,  1904,  p.  257;    8,  1904,  p.  225. 
Hydrolyse  des  Fleischextraktes.     Ibid.,  10,  1905,  p.  393;   ii,  1906,  p.  705. 


26o  FOOD  IMSPHCTION   AND   ANALYSIS. 

Micko,  K.     Hydrolyse   dcr  Albunioscn   des   FIcischextraktcs.      Zeits.   Untcrs.    Nahr. 

Genuss.,  14,  1Q07,  p.  25  v 
Ueber  die  Untersuchung  von  Fleischsaften.     Zcits.   Untcrs.   Xahr.   Genuss.,   20, 

iQio,  P-  537- 
Missouri  E.\p.  Station,  Bui.  25.     Composition  of  Flesh  of  Cattle. 
Mitchell,  C.  A.     Flesh  Foods.     London,  1900. 
OsTERT.'VG.     Handbuch  der  Fleischbcshau. 
Pennington,   M.   E.     Changes  Taking  Place  in   Chickens  in   Cold  Storage.     U.   S. 

Dept.  of  Agric,  Yearbook  1907,  p.  197. 
A    Chemical,    Bacteriological,    and    Histological    Study   of    Cold-stored    Poultry. 

Proc.  ist  Internal.  Congress  of  Refrig.  Industries,  2,  1909,  p.  216. 
Studies  of  Poultrv  from  the  Farm  \.o  the  Consumer.     U.  S.  I)c])t.  of  Agric,  Bur. 

of  Chem.,  Cir.  64. 
Pennington,  M.  E.,  and  Greenlee,  A.  D.     .\n  .Application  of  tin-  I'olin  Method  to 

the  Determination  of  the  Ammoniacal  Nitrogen  in  Meat.     Jour.  Am.   Chem. 

Sec,  32,  1910,  p.  561. 
Pennington,  M.  E.,  and  FIepburn,  J.  S.      The  Determination  of  the  Acid  Value  of 

Crude  Fat  and  Its  Application  in  the  Detection  of  Aged  Food.     Ibid.,  p.  568. 
Richardson,    W.    D.,    and    Scherubel,    E.       The    Deterioration    and    Commercial 

Preservation  of  Flesh  Foods.     Jour.  Am.  Chem.  Soc,  30,  1908,  p.  15 15. 
S.\Lmon,  D.  E.     Inspection  of  Meats  for  Animal  Parasites.     U.  S.  Dept.  of  Agric, 

Bureau  of  An.  Ind.,  Bui.  19. 
ScHMiDT-MuLHEiM.     Handbuch  der  Fleischkunde.     Leipsic,  1884. 
Searl,  a.     Yeast  Extract  and  Its  Detection.     Pharm.  Jour.,  71,   1903,  ])p.  516  and 

704;  72,  1904,  p.  86. 
Street,  J.  P.     Meat  Extracts  and  Meat  Preparations.     Conn.  Agl.  Exp.  Sta.,  Rep. 

1908,  Pt.  9,  p.  606. 
Trowuridge,  p.  F.     Report  on  the  Separation  of  Meat  Proteids.     Proceedings  of  the 

A.  O.  A.  C,  1908.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  j).  61. 
U.  S.  Food  Inspection  Decisions:    No.  no.     Shellfish.     No.  121.     The  Floating  of 

Sheimsh. 
Vaughan,  \.  C,  and  No\'\',  F.  G.     Cellular  Toxines. 
Walley,  Thos.     a  Practical  Guide  to  Meat  Inspection. 
Weber,  F".  C.     Report  on  Meat  and  Fish.     Proceedings  of  the  A.  O.  A.  C,  1908. 

U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  j).  42. 
Wiley,  H.  W.     Separation  of  Flesh  Bases  from  Proteids  by  Bromine.     U.  S.  Dept. 

of  Agric,  Div.  of  Chem.,  Bui.  54. 
Chemical  Comjx)sition  of  the  Carcasses  of  Pigs.     U.  S.  Dept.  of  Agric,  Bur.  of 

Chem.,  Bui.  53. 
Wiley,  H.  W.,  and  others.     A  preliminary  Study  of  the  Effects  of  Cold  Storage  on 

Eggs,  Quail  and  Chickens.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  115. 
Wintgen,    M.     Ueber    den    Nachweis    von    Hefeextrakt    in    Fleischextrakt.     Arch. 

Pharm.,  242,  1904,  p.  537. 
Woods,  C.  D.     Meats,  Comfjosition  and  Cooking.     U.  S.  Dept.  of  Agric,  Farmer's 

Bui.  34. 
Zeitschrift  fiir  Fleisch  und  Milch  Hygiene,  1891  et  seq. 


CHAPTER   IX. 
EGGS. 

Nature  and  Composition. — Though  eggs  of  various  birds  are  used  to 
sonie  extent  as  food,  it  is  the  egg  of  the  hen  that  is  in  universal  use  for 
this  purpose,  and  therefore  the  one  which  is  here  for  the  most  part  dis- 
cussed, bearing  in  mind  that  the  structure  and  composition  of  all  varieties 
of  birds'  eggs  are  closely  analogous. 

Fig.  60  shows  the  longitudinal  section  of  a  hen's  egg. 

'  '    g 


u 


Fig.  eo.—Longitudinal  Section  of  a  Hen's  Egg.  a.  Shell;  b.  Double  Membrane  of  Shell; 
c,  Air-chamber;  d,  Outer,  or  Fluid  Albuminous  Layer;  e,  Thick,  Middle  Albuminous 
Layer;  /,  Inner  Albuminous  Layer;  g,  Membrane  of  the  Chalaza;  hh,  the  Chalaza; 
i,  Vitelline  Membrane;    /,  Germ;    k,  Yolk;    /,  Latebra.     (After  Mace.) 

The  average  weight  of  a  hen's  egg  is  60  grams,  of  which  the  shell 
weighs  about  6,  the  white  36,  and  the  yolk  18.  Roughly  it  contains  70% 
of  water,  12%  of  albumin,  and  12%  of  fat. 

The  shell,  according  to  Konig,  has  the  following  composition: 

Calcium  carbonate 89-97% 

Magnesium  carbonate o-  2% 

Calcium  and  magnesium  phosphate 0.5-  5% 

Organic  substances 2.0-  5% 

261 


;6.- 


FOOD  INSPECTION  ^ND  ANALYSIS. 


The  mean  percentage  composition  of  the  eggs  of  the  hen,  duck,  and 
plover  are,  according  to  Konig,  as  follows: 


Water, 
Per  Cent. 


Proteins. 
Per  Cent. 


Fat, 
Per  Cent. 


Nitrogen - 
free  Sub-       Salts 
stance     I  Per  Cent. 
Per  Cent. 


In  the  Dry  Sub- 
stance. 


j  Nitrogen 
Per  Cent. 


Fat 
Per  Cent. 


Hcn-scRg 73-67  12.55 

Duck's  egg 71.11  12.24 

Plover'scgg |  74-43  10.75 

White  of  hen's  egg '  85.75  12.67 

Yolk     "     "        "    50.79  16.24 


15-49 
11.66 

0.25 
31-75 


0-55 
2.18 
0.13 


1.12 
1. 16 
0.98 

0.59 
1.09 


7.66 
6.78 

6-75 
14-25 

5-30 


45-99 

53-62 

45-78 

1.78 

64-43 


The  Egg-white. — The  white  of  egg  has  a  specific  gravity  of  1.045, 
and  its  reaction  is  always  alkaline.  It  is  a  transparent,  albuminous  fluid 
inclosed  in  a  framework  of  thin  meml^ranc.  The  fibrous  portion  of 
the  membrane  is  insoluble  in  water  and  in  dilute  acetic  acid. 

The  composition  of  the  fluid  substance  of  the  white  of  egg,  according 
to  Lehmann,  is  as  follows: 

Water 82  to  88% 

Solids 13. 3%  (mean) 

Proteins. 12.2%        " 

Sugar 0.5% 

Fats,  alkaline  soaps,  lecithin,  cholesterin traces 

Inorganic  residue 0.66% 

The  jjrotein  substance  is  for  the  most  part  albumin,  with  a  small 
amount  of  globulin. 

According  to  Osborne  and  Campbell  *  the  nitrogen  compounds  of 
the  white  of  egg  are  four  in  number,  which  they  name  ovalbumin,  ovo- 
mucin, conalbumin,  and  ovomucoid.  No  sharp  and  distinct  separation 
of  these  bodies  has  yet  been  made. 

Ovalbumin  (albumin)  is  the  chief  constituent,  and  forms  by  far  the 
largest  portion  of  the  protein  of  the  egg-white.  In  2.5%  solution  in  water, 
ovalbumin  starts  to  coagulate  at  60°,  and  yields  a  dense  coagulum  at  64°. 
Stronger  sf)lutions  require  a  somewhat  higher  temperature  for  coagulation. 

Ovomucin  is  a  globulin-hkc  substance,  precipitated  from  egg-white 
by  dilution  with  water.  It  is  partly  soluble  in  strong  sodium  chloride 
solution.     When  dried  and  washed  with  alcohol,  it  is  a  light  white  powder. 

Conalbumin  bears  a  close  resemblance  to  ovalbumin,  but  coagulates 
*  Jour.  Am.  Chem  See.,  22  (1900),  p.  422. 


EGGS.  263 

in  dilute  salt  solution  at  a  lower  temperature  (below  60°),  and  the  coagu- 
lum  is  more  flocculent  than  that  of  ovalbumin. 

Ovomucoid  is  not  coagulable  by  heat,  and  may  thus  be  separated 
(imperfectly)  by  filtering  out  all  the  coagulable  proteins. 

The  last  two  compounds  exist  in  very  small  amounts  only. 

Preparation  of  Albumin.* — By  beating,  up  the  white  of  egg  in  water, 
the  salts  and  the  albumin  are  dissolved,  while  the  fibrous  portion  is  insolu- 
ble  and  is  removed  by  filtration.  The  filtrate  is  then  treated  with  a  slight 
excess  of  basic  lead  acetate,  the  precipitate  decomposed  by  treatment  with 
carbon  dioxide,  and  the  lead  removed  by  hydrogen  sulphide.  The  solu- 
tion is  warmed  cautiously  to  60°  C,  thus  beginning  to  coagulate  the 
albumin,  a  small  part  of  which,  coming  down  in  a  flaky  form,  carries 
with  it  the  lead  sulphide.  On  filtering  or  pouring  off  the  supernatant 
liquid  after  cooling,  one  obtains  a  colorless  solution  of  the  albumin,  which 
is  evaporated  to  dryness  below  40°.  The  albumin  is  obtained  in  the  form 
of  transparent  yellowish,  horny  scales,  which  may  be  pulverized  in  a 
mortar,  if  desired.  Its  specific  gravity  is  1.262.  It  is  tasteless,  odorless, 
and  neutral  in  reaction,  and  slowly  soluble  in  water. 

The  Egg-yolk. — This  is  much  more  complex  in  composition  than 
the  white.     Halliburton  thus  enumerates  the  constituents  of  the  yolk: 

(a)  Proteins. — Vitellin,  the  chief  one,  a  globulin  resembling  myosin. 

Albumin,  in  small  quantities. 

Nuclein,  combined  chiefly  with  the  iron  present. 

{b)  Fats. — Olein,  palmitin,  and  stearin. 

A  yellow  lipochrome  or  lutein. 

(c)  Carbohydrates. — Grape  sugar  in  small  quantities. 

{d)  Other  Organic  Constituents.  —  Lecithin,  a  phosphorized  nitroge- 
nous body  allied  both  to  the  fats  and  to  the  proteins. 

Cerebrin. 

Cholesterin. 

{e)  Inorganic  Salts,  the  most  abundant  of  which  is  potassium  chloride. 
Gobley  gives  the  following  composition  to  the  egg- yolk: 

Per  Cent.  Per  Cent. 


Vitellin 15.8 

Nuclein 1.5 

Cerebrin 0.3 

Lecithin 7.2 

Glycerol  phosphoric  acid 1.2 


Cholesterin 0.4 

Fats 20.3 

Coloring  matters 0.5 

Salts I .  o 

Water 51.8 


Allen,  Com.  Org.  Anal.,  3  Ed.,  Vol.  IV,  p.  42. 


264 


FOOD  INSPECTION  AND  /tN A  LYSIS. 


Osborne  and  Campbell,*  as  the  result  of  long  and  careful  expen- 
ments,  consider  the  protein  of  egg-yolk  to  be  largely  if  not  wholly  a  lecithin 
compound,  having  properties  of  a  globulin,  and  soluble  in  sodium  chloride 
solution. 

The  fat  of  the  egg  yolk,  which  is  used  in  ointments,  has  the  following 
characteristics  according  to  Spaeth:! 

Specific  gravity  at  100°  C 0.881 

Iodine  number „ 68.48 

Reichert-Meissl  value 0.66 

Refractive  index  at  25°  C.  (on  butyro-rcfractometer  scale)  68.5 

Mehing-points  of  fatty  acids 36°  C. 

Iodine  number  of  fatty  acids 72.6 


The  mineral  content  of  the  egg  is  thus  shown  by  Konig: 
COMPOSITION  OF  THE  ASH  OF  EGGS. 


Ash  of 
the  Dry 

Sub- 
stance. 


Hen's  egg:  entire..  3.48 
white..  4.61 
yolk...    2.91 


Potash. 


17-37 

31-41 

9.29 


Soda. 


22.87 

31-57 

5-87 


Lime. 


10.91 

2.78 

13.04 


Mau- 


.14 
■79 
13 


Iron 
Oxide. 


0-39 
0.57 

1.65 


Phos- 
phoric 
Acid. 


37.62 

4.41 

65.46 


Sul- 
phuric 
Acid. 


Silica. 


0.31 
1.06 
C.86 


Chlo. 
rine. 


28.82 

1-95 


The  following  analyses  of  eggs  were  made  by  Wood  and  Merrill :  % 

AVERAGE  WEIGHTS  OF  EGGS  AND  PARTS  AS  PREPARED  FOR  ANALYSIS. 


Weifiht    I 

as         I 
Received.       Rhell 

'  fRefuse). 


Weight  Boiled. 


White. 


Yolk. 


Total.' 


Shell 
(Refuse). 


White 


Yolk. 


Turkey 

Goo.?e 

Duck 

Guinea  fowl 


Gram.s. 

Grams 

105.^ 

II. 7 

190.4 

24.1 

70  6 

7-2 

40.2 

5-<J 

Grams. 
60.1 
98-5 
36-5 
20.9 


Grams. 

30-9 
64.8 
24.4 
12-5 


Grr.ms. 

102.7 

187.4 

68.1 

39-0 


Per  Ceut.    Per  Cent. 

II-4    !    56-5 

12.3  52.6 
10.6      '      53.6 

14.4  i      53.6 


Per  Cent 

30.1 
34-6 
35.8 
32.0 


'  .Shrinkage  due  to  loss  in  preparation  and  cooking. 


*  Jour.  Am.  Chcm.  Soc,  XXII,  1900,  p.  413. 
t  Abst.  Analyst,   1896,  p.  233. 
X  Maine  Exp.  Sta.,  Bui.  75,  p.  90. 


EGGS. 
COMPOSITION  OF  ECxGS. 


26"; 


^ 

86.7 

48 

3 

73 

3 

63 

5 

86 

3 

44 

I 

69 

5 

59 

7 

«7 

0 

45 

8 

70 

5 

60 

9 

86 

6 

49 

7 

72 

8 

60 

6 

86 

2 

49 

5 

73 

7 

05 

5 

Protein. 


IS 


o  2; 


i 

< 

Trace 

0.8 

32-9 

1.2 

II. 2 

0.9 

9-7 
Trace 

0.8 
0.8 

36.2 

1-3 

14.4 

I.O 

12.3 
Trace 

0.9 
0.8 

36.2 

1.2 

14-5 

1.0 

12.5 

0.8 

Trace 

0.8 

31.8 

1.2 

12.0 

0.9 

9-9 

0.2 

0.7 
0.6 

33-3 

I.I 

10.5 

1.0 

9-3 

0.9 

Turkey- 


Goose — 


white 

yolk 

entire  edible  portion. 

as  f)urchased 

white 

yolk 

entire  edible  portion. 

as  purchased 

Duck —  white . 

yolk 

entire  edible  portion. 

as  purchased 

Guinea  fowl — white 

yolk 

entire  edible  portion. 

as  purchased 

Hen —  white 

yolk 

entire  edible  portion. 

as  purchased 


13.8 


14.2 


13-7 


16.9 


"■5 
17-4 
13-4 
II. 6 
II. 6 

17-3 
13.8 

II-5 

11. 1 
16.8 

^3-3 

1 1. 5 

11. 6 
16.7 

13-5 

11. 2 
12.3 

15-7 
^3-4 
II. 9 


7-6 
4-2 
2.2 

2-9 

8.4 

5-1 
2-9 
2.2 
6.8 
4.0 
2.1 
2.6 
7-3 
4-3 
1.9 

3-0 
6.1 

4-8 

3-1 


Cal. 

325 
187s 

850 

735 
33° 
1975 
985 
860 

315 
1980 

985 
880 

325 
1800 

875 
730 


METHODS    OF    ANALYSIS. 

Preparation  of  the  Sample.* — The  egg  is  first  weighed  as  a  whole  and 
afterwards  boiled  hard,  cooled,  and  again  weighed.  The  shell,  white,  and 
yolk  are  then  carefully  separated  and  each  weighed.  After  rejecting  the 
shell,  the  yolk  and  white  are  separately  reduced  by  a  chopping-knife  to 
the  size  of  wheat  grains.  These  portions  are  dried  partially  at  a  tem- 
perature not  exceeding  45*^,  weighed,  and  afterwards  ground  to  a  fine 
powder  in  a  mortar. 

Determinations  of  water,  fat,  ash,  and  total  nitrogen  are  made  in  practi- 
cally the  same  manner  as  with  flesh  foods. 

Little  attention  has  been  paid  as  yet  to  the  complete  separation  and 
determination  of  the  nitrogen  compounds  in  the  white  and  yolk,  and  it 
is  customary  in  most  cases  to  express  the  protein  of  the  whole  as  NX6.25. 

Determination  of  Lecithin. — Wiley's  Method.'\ — The  whole  egg,  ex- 
cluding the  shell,  is  placed  in  a  flask  with  a  reflux  condenser,  and  boiled  for 
six  hours  with  absolute  alcohol.  The  alcohol  is  then  evaporated  off,  and 
the  residue  treated  in  like  manner  for  ten  hours  with  ether.     After  evaporat- 

*  Woods  and  Merrill,  Maine  Exp   Sta.,  Bui.  75.  p.  92. 

t  Principles  and  Practice  of  .\gricultural  Analysis,  Vol.  Ill,  p.  431. 


206  FOOD  INSPECTION  /1ND   ANALYSIS. 

ing  off  the  ether,  the  dry  residue  is  rubbed  to  a  fine  powder,  placed  in  an 
extractor  and  treated  with  pure  ether  for  ten  hours.  The  ether  extract 
thus  secured  is  oxidized,  after  removal  of  the  ether,  by  fusion  with  mixed 
sodium  and  potassium  carbonates,  and  the  phosphorus  is  determined  in 
the  usual  way  as  magnesium  pyrophosphate.  The  amount  of  lecithin 
is  obtained  by  multiplying  the  weight  of  magnesium  pyrophosphate  by 
the  factor  7.2703,  on  the  basis  of  Hoppe-Seyler's  formula  for  lecithin: 
C,,H,,NPO«. 

If,  for  example,  an  amount  of  organic  phosphorus  yielding  0.0848 
gram  of  magnesium  pyrophosphate  is  found  in  54  grams  of  egg  exclusive 
of  shell,  then  0.0848X7.2703  =  0.61652  and  0.61652X  100-=- 54=1.14. 
Therefore  the  percentage  of  lecithin  in  the  egg  is  1.14. 

Preservation  of  Eggs. — Owing  to  the  porous  nature  of  the  shell,  the 
moisture  of  the  contents  gradually  grows  less  by  evaporation,  and  the  egg 
loses  in  weight.  Air  also  passes  in  through  the  shell  pores,  carrying 
various  microbes,  which  result  in  ultimate  decomposition  and  spoiling 
of  the  egg.  Nature  has  provided  the  shell  with  a  thin  surface  coating  of 
mucilaginous  matter,  which,  however,  is  easily  washed  off.  This  coating 
tends  to  partially  close  the  pores,  and  for  best  results  in  keeping  should 
not  be  removed  by  washing. 

Eggs  are  commonly  preserved  by  protecting  them  as  far  as  possible 
from  the  air.  This  is  accomplished  in  a  variety  of  ways,  the  most  common 
being  to  pack  the  eggs  in  salt  or  bran,  so  that  the  packing  medium  fills 
up  the  interstices  between  the  eggs.  Eggs  thus  packed  will  keep  con- 
siderably longer  then  when  exposed  to  the  air.  A  solution  of  salt  is  some- 
times employed,  and  also  lime  water,  the  eggs  being  simply  packed  in 
the  solution.  The  use  of  lime  water  is,  however,  open  to  the  serious  objec- 
tion that  a  disagreeable  odor  and  taste  are  imparted  to  the  eggs. 

Eggs  arc  sometimes  coated  with  gelatin,  vaseline,  wax,  or  gum,  so  as 
to  cover  them  with  an  impervious  layer,  either  by  dipping  them  in  the  coat- 
ing medium,  or  by  varnishing  or  otherwise  applying  the  substance  to  the 
egg  shell.  By  far  the  most  efficacious  egg  coating  has  been  shown  by 
experiments  in  the  North  Dakota  Experiment  Station,*  and  also  in  Ger- 
many, to  be  sodium  and  potassium  silicate,  or  water  glass.  The  fresh 
eggs,  preferably  unwashed,  are  packed  in  a  jar,  and  a  10%  solution  of 
water  glass  is  poured  over  them.  According  to  the  North  Dakota  experi- 
ments, at  the  end  of  three  and  a  half  months,  eggs  packed  in  this  manner 
the  first  of  August  appeared  to  be  perfectly  fresh. 

*  Farmer's  Bui.  103,  U.  S.  Dept.  of  Agric,  p.  18. 


EGGS.  267 

One  drawback  to  this  method  is  that  eggs  so  treated  break  more  easily 
on  boihng,  but  this  may  be  prevented  by  carefully  piercing  the  shell  with 
a  strong  needle. 

Cadet  de  Vanx  has  proposed  immersing  the  egg  in  boihng  water  for 
twenty  seconds,  the  result  being  that  a  very  thin  layer  of  the  egg-white 
next  the  shell  becomes  coagulated,  thus  forming  an  impervious  coating 
inside  the  shell. 

Cold-storage  Eggs. — The  preservation  of  eggs  by  storage  at  low 
temperatures  has  become  an  enormous  industry.  The  temperature 
employed  varies  from  24°  to  40°  C,  and  the  length  of  storage  from  one 
to  eight  months. 

Experiments  conducted  by  Wiley,*  under  authorization  from  Con- 
gress, have  brought  out  certain  points  as  to  the  physical  and  chemical 
changes  that  take  place  during  cold  storage.  After  breaking  the  shell 
and  keeping  at  room  temperature  one  day,  the  odor  of  eggs  stored  for 
3.5  months  was  different  from  that  of  fresh  eggs,  but  was  not  disagree- 
ble.  This  odor  increased  on  longer  storage,  and  after  12.6  months 
became  very  characteristic.  After  16.6  months,  a  musty  odor  was  noticed 
immediately  after  opening  the  egg. 

Chemical  analysis  by  Cook  showed  that  eggs  in  storage  for  one  year 
lost  10%  of  the  total  weight,  due  to  evaporation  of  water  from  the  whites. 
Storage  also  caused  a  lowering  of  the  amount  of  coagulable  protein  and 
of  lecithin  phosphorus,  but  an  increase  in  lower  nitrogen  bodies,  pro- 
teoses, and  peptones.  The  acid  reaction  of  yolks  diminished  during 
storage. 

Microscopical  examination  by  Howard  and  Read  brought  out  the 
interesting  fact  that  small  rosette  crystals  of  an  unidentified  substance 
appeared  in  the  yolk  after  storage  for  12  months  or  longer,  and  this 
observation  has  since  been  utilized  in  the  examination  of  suspected 
samples. 

Physical  Examination  of  Eggs. — Various  physical  tests  have  been 
prescribed  for  ascertaining  the  approximate  age  of  an  egg.  Thus,  accord- 
ing to  Delarne,  if  the  egg,  when  placed  in  a  10%  salt  solution,  sinks  to  the 
bottom,  it  may  be  considered  perfectly  fresh;  if  it  remains  immersed  in 
the  liquid,  it  is  to  be  considered  at  least  three  days  old;  and  if  it  rises  to 
the  surface  and  floats  thereon  it  is  more  than  five  days  old.     This  test 

*  U.  S.  Dept.  of  Agric,  Bureau  of  Chem.,  Bui.  115. 


2G8  FOOD    INSPECTION   AND    ANALYSIS. 

is  a  very  rough  one,  and  is  useful  only  for  eggs  that  have  been  kept  in  the 
air.      Treserveil  eggs  cannot  be  gauged  by  this  means. 

The  best  method  of  examining  eggs  for  freshness  is  "candling,"  con- 
sisting in  i)lacing  the  egg  between  a  bright  light  and  the  eye.  If  the 
egg  is  fresh,  it  will  show  a  uniform  rose-colored  tint,  without  dark  spots, 
the  air-chamber  being  small  and  occupying  about  one-twentieth  the 
capacity  of  the  egg.  If  the  egg  is  not  fresh,  it  will  appear  more  or  less 
cloudy,  being  darker  as  the  egg  grows  older,  becoming  in  extreme  cases 
opa(jue.  At  the  same  time  the  air  chamber  grows  larger  as  the  age 
increases.  So-called  "spots"  are  eggs  which  show  on  candling  black 
patches  due  to  fungi. 

Opened  Eggs. — In  the  handling  of  eggs  many  l)ecomc  cracked  or 
otherwise  injured  to  an  extent  which  renders  them  unfit  for  transporta- 
tion. These  are  either  sokl  to  bakers  for  immediate  use,  or  else  opened 
and  kept  from  spoiling  by  freezing,  the  addition  of  preservatives,  or 
drying.  The  portions  of  "  spot  eggs"  that  do  not  show  evidence  of 
damage  are  also  treated  by  one  of  these  methods.  Eggs  which, 
because  of  their  offensive  taste,  are  unfit  for  food,  are  used  in  the  tanning 
industry. 

Preservatives  commonly  employed  in  opened  eggs  are  boric  acid 
and  formaldehyde.  The  latter  is  especially  effective  as  an  egg  pre- 
servative. If  a  small  quantity  be  added  and  stirred  into  opened  eggs 
that  have  become  absolutely  putrid,  the  result  is  astonishing.  The 
product  is  completely  deodorized,  and  exhibits  the  outward  appearance 
at  least  of  fresh  eggs. 

Formaklehyde,  if  j)resent,  may  readily  be  detected  by  heating  some 
of  the  egg  directly  with  the  hydrochloric-acid  ferric-chloride  reagent  used 
in  testing  milk  for  formaldehyde,  carrying  out  the  process  exactly  as  in 
the  case  of  milk. 

Desiccated  Egg. — It  is  possible  to  evaj)orale  to  dryness  the  contents 
of  the  egg  to  form  a  jKjwder,  the  kcej)ing  (jualities  of  which  far  exceed 
that  of  ordinary  eggs,  while  it  forms  a  concentrated  food  which  lends 
itself  much  more  readily  to  transportation  than  does  the  fresh  egg  in  the 
shell.  Several  brands  of  desiccated  egg  arc  on  the  market,  which  from 
their  analyses  are  undoubtedly  genuine.  The  following  are  analyses 
of  two  of  them,  one  CAj  made  by  the  Bureau  of  Chemistry,  the  other  (B) 
bv  the  Massachusetts  State  Board  of  Health: 


EGGS.  269 

A.  B. 

Water 6.80  5.95 

Protein  (NX 6.25) 45-2o  48-15 

Protein  by  difference 51  -  20 

Fat 38.5  40.56 

Ash 3.5  5.34 

Egg  Substitutes. — There  have  been  many  preparations  in  powdered 
form  sold  under  this  name,  nearly  all  claiming  to  contain  all  the  ingredients 
of  eggs,  but"  most  of  them  falling  far  short  of  these  claims.  Some  of  them, 
as  for  instance  those  made  from  desiccated  skimmed  milk,  do  contain 
nitrogenous  matter,  but  as  a  rule  little  if  any  fat. 

Two  samples  of  "egg  substitute"  sold  in  Massachusetts  were  analyzed 
with  the  following  results :  * 

A.  B. 

Protein 16.94  18.72 

Fat 3.43  3-40 

Water 6.71  7.01 

Corn-starch,  salts,  and  color- 

ingmatter 72.92  70-87 

A  ten-cent  package  of  sample  A,  weighing  about  2  ounces,  was  alleged 
to  be  equivalent  to  12  eggs.  Starch  furnished  the  chief  ingredient  in 
both  samples. 

One  of  the  most  flagrant  examples  of  fraud  in  this  connection  was  a 
product  sold  under  the  name  "N'egg,"  advertised  to  contain  the  nutritive 
equivalent  of  the  whites  and  yolks  of  a  dozen  eggs,  "their  composition 
being  based  on  careful  scientific  analysis  of  natural  eggs."  It  was  put 
up  in  two  small  boxes,  one  containing  a  white  and  the  other  a  yellow 
dry  powder.  Both  were  entirely  devoid  of  nitrogen,  and  consisted  of 
nearly  pure  tapioca  starch  with  a  little  common  salt,  the  color  of  the 
"yolk"  being  due  to  Victoria  yellow. 

Some  egg  substitutes  are  sold  under  the  name  of  "custard  powders," 
and  are  alleged  to  take  the  place  of  eggs  in  cooking.  These  are  variously 
made  up  of  mixtures  of  skim-milk  powder,  coloring  matter,  and  baking 
powder  ingredients  as  shown  from  the  following  analyses  rf 

*  An.  Rep.   Mass.  State  Board  of  Health,  1895,  p.  675- 
■j"  Food  and  Sanitation,  Nov.  25,   1893. 


FOOD   INSPECTION  y4ND   ^N^ LYSIS. 


CUSTARD  POWDERS. 


Starch 

Albuminous  compounds 

Soluble  coloring  matter 

Baking  soda 

Tartaric  acid 

Phosphates 

Carbonates  of  lime  and  magnesia 

Chlorides  and  sulphates 

Water 

Ash 


86.25 
0-59 


11.83 
0-45 


84-45 


13.69 
0.38 


51-03 
6.01 


15-33 

13.69 

0.24 

2.70 


26.38 
2.96 

50.70 
10-33 


9-63 


52-32 
6.00 


22.11 
11-37 


8.20 


53-82 
5.06 

26.71 
6.19 


REFERENCES  ON  EGGS. 

BORCHMANN,  K.     AmtHche  Kontrolle  des  Marktverkehrs  mit  Eiern.     Zeits.  Fleisch.  u. 

Milchhyg.,  17,  1906,  pp.  3,  51,  97,  132. 
Langworthy,  C.  F.     Eggs  and  their  Uses  as  Food.     Farmer's  Bui.  128. 
Osborne,  T.  B.,  and  Campbell,  G.  F.     Proteids  of  the  Egg  Yolk.     Jour.  Am.  Chem. 

Sec,  22,  1900,  p.  413. 

Protein  Constituents  of  Egg  White.     Jour.  Am.  Chem.  Soc,  22,  1900,  p.  422. 

Prall,  F.     Ueber  Eier-Konservicrung.     Zeits.  Unters.  Nahr.  Genuss.,  14,  1907,  p.  445. 

Snyder,  H.     Digestibility  of  Potatoes  and  Eggs.     Exp.  Sta.  Bui.  43,  p.  20. 

Wiley,  H.  W.     A  Preliminary  Study  of  the  Eflects  of  Cold  Storage  on  Eggs,  Quail, 

and  Chickens.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  115. 


Farmer's  Bui.    87. 
"    103. 


Food  Value  of  Eggs,  p.  24. 
Preserving  Eggs. 


CHAPTER   X. 

CEREALS  AND  THEIR  PRODUCTS,  LEGUMES,  VEGETABLES, 

AND   FRUITS. 

The  chief  points  of  difference  in  composition  between  the  animal 
foods  already  treated  of,  and  those  of  the  vegetable  kingdom,  are  apparent 
in  the  relative  amounts  of  proteins  and  carbohydrates.  The  proteins 
present  in  the  cereals  and  vegetables  differ  materially  both  in  character 
and  amount  from  those  in  the  flesh  foods,  being  as  a  rule  present  to  a 
much  greater  extent  in  the  meats  than  in  the  grains  and  vegetables.  The 
leguminous  foods,  such  as  peas,  beans,  and  lentils,  are,  however  somewhat 
exceptional  in  this  respect,  being  comparatively  high  in  nitrogenous 
content. 

The  carbohydrates,  which  in  the  flesh  foods  are  almost  entirely  lack- 
ing, and  in  milk  make  up  about  one-third  of  the  solid  matter,  form 
the  most  important  and  abundant  class  of  constituents  in  the  vegetable 
foods. 

The  composition  of  the  principal  cereal  grains  is  tabulated  as  follows 
by  Villier  and  CoUin: 


Wheat. 


Barley. 


Rye. 


Oats. 


Rice. 


Com. 


MiUet. 


Buck- 
wheat. 


Water 

Nitrogenous  substances 

Fat 

Sugar 

Gum  and  dextrin 

Starch 

Cellulose 

Ash 


13-65 

12.35 

1-75 

1-45 

2.38 

64.08 

2-53 
1. 81 


13-77 

II. 14 

2.16 

1.56 

1.70 

61.67 

5-31 
2.69 


15.06 
11.52 
1-79 
0-95 
4.86 
62.00 
2.01 
1. 81 


12.37 
10.41 

5-32 
1. 91 

1-79 
54.08 
1 1. 19 

3.02 


13. II 

7-85 


16.52 

0.63 
1. 01 


13- 
9- 

4- 


-85 

.62 

.46 

3.38 

62.57 

2.49 

1-51 


11.66 
9-25 

3-50 

65-95 

7.29 
2-35 


12.93 

10.30 

2.81 

55-81 

16.43 

2.72 


The  following  results  of  the  analyses  of  cereal  grains  are  summarized 
from  the  work  of  the  Division  of  Chemistry,  United  States  Department 
of  Agriculture :  * 


*  Bulletin  13,  part  9. 


271 


■212 


FOOD   IS'SP^CTIOM  ^ND   ANALYSIS. 
CEREAL    GRAINS. 


Num- 
ber of 
.■Vnaly- 


Weight 
of  100 
Ker- 
nels, 
Grams.i 


Moist- 


Pro- 
teins. 


Ether     cr^^jg 
t^ac't.     !-»'-- 


Ash. 


Barley:                          14 
Mean 

Biukwheat:             I     10 
Moan 1 3 

Com,  domestic: 

Maximum ' 48 

Minimum 10 

Mean 38 

Oats,  domestic:       I 

Maximum 

Minimum 

Mean 

Rice: 

Unhuiled 4 

I'njKjlished 1       6 

Polished* 1      14 

Rye,  domestic:        I 

Maximum ' 

Minimum  . 

Mean 

A\"heat,  domestic: 

Maximum 6. 

Minimum ' 2. 

Mean 3. 

Wht-at,  foreign: 

Maximum 

Minimum.  .. 
Mean 


-533 
.069 

.312 
.608 
•979 
I 
.891 
.038 
.918 

.929 
.466 
.132 

.201 
-932 
-493 

190 

125 
866 

-723 
.250 
.076 


6.47, 

\ 

I2.3I| 

12.32I 

9-58I 

io-93j 

13.02; 

7-87! 
10.061 

10.28' 
11.88 
12.34' 

11-45 

9-54 

10.62I 

14-53 

7. II 

10.62 

12.97 

8.52 

11-47 


11.52 
10.86 

11-55 
8.^8 


15-05 

9.10 

12.15 

7-95 
8.02 
7.18 

18.99 

8.40 

12.43 

17-15 

8.58 

12.23 

14-52 

8.58 

12.08 


2.67      3. Si      2.87      72.66 
2.06      10.57      1.85    63.34 


5.06 
2.94 
4.17 


2.30 
1. 16 
1-65 

2.50 
0.28 
1-77 

2.26 

0-73 
1.78 


2.00 
1. 00 
1. 71 

6.14      16.65 
0.93  I  8.57 
4-33  i  12-07 


-55  '  75-07 
.19  ^  68.97 
•36  '  71.95 


4-37 
:-47 
3-46 

-09 


2.50 
1-65 
2.09 

3-72 
1.70 
2.36 

2.89 
1.87 
2.28 


2.41 
1.7  t 
I 


-35 
.40 


61.44 

53-70 
58-75 


1.65  I10.42  I  4.09     65.60 
1 .96  j  0.93  I  1.15      76.05 

0.26  I  0.40  !  0.46  '  79.36 


75-36 

7t   I   63.61 
92   1   71-37 


76.05 
66.67 


Wet 
Gluten 


.04   I    76.14 

.67   1   67.01 

i    1.73   '    70.66 


39-05 
12.33 


Dry 
Gluten. 


1.82      71.18    26.46 


32.57 
18.72 

25-36 


14.65 

4.70 
10.31 

12.33 
7.00 
9.82 


*  Polished  rice  in  the  United  States  is  commonly  coated  with  glu-.cse  and  talc,  ostensibly  as  a  pro- 
tection against  dust  and  the  ravages  of  insects.  Such  coating  is  alov;ed  if  declared  on  the  label  and 
directions  for  its  removal  are  also  given. 


Balland  f  gives  ihc  following  percentage  composition  of  beans,  lentils, 
and  [)cas: 


Beans. 

Lentils. 

Peas. 

Min.       !       Max. 

Min. 

Max. 

Min.               Max. 

Water 

10.10      1      20.40 

13.81      ,      25.46 

0.98      '        2.46 

52.91           60.98 

2.46             4.62 

2.38             4.20 

11.70 

20.42 

0.58 

56.07 

2.96 

1.99 

13-50 
24.24 

1-45 

62.45 

3-.56 

2.66 

10.60 

18.88 

1.22 

56.21 

2.90 

2-26 

14.20 

22.48 

1.40 

61.10 

5-52 

3-50 

Niiro:5cnous  substances 

Fat 

Sugars  and  starches. 

Cellulos.- 

As!. 

tjoiu.  Pharm.  Chem.,  1897,  pp.  196,  197. 


CERB^ILS,   LEGUMES,    VEGETABLES,   AND   FRUITS.  273 

The  composition  of  potatoes,  according  to  Balland,*  is  as  follows: 


Water. 

Nitroge- 
nous 
Sub- 
stances. 

Fat. 

Sugar 
and 
Starch. 

Cellulose. 

A.sh. 

Normal  state — minimum  . . 

maximum.  . 

Dried —              minimum  . . 

66 . 1 0 
80.60 

1-43 
2.81 

5-98 
13-24 

0.04 
0.14 
0.18 
0.56 

15-58 
29.85 
80.28 
89.78 

0.37 
0.68 
1.40 
3.06 

0.44 
1. 18 
I  66 

maximum.  . 

4.38 

The  composition  of  the  common  vegetables,  fruits,  and  berries  is  thus 
given  by  Atwatcr  and  Bryant. f 


VEGETABLES. 


Asparagus — 
Beans,  dried — • 
BeanSjfresh  Lima 

Beets,  fresh — 

Cabbage — 

Carrot,  fresh — 

Celery — 

Cauliflower — 
Cucumber — 

Lettuce — 

Mushrooms — 
Onion,  fresh — 

Parsnip — 

Pumpkin — 

Radish — 

Rhubarb — 

Squash — 

Tomato,  fresh — 
Turnip — 


as  purchased. . . 

as  purchased 

-edible  portion. . 
as  purchased. . . 
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as  purchased. . . 
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as  purchased 

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as  purchased 

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as  purchased. . . 
as  purchased. . . 
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as  purchased . . . 

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as  purchased. . . 


3 

II 

I 


24 
i6' 


II 
15 


10 


27 
19 


« 

c 

3 

0 

0 

1 

PL, 

94.0 

1.8 

12.6 

22.5 

68.5 

7-1 

55-0 

30.8 

3-2 

87-5 

1.6 

20.0 

70.0 

1-3 

91-s 

1.6 

15-0 

77-7 

1-4 

88.2 

1. 1 

20.0 

70.6 

-9 

94-5 

I.I 

20.0 

75-<' 

■9 

92.3 

1.8 

95-4 

.8 

I5-0 

81. 1 

-7 

94-7 

1.2 

15-0 

80.5 

I.O 

88.1 

3-5 

87.6 

1.6 

10. 0 

78.9 

1-4 

83.0 

1.6 

20.0 

66.4 

1-3 

93-1 

1.0 

50.0 

46.5 

•5 

91.8 

1-3 

30.0 

64-3 

-9 

94-4 

.6 

40. c 

56.6 

.4 

88.3 

1.4 

50.0 

44.2 

-7 

94-3 

■9 

89.6 

1-3 

30.0 

62.7 

■9 

02 


.2 

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3- 
59- 

-7 

22. 

-3 

9- 

.1 

9- 

.1 

7- 

-3 

5- 

.2 

4- 

-4 

9- 

.2 

7- 

.1 

3- 

.1 

2. 

•5 

4- 

.2 

3- 

.2 

2. 

-3 

2. 

.2 

2. 

-4 

6. 

-3 
•3 

9- 
8. 

-5 

13- 

•  4 

10. 

.1 

5- 

.1 

2. 

•3 

8. 

.1 

5- 

■7 

3- 

-4 

2. 

•5 

9- 

.2 

4. 

-4 
.2 

3- 
8. 

.1 

5- 

4-4 

1-7 

.8 

-9 
I.I 


I.I 


2-5 


1.2 


-7 

-7 

I.I 


.6 
1-3 


V   CJ   03 


105 
1605 

570 
255 
215 
170 

145 
125 
210 
160 

85 
70 
140 
80 
70 
90 

75 
210 
225 
205 
300 
240 
120 

60 
135 

95 
105 

65 
215 
105 
105 
185 
125 


*  Jour.  Pharm.  Chem.,  1897,  pp.  298-300. 

t  Bui.  28,  Office  of  Exp.  Station  U.  S.  Dept.  of  Agriculture. 


2  74 


FOOD  INSPECTION   .4ND    yINALYSIS. 


FRUITS. 


Apples — 

Apricots  — 

Bananas  — 

Blackberries  — 
Cherries  — 

Cranberries — 
Currants — 
Figs,  fresh — 
Grapes  — 

Huckleberries - 
Lemons  — 

Muskmclons — 

Oranges — 

Pears — 

Pineapple — 
Plums — 

Prunes — 

Raspberries — 
Strawberries — 

Watermelon — 


edible  portion 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
as  iiurchased. . 
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as  purchased. . 
as  purchased., 
as  purchased. . 
as  purchased. . 
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as  purchased. . 
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It  >> 


29 


9 
16 


28 

5 


23 


'84 

25.01  63 


6.0   79 

;  75 

35-0'  48 


5-0 


25.0 


30.0 
50.0 
27.0 


24 


5-0 
"s-8 

5.0 
59-4 


86 

3' 

80 

9 

76 

8 

88 

9 

85 

0 

79 

I 

77 

4 

58 

0 

81 

9 

89 

3 

62 

5 

89 

5 

44 

8 

86 

9 

63 

4 

84 

4 

76 

0 

8q 

3 

78 

4 

74 

5 

79 

6 

75 

6 

85 

8 

90 

4 

85 

9 

92 

4 

37 

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PLi 


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1.0 

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1-3 

1.0 

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1.0 

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.6 

-3 
.8 
.6 
.6 

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1.0 

-9 
-9 
-7 
1.0 
1.0 
-9 
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2    M 

C 

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fit 

Ph 

0  ■- 

lU 

03   >, 

-3 

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3 

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12. 

14. 
10. 
16. 

15- 
9- 

i: 

xi 

19. 

14. 

16. 
8. 
5- 
9- 
4- 

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8. 

14. 


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2.1 

2-7 

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1.4 

§T3 
153$ 


2  go 
220 
270 

255 
460 
300 
270 
365 
345 
2  I  215 
7  265 
6  j  380 
5  I  450 


335 
345 
205 

145 
185 
90 
240 
170 

295 
260 
200 
395 
370 
370 
335 
255 
180 

175 

140 

60 


The  following  analyses  of  apples  made  by  Browne  *  arc  of  interest. 
The  first  four  analyses  show  the  changes  that  occur  in  the  composition 
of  a  Baldwin  apple  at  different  stages  of  its  growth.  Below  these  is 
given  the  average  of  the  analysis  of  j6o  samples,  representing  27  varieties 
of  apjjles. 

COMPOSITION   OF  A   BALDWIN  APPLE  AT  DIFFERENT  PERIODS. 


Condition.      Water.      Solid.'*. 

Invert 
Sugar. 

1 

Su-        Total 
crose.      Sugar. 

1 

Total 
Sugar 
after  In- 
version. 

Starch. 

Free 

Malic 
Acid. 

Ash. 

Sugar 
Co- 
efficient. 

Very  green.. 

Orren 

Rif)^- 

Over-ri[>e.  .. 

81-53 
79.81 
80.36 
80.30 

18.47 
20.19 
19.64 
19.70 

6.40 
6.46 
7.70 
8.8i 

1.63   j      8.03 
4.05       10.51 
6.81       14.51 
5.26       14.07 

8. II 
10.72 
14.87 
14-35 

4.14 

3-67 
0.17 

1.14 

0.65 
0.48 

0.27 

0.27 
0.28 

47.16 
53-10 
75-71 
72.84 

*  Penn.  Dept.  of  Agriculture,  Bulletin  58. 


CEREALS,   LEGUMES,    yEGET/tBLES,   AND   FRUITS. 


275 


AVERAGE    COMPOSITION    OF   27    VARIETIES    OF    APPLES. 

Water 83 . 5  7 

Solids 16.43 

Invert  sugar 7.92 

Sucrose 3.99 

Total  sugar 11. 91 

Total  sugar  after  inversion 12.12 

Free  malic  acid 0.61 

Ash 0.27 

Sugar  coefficient 73-76 

The  composition  of  the  commoner  nuts  is  shown  in  the  following 
table:* 

NUTS. 


Almonds — 

Beechnuts — 

Brazil-nuts — 

Butternuts — 

Chestnuts,  fresh — 

Cocoanuts — 

Filberts — 

Hickory-nuts — 

Peanuts — 

Pecans — 

Pistachios — 
Walnuts,  Calif  nia- 


edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased . . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
as  purchased. . 
edible  portion, 
-edible  portion, 
as  purchased . . 


45-0 
40.8 

49-6 
86.4' 
16.0 


52.1 
62.2 


24-5 
53-2 


?3-i 


20.0 
ii-S 

21. Q 
13.0 
17.0 

8.6 
27.9 

3-8 
6.2 

5-2 

5-7 
2.9 

15-6 

7-5 
15-4 

5-8 
25-8 
19-5 

II. o 

5-2 

22.3 
18.4 

4-9 


OS  >> 

■tJa 


17-3 

9-5 

13.2 

7-8 
7.0 

3-5 
3  5 

-5 


42.1 
35-4 
27-9 
14.3 
13-0 

6.2 
II. 4 

4-3 
24-4 
18.5 

13-3 

6.2 

16.3 

13.0 

3-5 


1-4 


I.I 

3-5 
2.1 

3-9 
2.0 
2.9 
-4 
1-3 
I.I 

1-7 

■9 

2.4 

I.I 

2.1 


1-5 
1-5 

•7 
3-2 
1-7 

-5 


lad 


3030 
1660 

3075 
1820 

3265 
1655 
3165 
430 
II25 

945 
2760 

1413 
3290 

1575 
3345 
1265 
256c 
1935 
3455 
1620 

2995 
3306 


Vegetables  and  Fruits  furnish  a  large  and  most  important  portion 
of  our  food  supply,  but  are  naturally  not  included  in  their  fresh  state 
among  the  foods  examined  by  the  public  analyst  for  adulteration,  hence 


*  U.  S.  Dept.  of  Agric,  Off.  of  E.xp.  Station,  Bui.  28. 


276  FOOD   INSPECTiON  AND  ANALYSIS. 

but  little  space  need  be  given  ihem  beyond  a  resume  of  their  composition, 
and  an  outline  of  methods  of  proximate  analysis  applicable  to  their  exam- 
ination for  food  values.  A\licn,  however,  these  products  undergo  the 
various  processes  incidental  to  their  treatment  for  long  keeping,  such 
as  preserving,  canning,  dr}-ing,  pickling,  and  mixing  with  other  ingredients, 
il  is  then  that  many  varieties  of  fraudulent  adulteration  are  practiced. 
Vegetable  foods  thus  prepared  form  the  subject  of  a  separate  chapter. 
Besides  the  proximate  components  that  commonly  occur  in  vegetable 
products,  there  are  three  other  substances  worthy  of  mention  found  in 
vegetables  and  fruits,  viz.,  inosite,  pectose,  and  inulin. 

Inosite,  CoHjoOg,  2H2O,  is  not  a  carbohydrate,  but,  according  to  Ham- 
mersten,  is  an  aromatic  compound.  Besides  occurring  in  unripe  fruits, 
it  is  found  in  green  asparagus  and  beans. 

Pectose  is  a  substance  the  exact  nature  of  which  has  not  been  fully 
determined,  though  it  is  thought  to  be  a  carbohydrate.  It  gives  to  unripe 
fruits  and  vegetables  their  peculiar  hardness,  and  furnishes  the  basis  for 
their  gelatinous  constituents.  When  the  vegetable  or  fruit  ripens,  the 
insoluble  pectose  is  then  transformed  by  the  action  of  acids  and  possibly 
of  ferments  into  pectin,  a  vegetable  jelly,  which  gives  to  fruit  juice  the 
property  of  gelatinizing  when  boiled. 

luuUn,  (CeHioOg)^,  is  a  starch-like  substance,  occurring  in  the  roots 
of  chicory  and  dandelion,  and  in  the  tubers  of  the  artichoke.  It  is  a 
white,  starch-like  powder,  slightly  soluble  in  cold,  and  readily  soluble 
in  hot  water,  and  converted  into  levulosc  by  boiling  with  water,  or  by 
the  action  of  acids. 

METHODS   OF   PROXIMATE   ANALYSIS. 

Preparation  of  the  Sample. — Cereals  and  other  dry  products  should  be 
ground  in  a  hand  mill  or  iron  mortar  so  as  to  pass  a  sieve  with  round 
holes  I  mm.  in  diameter.  Green  vegetables,  roots,  fruits,  etc.,  may 
be  reduced  to  a  pulp  in  a  food  chopper. 

The  following  methods,  with  the  exception  of  the  Brown  and  Duvel 
methfxl,  are  those  of  the  Association  of  Official  Agricultural  Chemists 
for  the  analysis  of  foods  and  feeding  stuffs.* 

Moisture.— Dry  a  quantity  of  the  substance,  representing  about  2 
grams  of  the  dry  material,  to  constant  weight  (about  five  hours)  at  the 
temperature  of  boiling  water,  in  a  current  of  dry  hydrogen  or  in  vacuo. 
The  apparatus  described  on  page  62  may  be  used. 

•  U.  S.  Dcpt.  of  Agric,  Bur.  of  Chcm.,  FJuI.  107  (rev.). 


CEREALS,   LEGUMES,    VEGETABLES,   AND   FRUITS.  277 

Ash. — Burn  2  grams  of  the  substance  in  a  j)latinum  dish  at  the  lowest 
possible  red  heat,  as  described  on  pages  62  and  63.  If  a  white  or  light- 
gray  ash  cannot  be  obtained  in  this  manner,  exhaust  the  charred  mass 
with  water,  collect  the  insoluble  residue  on  a  filter,  burn,  add  this  ash 
to  the  residue  from  the  evaporation  of  the  acjueous  extract,  and  heat  the 
whole  at  low  redness  until  white  or  nearly  so. 

Ether  Extract  {Fat,  etc.). — Extract  the  residue  from  the  determination 
of  moisture  for  sixteen  hours  with  anhydrous  alcohol-free  ether  in  a 
continuous  extractor  (p.  63)  and  cry  the  extract  to  constant  weight  in 
a  water-oven.  The  ether  extract  may  also  be  determined  indirectly  from 
the  difference  in  weight  of  the  dried  substance  before  and  after  extrac- 
tion. 

Protein. — Determine  the  total  nitrogen  by  the  Gunning  or  Kjeldahl 
method,  using  i  gram  of  the  substance.  Calculate  the  protein  by  mul- 
tiplying the  total  nitrogen  by  the  appropriate  factor,  which  varies 
with  the  different  cereals  as  follows:  wheat,  5.70;  rye,  5.62;  oats,  6.31; 
corn,  6.39;  and  barley,  5.82.  Ordinarily  the  conventional  factor  6.25 
is  employed. 

Crude  Fiber  {Cellulose,  Lignin,  etc.). — Transfer  the  residue,  after 
extraction  for  the  determination  of  the  ether  extract,  to  a  500-cc.  Erlen- 
meyer  flask,  with  a  mark  showing  200  cc,  add  boiling  1.25%  sulphuric 
acid  to  the  mark,  heat  at  once  to  boiling,  and  boil  gently  for  thirty 
minutes,  shaking  cautiously  from  time  to  time  to  prevent  the  material  from 
crawling  up  on  the  sides  of  the  flask.  Filter  through  paper,  and  wash 
once  with  boiling  water.  Rinse  the  substance  back  into  the  same  flask 
with  200  cc.  of  a  boiling  1.25%  solution  of  sodium  hydroxide,  free,  or 
nearly  so,  from  sodium  carbonate,  boil  at  once,  and  continue  the  boiling 
for  thirty  minutes  in  the  same  manner  as  directed  above  for  the  treatment 
with  acid.  Filter  on  a  tared  filter-paper  or  Gooch  crucible,  and  wash 
with  boiling  water  till  the  washings  are  neutral.  Dry  at  110°  and  weigh, 
after  which  incinerate  completely  and  correct  for  ash. 

If  a  tared  filter  is  used,  it  should  be  previously  dried  at  110^  for 
one  hour  in  a  glass-stoppered  weighing  bottle,  cooled  for  fifteen  minutes 
and  weighed.  After  collecting  the  fiber  on  the  filter,  it  is  well  to 
wash  successively  with  alcohol  and  ether  to  facilitate  drying.  The 
filter  should  not  be  pushed  down  into  the  weighing  bottle  until  the 
fiber  is  dry  to  the  touch  after  which  two  hours'  drying  at  110°  will  be 
sufficient.  A  blank  should  ])e  made  to  ascertain  the  loss  sustained  by 
the  filter  on  treatment  with   alkali  and  the  necessary   correction  intro- 


27S 


FOOD  INSPECTION   AND   /IN  A  LYSIS. 


duced.  This  error  and  others  can  be  avoided  by  fihering  on  a  Gooch 
crucible,  Init  with  many  materials  this  cannot  be  used  "because  of 
clogging.  The  acid  and  alkali  solutions  must  be  exactly  1.25%  as 
determined  by  titration. 

Nitrogen-free  Extract  [Slarch,  Sugar,  Gums,  ^-/r.).— Subtract  the 
sum  of  the  moisture,  ash,  ether  extract,  protein,  and  crude  fiber,  from 
100. 

Determination  of  Moisture  in  Grain,  Legumes,  Oil  Seeds,  etc. — 
Brown  and  Duvcl  Method.* — This  method  is  especially  useful  in  guarding 

against  an  excessive  amount  of 
moisture  in  grain,  which  not  only 
adds  weight  but  also  causes  deterio- 
ration through  the  growth  of  bac- 
teria and  moulds. 

The  apparatus  (Fig.  61)  consists 
of  a  condenser-tank  (A)  and  an 
evaporating-chamber  {B)  with  a 
cover  ik)  and  a  mica  window  im), 
the  whole  supported  on  a  stand  (C). 
It  is  arranged  for  conducting  six 
distillations  at  the  same  time. 

The  distilling-flask  is  shown  at 
the  left  ip')  in  the  wooden  rack  used 
only  during  filling  and  at  the  right 
ip)  in  position  for  distillation. 

Weigh    into    the    dislilling-fiask 

100  grams  (corn,  barley,  wheat,  rye, 

unhulled  rice,   kafir,  flaxseed,  soy 

bean)  or  50  grams  (oats,  cottonseed) 

of  the  whole  grain  and  add  150  cc. 

Fig.  6 1. -Brown  and  Duvel  Apparatus  for     ^^j  hydrocarbon  engine  oil   with  a 

DeterminalJon    of    Moisture    in    Orain.       _     ,         .       . 

End  View.  flash-pomt  m  an  open  cup  of  200 - 

205°  C.  Close  the  neck  of  the 
flask  with  a  rubber  stopper  carrying  a  thermometer  iq),  the  bulb  of 
which  extends  well  into  the  mixture  of  oil  and  corn;  connect  the  side 
tube  by  means  of  another  cork  with  the  condenser-tube  is),  and  heat 
with    the    Bunsen    burner,    so    as    to  bring  (in  twenty  minutes)  to  the 


*  U.  S.  iJept.  of  Agric,  Hur.  of  I'lant.  Ind.,  Bui.  99,  and  Circular  72. 


CEREALS,  LEGUMES,    VEGETABLES,   AND   FRUITS,  279 

proper  lemperatvirc,  which  for  corn,  barley,  rice,  kafir,  and  cottonseed 
is  190°,  for*  wheat  180°,  for  rye  and  llaxseed  175°,  for  soy  bean  170°, 
and  for  oats  195°  C.  When  the  desired  temperature  is  reached  turn  off 
the  flame,  and  allow  to  stand  until  the  moisture  ceases  to  drop  from  the 
condenser-tube  into  the  <^raduate  (/).  The  number  of  cc.  in  the  graduate 
represents  the  amount  of  moisture  in  the  grain. 

The  results  agree  closely  with  those  by  drying  to  constant  weight  in 
a  water-oven  at  100°. 

After  the  determination  is  finished  empty  the  contents  of  the  flask 
on  a  suitable  strainer,  thus  recovering  the  oil  for  further  use. 

CARBOHYDRATES  OF  CEREALS  AND  VEGETABLES. 

Classification. — As  a  rule  the  same  carbohydrates  are  found  in  all 
cereals,  being  present,  however,  in  var}dng  proportions.  By  far  the  greater 
part  of  the  carbohydrate  content  of  cereals  is  starch,  the  other  carbohydrates 
being  comparatively  small  in  amount,  so  that  in  rough  work  it  is  sometimes 
customary,  though  incorrect,  to  assume  the  entire  amount  of  so-called 
*' nitrogen-free  extract"  or  carbohydrates  (as  determined  by  difference) 
to    be   starch. 

The  carbohydrates  occurring  in  cereals  may  be  classified  as  follows: 


Principal  carbohydrates 
of  cereals: 


r  Starch 

Insoluble \  Cellulose 

[  Pentosans 

f  Sucrose 
Dextrose 
Dextrin 
Raffinose  (traces) 


Starch  (CgHioOs)^. — Pure  starch  is  a  glistening,  white,  granular 
powder  having  a  peculiar  feeling  when  rubbed  betw^een  the  thumb  and 
finger.  It  is  a  very  hygroscopic,  commercial  starch  containing  about  18% 
of  moisture.  Starch  is  \ery  widely  distributed  in  the  vegetable  kingdom, 
occurring  in  almost  every  plant  at  some  stage  in  its  grow'th. 

Starch  is  insoluble  in  cold  water,  alcohol,  and  ether;  it  is  soluble  in 
hot  water,  though  not  without  change.  By  boiling  with  dilute  acids, 
starch  is  first  converted  by  hydrolysis  into  a  mixture  of  dextrin  and 
maltose,  and  finally  by  prolonged  boiling  into  dextrose.  Malt  extract 
also  hydrolizes  starch  in  solution. 

Detection. — Starch  is  best  detected,  when  present  to  any  appreciable 
extent  in  any  mixture,  by  boiling  a  portion  of  the  sample  in  water,  cooling, 
and  applying  a  solution  of  iodine.  A  characteristic  blue  color  is  pro- 
duced if  starch  is  present.     Verj'  small  amounts  of  starch  are  best  idea* 


2 So  FOOD  INSPECTION  AND  ANALYSIS. 

tified  in  powdered  mixtures  by  applying  a  drop  of  a  solution  of  iodine 
to  the  dn,-  powder  on  a  microscope  slide,  or,  better,  to  the  powdeV  previously 
rubbed  out  with  water  on  a  slide  under  a  cover-glass;  the  starch  granules, 
if  present,  will  be  colored  intensely  blue  by  the  iodine,  and  arc  at  once 
rendered  apparent  when  viewed  through  the  microscope. 

Though  the  cereal  and  vegetable  starches,  whatever  their  origin,  are 
identical  chemically,  the  various  starch  granules  have  certain  character- 
istics, when  viewed  under  the  microscope,  that  render  their  identifi- 
cation easy  in  most  cases.  A  knowledge  of  the  microscopical  appear- 
ance of  the  common  vegetable  starches  is  of  the  utmost  importance  to 
the  public  analyst,  who  frequently  finds  them  as  adulterants  of  various 
foods,  such  as  cofifee,  cocoa,  spices,  etc.  For  microscopical  examination, 
powdered  samples  should  be  ground  fme  enough  to  pass  through  a  60  or 
80  mesh  sieve. 

Classification. — As  seen  under  the  microscope  the  starch  granules 
of  various  grains  and  vegetables  dilTer  in  form,  size,  and  often  in  their 
manner  of  grouping.  Thus,  at  the  outset,  the  common  starches  may  be 
divided  as  to  the  microscopical  form  of  their  granules  into  three  classes, 
viz.,  lenticular,  irregularly  oval,  and  polygonal.  To  the  first  class,  in  which 
the  starch  granule  has  in  general  the  circular  disk  form,  ])elong  rye,  wheat, 
and  barley.  Representing  the  second  or  irregularly  elliptical  class  are 
the  pea,  bean,  potato,  and  arrowroot.  In  the  third,  or  ])olygonal  class, 
should  be  included  corn,  oats,  buckwheat,  and  rice.  In  thus  character- 
izing the  distinguishing  forms  as  lenticular,  oval,  and  polygonal,  it  should 
be  borne  in  mind  that  while  the  tendency  of  the  most  typical  starch  granules 
in  each  class,  when  viewed  in  normal  position,  is  toward  the  circular,  the 
oval,  or  the  jK^lygonal  as  the  case  may  be,  it  is  not  by  any  means  true  that 
all  or  even  most  of  the  granules  in  any  one  instance  ])erfectly  conform 
to  one  of  these  shapes  throughout.  Thus,  lenticular  wheat  granules,  when 
viewed  edgewise,  will  appear  elliptical,  and  are  often  distorted  in  shape, 
especially  when  roasted;  and  polygonal  buckwheat  granules  may  in 
many  instances  have  such  obtuse  angles  as  to  appear  circular.  It  is  the 
general  trend  of  all  the  starches  toward  one  or  another  of  these  shapes 
that  suggests  the  classification. 

The  identification  of  the  various  starches  morphologically  is  indeed 
the  most  natural  and  ready  method.  Not  only  the  character  of  the  starch, 
but  also  its  approximate  amount,  when  present  in  mixtures,  can  in  many 
instance,  be  ascertained  by  a  careful  examination  with  the  microscope. 
The    analyst    should    be    }jrovided  with    samples  of    starches  of    known 


CEREALS,   LEGUMES,   VEGETABLES,   AND  FRUITS.  281 

purity  conveniently  at  hand,  and  in  all  doubtful  cases  these  should  be 
referred  to  for  comparison. 

Wheat  Starch  (Fig.  152,  PI.  VIII j. — This  starch  is  frecjuenlly  present 
in  adulterated  pepper,  mustard,  ginger,  cocoa,  coffee,  and  other  foods. 
Its  granules  occur  for  the  most  part  in  two  sizes,  of  which  the  larger 
are  lenticulars,  varying  from  0.021  mm.  to  0041  mm.,  or  rarely  0.050 
mm.,  in  diameter,  while  the  smaller  are  rounded  or  polygonal,  averaging 
about  0.005  "'^"''-  iri  diameter.  The  smaller  granules  are  grouped  irregu- 
larly in  and  around  the  larger,  there  being  six  to  ten  of  the  former  to 
one  of  the  latter.  The  larger  granules  are,  however,  the  most  distinctly 
characteristic,  and  are  usually  readil)  recognized  in  a  mixture,  not  only 
by  their  shape,  but  by  reason  of  the  concentric  rings  with  which  they  are 
provided,  and  which  are  generally  but  not  always  apparent. 

Barley  Starch  (Fig.  124,  PI.  I). — This  much  resembles  wheat,  in  that 
it  has  two  sizes  of  granules,  but  both  sizes  are  respectively  smaller  than 
those  of  wheat,  though  jiresent  in  about  the  same  proportion.  The 
larger  lenticular  disk-like  granules  vary  from  0.013  mm.  to  0.035  ^J^-  i^ 
diameter,  while  the  smaller  average  0.003  n"^"^-  The  concentric  rings  are 
less  apparent  in  the  barley  than  in  the  wheat. 

Rye  Starch  (Fig.  148,  PI.  \TI)  has  also  two  sizes  of  granules,  but 
the  larger  vary  from  0.025  "in^-  to  over  0.05  mm.  in  diameter,  and  are 
considerably  larger  than  the  corresponding  wheat  granules.  The  smaller 
granules  average  about  0.004  ^nrn-  in  diameter.  As  in  the  case  of  wheat 
and  barley,  the  larger  granules  are  lenticular,  while  the  smaller  are 
rounded  or  polygonal.  The  concentric  rings  are  usually  indistinct  in  the 
large  granules,  and  many  of  these  show  cross-shaped  rifts  in  the  center. 

Corn  Starch  (Fig.  133,  PL  IV). — This- starch  is  a  common  adulterant 
of  spices,  cocoa,  and  other  foods.  It  is  placed  in  a  series  of  four  cereal 
starches  whose  granules  are  polygonal,  and  all  of  which  show  more  or 
less  tendency  to  arrange  themselves  in  close  contact  side  by  side  in 
masses  suggestive  of  a  tessellated  or  mosaic  floor.  Arranged  in  order 
of  the  size  of  their  grains,  these  starches  are:  Corn,  buckwheat,  oats, 
and  rice.  Corn  starch  granules  tend  toward  the  hexagonal  in  shape, 
varying  from  0.007  n^""*-  to  0.035  ""'"''•  '^  diameter,  and  having  very 
marked  rifted  hila.  They  are  most  readily  recognized  in  any  mixture, 
and  from  their  size  are  readily  distinguishable  from  the  other  polygonal 
starches,  which  never  reach  0.017  mm.  in  diameter. 

Buckwheat  Starch  (Fig.  128,  PI.  II,  and  Fig.  129,  PI.  III).— This  is  a 
very  common  adulterant  of  many  spices,  especially  pepper,  which,  as 


282  FOOD   INSPECTION   AND  ANALYSIS. 

shown  in  Fig.  2^<:),  PL  XXXIV.  it  much  resembles  in  the  manner  in 
which  its  masses  of  granules  group  themselves,  conforming  to  the  shape 
of  the  cells.  The  individual  granules  arc  coinmonly  0.006  mm.  to  0.012 
mm.  in  diameter.  Curious  .rod-shaped  aggregates  of  two  to  four  indi- 
viduals are  of  frequent  occurrence. 

Oat  Starch  (Fig.  13Q,  PI.  V). — The  granules  of  this  starch  vary  from 
0.002  mm.  to  0.012  mm.  in  diameter,  and  are  j)olygonal,  or  less  often 
rounded  or  spindle-shaped  in  form.  They  have  no  rings  or  hila,  and 
arrange  themselves  in  rounded  aggregates  of  from  two  to  many  granules 
that  at  first  sight  might  be  mistaken  for  large  grains;  careful  examina- 
tion, however,  shows  the  dividing  lines. 

Rice  Starch  (Fig.  143,  PI.  VI). — The  granules  of  rice  starch  resemble* 
closely  those  of  oats  both  in  form  and  size,  but  spindle-shaped  forms  are 
not  present.  As  in  the  case  of  oats,  the  granules  are  often  united  to  form 
rounded  aggregates. 

Starches  of  the  Pea  and  Bean. — The  starches  of  these  legumes  much 
resemble  each  other,  and  are  with  difficultly  distinguished  one  from  the 
other  (see  Fig.  164,  PI.  XI,  and  Fig.  154,  PL  IX),  The  granules  are 
more  nearly  oval  than  most  other  starches,  and  have  both  concentric 
rings  and  elongated  hila.  The  granules  of  the  pea  show  a  less  distinct 
hilum  than  those  of  the  bean,  and  some  of  them  are  irregularly  swollen. 
Both  peas  and  beans  roasted  are  commonly  used  as  adulterants  of 
coffee. 

Arrowroot. — There  arc  many  varieties  of  arrowroot,  including  Jamaica, 
Bermuda,  East  Indian,  Australian,  and  others,  all  having  certain  varia- 
tions in  form  and  size,  but  resembling  each  other  in  a  general  way. 
Fig.  167,  PL  XII,  shows  the  Bermuda  arrowroot,  the  granules  of  which 
are  somewhat  egg-shaped,  being  usually  smaller  at  one  end  than  the 
other,  and  having  rifted  hila  near  the  small  end. 

Potato  Starch  (Fig.  165,  PL  XII). — This  starch  has  large,  irregularly 
oval  granules,  with  very  apparent  hila  situated  eccentrically  near  one 
end,  and  with  rings  around  the  hilum.  The  granules  are  about  0.07  mm. 
in  large  diameter.  Fig.  134,  PL  IV,  and  Fig.  166,  PL  XII,  show  corn 
and  potato  starch  when  viewed  with  polarized  light  with  crossed  Nicol 
prisms,  the  specimens  being  mounted  in  Canada  balsam. 

Tapioca  Starch. — The  granules  of  this  starch,  as  shown  in  Fig.  168, 
PL  XII,  are  more  uniform  in  size  throughout  than  those  already  de- 
scribed, averaging  about  0.018  mm.  in  diameter,  and  being  quite  smoothly 
circular,  without  concentric  rings,  but  having  a  distinctly  dotted  hilum  in 


CERE/1  LS,  LEGUMES,  l^EGET/IBLES,  AND  FRUITS.  283 

the  center.  Many  of  the  <i;rains  arc  cup-shaped,  as  if  a  segment  of  the 
circle  had  been  removed. 

Sago  Starch  (Fig.  172,  PI.  XIII.) — The  granules  of  sago  starch  vary 
much  in  size,  and  might  be  called  irregularly  ellipsoidal  in  shape  with 
one  or  more  truncated  surfaces.  Some  of  them  have  indistinct  concentric 
rings,  and  in  some,  but  not  all,  a  hilum  is  apparent,  usually  near  one  end 
of  the  granule. 

Microscopical  Appearances  of  Starches  with  Polarized  Light. —  With 
polarized  light  starch  granules  show  dark  crosses,  the  point  of  mtcr- 
section  being  at  the  hilum  (Fig.  166,  PI.  XII).  These  crosses  vary 
in  distinctness  with  the  variety.  Certain  of  the  starches  show  a  j)lay 
of  colors  with  polarized  light  and  a  selenitc  plate,  especially  those  whose 
granules  have  some  sort  of  hilum.  This  is  particularly  striking  in  such 
starches  as  corn,  tapioca,  potato,  and  arrowroot.  Blyth  has  made  the 
phenomenon  a  means  of  classification  of  the  starches,  but  the  writer 
considers  their  appearance  with  ordinary  light  sufficient  for  identifica- 
tion. Canada  balsam  is  the  best  mountant  for  examination  in  polar- 
ized light. 

Estimation  of  Starch. — Direct  Acid  Conversion. — By  this  method  the 
hemicellulose,  if  present,  or  such  of  the  carbohydrates  as  are  capable  of 
being  converted  to  sugar,  are  reckoned  in  with  the  starch.  Where  little 
or  none  of  the  insoluble  carbohydrates  other  than  starch  are  present,  as 
for  instance  in  the  case  of  commercial  starches,  this  method  is  sufficiently 
accurate. 

Exhaust  3  grams  of  the  finely  divided  substance  on  a  fine  but  rapidly 
acting  filter  with  ether  by  washing  with  5  successive  portions  of  10  cc. 
each,  and  wash  the  residue  first  with  150  cc.  of  10%  alcohol  and  then 
with  a  little  strong  alcohol.  Transfer  by  washing  to  a  flask  with  200  cc. 
of  water  and  20  cc.  of  hydrochloric  acid  (specific  gravity  1.125),  connect 
with  a  reflux  condenser,  and  heat  the  flask  in  boiling  water  for  2|  hours. 
Cool,  and  carefully  neutralize  with  sodium  hydroxide,  clarifying  if  neces- 
sary with  alumina  cream.  Mix  well,  make  up  the  volume  to  500  cc, 
filter,  and  determine  the  dextrose  in  an  aliquot  part  of  the  filtrate  by 
any  of  the  methods  for  dextrose.  Convert  dextrose  to  starch  by  the 
factor  0.9. 

Diastase  Method. — By  this  method  the  hemicellulose  is  not  con- 
verted, only  the  starch  being  acted  upon.  Hence  for  exact  work  in  the 
presence  of  other  insoluble  carbohydrates  this  method  is  to  be  recom- 
mended.     Under  the  action  of  diastase,   starch   is  first  converted   into 


2S4  FOOD   INSPECTION  .-iND   ^N^ LYSIS. 

maltose  and  dextrin,  and  finally  into  dextrose,  in  somewhat  the  following 
manner : 

i2CeH.„0,+  4H,0  =  4C,Ji,,0„+2C,H3Ao 

Starch  Maltose  Dextrin 

C,,H,,0„  +  H,0  =  2C6H,,Oe     C,.,H,„0,„+  2H,0  =  2CoH,,06 

Maltose  Dextrose  Dextrin  Dextiose 

Exhaust  3  grams  of  the  material,  ground  to  an  impalpable  powder, 
with  ether  and  alcohol  as  in  the  acid  conversion  method,  wash  the  residue 
into  a  beaker  with  50  cc.  of  w"ter  and  immerse  in  a  l^oiling  water-bath. 
Keep  in  the  bath  for  15  minutes  or  until  completely  gelatinized,  stirring 
constantly,  and  cool  to  55°  C.  Add  20  cc.  of  malt  extract  and  digest 
at  55°  C.  one  hour.  Heat  again  to  boiling,  boil  for  15  minutes,  replacing 
the  water  lost  by  evaporation,  cool  to  55°  C,  and  digest  as  before  with 
20  cc.  of  malt  extract  for  one  hour  or  until  the  residue  treated  with  iodine 
solution  shows  no  starch  under  the  microscope.  Cool,  make  up  to  250 
cc,  filter,  pipette  200  cc.  into  a  flask,  add  20  cc.  of  hydrochloric  acid  (specific 
gravity  1.125)  and  proceed  as  in  the  acid  conversion  method.  Correct 
for  the  copper-reducing  power  of  ti^e  malt  extract  as  below. 

Preparation  of  Malt  Extract. — Digest  at  room  temperature  10  grams  of 
freshly  pulverized  malt  with  200  cc.  of  water  for  2  to  3  hours  with  occasional 
shaking  and  filter.  Determine  the  amount  of  dextrose  in  a  given  volume 
of  the  extract  after  heating  with  acid,  etc.,  as  in  the  actual  analysis  and 
make  the  proper  correction. 

Use  of  ''Animal  Diastase^ — Pancreatin  and  similar  powdered  prepara- 
tions, such  as  "  vera  diastase  "  and  "  panase,"  obtained  from  the  pancreas 
of  cattle  and  hogs,  arc  preferable  to  diastase  as  starch -converting  reagents, 
since,  as  a  rule,  they  have  no  copper-reducing  power,  thus  obviating  a 
correction. 

Use  instead  of  the  malt  extract  the  same  amount,  viz.,  20  cc,  of  a 
0.5%  aqueous  solution  of  powdered  U.  S.  P.  j)ancreatin  in  starch  deter, 
minations  as  above  described. 

Determination  of  Sugars  in  Grain  and  Cereal  Products. — Method  of 
Bryin,  Given  and  Straughn* — Place  12  grams  of  the  material  in  a  300- 
cc  graduated  flask  (if  acid  add  1-3  grams  of  precipitated  calcium  car- 
bonate), add  150  cc.  of  50%  (by  vol.)  alcohol  (carefully  neutralized),  mix 
and  boil  on  a  steam  bath  under  a  reflux  condenser  for  one  hour.  Cool, 
and  if  desired  allow  to  stand  overnight.  Make  u[)  to  volume  with  neutral 
95%  alcohol,  mix,  allow  to  settle,  pipette  200  cc.  into  a  beaker,  and  evaporate 

*  U.  S.  Dcpt.  of  Agric.  Bur.  of  Chcm.,  Circ.  71. 


CEREALS,  LEGUMES,  (VEGETABLES,  AND  FRUITS.  285 

on  the  steam  bath  to  20-30  cc.  Transfer  to  a  100  cc.  graduated  flask  with 
water,  add  enough  saturated  normal  lead  acetate  solution  to  produce 
a  flocculent  precipitate,  and  allow  to  stand  15  minutes  or  if  desired  over- 
night. Make  up  to  the  mark  with  water  and  j)ass  through  a  folded 
filter,  saving  all  the  liltrate.  Precipitate  the  lead,  with  anhydrous  sodium 
carbonate,  allow  to  stand  15  minutes  and  pour  onto  an  ashless  Alter. 
Dilute  25  cc.  of  this  clear  filtrate  with  25  cc.  of  water  and  determine  reduc- 
ing sugars  by  the  Munson  and  Walker  method  (p.  598). 

In  a  100  cc.  graduated  flask  place  50  cc.  of  the  same  filtrate,  neutrahze 
to  litmus  paper  with  acetic  acid,  add  5  cc.  of  concentrated  hydrochloric 
acid,  and  let  stand  overnight  (or  if  desired  48  hours)  for  inversion.  Neu- 
tralize in  a  large  beaker  with  anhydrous  sodium  carbonate;  return  to 
the  100  cc.  flask  and  make  up  to  the  mark.  Filter  and  determine  total 
sugars  as  invert  in  50  cc.  of  the  filtrate  by  the  Munson  and  Walker 
method. 

Multiply  the  difference  between  the  percentages  of  invert  sugar  before 
and  after  inversion  by  0.95,  thus  obtaining  the  per  cent  of  sucrose.  Cor- 
rect the  percentages  of  both  sucrose  and  reducing  sugars  for  the  volume 
of  the  alcohol  precipitate  by  multiplying  by  0.97. 

Cellulose  forms  the  framework  of  all  vegetable  organisms,  being 
next  to  water,  the  most  abundant  substance  in  the  vegetable  kingdom. 
Pure  cellulose  is  white,  translucent,  and  of  fibrous  or  silky  texture.  It 
is  insoluble  in  water,  alcohol,  and  ether,  but  dissolves  readily  in  an 
ammoniacal  solution  of  cupric  hydroxide  known  as  Schweitzer's  Reagent 
or  "  cuprammonia,"  (p.  93).  Cellulose  turns  violet  when  treated  with 
chloriodide  of  zinc,  and  blue  when  treated  with  sulphuric  acid  and  iodine 
in  potassium  iodide  (p.  91). 

The  "  crude  fiber,"  as  determined  in  foods,  being  the  portion  that 
resists  the  action  of  hot  dilute  acid  and  alkali,  is  composed  largely  of 
cellulose. 

The  Pentosans  are  amorphous,  insoluble  in  water,  l:)ut  soluble  in  dilute 
alkali,  and  are  converted  by  boiling  with  dilute  acids  into  so-called  pentose 
sugars,  the  best  known  of  which  are  xylose  and  arabinose,  corresponding 
to  the  pentosans  xylan  and  araban  respectively.  Hemicellulose  is  the 
more  appropriate  generic  term  for  the  insoluble  carbohydrates  capable 
of  hydrolysis  by  acids  to  sugars,  inasmuch  as  there  are  insoluble 
bodie  besides  the  pentosans  that  may  thus  be  converted  into  sugar, 
such  as  the  hexosans,  hydrolyzed  by  acid  to  hexose  sugars,  mannose, 
galactose,    etc.      Since   the    greater  portion  of  these   insoluble  hydroliz- 


2S6  FOOD  INSPECTION  AND  ANALYSIS. 

able  carbohydrates  are  pentosans,  it  is  simpler  to  calculate  them  all  as 
such. 

Determination  of  Pentosans. — Pentosans  are  determined  either  by 
hydrolyzing  to  reducing  sugar,  and  estimating  the  latter  as  described  on 
page  2qb  (Stone's  method)  or  by  calculation  from  the  furfuraP''  yielded 
on  distillation  with  hydrochloric  acid,  as  carried  out  in  the  provisional 
method  of  the  A.  O.  A.  C.f  as  follows: 

Place  3  grams  of  the  material  in  a  flask  together  with  loo  cc.  of  12% 
hydrochloric  acid  (specific  gravity  1.06)  and  several  pieces  of  recently 
heated  pumice  stone,  connect  with  a  condenser  and  heat  on  a  wire  gauze, 
rather  gently  at  first,  using  a  gauze  top  to  distribute  the  flame  so  as  to 
distil  over  30  cc.  in  about  ten  minutes  and  passing  the  distillate  through 
a  small  filter.  Replace  the  30  cc.  driven  over  with  a  like  amount  of  the 
12%  acid  added  through  a  separatory  funnel  in  such  a  manner  as  to  wash 
down  the  particles  on  the  sides  of  the  flask  and  continue  the  process  until 
the  distillate  amounts  to  360  cc.  To  the  distillate  add  gradually  a  quantity 
of  phloroglucinol  (free  from  diresorcin)  dissolved  in  12%  hydrochloric 
acid,  about  double  that  of  the^furfural  expected.  The  solution  first  turns 
yellowy  then  green,  and  soon  an  amorphus  greenish  precipitate  appears, 
which  rapidly  grows  darker,  finally  becoming  almost  black.  Make  the 
solution  up  to  400  cc.  with  12%  hydrochloric  acid  and  allow  to  stand  over- 
night. 

Filter  the  amorphous  black  precipitate  on  a  Gooch  crucible,  wash 
with  150  cc.  of  water,  keeping  the  precipitate  covered  with  the  liquid 
until  the  last  portion  has  run  through,  dry  for  four  hours  at  the  temperature 
of  boiling  water,  cool  in  a  weighing  bottle  and  weigh.  Calculate  by 
Krober's  formukc  as  follows: 

(a)    For  weight  of  phloroglucide  "a  "  under  0.03  gram: 

Furfural  =  (a +  0.0052)  X  0.5 170. 
Pentoses  =  (a +0.0052)  Xi. 0170. 
Pentosans  =  (a +0.0052)  X 0.8949. 

*  Furfural  or  furfuraldehyde  {jdlUOi)  is  the  aldehyde  of  pyromucic  acid.  Il  is  a  color- 
less liquid,  having  an  odor  suggestive  of  cassia.  Its  boiling-point  is  162°  and  its  specific 
gravity  1.164.  It  is  sparingly  soluble  in  water  and  readily  soluble  in  alcohol.  Nearly 
half  the  tissue  of  ordinary  bran,  exclusive  of  proteins  and  starch,  yields  furfural  on  distilla- 
tion with  add. 

t  U.  S.  Dept.  of  .'Vgric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  54. 


CEREALS,   LEGUMES,    VEGETABLES,   AND   FRUITS.  287 

ib)  For  weight  of  phloroglucide  "  a  "  over  0.300  gram. 

Furfural  =  (a  +  0.0052)  X0.5180. 
Pentoses  ={a-\-  0.005  2)  X  i  .0026. 
Pentosans  =  (a +  0.005  2)  X  0,8824. 

For  weight  of  phloroghicide  "a"  from  0.03  to  0.300  gram  use  Xrobcr's 
table  (pp.  288-294)  to  calculate  the  weight  of  pentoses  (arabinose, 
xylose),  and  pentosans  (araban,  xylan). 

The  reactions  that  take  place  are  thought  to  be  somewhat  as  follows: 

CsHsO.  +  H^O^QHioOs. 

Pentosan  Pentose 

C5H,o05  =  C,H,02  +  3H20. 

Pentose  Furfural 

2C5H402  +  C6H603  =  C,6Hi,,06  +  H20. 

Furfural         Phloroglucinol     Phloroglucide 

The  theoretical  yield  of  phloroglucide  should  be  2.22  parts  to  one  of 
furfural,  but  in  practice  this  is  never  obtained.  The  varying  factors  for 
calculation  as  above  given  are  based  on  experiment. 

The  phloroglucinol  used  should  be  free  from  diresorcin.  To  test  for 
the  latter,  dissolve  the  reagent  in  acetic  anhydride,  heat  nearly  to  boiling, 
and  add  a  few  drops  of  concentrated  sulphuric  acid.  If  more  than  a 
faint  violet  color  is  produced,  the  phloroglucinol  should  be  purified  as 
follows : 

Heat  in  a  beaker  about  300  cc.  of  hydrochloric  acid  (sp.  gr.  1.06) 
and  II  grams  of  commercial  phloroglucinol,  added  in  small  quantities 
at  a  time,  stirring  constantly  until  it  has  almost  dissolved.  Some  im- 
purities may  resist  solution,  but  it  is  unnecessary  to  dissolve  them. 
Pour  the  hot  solution  into  a  sufficient  quantity  of  the  same  hydrochloric 
acid  (cold)  to  make  the  volume  1500  cc.  Allow  it  to  stand  at  least 
overnight — better  several  days — to  allow  the  diresorcin  to  crystallize  out, 
and  filter  immediately  before  using.  The  solution  may  turn  yellow, 
but  this  does  not  interfere  with  its  usefulness.  In  using  it,  add  the 
volume  containing  the  required  amount  to  the  distillate. 


2SS 


FOOD   INSPECTION  ^ND   /iN  A  LYSIS. 


KROBER'S  TABLE  FOR  DETERMIXATION  OF  PENTOSES  AXD  PENTOSANS 

FROM  PllLOROGLUCID. 


I 

2 

.5 

4 

5 

6 

8   . 

Phloroglucii! 

Furfural. 

Arabinose. 

Araban. 

Xylose. 

Xylan. 

Pentose. 

Pentosan. 

0.030 

0.0182 

0.0391 

0.0344 

0.0324 

0.0285 

0.0358 

0.0315 

-031 

.0188 

.0402 

-0354 

•Oi55 

.0293 

.0368 

.0324 

.032 

-0193 

-0413 

-0363 

■0342 

.0301 

-0378 

-0333 

.033 

.0198 

.0424 

-0373 

-0352 

.0309 

.0388 

.0341 

-034 

.0203 

•0435 

-0383 

.0361 

-0317 

-0398 

-0350 

-035 

.0209 

.0446 

-0393 

.0370 

.0326 

.0408 

-0359 

.036 

.0214 

-0457 

.0402 

-0379 

-0334 

.0418 

.0368 

.037 

.0219 

.0468 

.0412 

.0388 

.0342 

.0428 

-0377 

.038 

.0224 

.0479 

.0422 

.0398 

-0350 

-0439 

.0386 

-039 

.0229 

.0490 

-0431 

.0407 

-0358 

.0449 

-0395 

.040 

•0235 

.0501 

.0441 

.0416 

.0366 

-0459 

.0404 

.041 

.0240 

.0512 

-0451 

.0425 

.0374 

.0469 

-0413 

.042 

.0245 

-0523 

.0460 

-0434 

.0382 

.0479 

.0422 

-043 

.0250 

-0534 

.0470 

-0443 

.0390 

.0489 

.0431 

.044 

-0255 

-0545 

.0480 

.0452 

.0398 

.0499 

.0440 

•045 

.0260 

.0556 

.0490 

.0462 

.0406 

■0509 

.0448 

.046 

.0266 

-0567 

.0499 

.0471 

.0414 

-0519 

-0457 

.047 

.0271 

-0578 

.0509 

.0480 

.0422 

.0529 

.0466 

.048 

.0276 

.0589 

-0519 

.0489 

.0430 

■0539 

.0475 

.049 

1 

.0281 

.0600 

.0528 

.0498 

.0438 

.0549 

.0484 

.050 

.0286 

.0611 

-0538 

.0507 

.0446 

■0559 

.0492 

-051 

.0292 

.0622 

.0548 

.0516 

-0454 

.0569 

.0501 

-052 

.0297 

-0633 

-0557 

-0525 

.0462 

■0579 

.0510 

•053 

.0302 

.0644 

-0567 

■0534 

.0470 

.0589 

-0519 

.054 

.0307 

-0655 

.0576 

-0543 

.0478 

•0599 

.0528 

.055 

.0312 

.0666 

.0586 

•0553 

.0486 

.0610 

.0537 

.056 

.0318 

.0677 

.0596 

.0562 

.0494 

.0620 

.0546 

.057 

-0323 

.0688 

.0605 

-0571 

.0502 

-  0630 

-0555 

.058 

.0328 

.0699 

.0615 

.0580 

.0510 

.0640 

.0564 

-059 

-0333 

.0710 

.0624 

.0589 

.0518 

.0650 

-0573 

.060 

.0338 

.0721 

.0634 

.0598 

.0526 

.0660 

.0581 

.061 

.0344 

.0732 

.0644 

.0607 

-0534 

.0670 

.0590 

.062 

•0349 

-0743 

-0653 

.o6j6 

-0542 

.0680 

-0599 

.063 

.0354 

-0754 

.0663 

.0626 

-0550 

.0690 

.0608 

-064 

■0359 

-0765 

-0673 

-0635 

■0558 

.0700 

.0617 

.065 

.0364 

.0776 

.0683 

.0644 

.0567 

.0710 

.0625 

.066 

.0370 

.0787 

.0692 

-0653 

-0575 

.0720 

.0634 

.067 

-0375 

.0798 

.0702 

.0662 

-0583 

.0730 

.0643 

.068 

.0380 

.0809 

.0712 

.0672 

-0591 

.0741 

.0652 

.069 

•038s 

.0820 

.0721 

.0681 

-0599 

.0751 

.0661 

CERE/1LS,   LEGUMFS,    VEGETABLES,   AND   FRUITS. 


289 


KROBER'S  TABLE  FOR  DETERMINATION  OF  PENTOSES  AND  PENTOSANS 
FROM  PHLOROGLUCID— Co«/j«MC<f. 


I 

2 

^ 

4 

5 

6 

7 

8 

Phloroglucifl 

Furfural. 

Arabinose. 

Araban. 

Xylose. 

Xylan. 

Pentose. 

Pentosan. 

0.070 

0.0390 

0.0831 

0.0731 

0 . 0690 

0.0607 

0.0761 

0.0670 

.071 

.0396 

.0842 

.0741 

.0699 

.0615 

.0771 

.0679 

.072 

.0401 

•0853 

.0750 

.0708 

,0623 

.0781 

.0688 

.073 

.0406 

.0864 

.0760 

.0717 

.0631 

.0791 

.0697 

.074 

.0411 

.0875 

.0770 

.0726 

.0639 

.0801 

.0706 

.075 

.0416 

.0886 

.0780 

■0736 

.0647 

.0811 

.0714 

.076 

.0422 

.0897 

.0789 

-0745 

•0655 

.0821 

.0722 

.077 

.0427 

.0908 

.0799 

-0754 

.0663 

.0831 

-0731 

.078 

.0432 

.0919 

.0809 

.0763 

.0671 

.0841 

.0740 

.079 

.0437 

.0930 

.0818 

.0772 

.0679 

.0851 

.0749 

.080 

.0442 

.0941 

.0828 

.0781 

.0687 

.0861 

.0758 

.081 

.0448 

.0952 

.0838 

.0790 

.0695 

.0871 

.0767 

.082 

•0453 

.0963 

.0847 

.0799 

.0703 

.0881 

.0776 

.083 

.0458 

.0974 

-0857 

.0808 

.0711 

.0891 

.0785 

.084 

.0463 

.0985 

.0867 

.0817 

.0719 

.0901 

.0794 

.085 

.0468 

.0996 

.0877 

.0827 

.0727 

.0912 

.  0803 

.086 

.0474 

.1007 

.0886 

.0836 

-073s 

.0922 

.0812: 

.087 

.0479 

.1018 

.0896 

.0845 

-0743 

.0932 

.0821 

.088 

.0484 

.1029 

.0906 

.0854 

-0751 

.0942 

.0830 

.089 

.0489 

.1040 

.0915 

.0863 

-0759 

.0952 

.0838 

.090 

.0494 

.1051 

.0925 

.0872 

.0767 

.0962 

.0847 

.091 

.0499 

.1062 

-0935 

.0881 

■0775 

.0972 

.0856 

•  092 

.0505 

•1073 

.0944 

.0890 

-0783 

.0982 

.0865 

.093 

.0510 

.1084 

-0954 

.0900 

.0791 

.0992 

.0874 

.094 

•0515 

■1095 

.0964 

.0909 

.0800 

.1002 

.0883 

•095 

.0520 

.1106 

.0974 

.0918 

.0808 

.1012 

.0891 

.096 

-0525 

.1117 

.0983 

.0927 

.0816 

.1022 

.0899 

.097 

-0531 

.1128 

.0993 

.0936 

.0824 

.1032 

.0908 

.098 

.0536 

•II39 

.1003 

.0946 

.0832 

•  1043 

.0917 

.099 

-0541 

.1150 

.1012 

-0955 

.0840 

-1053 

.0926 

.100 

.0546 

.1161 

.1022 

.0964 

.0848 

.1063 

•0935 

.101 

•0551 

.1171 

.1032 

-0973 

.0856 

•1073 

.0944 

.102 

■0557 

.1182 

.1041 

.0982 

.0864 

.1083 

-0953 

.103 

.0562 

•II93 

.1051 

.0991 

.0872 

-1093 

.0962 

.104 

-0567 

.1204 

.1060 

.1000 

.0880 

.1103 

.0971 

.105 

.0572 

.1215 

.1070 

.1010 

.0888 

.1113 

.0976 

.106 

-0577 

.1226 

.1080 

.1019 

.0896 

.1123 

.0988 

.107 

.0582 

-1237 

.1089 

.1028 

.0904 

•I133 

.0997 

.108 

.0588 

.1248 

.1099 

-1037 

.0912 

.1143 

.Toc6 

.109 

-0593 

.1259 

.1108 

.1046 

.0920 

-1153 

.1015 

zgo 


FOOD   INSPECTION  AND   /ANALYSIS. 


KROBER'S  TABLE  FOR  DETERMINATION  OF  PENTOSES  AND  PENTOSANS 
FROM  PHLOROGLUCID— (Co«//««c(f). 


I 

I 

3 

4 

s 

6 

7 

8 

Phloroglucid 

Furfural. 

Arabinose. 

Araban. 

Xylose. 

Xylan. 

Pentose. 

Pentosan. 

O.IIO 

0.0598 

0.1270 

O.II18 

0-1055 

0.0928 

0.1163 

0.1023 

.HI 

.0603 

.1281 

.1128 

.1064 

.0936 

-"73 

.1032 

.112 

.0608 

.1292 

-"37 

-1073 

.0944 

.1183 

.1041 

.113 

.0614 

-1303 

.1147 

.1082 

-0952 

-"93 

.1050 

.114 

.0619 

.1314 

.1156 

.  1091 

.0960 

.1203 

•1059 

.115 

.0624 

-1325 

.1166 

.  I  lOI 

.0968 

.1213 

.1067 

.116 

.0629 

-1336 

.1176 

.  I  HO 

.0976 

.1223 

.1076 

.117 

.0634 

-1347 

.1185 

.1119 

.0984 

-1233 

.1085 

.118 

.0640 

-1358 

-"95 

.1128 

.0992 

-1243 

.1094 

.119 

.0645 

.1369 

.1204 

-II37 

.1000 

•1253 

.1103 

.120 

.0650 

.1380 

.1214 

.  I  146 

.IC08 

.1263 

.1111 

•  121 

-0655 

-1391 

.1224 

-II55 

.  1016 

-1273 

.1120 

.122 

.0660 

.1402 

-1233 

.1164 

.1024 

.1283 

.1129 

-123 

.0665 

.1413 

-1243 

-"73 

-1032 

.1293 

.1138 

.124 

.0671 

.1424 

■1253 

.1182 

.1040 

-1303 

-"47 

.125 

.0676 

-1435 

.1263 

.1192 

.1049 

-1314 

.1156 

.126 

.0681 

.1446 

.1272 

.1201 

-1057 

•  1324 

.1165 

-127 

.0686 

-1457 

.1282 

.1210 

.1065 

-1334 

."74 

.128 

.0691 

.1468 

.1292 

.1219 

-1073 

.1044 

."S3 

.129 

.0697 

-1479 

.1301 

.1228 

.1081 

•1354 

.1192 

-130 

.0702 

.1490 

.1311 

-1237 

.1089 

-1364 

.1201 

-131 

.0707 

.1501 

.1321 

.1246 

.1097 

-1374 

.1210 

.132 

.0712 

.1512 

•1330 

-1255 

.1105 

-1384 

.1219 

■  ^ii 

.0717 

-T523 

-1340 

.1264 

.1113 

-1394 

.1227 

.134 

-0723 

-1534 

-1350 

■1273 

.1121 

.1404 

.1236 

•  135 

.0728 

-1545 

.1360 

.1283 

.1129 

.1414 

.1244 

.136 

.0733 

-1556 

-1369 

.1292 

-"37 

.1424 

.1253 

.137 

.0738 

-1567 

-1379 

•  1 301 

■  "45 

-1434 

.1262 

.138 

•0743 

-1578 

.1389 

.1310 

-"53 

.1444 

.1271 

-139 

.0748 

-'589 

-1398 

•1319 

.  1161 

-1454 

.1280 

.140 

•0754 

.1600 

.1408 

.1328 

.1169 

.1464 

.1288 

.141 

■0759 

.1611 

.1418 

-1,337 

-"77 

-1474 

.1297 

.142 

.0764 

.1622 

.1427 

-1346 

.1185 

.1484 

.1306 

•»43 

.0769 

•1633 

.1437 

-1355 

-"93 

.1494 

-1315 

.144 

.0774 

.1644 

.1447 

-1364 

.1201 

-1504 

-1324 

.145 

.0780 

.1655 

-1457 

-1374 

.  1209 

•1515 

-1333 

.146 

■0785 

.1666 

.1466 

.1383 

.1217 

•1525 

-1342 

.147 

.0790 

.1677 

.1476 

.1392 

-1225 

-1535 

.1351 

.148 

.0795 

.1688 

.i486 

.1401 

-1233 

•1545 

.1360 

.149 

.0800 

.1699 

1495 

.  1410 

.1241 

.1555 

.1369 

CEREALS,   LEGUMES,    l/EGETABLES,   AND   FRUITS. 


291 


KROBER'S  TABLE  FOR  DETERMINATION  OF  PENTOSES  AND  PENTOSANS 
FROM    VHU)KOV,1.\jC11l>— (Continued). 


I 

2 

3 

4 

Xylose. 

6 

7 

8 

Phloroglucid 

Furfural. 

Arabinose. 

Araban. 

Xylan. 

Pentose. 

Pentosan. 

0.150 

0.0805 

0.1710 

0-1505 

0.1419 

0. 1249 

0.1565 

0-1377 

•151 

.0811 

.1721 

-1515 

.1428 

-1257 

-1575 

.1386 

.152 

.0816 

-1732 

-1524 

■1437 

.1265 

-1585 

•1395 

.153 

.0821 

-^743 

-1534 

.1446 

-1273 

-1595 

.1404 

.154 

.0826 

•1754 

-1544 

■1455 

.1281 

.1605 

-I413 

-15s 

.0831 

■1765 

-1554 

.1465 

.1289 

.1615 

.1421 

.156 

.0837 

.1776 

•1563 

.1474 

.1297 

.1625 

-1430 

-157 

-0842 

.1787 

■1573 

.1483 

-1305 

-1635 

-1439 

.158 

.0847 

.1798 

-1583 

.1492 

■1313 

.1645 

.1448 

-159 

.0852 

.  1 809 

-1592 

.1501 

.1321 

-1655 

.1457 

.160 

.0857 

.1820 

.1602 

.1510 

.1329 

.1665 

-1465 

.161 

.0863 

.1831 

.1612 

-1:519 

-1337 

-1675 

.1474 

.162 

.0868 

.1842 

.1621 

.1528 

-1345 

.1685 

-1483 

.163 

.0873 

-1853 

.1631 

-1537 

-1353 

.1695 

.1492 

.164 

.0878 

.1864 

.1640 

.1546 

.1361 

•1705 

.1501 

.165 

.0883 

-1875 

.1650 

-1556 

.1369 

.1716 

.1510 

.166 

.0888 

.1886 

.1660 

-1565 

.1377 

.1726 

-1519 

.167 

.0894 

.1897 

.1669 

-1574 

-1385 

-1736 

.1528 

.168 

.0899 

.1908 

.1679 

-1583 

-1393 

.1746 

.1537 

.169 

.0904 

.1919 

.1688 

-1592 

.1401 

.1756 

.1546 

.170 

.0909 

-1930 

.1698 

.1601 

.1409 

.1766 

-1554 

.171 

.0914 

.1941 

.1708 

.1610 

-1417 

.1776 

.1563 

.172 

.0920 

-1952 

.1717 

.1619 

.1425 

.1786 

-1572 

.173 

.0925 

.1963 

.1727 

.1628 

-1433 

.1796 

.1581 

.174 

.0930 

-1974 

-1736 

-1637 

-I441 

.1806 

•1590 

•175 

•0935 

.1985 

.1746 

.1647 

.1449 

.1816 

.1598 

.176 

.0940 

.1996 

-1756 

.1656 

.1457 

.1826 

.1607 

.177 

.0946 

.2007 

-1765 

.1665 

-1465 

.  1836 

.1616 

.178 

•0951 

.2018 

-1775 

.1674 

-1473 

.1846 

.1625 

.179 

.0956 

.2029 

.1784 

.1683 

.1481 

.1856 

.1634 

.180 

.0961 

.2039 

•1794 

.1692 

.1489 

.1866 

.1642 

.181 

.0966 

.2050 

.1804 

.1701 

-1497 

.1876 

.1651 

.182 

.0971 

.2061 

.1813 

.1710 

-1505 

.1886 

.1660 

.183 

.0977 

.2072 

.1823 

.1719 

-1513 

.1896 

.1669 

.184 

.0982 

.2082 

.1832 

.1728 

.1521 

.1906 

.1678 

.185 

.0987 

.2093 

.1842 

-1738 

-1529 

.1916 

.1686 

.186 

.0992 

.2104 

.1851 

-1747 

-1537 

.1926 

.1695 

.187 

.0997 

.2115 

.1861 

-1756 

-1545 

.1936 

.1704 

.188 

.1003 

.2126 

.1870 

-1765 

-1553 

.1946 

.1712 

.189 

.1008 

,2136 

.1880 

-1774 

.1561 

-1955 

.1721 

393 


FOOD  INSPECTION  AND   AN /I  LYSIS. 


KROBER'S  TABLE  FOR  DETERMINATION  OF  PENTOSES   AND  PENTOSANS 
FROM  PHLOROGLUCID— (Co;i//;/z<e«i). 


I 

3 

3 

4 

s 

6 

7 

8 

Phloroglucid 

Furfural. 

Arabinose. 

Araban. 

Xylose. 

Xylan. 

Pentose. 

Pentosan. 

0.190 

0. 1013 

0.2147 

0.1889 

0.1783 

0.1569 

0.1965 

0.1729 

.191 

.1018 

.2158 

.1899 

.1792 

-1577 

■1975 

-1738 

.192 

.1023 

.2168 

.1908 

.1801 

.1585 

.1985 

•1747 

-193 

.1028 

.2179 

.1918 

.1810 

■1593 

•1995 

.17^6 

.194 

-1034 

.2190 

.1927 

.1819 

.1601 

.2005 

.1764 

.195 

-1039 

.2201 

•1937 

.1829 

.1609 

.2015 

•1773 

.196 

.1044 

.2212 

.1946 

.1838 

.1617 

.2025 

.1782 

.197 

.1049 

.2222 

.1956 

.1847 

.1625 

■2035 

.1791 

.198 

.1054 

•  2 -:•,?> 

.1965 

.1856 

-1633 

.2045 

.1800 

.199 

•1059 

.2244 

.1975 

.1865 

.1641 

-2055 

.1808 

.200 

.1065 

.2255 

.1984 

.1874 

.1649 

.2065 

.1817 

.201 

.1070 

.2266 

.1994 

.1883 

■  -1657 

.2075 

.1826 

.202 

.1075 

.2276 

.2003 

.1892 

.1665 

.2085 

-1835 

.203 

.1080 

.22S7 

.2013 

.  1901 

.1673 

.2095 

.1844 

.204 

.1085 

.2298 

.2022 

.1910 

.1681 

.2105 

-1853 

.205 

.1090 

.2309 

.2032 

.1920 

.1689 

.2115 

.1861 

.206 

.1096 

.2320 

.2041 

.1929 

.1697 

.2125 

.1869 

.207 

.1101 

•  2330 

.2051 

.1938 

-1705 

-2134 

.1878 

.208 

.1106 

-2341 

.2060 

.1947 

•I713 

.2144 

.1887 

.209 

.1111 

.2352 

.2069 

.1956 

.1721 

-2154 

.1896 

.210 

.1116 

•  2363 

.2079 

.1965 

.1729 

.  2 1 64 

.1904 

.211 

.1121 

.2374 

.  2089 

-1975 

-1737 

.2174 

-1913 

,212 

.1127 

.2384 

.2098 

.1984 

■1745 

.2184 

.  1922 

-213 

.1132 

■  2395 

.2108 

■1993 

-1753 

.2194 

■1931 

.214 

-I137 

.2406 

.2117 

.  2002 

.1761 

.2204 

.1940 

■215 

.1142 

.2417 

.2127 

.2011 

.1770 

.2214 

.1948 

.216 

.1147 

.2428 

.2136 

.20  20 

.1778 

.2224 

-1957 

.217 

.1152 

.2438 

.2146 

.2029 

.1786 

.2234 

.1966 

.218 

.1158 

.2449 

.2155 

.2038 

•1794 

.2244 

-1974 

.219 

.1163 

.2460 

.2165 

.2047 

.1802 

.2254 

.1983 

.220 

.1168 

.2471 

.2174 

.2057 

.1810 

.2264 

.1992 

.221 

■'173 

.2482 

.2184 

.  2066 

.1818 

.2274 

.2001 

.222 

.1178 

.2492 

-2193 

.2075 

.1826 

.2284 

.2010 

.223 

.1183 

-2503 

.2203 

.2084 

.'834 

.2294 

.2019 

.224 

.1189 

-2514 

.2212 

•  2093 

.1842 

-2304 

.2028 

.225 

.1194 

-2525 

.2222 

.2102 

.i8so 

-2314 

■2037 

.226 

.1199 

-2536 

.2232 

.2111 

.1858 

.2324 

.2046 

-227 

.1204 

.2546 

.2241 

.2121 

.1866 

•2334 

.2054 

.228 

.1209 

-2557 

.2251 

.  2 1 30 

.1874 

.  2344 

-  2063 

.229 

.1214 

.2568 

.2260 

■2139 

.1882 

-2354 

.2072 

CEREALS,   LEGUMES,    yEGET/IBLES,   AND   FRUITS. 


2-)3 


KROBER'S  TABLE  FOR  DETERMINATION  OF  PENTOSES  AND  PENTOSANS 
FROM  PHLOROGLUCID— fCow/inMed). 


I 

2 

,? 

4 

Xylose. 

6 

7 

8 

Phloroglucid 

Furfural. 

Arabinose. 

Araban. 

Xylan. 

Pentose. 

Pentosan. 

0.230 

0.1220 

0.2579 

0.2270 

0.2148 

0.1890 

0.2364 

0.2081 

.231 

.1225 

.2590 

.2280 

•2157 

.1898 

-2374 

.2089 

.232 

.1230 

.2600 

.2289 

.2166 

.1906 

.2383 

.2097 

.233 

-123s 

.2611 

.2299 

•2175 

.1914 

-2393 

.2106 

.234 

.1240 

.2622 

.2308 

.2184 

.1922 

.2403 

-2115 

.235 

.1245 

-  2633 

.2318 

-2193 

.1930 

.2413 

.2124 

.236 

.1251 

.2644 

.2327 

.2202 

.1938 

-2423 

.2132 

•237 

.1256 

.2654 

-2337 

.2211 

.1946 

■2433 

.2141 

.238 

.1261 

.2665 

.2346 

.2220 

-1954 

•  2443 

.2150 

.239 

.1266 

.2676 

.2356 

.2229 

.1962 

.2453 

.2159 

.240 

.1271 

.2687 

.2365 

-2239 

.1970 

.2463 

.2168 

.241 

.1276 

.2698 

-2375 

.2248 

.1978 

-2473 

.2176 

.242 

.1281 

.2708 

.2384 

.2257 

.1986 

.2483 

.2185 

.243 

.1287 

.2719 

•  2394 

.2266 

.1994 

.2493 

.2194 

.244 

.1292 

.2730 

.2403 

.2275 

.2002 

•2503 

.2203 

.245 

.1297 

.2741 

•2413 

.2284 

.2010 

-2513 

.2212 

.245 

.1302 

.2752 

.2422 

.2293 

.2018 

.2523 

.2220 

.247 

-1307 

.2762 

-2432 

.2302 

.2026 

-2533 

.2229 

.248 

.1312 

-2773 

.2441 

-2311 

.2034 

-2543 

.2238 

.249 

.1318 

.2784 

.2451 

.2320 

.2042 

-2553 

.2247 

.250 

.1323 

.2795 

.2460 

-2330 

.2050 

-2563 

.2256 

.251 

.1328 

.2806 

.2470 

-2339 

.2058 

-2573 

.2264 

.252 

■^333 

.2816 

-2479 

.2348 

.2066 

.2582 

.2272 

.253 

.1338 

.2827 

.2489 

-2357 

.2074 

-2592 

.2281 

.254 

.1343 

.2838 

.2498 

.2366 

.2082 

.2602 

.2290 

.255 

-1349 

.2849 

.2508 

•2375 

.2090 

.2612 

.2299 

.256 

-1354 

.2860 

-2517 

.2384 

.2098 

.2622 

.2307 

.257 

-1359 

.2870 

.2526 

■2393 

.2106 

.2632 

.2316 

.258 

.1364 

.2881 

-2536 

.2402 

.2114 

.2642 

-2325 

.259 

.1369 

.2892 

.2545 

.2411 

.2122 

.2652 

•2334 

.260 

.1374 

.2903 

-2555 

.2420 

.2130 

.2662 

-2343 

.261 

.1380 

.2914 

■2565 

.2429 

.2138 

.2672 

-2351 

.262 

-1385 

.2924 

-2574 

.2438 

.2146 

.2681 

■2359 

.263 

.1390 

-2935 

.2584 

.2447 

-2154 

.2691 

.2368 

.264 

-1395 

.2946 

.2593 

.  2456 

.2162 

.2701 

•2377 

.265 

.1400 

•2957 

■2*03 

.2465 

.2170 

.2711 

-2385 

.266 

.1405 

.2968 

.2612 

.2474 

.2178 

.2721 

-2394 

.267 

.1411 

.2978 

.2622 

.2483 

.2186 

■2731 

.2403 

.268 

.  1416 

.2989 

.2631 

.2492 

.2194 

.2741 

.2412 

.269 

.1421 

.3000 

.2641 

.2502 

.2202 

•2751 

.2421 

'04 


FOOD   INSPECTION  ^ND   /ANALYSIS. 


KROBER'S  TABLE  FOR  DETERMINATION  OF  PENTOSES  AND  PENTOSANS 
FROM    PHLOROGLUCID— (Co«c/M(f<-(/). 


I 

3 

3 

4 

5 

6 

8 

Phloroglucid 

Furfural. 

Arabinose. 

Araban. 

Xy  lose. 

Xylan. 

Pentose. 

Pentosan. 

0.270 

0.1426 

0.3011 

0.2650 

0.2511 

0.2210 

0.2761 

0.2429 

.271 

-1431 

.3022 

.2660 

.2520 

.2218 

.2771 

.2438 

.272 

-1436 

-3032 

.2669 

.2529 

.2226 

.2781 

■  2447 

.273 

.1442 

-3043 

.2679 

-2538 

.2234 

.2791 

-2456 

•274 

.1447 

■3054 

.2688 

•2547 

.2242 

.2801 

.2465 

•275 

.1452 

-3065 

.2698 

-2556 

.2250 

.2811 

-2473 

.276 

-1457 

.3076 

.2707 

-2565 

.2258 

.2821 

.2482 

.277 

.1462 

.3086 

.2717 

-2574 

.2266 

.2830 

.2490 

.278 

.1467 

.3097 

.2726 

■2583 

.2274 

.2840 

-2499 

.279 

-1473 

.3108 

.2736 

-2592 

.2282 

.2850 

.2508 

.2S0 

.1478 

•3119 

-2745 

.2602 

.2290 

.2861 

-2517 

.281 

.1483 

-3130 

-2755 

.2611 

.2298 

.2871 

.2526 

.282 

.1488 

•3140 

.2764 

.2620 

-  2306 

.2880 

-2534 

.283 

.1493 

.3151 

-2774 

.2629 

-2314 

.2890 

-2543 

.284 

.1498 

.3162 

.2783 

■  2638 

.2322 

.2900 

.2552 

.285 

.1504 

•3173 

-2793 

.2647 

-  2330 

.2910 

.2561 

.286 

-1509 

-3184 

.2802 

.2656 

.2338 

.2920 

.2570 

.287 

.1514 

■3194 

.2812 

.2665 

.  2346 

.2930 

■2578 

.288 

•1519 

-3205 

.2821 

.2674 

•2354 

.2940 

.2587 

.289 

•  1524 

.3216 

.2831 

.2683 

.2362 

.2950 

.2596 

.290 

.1529 

.3227 

.2840 

.2693 

-2370 

.2960 

.2605 

.291 

•1535 

-3238 

.2850 

.2702 

.2378 

.2970 

.2614 

.292 

.1540 

.3248 

.2859 

.2711 

■  2386 

.2980 

.2622 

.293 

.1545 

-3259 

.2868 

.2720 

-  2394 

.2990 

.2631 

.294 

.1550 

.3270 

.2878 

.2729 

.2402 

.3000 

.2640 

.295 

•1555 

.3281 

.2887 

.2738 

.2410 

.3010 

.2649 

.296 

.1560 

.3292 

.2897 

-2747 

.2418 

.3020 

.2658 

•297 

.1566 

-3302 

.2906 

.2756 

.2426 

.3030 

.2666 

.298 

.1571 

■  ?,i^i 

.2916 

.2765 

.2434 

.3040 

.2675 

•299 

.1576 

•3324 

.2925 

.2774 

.2442 

.3050 

.2684 

.300 

.1581 

.3335 

•2935 

.2784 

.2450 

.3060 

.2693 

CEREALS,   LEGUMES,    VEGETABLES,  AND  FRUITS. 


«9S 


SEPARATION   AND   DETERMINATION   OF   THE   VARIOUS   CARBOHYDRATES 
OF    CEREALS,    ETC.       STONE'S    METHOD. 

Stone  has  thus  tabulated  the  results  of  a  series  of  analyses  of  various 
samples  of  wheat,  flour,  corn,  and  bread,  in  which  he  has  separated  the 
principal  carbohydrates.* 

PERCENTAGES  OF  VARIOUS  CARBOHYDRATES  IN  CERTAIN  FOODSTUFFS. 


Whole  wheat,  I.  .  . 
Whole  wheat,  II.  . 
Wheat  flour,  I.  .  .  , 
Wheat  flour,  II.  .  . 

Corn 

Sugar-beet 

Bread  (wheat,  I). 
Bread  (wheat,  II). 
Bread  (flour,  I).  . 
Bread  (flour,  II).  . 
Corn  cake  (maize) 


Sucrose. 


0.52 
0.72 


9.27 
8.38 
0.05 
0.06 
o.oi 
0.15 
0.16 


Invert 
Sugar. 


0.08 
0.00 
0.00 
0.00 
0.00 
0.07 
0.32 

0-37 
0.10 
0.38 
0.19 


Dextrin. 


0.27 
0.41 
0.90 
1.06 
0.32 

0-35 
0.68 
0.23 
0.27 
0.91 
0.00 


Soluble 
Starch. 


o.co 
0.00 
0.00 
0.00 
0.00 
0.00 

1-37 
2.36 
1.99 
1-74 
2.80 


Pento- 
sans. 


4-54 
4-37 
0.00 
0.00 

5-14 
4.89 
4. 16 
4-34 
0.00 
0.00 
3-54 


Crude 
Fiber. 


2.68 

2-51 
0.25 
0.25 

1-99 
1. 00 
2.70 
2.02 
0.34 
0.17 
2.22 


Determination  of  Cane  Sugar. — ico  grams  of  the  finely  ground  ma- 
terial are  extracted  by  boiling  under  a  reflux  condenser  with  500  cc.  of 
95%  alcohol  for  three  hours,  the  alcoholic  extract  is  filtered,  evaporated 
nearly  to  dryness,  and  then  taken  up  with  a  small  amount  of  water,  to 
separate  the  sugar  from  the  oils  and  waxes  dissolved  by  the  alcohol.  This 
aqueous  solution  is  invariably  dextro-rotary,  and  seldom  contains  any 
reducing  sugar.  If  the  latter  is  present,  it  is  determined  in  an  aliquot 
part  of  the  aqueous  solution  with  Fchling's  solution,  the  result  being 
calculated  to  dextrose.  The  remainder  of  the  aqueous  sugar  solution,  or 
the  whole  of  it,  if,  as  is  almost  always  the  case,  dextrose  is  absent,  is 
then  inverted  by  heating  with  hydrochloric  acid  in  the  usual  manner 
(page  588)  and  the  sugar  is  estimated  with  Fehling's  solution,  calcu- 
lating the  result  to  sucrose  (page  612). 

Determination  of  Dextrin. — Digest  the  residue  from  the  above  alco- 
holic extraction  from  eighteen  to  twenty-four  hours  with  500  cc.  of  cold 
distilled  water,  shaking  frequently.     On  filtering,  a  clear  solution  is  ob- 


♦  Jour.  Am.  Chem.  Soc,  19,  1897,  p.  183,  and  U.  S.  Dept.  of  Agric,  Off.  of  Exp.  Sta., 
Bui.  34.  The  percentages  of  normal  starch  found  by  Stone  are  obviously  erroneous,  and 
are  for  this  reason  excluded  from  the  table  as  here  given. 


2g6  FOOD  INSPECTION  yIND  AN/tLYSIS. 

tained,  which  should  be  tested  with  iodine  for  soluble  starch.  If  the 
latter  is  not  found  (which  is  nearly  always  the  case),  the  solution  is  con- 
centrated to  a  small  volume,  avoiding  a  temperature  higher  than  80"^  to 
90°,  and  this  is  boiled  under  a  reflux  condenser  for  two  hours  with  one- 
tenth  its  volume  of  hydrochloric  acid  (specific  gravity  1.125).  Deter- 
mine the  dextrose  by  Fehling's  solution  and  calculate  to  dextrin  by  the 
factor  0.9.  Or,  instead  of  submitting  the  concentrated  aqueous  extract  to 
hydrolysis  as  above,  the  dextrin  may  be  roughly  determined  gravimetrically 
therein  by  treating  with  several  volume's  of  strong  alcohol  until  no  further 
precipitation  is  produced.  The  flocculent  precipitate  thus  obtained  is 
collected,  dried,  and  weighed. 

Determination  of  Starch. — Dr}'  in  an  oven  the  residue  from  the  pre- 
ceding treatment  and  determine  its  quantitative  relation  to  the  original 
sample ;  2  grams  are  then  accurately  weighed  and  subjected  to  the  dias- 
tase method  of  starch  determination  (page  28:;). 

Determination  of  Pentosans  and  Hemicelluloses. — The  washed  resi- 
due, left  after  filtering  off  the  starch-containing  solution  from  the  process 
of  heating  with  malt  extract  in  the  preceding  starch  determination,  is 
boiled  for  an  hour  with  ico  cc.  of  1%  hydrochloric  acid,  which  converts 
all  the  pentosans  into  sugar.  Filter,  and  wash  the  residue  thoroughly, 
make  up  the  solution  to  200  cc,  and  determine  the  sugar  with  Fehling's 
solution,  calculating  the  results  for  xylan,  assuming  that  the  chief  sugar 
formed  is  xylose.  The  reducing  power  of  xylose  is  assumed  to  be  4.61 
milhgrams  for  each  cubic  centimeter  of  Fehling's  solution.  If  the  volu- 
metric Fehling  method  is  used,  10  cc,  of  Fehling's  solution  are  thus 
equivalent  to  0.046  gram  xylose.     Xylose  X  0.88  =  xylan. 

Crude  Fiber  {Cellulose,  etc.). — The  residue  from  the  last  rlilute  acid 
hydrolysis  is  boiled  with  200  cc.  of  1.25%  solution  of  sodium  hydroxide 
for  half  an  hour,  filtered,  dried,  and  weighed.  It  is  then  ignited,  and 
the  weight  of  the  ash  deducted  from  the  first  weight. 

PROTEINS  OF  CEREALS  AND  VEGETABLES. 

Different  cereal  and  vegetable  foods  present  considerable  variations 
in  the  character  and  extent  of  their  protein  constituents,  and  by  no  means 
all  of  the  common  vegetable  foods  have  been  studied  in  detail. 

Osborne,  in  connection  with  Voorhees  and  Chittenden,  has  made 
a  careful  study  of  the  [proteins  of  many  of  the  cereals,  of  potatoes,  and 
of  peas.     A  brief  outline  only  will  be  given  in  what  follows  of  methods 


CEREALS,   LEGUMES,    VEGETABLES,   AND   FRUITS.  297 

for  separation  of  the  vegetable  proteins.  For  fuller  details  the  reader 
is  referred  to  the  work  of  Osborne  et  al.  in  the  American  Chemical  Journal, 
Vols.  '-  14,  and  15,  and  to  the  Jcnirnal  of  the  American  Chemical  Society, 
Vols.  17,  i?>,  10,  and  20. 

Proteins  Soluble  in  Water  and  Dilute  Salt  Solution. — By  the  action 
of  various  solvents  it  is  possible  to  sej)arate  the  different  classes  of  pro- 
teins for  examination  or  analysis.  Thus  water  at  first  applied  extracts 
certain  of  the  soluble  proteins,  as  does  a  weak  salt  solution.  Osborne 
and  Voorhees  recommend  the  use  of  a  10%  solution  of  sodium  chloride 
as  the  first  solvent  to  a])])ly  for  separating  vegetable  proteins,  shaking 
the  finely  ground  material  with  twice  its  weight  of  the  salt  solution.  The 
salt  solution,  after  filtering,  is  then  subjected  to  dialysis,  the  protein  matter 
thus  separated  out  being  a  globulin,  while  that  not  precipitated  on  dialysis 
is  assumed  as  the  protein  matter  of  the  substance  soluble  in  water.  Two 
albumins  and  a  proteose  are  found  in  wheat  to  be  thus  soluble  in  water. 

If  the  proteins  soluble  in  salt  solution  are  to  have  their  total  nitrogen 
determined,  they  are  completely  precipitated  from  the  solution  by  satu- 
rating with  zinc  or  ammonium  sulphate. 

There  a.re  thus  two  classes  of  proteins  soluble  in  10%  salt  solution: 
(a)  globulins,  insoluble  in  water  alone,  and  {h)  albumins  and  proteoses, 
which  are  soluble  in  water. 

Separation  of  Albumins,  Proteoses,  and  Globulins. — Starting  with  the 
aqueous  solution  containing  the  albumins  and  proteoses,  if  present,  the 
former  are  best  separated  according  to  Osborne  and  Vorhees  by  fractional 
coagulation,  effected  by  heating  at  different  temperatures,  those  that 
precipitate  out  at  a  temperature  under  65°  being  first  filtered  out,  and 
the  filtrate  submitted  to  a  higher  temperature  not  exceeding  85°.  The 
two  portions  thus  separated  may  be  collected  in  filters,  and  their  nitrogen 
separately  determined. 

The  proteose  may  be  precipitated  from  the  filtrate  by  saturating  w^ith 
ground  salt,  or  by  adding,  first  salt  to  the  extent  of  20%,  and  finally  acetic 
acid. 

The  globulins,  precipitated  in  the  original  10%  salt  solution  by  the 
process  of  dialysis  as  described,  may  themselves  be  separated  by  employing 
salt  solution  of  varying  strength  as  solvents.* 

Proteins  Soluble  in  Dilute  Alcohol,  but  Insoluble  in  Water. — The 
residue  from  the  treatment  with  10^'^'  sodium  chloride  is  digested  with  75% 
alcohol  at  about  46°  C.  for  some  time  and  filtered.     The  residue  is  further 

*  Am.  Chem.  Jour.,  13,  p.  464. 


29S  FOOD    INSPECTION  /iND    y4Ny4LYSIS. 

digested  at  about  60°  with  75^  alcohol  three  separate  times.  The  evapo- 
rated filtrates  contain  the  alcohol-soluble  proteins.  In  this  class  are  the 
hordein  of  barley,  the  gliadin  of  wheat  arfd  rye,  and  the  zein  of  corn. 

Proteins  Insoluble  in  Water,  Salt  Solution,  and  Dilute  Alcohol. — It  is 
customary  to  delcrmine  the  nitrogen  in  the  fmal  residue  without  further 
attempt  to  separate  the  remaining  protein  matter.  It  is,  however,  possi- 
ble to  further  extract  with  alkaline  and  acid  solvents,  if  desired,  which 
process,  however,  changes  the  nature  of  the  proteins  from  that  in 
which  they  originally  exist  in  the  substance. 

Character  and  Amount  of  Proteins  in  Wheat."*' — The  proteins  of 
wheat,  according  to  Osborne,  are  five  in  number,  as  follows: 

Amount  Present, 
Per  Cent. 

«   ,  ,  ■     .  .  f  Albumin  (leucosin) o .  •;  to  o .  4 

Soluble  in  water:  {  ^  '  j  t 

I  Proteose 0.3 

Soluble  in  10  per  cent  NaCl:      Globulin  (edestin) 0.6  to  0.7 

Soluble  in  dilute  alcohol:  Gliadin 4  25 

Insoluble  in  above:  Glutenin 4  .  00  to  4 . 5 

The  term  gluten  is  applied  to  the  protein  content  of  wheat  flour 
insoluble  in  water,  the  value  of  flour  for  baking  bread  depending  on 
the  amount  present.  Gluten  contains  the  two  definite  proteins,  gliadin 
and  glutenin.  Crude  gluten,  as  obtained  by  washing  the  dough  in  the 
analytical  process  (page  320),  is  a  complex  mixture  of  many  bodies, 
containing,  besides  the  two  proteins  above  named,  small  quantities  of 
cellulose,  mineral  matter,  lecithin,  and  starch. 

Separation  and  Determination  of  Wheat  Proteins. — Teller'' s  Method.^ — ■ 
Non-gluten  Nitrogen. — Two  grams  of  the  finely  divided  sample  are  mixed 
with  about  15  cc.  of  1%  salt  solution  in  a  250-cc.  flask.  The  flask  is  shaken 
at  inter\'als  of  ten  minutes  during  one  hour,  after  which  it  is  filled  to  the 
mark  with  the  salt  solution  and  allowed  to  stand  two  hours.  The  super- 
natant liquid  is  then  filtered  through  a  dry  filter  into  a  dry  flask,  leaving 
most  of  the  solid  material  n  the  flask,  passing  the  first  part  through  twice, 
if  necessary,  for  a  clear  filtrate.  With  a  pipette,  exactly  50  cc.  of  clear 
filtrate  are  run  into  a  500-cc.  Kjeldahl  digestion- flask,  20  cc.  of  the  usual 
reagent  sulphuric  acid  for  the  Gunning  process  (p.  69)  are  added,  and 
the  contents  of  the  flask  brought  to  a  gentle  boil.     After  the  water  has 

*  Am.  Chem.  Jour.  XV,  392-471;  XVI,  524. 
■f'.^rk.  E.\p.  Stc.  Bui.  42,  p.  96. 


CEREALS,   LEGUMES,   l^EGETABLES,  AND  FRUITS.  2cg 

been  driven  ofT  and  the  acid  has  stopped  foamin^^,  the  potassium  sul- 
phate is  added  and  the  digestion  completed.  From  the  per  cent  of 
nitrogen  thus  obtained  0.27%  is  deducted,  this  figure  corresponding  to 
the  amount  of  gliadin  soluble  in  1%  salt  solution  under  the  above  con- 
ditions.    The  remainder  is  the  percentage  of  non-gluten  nitrogen. 

Gluten  Nitrogen. — This  is  obtained  by  difference  between  the  total 
nitrogen  and  the  non-gluten  nitrogen  as  above  obtained,  or  by  deducting 
the  combined  nitrogen  of  the  edestin,  leucosin,  and  the  amido-nitrogen 
from  the  total  nitrogen. 

Edestin  and  Leuco:;in. — Edestin  is  a  globulin  belonging  to  the  vegetable 
vitellins,  and  is  precipitated  from  salt  solutions  by  dilution,  or  by  satu- 
ration with  magnesium  or  ammonium  sulphate,  but  not  by  saturating 
with  sodium  chloride.  It  is  not  coagulated  below  100°  C,  but  is  partly 
precipitated  by  boihng.  Leucosin  is  an  albumin,  coagulating  at  52°, 
but  precipitates  from  salt  solution  by  saturating  with  sodium  chloride 
or  magnesium  sulphate. 

To  50  cc.  of  the  clear  salt  extract,  obtained  as  described  under  non- 
gluten  nitrogen,  250  cc.  of  pure  94%  alcohol  are  added  in  a  Kjcldahl  500-cc. 
digestion-flask,  the  contents  thoroughly  mixed,  and  allowed  to  stand 
over  night.  The  precipitate  is  collected  in  a  lo-cm.  filter,  which  is 
returned  to  the  flask  and  the  nitrogen  determined.  This  represents 
the  nitrogen  of  the  combined  edestin  and  leucosin.  These  proteins 
may,  however,  be  separated  by  coagulating  the  leucosin  at  60°,  and  pre- 
cipitating the  edestin  by  adding  alcohol  to  50  cc.  of  the  clear  filtrate, 
determining  the  nitrogen  separately  in  each  precipitate. 

Amido-nitrogen. — Allantoin,  asparagin,  cholin,  and  betaine  are  nitrog- 
enous bases  present  in  wheat. 

Ten  cc.  of  a  10%  solution  of  pure  phosphotungstic  acid  are  added 
to  100  cc.  of  the  clear  salt  extract  as  above  obtained,  thus  precipitating 
all  the  proteins,  which  are  allowed  to  settle  preferably  over  night.  Fil- 
ter, and  determine  the  nitrogen  in  the  clear  filtrate.  The  filtrate 
should  be  tested  with  a  little  of  the  phosphotungstic  acid  reagent  to 
make  sure  that  all  the  proteins  have  been  separated.  In  some 
cases,  as  in  bran  for  instance,  more  than  10  cc.  of  the  reagent  are 
necessary. 

Gliadin  is  dissolved  most  readily  from  flour  by  hot  dilute  alcohol, 
but  is  entirely  insoluble  in  absolute  alcohol.  One  gram  of  the  mate- 
rial is  extracted  with  100  cc.  of  hot  75%  alcohol,  by  shaking  the  mixture 
thoroughly  in  a  flask,  and  heating  for  an  hour  at  a  temperature  just  below 


3CO  FOOD    INSPECTION  AND   ANALYSIS. 

the  boiling-point  of  alcohol,  with  occasional  shaking.  After  standing 
for  an  hour,  the  hot  liquid  is  decanted  upon  a  lo-cm.  filter,  and  25  cc. 
of  the  hot  alcohol  are  added  to  the  residue  and  shaken,  after  which  the 
residue  is  again  allowed  to  settle,  and  the  liquid  decanted.  This  is 
repeated  six  times.  The  remainder  of  the  alcohol  is  then  driven  off 
bv  evaporation,  and  the  nitrogen  determined  in  the  residue.  The 
dilTerence  between  the  total  nitrogen  and  the  nitrogen  thus  obtained, 
gives  the  nitrogen  of  the  alcoholic  extract,  whicli  includes  the  amides. 
Subtracting  the  latter,  or  amido-nitrogen,  the  remainder  is  the  gliadin 
nitrogen. 

GUitcnin  Nitrogen. — This  is  the  difference  between  the  gluten  nitro- 
gen and  the  gliadin  nitrogen. 

The  factor  by  which  the  nitrogen  should  be  multiplied  in  determin- 
ing the  various  proteins,  according  to  Osborne  and  \'oorhees,  is  5.7  for 
wheat. 

Proteins  of  the  Common  Cereals  and  Vegetables. — Osborne  and  his 
coworkers  have  made  a  detailed  study  of  the  protein  constituents  not 
onlv  of  wheat  as  above  outlined,  but  of  other  common  grains  and  vegeta- 
bles, and  the  results  of  these  investigations  may  be  thus  briefly  sum- 
marized : 

Proteins  of  r\-e:  * 

Per  Cent. 

Ins!)luble  in  salt  solution 2.44 

Soluble  in  alcohol,  gliadin 4 .  00 

Soluble  in  water,  Icucosin 0.43 

Soluble  in  salt  solution:  |  proteose  f ^  ■  7^ 

8.63 

Proteins  of  barley:t  Per  Cent. 

„  ,  ,  ,    .  ,        I  Leucosin  I 

Soluble  in  water:  -^  „     .  ,- o.  ^ 

(  Proteose   \  -^ 

SoIuVjIc  in  salt  solution,  edestin i  .95 

Soluble  in  dilute  alcohol,  hordein 4.00 

Insoluble  in  water,  salt  solution,  and  alcohol 4-50 

Proteins  of  corn: J 

Soluble  in  water:   Proteose 0.06 

{Very  soluble  globulin c.04 

Maysin 0.25 

P>kstin 1 .  10 

Soluble  in  dilute  alcohol:  Zein 5- 00 

Insoluble  in  above,  but  soluble  in  two-tenths  percent  potash  scjluaon 2>-^S 

Protein  of  pca:§ 

Soluble  in  salt  solution:  Globulins  \  •C','^-       '  ■° 

\  Vicilin 3 -oo 

Soluble  in  water:  Albumin,  legumelin,  proteose 2 .03 

*  Jour.  ,\m.  Chem.  Soc.,  17,  page  429.  f  Ibid.,  17,  p,  539. 

X  Ibid.,  19,  p.  525.  §  Ibid.,  18,  p.  583;   20,  pp.  348  and  410. 


CERE/ILS,  LEGUMES,    VEGETABLES,   AND   FRUITS.  301 

Proteins  of  Potato.'^ — Almost  the  whole  protein  content  of  the  potato 
consists  of  a  globulin  to  which  Osborne  has  applied  the  name  "tuberin." 
Proteose  is  also  present  in  very  small  amount. 

MINERAL   CONSTITUENTS   OF   CEREALS   AND   VEGETABLES. 

The  food  analyst  often  finds  the  determination  of  one  or  more  of  the 
mineral  constituents  of  a  food  product  of  value  as  a  means  of  detecting 
adulteration,  since  the  addition  of  foreign  material  may  alter  materially 
the  composition  of  the  ash. 

The  tablet  on  page  302  shows  the  composition  of  the  pure  ash  of 
common  cereals. 

Scheme  for  Complete  Ash  Analysis. — The  following  scheme  in 
essential  details  was  suggested  by  the  late  Prof.  S.  L.  Penfield  of  Yale 
University,  and  has  been  in  use  for  over  twenty  years  at  the  Connecticut 
Agricultural  Experiment  Station. 

Preparation  of  ^5/2.— The  amount  of  material  which  should  be  re- 
duced to  ash  depends  on  the  percentage  of  total  ash  present  and  the 
amount  of  material  available.  Usually  100  grams  is  a  suitable  amount; 
if,  however,  the  material  (e.g.,  tobacco)  is  rich  in  ash,  50  grams  is  suffi- 
cient, while  if  it  contains  but  a  small  amount  of  ash,  200  grams  or  even 
more  may  be  required.  About  5  gramr.  of  ash  is  a  liberal  amount  for  a 
complete  analysis,  but  in  case  of  necessity  i  gram  will  suffice  if  care  is 
taken  to  so  adapt  the  scheme  as  to  make  as  many  determinations  as 
possible  on  one  weighed  portion. 

The  ashing  is  carried  on  in  a  platinum  dish  heated  below  redness 
by  a  Bunsen  burner.  In  order  to  distribute  the  heat  and  prevent  over- 
heating, a  piece  of  asbestos  paper  is  introduced  between  the  dish  and  the 
flame.  The  material  first  chars,  then  begins  to  glow  just  below  the 
surface,  and  the  combustion  gradually  extends  downward  until  it  reaches 
the  bottom  of  the  dish.  Then,  and  not  until  then,  the  unburned  carbon 
on  the  surface  should  be  stirred  in  with  the  ash  to  facilitate  burning. 
Care  should  be  taken  not  to  heat  higher  than  dull  redness,  thus  avoiding 
the  loss  of  alkali  chlorides  and  the  fusion  of  alkali  phosphates  about 
the  particles  of  carbon.  A  muffle  furnace  may  be  used  to  complete  the 
burning. 

Substances  rich  in  starch  or  sugar  are  most  difficult  of  combustion, 

*  Jour.  Am.  Chem.  Soc,  18,  1896,  p.  575. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chera.,  BuL  13,  part  9,  p.  121 2. 


302 


FOOD  INSPECTION  AND  ANALYSIS. 
COMPOSITION  OF  ASH  OF  CEREALS. 


KsO. 


NazO. 


CaO. 

MgO. 

FeaOa. 

3.50     13.24 

0.52 

5-56'   11-73 

5-23 

2.44 

8.23 

0-33 

4.09 

7.18 

0.20 

3.18 

17.99 

0.1^0 

4.48 

9.60 

0.89 

6.62 

20-55 

1.68 

PoOs 


SOa. 

CI. 

O.OI 

0.00 

0.52 

0.58 

0.22 

0.56 

0.48 

1.02 

0.44 

0.00 

0.24 

0.80 

3-59 

0.67 

SiOz 


Wheat  (Canada") 

Rve  (Minnesota) 

Barlev  (U.  S.) 

Oats  (U-  S") 

Com  (T.  S.") 

Rice,  polished  (Guatemala) 
Buckwheat  (U.  S.) 


24.03 
27.60 

24-15 
15.91 

33-92 
20.84 

35-15 


9-55 
4.64 
6.42 
4-38 
7.72 
13.98 
2.26 


46.87 
41.81 
35-47 
24.34' 
35-25 
43-21 
24.09 


2.28 

2-45 
22.30 
42.64 
1 .00 
6. 14 
5-54 


Teller  *  obtained  the  following  results  of  ash  analyses  of  Hour,  bran, 
and  wheat: 

ASH  OF  WHEAT  PRODUCTS. 


Patent 

Fl.'ur. 


Straight 
Flour. 


Low 
Grade. 


Bran. 


Wheat. 


Silica 

Alumina 

Ferric  oxide 

Potash 

Soda 

Lime 

Magnesia 

Phosphoric  acid. 
Sulphur  trioxide. 

Chlorine 

Zinc  oxide 


Sum 

Per  cent  of  total  ash 


2-33 
.41 

-47 

38-50 

0.00 

5-59 

4-39 

48-05 

.16 


99.90 
•31 


1.28 

•15 
.26 

36-31 
0.00 

5-65 

6-44 

49-32 

-52 

.04 


•50 
.12 

-25 

32.27 

0.00 

4-51 

9-33 

53-10 

.00 


99-97 
.40 


100. oS 
.70 


•97 
.07 

-27 

28.19 

0.00 

2.50 

14.76 

52.18 


.27 


99-95 


1.04 
.11 

■27 

29.70 

0.00 

3.10 

13-23 

52.14 

.22 

.01 

-24 


100.06 


1.62 


Konig  gives  the  following  analyses  of  the  ash  of  various  leguminous 
and  other  vegetables: 


5< 


P§ 


0 

01 

0 

•c 

0 

c 

S 

t-^ 

7.08 

0-57 

38-74 

7.96 

0.86 

36-43 

4.69 

1. 18 

17-33 

4-54 

0.82 

8.45 

4-73 

1.03 

12.46 

3-69 

0.81 

12.71 

UJ 

UJ         1 

2-53 

0-73 

3-49 

0.86 

6-49 

2.13 

3-17 

2.38 

6.72 

2-47 

II. 19 

1.87 

Beans 15 

Peas 29 

Potatoes. I  53 

Beets I  15 

Carrots |  11 

Turnips '  32 


3.57,  42.49 

1-34 

4-73 

2.73'  41-79 

0.96 

4-99 

3.77    60.37 

2.62J      2.57 

6.44    54.02 

15.90,     4.12 

5-58    35-21 

22.07 

11.42 

8.01    45.40 

9.84 

10.60 

1-57 
1-54 
3-11 
8.40 

5-13 
5.01 


*  Ark.  Exp.  Sta.  Bui.  42. 


CEREALS,   LEGUMES,    VEGETABLES,    AND   FRUITS.  303 

as  the  charcoal  forms  a  hard  mass,  while  substances  rich  in  fibrous  or 
woody  matter  burn  quite  readily  without  losing  their  powdered  con- 
dition. A  certain  amount  of  unburned  carbon  is  no  disadvantage,  as 
it  is  determined  in  the  course  of  the  analysis. 

Finally  cool  the  ash,  grind  to  a  [jowder,  mix  without  loss,  and  weigh, 
thus  determining  the  percentage  of  crude  ash. 

Determination  of  Water. — Heat  i  gram  of  the  ash  in  a  ])latinum 
crucible  well  below  redness  to  constant  weight. 

Determination  of  Carbonic  Acid.  —  Determine  carbonic  acid  as 
described  on  p.  336  using  the  portion  dried  for  the  determination  of 
water. 

Determination  of  Charcoal  and  Sand. — Weigh  i  gram  of  the  ash, 
or  transfer  the  solution  and  residue  from  the  determination  of  carbonic 
acid,  into  a  beaker,  add  25  cc.  of  water  and  25  cc.  of  10  per  cent  hydro- 
chloric acid,  and  boil  gently  for  10  minutes.  Filter  on  a  Gooch  crucible, 
and  wash  thoroughly  with  hot  water.  Reserve  the  filtrate  for  determina- 
tion of  silica,  iron  oxide,  alumina,  lime,  and  magnesia.  Wash  the  residue 
on  the  crucible  once  with  alcohol  and  once  with  ether,  and  dry  to 
constant  weight  at  100°  C.  Ignite  and  weigh  again.  The  loss  on 
ignition  is  the  charcoal,  the  residue  is  sand. 

Determination  of  Silica,  Iron  Oxide,  Alumina,  Lime  and  Magnesia. — 
Evaporate  to  dryness  in  a  platinum  dish  the  filtrate  from  the  determina- 
tion of  charcoal  and  sand,  heat  for  some  hours  on  the  water  bath,  and 
dry  at  130°  C.  until  all  hydrochloric  acid  is  removed.  Moisten  the 
residue  thoroughly  wath  concentrated  hydrochloric  acid,  add  hot  water, 
stir,  and  decant  the  solution  on  an  ashless  filter.  Treat  the  residue 
again  with  acid  and  hot  water,  and  repeat  the  treatment  until  nothing 
but  silica  remains  undissolved.  Finally  collect  the  silica  on  the  paper, 
wash  with  hot  water,  ignite  in  a  platinum  crucible,  and  weigh. 

To  the  filtrate  add  ammonia  until  a  precipitate  forms  which  remains 
on  stirring,  and  then  add  sufficient  hydrochloric  acid  to  just  dissolve  the 
precipitate.  Heat  to  50°  C.  and  add  an  excess  of  ammonium  acetate 
solution  and  4  cc.  of  80  per  cent  acetic  acid.  Digest  at  50°  C.  until 
the  mixed  phosphates  of  iron  and  alumina  have  settled,  filter,  wash  with 
hot  water,  ignite  in  a  platinum  crucible,  and  weigh.  As  the  precipitate 
is  usually  slight  and  consists  almost  entirely  of  iron  phosphate,  the 
iron  oxide  may  be  calculated  with  reasonable  accuracy  using  the 
factor  0.53.  If,  however,  greater  accuracy  is  desired  fuse  the  weighed 
precipitate  with  10  parts  of    sodium    carbonate,  dissolve  in  dilute  sul- 


304  FOOD  INSPECTION  AND  ANALYSIS. 

phuric  acid,  reduce  with  hydrogen  sulphide,  determine  iron  by  the 
volumetric  permanganate  method,  and  in  the  same  solution  determine 
phosphoric  acid  by  the  molybdic  method.  The  alumina  is  obtained  bv 
ditTerence.  subtracting  the  sum  of  the  weights  of  the  oxide  of  iron  and 
phos]>horic  acid  from  the  total  weight  of  the  precipitate. 

To  the  llltrate  from  the  mixed  j)hosphates  add  an  excess  of  ammo- 
nium oxalate,  allow  to  stand  in  a  warm  place  over  night,  filter,  ignite 
the  precipitate  in  a  ])latinum  crucible  over  a  Bunsen  burner,  and  finally 
to  constant  weight  over  a  blast  lamp,  thus  obtaining  the  calcium  oxide. 

Precipitate  the  magnesia  in  the  filtrate  from  the  lime  by  adding 
ammonia  to  alkaline  reaction,  then  an  excess  of  sodium  phosphate  solu- 
tion with  constant  stirring,  and  finally  sufficient  concentrated  ammonia 
to  form  one-tenth  the  final  volume.  Let  stand  over  night,  collect  the 
magnesium  ammonium  phosphate  on  a  Gooch  crucible,  ignite  to  mag- 
nesium pyrophosphate,  and  weigh. 

Determination  of  Sulphuric  Acid,  Potash,  and  Soda. — Boil  i  gram 
of  the  ash  with  dilute  hydrochloric  acid,  and  remove  charcoal,  sand,  and 
silica,  as  described  in  the  preceding  section.  Evaporate  nearly  to  dryness 
to  remove  the  excess  of  acid.  Dilute  to  loo  cc,  heat  to  boiling,  and  add 
barium  chloride  solution  drop  by  drop  until  the  sulphuric  acid  is  prc- 
cij)itated.  Allow  to  stand  over  night,  filter,  ignite,  and  weigh  as 
BaS04. 

Heat  the  filtrate  to  boiling,  add  enough  barium  hydroxide  to  make 
the  solution  strongly  alkaline,  filter,  and  proceed  with  the  determina- 
tion of  potash  and  soda,  as  described  on  p.  345. 

Determination  of  Phosphoric  Acid. — Dissolve  0.5  gram  of  the  ash 
in  hydrochloric  acid,  filter,  and  wash.  Neutralize  with  ammonia,  clear 
with  nitric  acid,  and  proceed  as  described  on  p.  346. 

Determination  of  Chlorine. — Dissolve  i  gram  of  the  ash  in  cold,  very 
dilute  nitric  acid,  filter,  and  wash.  To  the  filtrate  add  an  excess  of 
silver  nitrate,  and  heat  nearly  to  boiling  with  constant  stirring.  Filter 
on  a  Gooch  crucible,  wash  with  hot  water,  dry  the  j)recipitale  at  a  low 
heat,  and  heat  cautiously  at  dull  redness  until  the  silver  chloride  has 
partially  melted. 

If  desired  the  chlorine  may  be  determined  volumetrically  by  Vol- 
harrh's  method,  as  follows:  To  the  nitric  acid  solution  add  a  known 
volume  of  decinormal  silver  nitrate  solution  sufficient  to  precipitate  the 
chlorine,  and  5  cc.  of  saturated  solution  of  ferric  alum.  Titrate  with 
decinormal   ammonium   tliiocyanate   solution    until   a  permanent   brown 


CEREALS,  LEGUMES,   VEGETABLES,  AND   FRUITS.  305 

color  is  formed.  Subtract  the  volume  required  from  (he  volume  of 
decinormal  silver  nitrate  added,  and  calculate  the  chlorine. 

Determination  of  Sulphur  in  Vegetable  Materials.* — Place  from 
1.5  lo  2.5  i^rams  of  material  in  a  nickel  crucible  of  about  100  cc.  capacity, 
and  moisten  with  approximately  2  cc.  of  water.  Alix  thoroughly,  using 
a  nickel  or  platinum  rod.  Add  5  grams  of  pure  anhydrous  sodium 
carbonate,  and  mix.  Add  pure  sodium  j)eroxide,  small  amounts  (approx- 
mately  0.50  gram)  at  a  time,  thoroughly  mixing  the  charge  after  each 
addition.  Continue  adding  the  peroxide  until  the  mixture  becomes 
nearly  dry  and  quite  granular,  requiring  usually  about  5  grams  of 
peroxide.  Place  the  crucible  over  a  low  alcohol  flame  (or  other  flame 
free  from  sulphur),  and  carefully  heat  with  occasional  stirring  until 
contents  are  fused.  (Should  the  material  ignite  the  determination  is 
worthless.)  After  fusion,  remove  the  crucible,  allow  to  cool  somewhat, 
and  cover  the  hardened  mass  with  peroxide  to  a  depth  of  about  0.5  cm. 
Heat  gradually,  and  finally  with  full  flame  until  complete  fusion  takes 
place,  rotating  the  crucible  from  time  to  time  in  order  to  bring  any 
particles  adhering  to  the  sides  into  contact  with  the  oxidizing  material. 
Allow  to  remain  over  the  lamp  for  ten  minutes  after  fusion  is  complete. 
Cool  somewhat.  Place  warm  crucible  and  contents  in  a  600  cc.  beaker, 
and  carefully  add  about  100  cc.  of  water.  After  violent  action  has  ceased, 
wash  material  out  of  crucible,  make  slightly  acid  with  hydrochloric  acid 
(adding  small  portions  at  a  time),  transfer  to  a  500  cc.  flask,  cool,  and 
make  to  volume.  Filter,  and  take  a  200  cc.  ahquot  for  determination 
of  sulphates  by  precipitating  with  barium  chloride  in  the  usual  manner. 

Determination  of  Chlorine  in  Vegetable  Substances.*  —  Impreg- 
nate 5  grams  of  substance  in  a  platinum  dish  with  20  cc.  of  a  5  per  cent 
solution  of  sodium  carbonate,  evaporate  to  dryness,  and  ignite  as 
thoroughly  as  possible.  Extract  the  residue  with  hot  water,  Alter,  and 
wash.  Return  to  the  platinum  dish,  ignite  to  an  ash,  dissolve  in  nitric 
acid,  and  determine  chlorine  by  the  Volhard  method  (p.  304). 

Detection  of  Sulphuring  in  Grain. — Carroll  t  has  shown  that  the 
following  method  distinguishes  sharply  barley,  oats  and  other  grains 
in  their  natural  condition  from  those  bleached  by  sul[)hurous  acid. 

Introduce  into  a  500  cc.  flask,  provided  with  a  desulphurized  perforated 
stopper  and  a  double-bent  delivery  tube,  10  grams  of  mossy  zinc,  a  few 
drops  of  ferric  chloride  solution,  100  grams  of  the  grain  and  enough  8% 

*  A.  O.  A.  C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  pp.  23,  24. 
t  U.  S.  Dept.  of  Agric,  Bur.  of  Plant  Ind.,  Circ.  40. 


3o6  FOOD  INSPECTION  /IND  ANALYSIS. 

hydrochloric  acid  to  cover  the  grain.  Place  a  loose  plug  of  cotton  in  the 
neck,  attach  the  stopper,  and  run  the  delivery  tube  into  a  test-tube  con- 
taining ID  cc.  of  2*  t^  lead  acetate  solution.  If  a  brownish  black  pre- 
cipitate of  lead  sulphide  foims,  the  grain  has  been  sulphured.  Particles 
of  dust  or  zinc,  occasionally  carried  over  mechanically,  are  distinguished 
from  lead  sulphide  by  their  insolubility  in  lo^  ^  ferric  chloride  solution. 

MICROSCOPY  OF  CEREAL  PRODUCTS. 

The  histology  of  the  cereals  is  more  fully  considered  in  the  works  on 
food  microscopy,  the  brief  descriptions  here  given  should,  however,  enable 
the  food  chemist  to  identify  the  commoner  products.  The  tissues  of  the 
various  cereals  are  quite  distinctive,  serving  usually  to  determine  the 
particular  grain  from  which  a  given  product  is  made.  In  the  case  of 
tlour  the  tissues  are  largely  removed  in  milling,  the  fragments  remaining 
being  small  and  few  in  number.  Such  products  are  identified  either  by 
the  character  of  the  starch  grains — as  in  the  detection  of  wheat  or  com 
flour  in  buckwheat  flour — or  else,  if  the  starch  is  not  sufficiently  character- 
istic— as  in  the  detection  of  wheat  flour  in  rye  flour — by  examining 
the  tissues  from  a  considerable  amount  of  the  material. 

The  most  convenient  method  of  accumulating  the  tissues  from  flour 
is  to  mix  thoroughly  2  grams  of  the  material  with  200  cc.  of  water  and  3  cc. 
of  sulphuric  acid,  bring  to  a  boil,  allow  to  settle,  and  carefully  decant  off 
the  Uquid  from  the  deposit  of  tissues.  The  tissues  are  mounted  for 
examination  in  very  dilute  sodium  hydroxide  solution 

Wheat  Products. — Fig.  O2  and  PI.  \'I1I  show  the  principal  elements 
of  the  wheat  kernel. 

The  outer  layer  or  epicarp  (Fig.  62,  epi^  and  epi-)  consists  of  beaded 
cells,  which  on  the  body  of  the  kernel  are  elongated,  but  at  the  end  are 
polygonal.  From  this  layer  at  the  end  of  the  kernel  arise  the  hairs  (Fig. 
62,  /,  PI.  VIII,  Fig.  151)  which  form  a  beard  clearly  visible  under  a 
lens.  Some  of  these  hairs  become  detached  in  milling,  and  pass  endwise 
through  the  bolts,  hence  their  presence  in  even  the  highest  grade  of 
flour.  The  second  layer  or  hypoderm  (hy)  resembles  the  first,  while  the 
third,  although  likewise  made  up  of  beaded  cells,  is  strikingly  different  and 
forms  the  most  characteristic  tissue  of  the  grain.  These  cells  (Fig.  62, 
ir,  PI.  V'lII,  Fig.  150J  being  transversely  extended  are  known  as  "cross 
cells,^'  and  are  further  distinguished  from  the  outer  layers  by  their 
arrangement  side  by  side  in  rows.     The  cells  of  the  intermediate  layer 


CEREALS,   LEGUMES,    yEGETABLES,   AND  FRUITS. 


307 


(Fig.  62,  in)  and  the  lube  cells  (lii^  and  /;<-),  although  of  striking  appear- 
ance, are  not  of  as  frequent  occurrence  as  the  other  layers.  The  crossing 
layers  of  the  seed  coat  or  spermoderm  {i  and  0),  are  often  met  with,  and 
are  characterized  by  the  thin  walls  of  the  cells  and  their  brownish  color. 
The  perisperm  (P),  consisting  of  colorless  cells,  is  seldom  seen,  except 
after  special  preparation,  while  the  next  layer,  made  up  of  alciirone  cells 


Fig.  62. — Wheat.     Elements  in  Surface  View.      Xi6o.     (WiNTON.) 
epi^  epicarp  at  end  of  grain,  with  /  hairs;  eph  epicarp    on  body  of  grain;    hy  hypoderm 
(first  layer  of  mesocarp);  in  intermediate  cells;  tr  cross  cells;  tu^  typical  tube  cells;  lu-  tube 
cells  passing  into  spongy  parenchyma;  o  outer  layer  of  spermoderm;  /  inner  layer  of  sperni" 
oderm;  P  perisperm;  al  aleurone  cells;  am  starch  grains. 


(Fig.  62,  al\  PL  VIII,  Fig.  150),  is  the  most  conspicuous  of  the  kernel. 
This  layer  is  not,  however,  characteristic  of  wheat,  as  it  is  found  in  all 
cereal  grains  and  in  buckwheat.  The  aleurone  cells  do  not  contain,  as 
was  formerly  supposed,  the  gluten  of  the  grain;  this  occurs  with  the 
starch  in  the  thin-walled  cells  within  the  aleurone  layer. 

The  starch  granules  (Fig.  62,  am;    PI.  VIII,  Fig.  152)  arc  described 


3o8 


FOOD    INSPECTION   AND    ANALYSIS. 


on  page  2S1.  The  starch  cells  and  the  alcuronc  cells  together  form  the 
endosperm. 

The  germ,  situated  at  one  side  of  the  lower  end  of  the  kernel,  is  made 
up  of  verv  small  cells  containing  fat  and  protein,  but  no  starch. 

Rye  Products. — The  structure  of  rye  (Fig.  63;  PI.  VII)  resembles 
closely  that  of  wheat.  The  number  and  general  characters  of  the  cell 
layers  are  the  same  in  both,  and  the  starch  granules  are  very  much  alike. 
There   are,   however,   certain   points   of  difference   which   serve   to   dis- 


FlG.  63. — Rye,  Outer  Bran  Layers  in  Surface  View.    Epicarp  consists  of  porous  cells  with  t 
hairs,  and  v  hair  scars;  Ir  cross  cells.      X  i6o.      (Moeller.) 


tinguish  the  products  of  the  two  cereals,  and  even  to  detect  the  presence 
of  a  wheat  product  in  a  rye  j^roduct,  and  vice  versa: 

First.  The  breadth  of  the  cavities  of  wheat  hairs  is  usually  less  than 
the  thickness  of  the  walls,  whereas  in  r}e  hairs  tlie  reverse  is  often  true 
(Fig.s.  62  and  63,  t). 

Second.  The  cro.ss  cells  of  wheat  have  rather  thick,  distinctly  beaded 
side  walls,  and  thin,  pointed  end  walls;  the  cross  cells  of  rye  have  rather 
thin,  indistinctly  beaded  sifle  walls,  and  usually  swollen,  rounded  end 
walls  f^Figs.  62  and  63,  tr;  Figs.  150  and  146). 

Third.  The  large  .starch  granules  of  wheat  .seldom  reach  0.050  mm, 
in  diameter,  while  tho.se  of  rye  frequently  exceed  that  limit.  Radiating 
clefts  often  occur  in  the  .starch  granules  of  rye  (PI.  VII,  Fig.  148). 

Fourth,     Wheat  flour  yields  a  considerable  amount  of  gluten  when 


CERE/1LS,   LEGUMES,    l^EGETABLES,   /1ND  FRUITS,  309 

treated  according  10  Bamihrs  test  (page  322);    rye  flour  yields  none  or 
only  a  trace. 

Barley  Products. — The  common  varieties  of  barley  are  "  chaffy," 
that  is,  the  grain  after  threshing  is  still  closely  invested  by  the  chaff 
(PI.  I,  Fig.  123).  The  grain  within  the  chaff  is  analogous  in  structure 
to  wheat  and  rye,  bi't  diffc'-s  from  tliese  in  that  the  cross  cells  are  not 
beaded  and  form  a  double  layer  (Fig.  64,  tr),  and  the  starch  granules 


Fig.  64. — Barley.     Surface  view  of  ir  double  layer  of  cross-cell;  In  tube  cells;  -je  seed  coat. 

X3OO.       (MOELLER.) 

seldom  exceed  0.035  ^^-  ^^  diameter  (PI.  I,  Fig.  124).  The  starch  is 
more  fully  described  on  page  281. 

Corn  Products. — The  most  characteristic  element  of  corn  is  the 
starch  (page  281;  PI.  I\').  Polygonal  starch  granules  0.017  to  0.030 
mm.  in  diameter  occur  in  no  other  vegetable  product  of  economic  im- 
portance, excepting  the  seeds  of  Kafifir  corn  and  other  grains  belonging 
to  the  genus  SorgJnim,  which  are  used  chiefly  for  cattle  or  poultry  foods. 

Oat  Products. — The  oat  kernel  resembles  barley  in  appearance, 
but  is  not  ribbed.  In  the  preparation  of  oat  meal  and  other  breakfast 
foods,  the  chaff  (PI.  IV,  Fig.  135;  PI.  \\  Fig.  137)  is  removed  and 
utilized  as  a  cattle  food.  The  elements  of  the  grain  of  chief  value  in 
identification  are  the  hairs  and  the  starch  granules.  The  hairs  (PI.  V, 
Fig.  138)  are  much  longer  than  those  of  wheat,  rye,  and  barlev,  often 
reaching  i  mm.  They  taper  toward  both  ends,  so  that  when  detached 
they  often  appear  to  be  pointed  at  the  base  as  well  as  at  the  apex.     The 


;io 


FOOD  INSPECTION  /1ND   ANALYSIS. 


Starch  granules  are  small,  of  the  polygonal  type,  and  often  occur  in  egg- 
shaped  aggregates  (page  282;   PI.  V,  Fig.  139). 

Rice   Products. — The  chatT  wliich  envelopes  this  grain  is  rough  and 
silicious.  and  alter  removal  from  tlu'  inner  kernel  is  not  suited  even  for 

(■/)/  III 


Fig.  65. — Rice.      Bran    coats  in    surface    view.      epi  epicarp;   mes  mesocarp;  tr  cross  cells; 
/«  tube  cells;  5  seed  coal;   N  perisperm.      X300.      (Winton.) 

cattle  food.     Its  appearance  under  the  microscope  is  shown  in  Plate  VI, 
Fig.  142.     The  thin  skin  of  the  kernel  proper  is  largely  but  not  entirely 


P/iW 


Fig.  66. — Buckwheat.      Bran  coats  in  surface  view.    Seed  coat  consists  of  0  outer  epidermis, 
m  spongy  parenchyma,  and  ep  inner  epidermis;   al  alcurone  cell.      X.300.      (Moeller.) 


CEREALS,   LEGUMES,    VEGETABLES,   AND   FRUITS.  31 1 

removed  in  the  i)reparation  of  rice  for  llie  market.  The  elements  of  this 
skin  are  shown  in  Fig.  65,  the  outer  hiyer  (cpi)  bein,^  the  most  char- 
acteristic. Unlike  wheat,  rye,  and  barley,  it  has  no  beard.  Rice  starch 
(PL  VI,  Fig.  143')  is  hardly  distinguishable  from  oat  starch.  It  is 
described  on  page  282. 

Buckwheat  Products. — In  the  i)reparation  of  buckwlieat  flour  the 
black  outer  hulls  and  the  inner  skin  or  bran  are  largely,  but  not  com- 
pletely, removed.  The  bran  elements  are  characteristic  constituents  of 
the  flour,  and  are  rendered  especially  distinct  l)y  adding  a  drop  of  dilute 
potassium  hydroxide  solution  to  a  water  mount  (Fig.  66).  The  cells 
with  wavy  walls  (0)  and  the  spongy  j^arenchyma  {m)  are  especially 
noticeable.  The  starch  of  buckwheat  resembles  that  of  oats,  but  the 
indi\-idual  granules  are  somewhat  larger  and  occur  in  rod-shaped,  not 
egg-shaped,  aggregates  (page  281;  PI.  II,  Fig.  128).  Masses  of  starch 
granules  (PI.  Ill,  Fig.  129)  conforming  to  the  shape  of  the  ceils,  occur 
in  abundance  in  the  flour. 

FLOUR. 

Flour  is  the  term  applied  to  the  finely  ground  and  bolted  substance 
of  wheat  and  other  grains,  though,  unless  otherwise  qualified,  by  the 
term  "flour"  is  generally  undertsood  that  of  wheat. 

Graham  flour  is  an  unbolted  meal  prepared  from  the  whole  wheat 
kernel. 

Process  of  Milling. — The  crude  milling  process  which  prevailed  until 
the  last  quarter  of  the  nineteenth  century  consisted  in  grinding  the  wheat 
between  millstones  and  bolting  to  remove  the  bran  and  shorts.  In  the 
modern  or  Hungarian  process  the  wheat  is  first  crushed  between  cor- 
rugated rollers,  then  by  sifting  separated  into  middlings,  break  flour,  and 
bran.  The  middlings,  consisting  of  the  hard  glutinous  portions  of  the 
grain  in  granular  form,  are  gradually  reduced  to  fine  flour  between  smooth 
rollers  and  freed  from  impurities  by  means  of  a  series  of  bolts.  A  number 
of  grades  of  flour  are  thus  produced,  the  streams  of  which  are  so  combined 
with  each  other  and  the  break  flour  as  to  form  the  finished  products. 

The  Grades  of  Flour  commonly  made  are  (i)  patent,  forming  85% 
or  less  of  the  flour  output;  (2)  clear  or  bakers' ,  an  intermediate  grade 
inferior  to  the  patent  in  color  and  rising  properties;  and  (3)  low  grade 
or  "rer/  dog,'''  about  5'/(,.  suitable  only  for  cattle  food.  Some  mills  make 
two  or  more  grades  of  patent  and  clear.  On  the  other  hand,  it  is  a  fre([uent 
practice  to  combine  all  the  flour  streams  other  than  of  low  grade  to  form 
a  straight. 


3I-' 


FOOD   I>JSPFCTION  AND   y4Nyi LYSIS. 


The  By-products  are  (i)  Iran,  the  outer  coalings  of  the  grain  in 
flakes,  {2)  slwrls,  the  liner  olTal  containing  both  starchy  matter  and  bran 
elements,  and  (3)  j;<t;;/,  rich  in  oil,  often  run  in  with  the  bran. 

Composition  of  Wheat  Flour  and  By-products. — The  following  analyses 
by  Clifford  Richardson  *  represent  the  products  of  the  same  milling: 


Mois-    Protein 
ture.     NXs-7 

Moist 
Gluten. 

Drv 

Gluten. 

Ether 
Ex- 
tract 
(Fat). 

Nitro- 
gen-free 
Extract 
(Starch, 

etc). 

Crude 
Fiber. 

Ash. 

Phos- 
phoric 
Acid. 

Wheat  (Spring) 

9-07 
11-48 
12.18 
12.01 
10.94 
10.91 

12.93 
II. 81 

13-57 
16.37 
15-32 
14-84 

36-14 
51-51 

lO-OI 

10.85 
16.97 
4.26 

2-74 
1-45 
2.00 
3-86 
4.67 
5-03 

71-77 
74-69 

71-30 
64-84 
61-76 
57-65 

1.70 
0.18 
0-55 
0-93 
3-90 
5.98 

1-79 
0-39 
0.62 
1.99 
3-41 
5-59 

0.82 

Patent  flour 

0.18 

Clear  flour 

0-31 
1. 16 
1.62 
2.78 

I>>\v-grade  flour 

Shorts 

Bran 

P>om  the  above  it  appears  that  the  fat,  fiber,  ash,  and  phosphoric  acid 
increase  through  the  series,  being  least  in  the  patent  flour  and  greatest 
in  the  bran,  while  the  nitrogen-free  extract  decreases.  Considering 
only  the  flour,  the  protein  is  least  in  the  patent  and  greatest  in  the  low  grade, 
but  the  gluten,  although  greater  in  the  clear  than  in  the  patent,  drops 
down  sharply  in  the  low  giade. 

The  ash  of  flour  is  a  valuable  index  of  grade.  In  a  true  j)atcnt  it 
should  not  exceed  0.459^.  As  pointed  out  by  Snyder, f  the  acidity  is 
also  a  guide,  although  this  increases  in  all  grades  on  aging. 

Hani  Wheals,  such  as  the  Spring  varieties  of  the  Northwest  and 
Turkey  red  Winter  wheat  of  Kansas,  yield  a  "strong"  flour  rich  in 
protein  and  gluten,  the  latter  being  of  good  tenacity,  while  Soft  Wheats, 
such  as  are  grown  in  States  adjoining  the  Ohio  river,  yield  a  white 
starchy  flour,  the  gluten  being  smaller  in  amount  and  lacking  in  tenacity. 

Analyses  of  tyyjical  hard  and  soft  wheat  flour  freshly  ground,  are  given 
in  the  table  on  top  of  page  313.  The  percenta<.%'s  are  of  the  total  flour, 
excluding  the  low  grade.     Color  values  are  given  on  ])agc  316. 

Color  of  Flour. — The  time-honored  test  for  grade  is  ])y  the  color. 
A  jjatent  is  practically  free  from  bran  specks  while  a  clear  contains 
such  specks  in  noticeable  amount.  Both  grades  have  a  yellowish  tint 
due  to  the  color  associated  with  the  fat,  which  is  more  or  less  i)ron(Hinced, 


*  U.  S.  Dept.  of  Agric,  Bui.  4,  1884,  p.  38. 
t  Minn.  .\gri( .  Kxp.  Sta.,  Hul.  85. 


CFRF.4LS,  LEGUMES,  VEGETABLES,  /IMP  I RUITS. 


2>^Z 


Moisture 

Ash 

Crude  fiber 

Protein  (NX 5.7) 

Alcohol  sol.  protein  .. 

Salt  sol.  protein 

Moist  gluten 

Dry  glulLn 

Nitrogen-free  e.xtract. 

Fat 

Acidity  as  lactic 


Minnesota. 
Hard  Spring. 


78% 
Patent. 


13-74 
0.44 
0.06 

10.60 

5-84 
1.62 

36-93 

12.48 

74.07 

I  09 

o.io^ 


22% 
Clear. 


13.26 
0.85 
0.26 

11.74 
6.21 

2.19 

38.76 

13-41 
71.91 
1.98 
0.230 


Nebraska. 
Hard  Winter. 


80% 
Patent. 


0-39 

0.18 
11.09 

5-79 

1.48 

30.48 

9-85 

75-16 

0.85 

o.oSi 


20% 
Clear. 


12.85 
0.67 
0.24 

11.86 

6.55 

2.02 

42.50 

13.08 

73.06 

1-3- 
0.158 


Michigan. 
Soft  Winter. 


80% 
Patent. 


13.22 
0.42 
0.19 

8.66 
5-24 

1-45 
20.23 

6.97 
76.40 

I. II 

O.IIO 


20% 
Clear. 


12.62 
0.89 
0.27 

12.26 

5-53 

2.19 

31.24 

IO-55 
72.19 

1-77 
0.250 


Missouri. 
Soft  Winter. 


40% 
Patent. 


12.27 
0-39 
0-34 
9.01 
5.04 
1.25 

17.90 

5-90 
77.12 
0.87 
0.063 


60% 
Clear. 


12.02 
0.50 
0.38 

10.72 
6.21 
i--43 

33-21 

10.22 

75-23 
1. 15 
0.095 


according  to  the  kind  of  wheat,  but  is  not  proportional  to  the  per  cent 
Ci  f"t.     This  is  measured  by  the  gasoline  color  value  (pp.  316  and  32-). 

Composition  of  Various  Flours, — The    following  analyses  are   from 
Bulletin  13,  Part  9,  of  the  Bureau  of  Chemistry: 


No.  of 
Analyses. 


Moisture. 


Protein 
NX6.25. 


Ether 

Extract 

(Fat). 


Nitrogen- 
free  Ex- 
tract 
(Starch, 
etc.). 


Crude 
Fiber. 


Ash. 


Calcu- 
lated 
Calories 
of  Corn- 
bus;  ion. 


Corn  flour 

Rye  flour 

Barley  flour 

Buckwheat  flour 


12.57 
II. 41 
10.92 
11.89 


7-13 

13-56 

7-50 

8-75 


1-97 
0.89 
i.s8 


78.36 

73-37 
80.50 

75-41 


0.87 
1.86 
0.67 
0.52 


0.61 

1-55 
0.86 
1.8^ 


38-3; 


38-54 


Damaged  Flour. — Grain  is  often  damaged  by  the  growth  of  smuts, 
rusts,  and  ergot.  Both  grain  and  flour  are  also  liable  to  attacks  of  molds, 
yeasts,  algae,  and  bacteria. 

Various  insects  and  other  forms  of  animal  life  frequently  infest  grain 
or  flour.  Among  these  are  weevils  and  various  other  beetles,  flour  moths, 
mites,  and  the  wheat  worm,  a  nematode  related  to  trichina. 

Grain  may  also  be  damaged  by  sprouting,  the  diastate  thus  formed 
partially  dissolving  the  starch  granules  with  the  formation  of  fissures 
and  branching  channels,  readily  seen  under  the  microscope.  Flour  thus 
damaged  is  high  in  cold-water  extract  (p.  320 1. 

Ergot. — Ergot,  a  fungous  growth  containing  a  poisonous  alkaloid, 
sometimes  develops  in  rye  and,  less  often,  in  wheat.  Under  the  micro- 
scope it  appears  as  a  fine  network  of  mostly  colorless  parenchyma  cells, 
containing  globules  of  fat  (Fig.  67).  Some  of  the  cells  are  circular, 
others  considerably  elongated,  and  some  contain  a  deep-brown  coloring 


314 


FOOD  INSPECTION   AND   ANALYSIS. 


matter,  which,  whh  ammonia,  becomes  violel-red,  chan<j;ing  to  red  with 
acid.  Occasionally  the  cell  walls  appear  of  a  dark  color.  If  flour  con- 
taining ergot  be  treated  with  a  very  dilute  solution  of  anilin  violet,  the 
stain  will  be  practically  absorbed  by  the  damaged  particles  of  the  grain, 
and  resisted  by  the  normal  granules.  A  hot,  alcoholic  extract  of  flour 
containing  ergot  is  colored  red  when  treated  with  dilute  sulphuric  acid. 


P,^ml??^l 

■    ■  ■■    ~  :^3 

■Tfli 

'^ 

:0i 

^^.^ 


i',2t^-'^' 


iS^^Z^^^ 


Fig.  67— .4,  Transverse  Section  of  the  F.rp;ot  of  \ATieat  under  the  Microscope;  B  Powdered 
Wheat  Ergot,     (.\fter  Villiers  and  Collin.A 


Adulteration  of  Flour.  —  Besides  the  substitution  of  cheaper  or 
inferior  grades  for  those  of  higher  quality,  the  fraudulent  admi.xture  of 
com  llour  to  wheat  flour  was  at  one  time  extensively  practiced.  This 
adulterant  is  best  detected  by  the  microscope  (p.  281). 

Rye  flour  is  often  adulterated  with  cheap  grades  of  wheat  flour  or 
middlings.  These  admixtures  are  detected  by  the  Bamihl  test  (p.  322) 
and  In'  microscopic  examination  of  the  residue  after  boiling  with  dilute 
acid  fp.  306),  noting  especially  the  cross  cells. 

Much  of  the  so-called  buckwheat  flour  consists  of  mixtures  containing 
wheat  or  com  flour,  or  both.  Rice  flour  is  also  used  in  pancake  flours, 
although  probably  not  to  cheapen  the  product.  Self-rp-ising  pancake 
flours  are  usually  mixtures  of  two  or  more  flours  with  leavening  material. 
The  microscopic  characteristics  of  the  starch  grains  and  tissues,  serve 
to  identify  the  different  flours  present  in  such  mixtures. 


CERE/tlS,  LEGUMES,  yEGETABLES,  AND   FRUITS.  315 

Finely  ground  mineral  adulterants  are  said  to  have  ])een  used  in  flours, 
but  no  authentic  instance  of  this  kind  has  come  to  the  writer's  knowledge. 
Any  considerable  admixture  of  such  a  nature  would  be  manifest  in  the 
increased  ash. 

Alum  in  Flour. — Alum  was  formerly  used  in  Europe,  both  by  miller 
and  baker,  to  improve  the  appearance  of  inferior  or  slightly  damaged 
flour,  but  now  is  rarely  if  ever  employed,  and  the  presence  of  notable 
quantities  of  aluminium  compounds  in  flour  or  bread  is  usually  due  to 
alum  baking  powder. 

Detection. — Mix  10  grams  of  the  sample  with  10  cc.  of  water  and 
stir  in  i  cc.  of  logwood  tincture  (5  grams  logwood  digested  in  100  cc. 
alcohol)  and  i  cc.  of  a  saturated  solution  of  ammonium  carbonate.  If 
the  sample  is  pure,  the  color  will  be  a  faint  brown  or  j)ink,  but  if  alum 
is  present,  a  distinct  lavender-blue  color  is  produced,  which  should 
remain  after  heating  for  two  hours  in  the  water-oven. 

Alum  may  also  be  detected  by  the  ammonium  chloride  method, 
described  on  page  344. 

Bleaching  of  Flour. — In  1908  about  80%  of  the  flour  produced  in  the 
United  States  was  bleached  by  nitrogen  peroxide,  but  as  a  result  of  the 
enforcement  of  the  federal  law  the  practice  has  been  largely  discon- 
tinued. The  gas  is  generated  by  electrical,  chemical,  or  electro-chemical 
means,  and  is  diluted  with  air  before  treatment  of  the  flour.  In  the 
Alsop  process,  which  is  most  commonly  employed,  it  is  formed  by  a 
flaming  discharge  of  electricity,  which  causes  the  nitrogen  and  oxygen 
of  the  air  to  combine. 

Nitrogen  peroxide  destroys  almost  immediately  the  yellow^  color  which 
is  associated  with  the  fat  of  the  flour,  thus  increasing  the  whiteness  of 
the  product.  It  also  forms  with  the  moisture  of  the  flour  nitrous  and 
nitric  acids,  the  former  (free  or  combined)  being  easy  of  detection.  A 
considerable  part  of  the  nitrous  nitrogen  remains  in  yeast  bread  after 
baking  and  nearly  all  of  it  in  soda  biscuit.  Bleaching  also  diminishes  the 
iodine  number  of  the  fat,  affects  the  quality  of  the  gluten,  and  injures 
the  flavor  of  the  bread. 

Aging  versus  Bleaching.  —  Storage  under  proper  conditions  slowly 
whitens  flour,  improves  its  baking  properties,  increases  its  organic 
acidity,  diminishes  its  water-content  and  brings  about  other  changes 
not  well  understood.  Bleaching  immediately  whitens  flour  but  does 
not  improve  its  baking  properties,  increase  its  organic  acidity  nor 
appreciably  affect  its  water-content.     It  does,  however,  introduce  nitrous 


3i6 


FOOD   ISSPECTION  AND    AN.-1L  )  SIS. 


and  nitric  acids.  Often  2  parts  of  nitrous  nitrogen  jier  million  arc 
recoverable  and  sometimes  6  or  7  parts,  but  this  gradually  disappears 
so  that  after  some  months  hardly  a  trace  remains. 

The  extent  to  which  typical  flours  are  wiiitcncd  by  aging  and  by 
bleaching  so  as  to  contain  2  parts  of  nitrous  nitrogen  per  million  is  apparent 
from  the  gasoline  color  values  in  the  following  table  by  Winton: 


Minnesota, 
Hara  Spring. 

Nebraska, 
Hard  Winte-. 

Michigan, 
Soft  Winter. 

Missouri, 
Soft  Winter. 

78% 
Patent. 

22% 
Clear. 

80%          20% 
Patent.      Clear. 

80% 
Patent. 

20% 
Clear. 

40% 
Patent. 

60% 
Clear. 

(>as<-)linc  cdIof  value  of 
Ln.jieached: 

New 

2.00 
1.7S 
1.20 
0.72 

0.60 
0.44 
0.30 
0.30 

2.00 
1.82 
1-34 
0.88 

0.66 

0.54 
0.50 
0.50 

2.63 
2. 12 
1.36 
0.70 

0.80 
0.46 

0-34 
0.24 

2.50 
2.17 
1.68 
0.82 

0.80 
0.48 
0.40 
0.36 

i--;3 

1.22 
0.80 
0.56 

0.40 
0.26 
o.:o 
0.18 

1. 61 

1-A9 
1.20 

0.72 

0.50 
0.38 
0.36 
0.40 

1-47 
1.22 
0.68 
O.J  8 

0.32 
0.22 

0.18 
0.14 

1.60 

Aged  10  weeks. . . . 
.^ged  20  ■    "      .... 

Aged  30      "      

Bleached: 

New 

^■33 
0.88 
0.52 

0.40 
0.26 

0.24 

0. 16 

,\ged  10  weeks. . . . 
Aged  20      "      .... 
Aged  30      "     

INSPECTION  AND  ANALYSIS  OF  FLOUR. 

In  some  of  the  larger  cities,  authorized  inspectors  are  appointed 
by  boards  of  trade  to  pass  upon  the  quality  of  flour.  To  such  inspectors 
dealers  submit  samples,  which  are  gauged  as  to  color,  soundness,  weight, 
etc.,  comparing  them  usually  with  a  series  of  graded  samples,  and  stamp- 
ing or  branding  them  ofiicially  with  the  date  as  well  as  the  grade.  Market 
quotations  also  are  based  on  the  standard  terms  adopted.  The  names 
of  the  various  grades  difl"er  with  the  locality.  In  St.  Louis,  the  following 
names  are  adopted  in  order  of  their  cjuality,  viz..  Patent,  E.xtra  Fancy, 
Fancy,  Choice,  and  Family. 

The  grade  or  riuality  of  flour  is  determined  largely  by  its  color,  fine- 
ness, odor,  absorption,  and  dough-making  properties.  Baking  tests  are 
also  relied  on  to  a  considerable  extent  by  millers  and  buyers. 

Of  the  chemical  methods  those  for  ash,  protein,  gluten,  acidity,  fat, 
and  fiber  are  of  chief  importance. 

Fineness. — The  granulation  is  determined  ])y  ruljbing  the  flour  between 
the  thumb  and  fingers.  A  gritty  flour  is  one  that  feels  rough  and  granular, 
due  to  aggregates  of  cells  with  contents  intact.  Smooth  flour,  on  th^ 
other  hand,  feels  soft  and  slippery.  It  is  so  finely  ground  that  the  cells 
arc  i.solatcd  and  often  ruptured,  thus  liberating  the  contents. 


CEREALS,  LEGUMES,  l/EGETARLES,  AND    FRUITS.  317 

PeJiar  Color-test. — Place  10-15  gr^-iris  of  the  flour  on  a  rectangular 
glass  plate,  about  12  cm,  long  and  8  cm.  wide,  and  pack  on  one  side  in  a 
straight  line  by  means  of  a  flour  trier.  Treat  the  same  amount  of 
the  standard  flour  used  for  comparison  in  the  same  manner,  so  that  the 
straight  edges  of  the  two  flours  are  adjacent.  Carefully  move  one  of  the 
portions  so  as  to  be  in  contact  with  the  other,  and  "slick"  both  with 
o«iie  stroke  of  the  trier,  in  such  a  manner  that  the  thickness  of  the 
layer  diminishes  from  about  0.5  cm.  on  the  middle  of  the  plate  to  a  thin 
film  at  the  edge,  and  the  line  of  demarcation  between  the  two  flours  is 
distinct.  Cut  off  the  edges  of  the  layer  with  the  trier,  so  as  to  form 
a  rectangle,  and  compare  the  color  of  the  two  flours.  The  difference  in 
color  becomes  more  apparent  after  carefully  immersing  the  plate  with 
the  flour  in  water,  and  still  more  apparent  after  drying. 

Gasoline  Color  Value.  —  Winton  Method. —  Place  20  grams  of  the 
ilour  in  a  wide-mouthed  glass-stoppered  bottle  of  about  120  cc.  capacity 
and  add  100  cc.  of  colorless  gasoline.  Stopper  tightly  and  shake  vigor- 
ously for  five  minutes.  After  standing  sixteen  hours,  shake  again  for  a 
few  seconds  until  the  flour  has  been  loosened  from  the  bottom  of  the 
the  bottle  and  thoroughly  mixed  with  the  gasoline,  then  filter  immediately 
through  a  dry  ii-cm.  paper,  previously  fitted  to  the  funnel  with  water 
and  thoroughly  dried,  into  a  flask,  keeping  the  funnel  covered  with  a 
watch-glass  to  prevent  evaporation.  In  order  to  secure  a  clear  filtrate, 
a  certain  quantity  of  the  flour  should  be  allowed  to  pass  over  on  to  the 
paper  and  the  first  portion  of  the  filtrate  passed  through  a  second  time. 

Determine  the  color  value  of  the  clear  gasoline  solution  in  a  Schreiner 
colorimeter,  using  for  comparison  a  0.005%  water  solution  of  potassium 
chromate.  This  solution  corresponds  to  a  gasoline  number  of  i.o  and 
may  be  prepared  by  making  10  cc.  of  a  0.5%  solution  up  to  one  liter. 
The  colorimeter  tube  containing  the  gasoline  solution  should  first  be 
adjusted  so  as  to  read  50  mm.,  then  the  tube  containing  the  standard 
chromate  solution  raised  or  lowered  until  the  shades  in  both  tubes  match. 
The  reading  of  the  chromate  solution,  divided  by  the  reading  of  the 
gaso'ine  solution  gives  the  gasoline  color  value. 

Absorption  and  Dough  Test. — Stir  30  grams  of  the  flour  in  a 
heavy  coffee  cup  with  15  cc.  of  water  by  means  of  a  spatula  until  a 
smooth  ball  of  dough  has  been  formed.  If  after  standing  two  minutes 
the  amount  of  water  proves  insufficient  to  thoroughly  dough  up  the  flour, 
repeat  the  operation,  using  15.5  cc.  of  water,  and,  if  necessary,  continue 
to  repeat  until  the  quantity  is  found  that  will  yield  a  stiff,  but  thoroughly 


3i8  FOOD  INSPECTION  AND  ANALYSIS. 

elastic  dough.  From  the  rcsuhs  of  this  test,  calculate  the  absorption  of 
looo  grams  of  flour  in  terms  of  cc.  of  water. 

The  physical  characters  of  the  dough,  such  as  color  and  elasticity, 
furnish  valuable  indications  of  the  quality  or  grade  of  the  flour. 

Expansion  of  Dough. — Rub  to  a  smooth  paste  3.5  grams  of  granu- 
lated sugar,  1.2  grams  of  salt,  and  3  grams  of  compressed  yeast,  and 
thoroughly  mix  with  60  cc.  of  water  at  35°  C.  Warm  100  grams  of  the 
flour  in  a  shallow  pan  to  35°  C,  add  to  it  the  yeast  mixture,  mix  with  a 
spatula,  and  knead  with  the  fingers  until  a  smooth  ball  of  dough  has  been 
formed.  Drop  the  dough  into  a  graduated,  500-cc.  cylinder,  pat  down 
so  as  to  force  out  the  air,  and  note  the  volume  of  the  mass.  Place  in  a 
raising  closet  kept  at  35°  C.  Read  the  volume  at  the  end  of  the  first 
hour  and  ever)-  half  hour  thereafter  until  the  maximum  is  reached. 

Baking  Tests.* — Koelner  or  Straight  Dough  Method. — This  process 
yields  a  close-grained  loaf  of  even  texture,  and  serves  well  to  determine 
the  flavor  and  relative  size  of  the  loaf. 

Place  220  grams  of  the  flour,  previously  warmed  in  a  shallow  pan,  in 
a  raising  closet  kept  at  35°  C,  in  a  Koelner  dough  kneader,  which  has 
previously  been  warmed  to  35°  C.  by  means  of  water  placed  in  the 
special  comi)artment  for  this  purpose.  To  the  flour  add  12  grams  of 
sugar,  5  grams  of  salt,  and  10  grams  of  compressed  yeast,  rubbed  smooth 
and  thoroughly  mixed  in  a  cup  with  100  cc.  of  water  at  35°  C.  Rinse  the 
cup  with  sufficient  water  to  make  the  total  cjuantity  required,  as  calcu- 
lated from  the  absorption  test.     This  amount  is  usually  about  87  cc. 

Adjust  the  blades  of  the  kneader  for  mixing,  and  turn  the  crank  at 
the  rate  of  90  revolutions  per  minute  for  10  minutes.  Adjust  the  blades 
for  kneading,  add  120  grams  of  flour,  previously  warmed  to  35°  C,  and 
turn  the  crank  for  ten  minutes  at  the  rate  of  60  revolutions  per  minute. 
Remove  the  dough  immediately  to  a  warmed  plate,  cut  into  two  equal 
parts,  mould  the  two  separately,  and  place  end  to  end  in  a  warmed, 
greased,  and  tared  baking  tin  measuring  27X6.3  cm.  at  the  top,  25.4X5 
cm.  at  the  bottom,  and  8.8  cm.  deep — all  inside  measurements. 

Weigh  the  tin  with  dough,  place  a  tin  gauge  across  the  top,  and  set 
the  whole  in  the  raising  closet.  After  the  dough  has  risen  to  the  gauge, 
place  the  tin  in  a  suitable  oven  heated  to  200°  C,  and  bake  at  200  to 
205°  until  30  grams  of  water  have  been  removed,  which  usually  rec^uires 
from  30  to  35  minutes.  Break  the  kmf  in  two,  and  note  the  odor  when 
hot  and  again  when  cold,  also  the  flavor  when  cold. 

*  Descriptions  by  .Miss  H.  L.  Wessling,  Chicago  LahKjratory,  Bur.  of  Chembtry. 


CEREALS,  LEGUMES,  VEGETABLES,  AND  FRUITS.  319 

When  thoroughly  cool,  determine  the  volume  of  the  loaf  as  follows: 
cover  the  bottom  of  a  box  7.6X12,7X28  cm.,  inside  measurements,  with 
flaxseed,  place  the  loaf  in  the  box,  pour  flaxseed  without  jarring  into 
the  box  until  filled,  and  strike  off  the  surplus  seed  by  means  of  a  straight 
edge.  Remove  the  seed  from  tlie  box,  weigh,  and  di\ide  the  weight  by 
the  weight  of  i  cc.  of  the  seed,  as  calculated  from  an  actual  weighing  of 
the  seed  required  to  fill  the  box.  Subtract  this  figure  from  the  cubic 
contents  of  the  box  in  cc,  thus  obtaining  the  volume  of  the  loaf. 

Long  Fermentation  Method. — This  method,  used  in  some  of  the  large 
mills  in  the  northwest,  differs  from  the  Koelner  method  in  that  (i)  a 
sponge  is  set,  (2)  the  dough  is  kneaded  twice,  and  (3)  the  dough  is 
finally  expanded  to  the  limit.  The  bread  is  coarse  in  texture,  but  serves 
well  to  test  the  strength  and  flavor. 

To  255  grams  of  warmed  flour  contained  in  a  jar  or  earthenware 
crock,  add  3.5  grams  of  salt  and  8.6  grams  of  compressed  yeast,  mixed 
thoroughly  with  170  cc.  of  water  at  35°  C.  Stir  together  until  a  soft 
sponge  is  formed,  and  keep  in  the  raising  closet,  at  35°  C,  until  the 
volume  has  been  doubled,  then  mix  with  85  grams  of  warmed  flour,  12 
grams  of  sugar,  6  grams  of  lard,  and  the  remainder  of  the  water,  the  total 
quantity  for  340  grams  of  flour  being  calculated  from  the  absorption 
test.  Knead  steadily  for  six  minutes,  transfer  the  dough  to  the  jar  or 
crock,  and  set  it  in  the  raising  closet  until  it  has  again  doubled  its  volume. 

Remove  the  dough  to  a  warmed  plate,  knead  lightly  in  the  hands  for 
a  minute  or  two,  then  place  in  a  warmed  and  greased  standard  baking 
tin,  16.8X8.8  cm.  across  the  top,  14.9X6.9  cm.  across  the  bottom,  and 
13.9  cm.  deep,  all  inside  measurements,  with  extensions  of  the  metal  at 
the  top  of  the  two  sides.  Prick  the  dough  about  a  dozen  times  with  a 
fine-pointed  wire,  and  raise  again  in  the  closet,  until  the  bubbles  of  gas 
just  begin  to  break  and  form  larger  ones.  This  is  a  matter  of  judgment 
and  can  be  learned  only  by  experience.  The  dough  must  not  be  raised 
to  its  limit  beforehand,  but  must  be  put  in  the  oven  at  such  a  stage  that 
with  the  additional  rising  in  the  oven  it  will  have  attained  the  maximum 
volume.  Bake  from  30  to  35  minutes,  raising  the  temperature  gradually 
from  180°  C.  at  the  beginning  to  210°  C.  at  the  end. 

Determination  of  Moisture,  Protein,  Crude  Fiber  and  Fat.  Employ 
the  methods  described  on  pages  277  to  279.  The  crude  fiber  should  be 
collected  and  weighed  on  a  Gooch  crucible. 

Determination  of  Ash. — Char  5  grams  of  the  flour  in  a  flat-bottomed 
platinum  dish  heated  on  a  piece  of  thin  asbestos  board  over  aBunsen  burner. 


320  FOOD  INSPECTION  /iND  ANALYSIS. 

Complete  the  burning  at  dull  redness,  preferably  in  a  muffle  furnace. 
If  the  ash  is  black  or  dark  gray  add  a  few  drops  of  nitric  acid,  evaporate 
to  dr}Ticss  on  a  water-bath  and  again  heat  at  dull  redness,  repeating 
the  treatment  if  necessary. 

Determination  of  Moist  and  Dry  Gluten.* — Place  25  grams  of  the 
Hour  in  a  colToc  cup,  add  15  cc.  of  water  at  a  lcm])craturc  not  to  exceed 
15°,  and  work  the  mass  into  a  ball  with  a  s])atula,  taking  care  that  none 
of  it  adheres  to  the  dish.  Allow  the  dough  to  stand  one  hour,  then  knead 
in  a  stream  of  cold  water  over  a  piece  of  bolting  cloth  held  in  place  by 
two  embroidery  hoops,  until  the  starch  and  soluble  matters  are  removed. 
Place  the  gluten  thus  obtained  in  cold  water,  and  allow  to  remain  for 
one  hour,  after  which  press  as  dry  as  possible  between  the  hands,  roll 
into  a  ball,  place  in  a  tared  flal-bollomed  dish,  and  weigh  as  moist 
gluten.  Spread  the  gluten  out  in  the  dish,  dry  for  24  hours  in  a  boiling 
water-oven,  and  weigh  again,  thus  obtaining  the  dry  gluten. 

Determination  of  Alcohol  -  soluble  Protein  (Crude  Gliadin.)— 
Chumbcrlain  MetJiod* — Digest  5  grams  of  the  sample  with  250  cc.  of 
yo%  (by  vol.)  alcohol  for  24  hours,  s'^.akin'^  every  half  hour  during  the 
first  8  hours.  Filter  through  a  dry  paper,  determine  nitrogen  in  100  cc. 
of  the  filtrate  and  multiply  the  result  by  5.7. 

The  amount  of  alcohol-soluble  protein  may  also  be  expressed  in  terms 
of  percentage  of  the  total  protein.  This  percentage  is  known  by  some 
authors  as  the  "  gliadin  ratio." 

Determination  of  Salt-soluble  Protein.  —  Chamberlain  Method. '^ — 
Digest  10  grams  of  the  flour  with  250  cc.  of  5^0  potassium  sulphate 
solution,  as  described  under  Alcohol-soluble  Protein.  Determine  nitro- 
gen in  50  cc.  of  the  filtrate,  and  multiply  the  result  by  5.7. 

Determination  of  Acidity  of  Flour. — Titrate  100  cc.  of  the  solution 
prepared  as  described  for  the  determination  of  nitrites  (p.  321),  with 
tenth-normal  sodium  hydroxide  solution,  using  phenolphthalein  as  indi- 
cator. If  the  distilled  water  used  contains  an  appreciable  amount  of 
carbon  dioxide,  it  should  previously  be  boiled  in  a  Jena  flask  until  neutral 
but  not  long  enough  to  dissolve  alkali  from  the  glass.  Two  hundred  cc, 
of  the  Ixjiled  water  should  remain  colorless  on  addition  of  phenolphthalein, 
but  should  take  on  a  distinct  pink  color  when  mixed  with  a  single  droj) 
of  tenth-normal  alkali. 

Determination     of     Cold-water     Extract.  —  Wanklyn    Method. —  Mix 


*  U.  S.  lJ(-j,l.  (,f  Agri.:.,  Bur.  <;f  Chcm.,  liul.  8i,  p.  ii8. 


CEREALS,  LEGUMES,  l^EGET/IRLES,  AND  FRUITS.  321 

100  grams  with  distilled  water  in  a  graduated  liter  flask,  shake  frecjuently 
during  six  or  eight  hours  and  allow  to  stand  over  night.  Decant  on  a 
filter,  rejecting  the  first  portions  that  run  through,  and  evaporate  50  cc. 
of  the  clear  filtrate  to  dryness  in  a  tared  metal  dish  on  a  water- 
bath.  The  weight  of  the  dried  residue  multiplied  by  20  gives  the 
cold-water   extract    which,    according  to  Wanklyn,  should  not   exceed 

5%- 

Determination  of  Iodine  Number  of  the  Fat. — Dry  over  sulphuric 
acid  for  three  days  sufficient  flour  to  yield  0.2  to  0.25  gram  of  fat  and 
extract  for  sixteen  hours  in  a  Johnson  extractor  with  25  cc.  of  absolute 
ether,  into  a  tared  35-cc.  flask.  Drive  off  the  ether  and  dry  at  100°  C. 
for  fifteen-minute  periods  to  constant  weight,  passing  a  current  of  dry 
hydrogen  through  the  flask.  Proceed  according  to  the  Hanus  method, 
adding  the  chloroform  and  iodine  solution  directly  to  the  flask,  and 
breaking  the  flask  within  a  wide-mouthed  glass  stoppered  bottle  for  the 
final  dilution  and  titration. 

Detection  of  Bleaching  in  Flour. — Place  on  the  "slicked"  surface  of 
the  flour  a  drop  or  two  of  a  mixture  of  equal  parts  of  solutions  {a)  and  (/>), 
described  in  the  following  section.  If  the  flour  is  unbleached  and  has 
not  been  stored  under  conditions  permitting  absorption  of  nitrous  acid 
the  liquid,  which  does  not  immediately  soak  into  the  flour,  will  remain 
colorless  or  nearly  so,  while  if  it  is  bleached  it  soon  takes  on  a  marked 
pink  or  crimson  color,  varying  in  degree  with  the  extent  of  bleaching. 
A  positive  test  should  be  supplemented  by  determinations  of  nitrous 
nitrogen  and  gasoline  color  value. 

Determination  of  Nitrous  Nitrogen. — Griess-Ilosvay  Method.* — This 
method,  commonly  employed  for  the  determination  of  nitrites  in  water,  is 
well  adapted  for  the  estimation  of  the  extent  to  which  flour  has  been 
bleached  by  nitrogen  peroxide  or  nitrosyl  chloride. 

I.  Reagents. — (a)  Sulphanilic  Acid  Solution. — Dissolve  0,5  gram  of 
sulphanilic  acid  in  150  cc.  of  20%  acetic  acid. 

{b)  Alpha-naphtylamiiie  Hydrochloride  Solution. — Dissolve  0.2  gram 
of  the  salt  in  150  cc.  of  20%  acetic  acid  with  the  aid  of  heat. 

(c)  Standard  Sodium  Nitrite  Solution. — Dissolve  0.1097  gram  of  dry 
C.P,  silver  nitrite  in  about  20  cc.  of  hot  water,  add  0.05  gram  of  C.P. 
sodium  chloride,  shake  until  the  silver  chloride  flocks  and  make 
up  to  1000  cc.     Draw   oft'    10   cc.    of  the   clear   solution  and  dilute  to 

*  Bull.  chim.  [2],  2,  p.  317, 


T,22  FOOD   IXSPHCTION  yfND   ANAL  YSIS. 

one  liter.     One  cc.  of  this  solution  contains  o.oooi   mg.  of  nitrogen  as 
nitrite. 

Suitable  silver  nitrite  is  on  the  market;  it  may  also  be  prepaied  as  fol- 
lows: mix  a  warm  concentrated  solution  of  8  parts  of  sodium  nitrite  with 
a  warm  concentrated  solution  of  i6  parts  of  silver  nitrate.  When  cool 
collect  the  precipitate  on  a  Buclmer  funnel  and  wash  with  cold  water. 
Dr}'  quickly  on  a  water-bath  with  as  little  exposure  to  light  as  possible. 
Long  continued  drying  at  ioo°  C.  causes  it  to  slowly  decompose. 

2.  Determination.— Weigh  out  20  grams  of  the  flour  into  an  Erlen- 
meyer  tlask,  add  200  cc.  of  water  free  from  nitrites,  previously  heated' 
to  40°  C,  close  the  tlask  with  a  rubber  stopper,  shake  vigorously  for  five 
minutes,  digest  one  hour  at  40°,  shaking  every  ten  minutes,  and  filter  on  a 
dry-  folded  filter  free  from  nitrites.  As  the  first  portion  of  the  filtrate  is 
usually  turbid,  it  should  be  returned  to  the  filter  and  the  operation  re- 
peated until  a  clear  liquid  is  secured.  Dilute  50  cc.  of  the  filtrate  and  also 
50  cc.  of  the  standard  nitrite  solution  each  with  50  cc.  of  water,  add  2  cc. 
each  of  solutions  (a)  and  (b);  shake  and  allow  to  stand  one  hour  to  bring 
out  the  color.  Compare  the  two  solutions  in  a  colorimeter  (page  77). 
Divide  the  height  of  the  column  of  the  standard  solution  by  that  of  the 
solution  of  the  sample,  thus  obtaining  the  parts  of  nitrogen  as  nitrous 
acid  (free  or  combined)  per  million  of  flour. 

Bamihl  Test  for  Gluten  (Modified  by  Winton*).— This  test  serves 
to  detect  wheat  flour  mixed  with  rye  and  other  flours. 

Place  a  very  small  quantity  of  the  flour  (about  1.5  milligrams)  on  a 
microscope  slide,  add  a  drop  of  water  containing  0.2  gram  of  water- 
soluble  eosin  in  1000  cc,  and  mix  by  means  of  a  cover  glass,  holding  the 
latter  at  first  in  such  a  manner  that  it  is  raised  slightly  above  the  slide, 
and  taking  care  that  none  of  the  flour  escapes  from  beneath  it.  Finallv 
allow  the  cover  glass  to  rest  on  the  slide,  and  rub  it  back  and  forth  until 
the  gluten  has  collected  into  rolls.  The  operation  should  be  carried 
out  on  a  white  paper  so  that  the  formation  of  gluten  rolls  can  be 
noted. 

Wheat  flour  or  other  flours  containing  it  yields  by  this  treatment  a 
copious  amount  of  gluten,  which  absorbs  the  amn  with  avidity,  taking 
on  a  carmine  color.  Rye  and  corn  flour  yield  only  a  trace  of  gluten,  and 
buckwheat  flour  no  appreciable  amount.  The  preparations  are  best 
examined  with    the   naked  eye,   thus  gaining  an  idea   of  the  amount  of 

*l'.  S.  Dept.  of  Agric,  Bur.  of  Chem. ,  Bui.  122,  p.  217. 


CEREALS,  LEGUMES,  yEGETABLES,  AND   FRUITS.  32* 

gluten  present.  Under  the  microscope  traces  of  gluten,  such  as  ar* 
formed  in  rye  flour,  are  so  magnified  as  to  be  misleading. 

In  case  the  flour  is  coarse,  or  contains  a  considerable  amount  of  bran- 
elements,  as  is  true  of  buckwheat  flour  and  low  grade  wheat  flour,  the 
iCSt  should  be  made  after  bolting,  as  the  bran  particles  and  coarse  lump., 
interfere  with  the  formation  of  gluten  rolls. 

This  test  should  be  supplemented  by  microscopic  examination  of  the 
untreated  flour  and  also  of  the  tissues,  accumulated  after  boiling  with  i\% 
sulphuric  acid  as  described  on  page  306.  In  the  case  of  rye  flour  adult- 
crated  with  wheat  flour  the  difference  in  the  cross  cells  (pp.  306-308) 
should  be  especially  noted;  these,  however,  are  present  in  considerable 
amount  only  in  the  cheaper  grades  of  wheat  flour. 

BREAD. 

Bread  is  a  term  broadly  applied  to  any  baked  mixture  of  finely  divided 
grain  and  water,  whether  or  not  other  ingredients  are  used.  Pilot,  or 
ship  bread,  crackers,  and  unleavened  bread,  consist  almost  entirely  of 
flour  and  water  with  a  slight  addition  of  salt. 

Similarly,  corn  bread  or  corn  cake  is  frequently  made  exclusively  from 
corn  meal  and  water.  In  a  narrower  sense,  however,  bread  is  generally 
understood  to  mean  the  raised  or  leavened  product,  rendered  light  and 
porous  by  the  aid  of  gas,  which  is  generated  either  before  or  during  baking. 
Commonly  the  gas  employed  is  carbon  dioxide,  generated  either  by  the 
fermentative  action  of  yeast  on  the  sugar  of  the  dough,  yielding  both 
alcohol  and  gas,  or  by  the  agency  of  baking  chemicals  mixed  with  the 
dough,  whereby  an  alkaline  bicarbonate  is  decomposed  by  the  action 
of  an  acid  to  produce  the  gas.  Again,  the  gas  may  consist  wholly  or  in 
part  of  ammonia,  yielded  by  the  vaporization  during  baking  of  ammo- 
nium carbonate  mixed  with  the  dough;  and  finally,  the  expansion  dur* 
ing  baking  of  the  air  itself  confined  in  the  dough  may  be  the  leavening 
agent,  as  in  the  case  of  puff  paste  and  pie  crust. 

Wheat  flour  is  of  chief  value  for  bread  on  account  of  its  high  content 
of  gluten,  in  which  other  cereals  are  lacking.  In  the  preparation  of 
ordinar)'  w-hite  bread,  the  flour  is  mixed  with  water  or  milk,  salt,  and  yeast, 
the  materials  are  mingled  thoroughly  by  kneading  and  allowed  to  remain 
for  some  time  in  a  warm  place,  during  which,  by  the  vinous  fermentation 
induced  by  the  yeast,  the  mass  "rises"  or  forms  a  light  sponge,  due  td 
ihe  action  of  the  gas  on  the  glutinous  dough. 

D;-'rine  the  subsequent  process  of  baking,  which  should  take  place  at 


.<^' 


-4 


FOOD  INSPECTION  .^ND  ANALYSIS. 


a  temperature  between  230°  and  260°  C,  further  expansion  pnsues,  much 
of  the  water  is  driven  off,  and  the  porous  mass  sets  to  form  the  loaf,  the 
outside  of  which  is  converted  into  a  brown  crust,  due  to  the  Caramelizing 
of  the  dextrin  and  sugar  into  which  the  starch  of  the  outer  layers  is  con- 
verted. Among  other  changes  that  take  place  in  the  interior ^or  "crumb" 
during  baking  are  (i)  the  partial  breaking  up  of  the  starch  grj^ins,  which, 
however,  largely  retain  their  identity,  though  in  some  degree  aistorted  in 
shape;  (2)  somewhat  obscure  changes  in  the  character  of  the  proteins; 
and  (3)  partial  oxidation  of  the  oil  or  fat. 

The  standard  for  judging  the  quality  of  commercial  brccfd  may  we.l 
be  based  on  that  of  the  best  home-baked  family  loaf.  Tn«  well-made 
loaf  should  possess  an  agreeable  odor,  and  a  sweet,  nutt^^  flaVor,  entirely 
free  from  musriness.  It  should  be  well  "raised,"  with  a  good  crumbhng 
fracture;  it  should  not  be  tough  or  soggy  on  the  one  hand  (due  to  under- 
raising),  nor  extremely  drj'  and  spongy  on  the  other  (indicat^t^v-e  of  over- 
raising).  Over-raising,  moreover,  produces  sourness,  due  to'  advanced 
lactic  fermentation. 

Composition  of  Bread. — The  following  analyses  made  in  the  U.  S. 
Bureau  oi  Chemistry  of  common  varieties  of  bread  were  summarized 
from  Bulletin  13,  part  9,  averages  of  a  number  of  analyses  being  given  in 
each  case: 


No.  of 
Analyses. 


Moisture. 


Protein, 
NX6.2S. 


Proteif 


Ether 
Extract. 


Vienna  brc.i'l 

Homc-mj-dc  bread  . 

Graham  bread 

Rye  bread 

Misfcllancous  bread 
Biscuits  or  crackers. 
Rolls 


2 
9 
7 
9 
48 


38-71 
33-02 
34-80 
33-42 
34-41 
7-13 
27.98 


8 

^7 

7 

94 

8 

93 

8 

63 

7 

60 

10 

34 

8 

20 

8.09.- 

7-24>. 
8-15V 

6-93^ 
9-43  .\ 
7-48X^ 


1.06 

1-95 
2.0^ 
0.66 
J. 48 
8.67 
3-41 


Crude 
Fiber. 


Salt. 


Ash. 


Carbohy- 
drates, 

Excluding 
Fiber. 


Calculated 
Calories  of 
Combus- 
tion. 


Vienna  bread 

Home-made  bread  . 

Graham  bread 

R\e  bread 

Mi.srcllaneous  bread 
Biscuits  or  crackers. 
Rolls 


0.62 
0.24 

I -13 
0.62 
0.30 
0.47 
0.60 


0.57 
0.56 
0.69 
1. 00 
0.49 
0.99 
0.69 


1.19 
1-05 
1-59 
1.84 
1. 00 
1-57 
1-31 


53-72 
56-75 
53-40 
56.21 
56.13 

73-17 
59.82 


4435 
4467 

4473 
4338 
4429 
4755 
4538 


In  the  examination  of  Vjread  for  its  general  quality,  without  regard  to  its 
food  value,  much  information  may  be  gained  by  carefully  observing  the 


CEREALS,   LEGUMES,    VEGETABLES,   AND  FRUITS. 


325 


physical  characleristics  of  the  loaf,  its  color,  taste,  odor,  porosity,  etc. 
In  addition  to  such  data,  determination  of  moisture,  ash,  and  acidity 
will  usually  suffice  to  enable  the  analyst  to  pass  judgment  on  its  whole- 
somcness.  The  following  summary  gives  such  analytical  data  on 
upwards  of  fifty  samples  of  bread,  purchased  from  cheaper  bakeries 
and  stores,  and  examined  in  the  author's  laboratory. 

BREAD. 


Kind  of  Bread. 

No.  of 

Analyses. 

Weight  of 
Loaf  in 
Grams. 

Water, 
Per  Cent. 

Per  Cent 
Ash  in 

Terms  of 
Solids. 

Acidity.* 

White 

44 

653 
126 

430 

500 

367 
420 

507 

445 

194 

1 29 1 

550 
417 
500 
IIO 

45.20 
33-00 
40.72 

45-20 
40.10 
41-50 
45.10 
47-00 
48.20 

47-15 
47.00 
42.30 
48. 10 
8.00 

1-83 
0.60 
0.85 

1-55 
0.96 
1.26 

1.20 
2.20 
1-15 
2-13 
2.20 

0-9S 
3-50 
1.94 

Maximum 

6  2 

Minimum 

1-3 

2.6 

Mean 

Graham 

Maximum 

4-2 

Minimum 

Mean 

3-5 

Whole  wheat 

Diabetic 

Muffins 

1.7 

10. 0 

Rve 

"Black" 

German  with  seeds 

Brown 

"Knackerbrod" 

*  Cubic  centimeters  of  tenth-normal  soda  required  to  neutralize  10  grams  of  the  fresh  bread. 


Water  in  Bread. — The  amount  of  water  is  of  considerable  importance, 
and,  in  the  best  bread,  varies  from  i^t^  to  40  per  cent.  A  larger  content  of 
water  than  40%  should  be  considered  objectionable  in  a  white  bread, 
both  on  the  ground  of  acting  as  a  make  weight,  and  because  a  large  excess 
of  moisture  tends  to  cause  the  growth  of  mold. 

Acidity  of  Bread. — The  degree  of  sourness  of  a  sample  of  bread  is  one 
of  the  most  important  indications  as  to  its  quality,  and  is  most  readily 
obtained  by  rubbing  up  in  water,  by  means  of  a  pestle,  10  grams  of  the 
"crumb,"  and  titrating  with  tenth-normal  alkah,  using  phenolphthalein 
as  an  indicator.  To  neutralize  the  acidity  of  10  grams  of  the  normally 
sweet  loaf,  an  average  of  2  cc.  of  the  standard  alkah  solution  is  required, 
correspondijig  to  0.72  gram  of  lactic  acid  per  loaf  of  an  average  weight 
of  400  grams.  The  loaf  exhibiting  the  maximum  sourness  or  acidity 
in  the  above  table  required  10  cc.  of  standard  alkali  per  10  grams  of 
bread,  corresponding  to  11. 61  grams  lactic  acid  in  the  loaf  of  1,291  grams. 


3 -'6  FOOD  INSPECTION  AND  ANALV^IS. 

Fat  in  Bread. — It  is  well  known  thai  the  results  of  fat  or  ether  extract 
as  obtained  by  the  ordinary  method  and  expressed  in  most  bread  analyses 
are  loo  low,  being  considerably  less  than  the  ct)mbincd  fat  of  the  materials 
entering  into  its  composition.  This  is  probably  due  to  the  fact  that 
during  baking  the  fat  particles  are  incrusted  with  insoluble  matter, 
which  protects  them  from  the  subsequent  action  of  the  ether.  It  is  further 
claimed  by  some  that  the  partial  oxidation  of  the  fat  during  baking 
has  something  to  do  with  the  lov/  results.  No  perfectly  satisfactory 
improvement  over  the  regular  ether  method  for  fat  extraction  in  bread 
has  been  discovered,  and  therefore  this  method,  as  described  elsewhere, 
is  recommended. 

Adulteration  of  Bread. — The  fraudulent  addition  of  inert  foreign 
ingredients  to  bread  is  almost  never  practiced,  and  is  mainly  of  historic 
interest.  Gypsum,  chalk,  bone  ash,  and  various  other  minerals  have  been 
mentioned  as  possible  adulterants,  but  the  amount  of  any  of  these 
materials  necessary  to  add  for  purposes  of  profit  could  scarcely  be  present 
without  ver)'  apparent  injury  to  the  quality  of  the  bread.  Their  presence 
in  any  considerable  degree  would  be  apparent  in  the  abnormally  high 
ash  content  of  the  bread. 

The  employment  of  alum  to  "improve"  inferior  or  unsound  flour 
has  already  been  referred  to,  and,  for  the  same  purpose,  sulphate  of  copper 
in  small  quantities  is  also  said  to  have  been  used,  enabling  the  making 
of  bread  of  fairly  good  appearance  from  flour  that  was  distinctly  damaged. 

Alum  in  Bread  *  is  tested  for  by  a  modification  of  the  logwood  process 
described  on  page  315  as  follows:  5  cc.  of  the  logwood  tincture  and  5  cc. 
of  the  saturated  ammonium  carbonate  solution  are  diluted  to  100  cc, 
and  the  freshly  prepared  mixture  poured  over  about  10  grams  of  the 
brearl  crumbs  in  a  porcelain  evaporating-dish.  After  standing  a  few 
minutes,  as  much  as  possible  of  the  liquid  is  drained  off,  the  bread  is 
slightly  washed  by  one  treatment  with  water,  and  dried  in  the  water- 
oven.  In  presence  of  alum,  a  dark-blue  color  is  given  to  the  bread,  which 
becomes  deeper  on  drying.  The  color  is  proportional  to  the  amount 
of  alum  present.  If  the  sample  is  free  from  alum,  the  color  varies  from 
red  to  light  brown.  The  reagent  solution  must  be  freshly  jjrepared.  This 
test  is  not  perfectly  rehable  in  the  case  of  very  old  or  sour  breads,  which 
have  been  known  to  give  the  color  test  with  logwood  in  the  absence  of 
alum. 


*  Jago  on  Bread,  p.  634. 


CEREALS,  LEGUMES,    I^EGHT.4BLES,  AND   FRUITS. 


327 


Copper  Salts  in  Bread  arc  detected  in  the  ash  by  the  same  method 
as  that  used  for  canned  goods  (p.  918). 

Cake  and  Similar  Preparations. — These  (h'ffer  from  bread  chiefly  by 
the  addition  of  considerable  sugar,  butter,  spices,  and  other  flavoring 
materials.  In  gingerbread,  molasses  is  used  as  an  important  ingredient 
besides  ginger.  The  adulterants  of  molasses,  such  as  glucose,  salts  of 
tin,  etc.,  would  thus  sometimes  occur  in  gingerbread.  In  fact  stannous 
cliloride  has  been  found  in  ginger  cakes.* 

The  following  analyses  of  a  few  ty])ical  varieties  of  cakes  are  selected 
from  Bulletin  13  of  the  Bureau  of  Chemistry: 


Moisture. 


Proteins, 

NX6.25. 


Proteins, 

NX5.70. 


Ether 

Extract. 


Crude 
Fiber. 


Doughnuts  . . 
Ginger  snaps 

Fruit  cake 

Gingerbread. 
Cup  cakes. . . 
Macaroons  . . 
Jumbles 


21.61 
4.86 
24.47 
21.49 
14.81 
8.06 
13-34 


6-73 
6.06 

4-56 
6.25 

5-24 
6.67 
7.62 


6.14 

5-53 
4. 16 

5-70 
4.78 
6.08 

6-95 


19-33 

15-44 

12.35 

8.42 

15-56 
12.97 

14-79 


0.60 
0.79 

0.90 
0.27 
1. 41 
1.04 


Ash. 


Salt. 


Sugar. 


Carbohy- 
drates 
other  than 

Fiber  and 
Sugar. 


Calculated 
Calories. 


Doughnuts  . . 
Ginger  snaps 
Fruit  cake. . . 
Gingerbread. 
Cup  cakes. . . 
Macaroons  . . 
Jumbles 


.40 
.82 


1-55 
1.21 
0.82 
0.97 


0.03 

0.47 

0.28 

0.34 
0.07 

0-39 


1.28 
28.66 

9-48 
32-48 

58-77 
16.60 


50.64 
24.90 

52-46 
30.89 
10.89 
46.31 


5529 
4971 

4757 
5073 
4835 
5133 


YEAST. 

The  yeast  plant  is  a  fungus  of  the  genus  Saccharomyces,  widely 
distributed  through  the  vegetable  kingdom  and  in  the  air.  It  is  capable 
of  rapid  growth  by  the  multiplication  of  its  cells  when  present  in  a 
favorable  medium,  such  as  malt  wort,  and  with  propitious  conditions 
of  temperature,  moisture,  etc.  Under  such  conditions,  it  forms  a 
yellowish,  viscous,  frothy  substance,  the  chief  value  of  which,  in  the  liquor 
industry,  is  the  production  of  alcohol,  while  for  bread-making,  as  a  result 
of  the  same  kind  of  fermentation,  the  end  desired  is  the  leavening  of  the 
doughy  mass  by  the  carbon  dioxide  liberated. 


*  See  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  13,  p.  1369. 


3^8  FOOD  INSPECTION  AND  ANALYSIS. 

A  vigorous,  pure  yeast  which  will  "raise"  quickly  is  a  great  preventive 
against  sour  bread,  for  not  only  is  it  comparatively  free  from  the  germs  and 
products  of  lactic  acid  fermenlalion,  but  by  doing  its  work  quickly  it 
enables  the  baker  to  check  the  fermenlalion  or  raising  process  before  the 
laclic  acid  or  sour  decomposilion  is  far  advanced. 

Veast  most  commonly  used  in  bread-making  is  of  the  so-called  "com- 
pressed" variety.  The  use  of  compressed  yeast  is  almost  universal  for 
domestic  purposes,  and  is  more  or  less  common  in  bakeries.  A  small 
amount  of  brewers'  yeast  in  liquid  form  from  beer  wort  is  used,  especially 
in  the  immediate  neighborhood  of  breweries,  and  dry  yeasts  are  used  to 
some  extent  in  localities  so  remote  that  fresh  compressed  yeast  cannot 
readily  be  obtained. 

Compressed  Yeast  is  a  product  of  distilleries  where  malt  and  raw 
grain  are  fermented  for  spirits.  Most  of  it  comes  from  whisky  wort,  and 
some  from  the  worts  used  in  the  manufacture  of  gin  and  other  distilled 
liquors.  Little  if  any  of  the  commercial  compressed  yeast  is  made  from 
beer  wort  yeast. 

In  the  manufacture  of  compressed  yeast,  the  yeast  floating  on  the  top 
of  the  wort  is  separated  by  skimming,  while  that  settling  to  the  bottom 
is  removed  by  running  the  wort  into  shallow  settling  trays.  Top  yeast 
is  considered  more  desirable  than  bottom  yeast  for  bread-making.  The 
separated  yeast  is  washed  in  cold  water,  and  impurities  are  removed, 
either  by  sieving  through  silk  or  wire  sieves,  or  by  fractional  j)recipitation 
while  washing.  The  yeast,  with  or  without  the  addition  of  starch,  is 
finally  pressed  in  bags  in  hydraulic  presses,  after  which  it  is  cut  into  cakes, 
packed  in  tin-foil,  and  kept  in  cold  storage  till  distributed  for  use. 

Such  yeast  should  be  used  when  fresh,  as  it  readily  decomposes  and 
soon  becomes  stale.  When  fresh,  it  should  have  a  creamy,  white  color, 
uniform  throughout,  and  should  possess  a  fine,  even  texture;  it  should 
be  moist  without  being  slimy.  It  should  quickly  melt  in  the  mouth 
without  an  acid  taste.  Its  odor  is  characteristic,  and  should  be  some- 
what suggestive  of  the  apple.  It  should  never  be  "cheesy,"  such  an 
odor  indicating  incipient  decomposition,  as  does  a  dark  or  streaked  color. 

Dry  Yeast  is  fjrepared  by  mixing  fresh  yeast  with  starch  or  meal, 
molding  into  a  stiff  dough,  and  drying,  either  in  the  sun  or  at  a  moderate 
temperature  under  reduced  pressure.  Such  yeast,  when  dry,  is  cut  into 
cakes  and  put  in  packages.  It  will  keep  almost  indefinitely.  During 
the  dr}'ing  process,  many  of  the  yeast  cells  are  rendered  torpid  and  tem- 
IX)rarily  inert,  and  for  this  reason  the  dried  yeast  does  not  act  so  promptly 


CEREALS,   LEGUMES,    VEGETABLES,   AND   FRUITS.  329 

in  leavening  as  docs  compressed  or  brewers'  yeast,  but  when  once  it  begins 
to  act  it  is  quite  as  efficacious. 

Composition  of  Yeast. — The  following  is  the  result  of  the  analysis 
of  under- fermentation  yeast,  after  drying,  by  Nagele  and  Loew: 

Cellulose  and  mucilage 37 

Albuminoids  (mycroprotein,  etc.) 36 

"            soluble  in  alcohol 9 

Peptones  (precipitable  by  subacetate  of  lead)  ...  2 

Fat... [ 5 

Extractive  matters  (leucin,  glycerin,  etc.) 4 

Ash 7 

100 

Lintrier  gives  the  following  average  analyses  of  the  ash  of  three  samples 
of  yeast,  analyzed  by  him: 

Silica 1.34 

Iron  (FcoOs) o. 50 

Lime  (CaO), 5 .47 

Sulphuric  anhydride  (SO3) o.  56 

Magnesia  (MgO) 6.12 

Phosphoric  anhydride (P-^O 5) 50.60 

Potash  (K2O)  and  a  little  soda 33-49 

98.08 

Matthews  and  Scott  give  the  following  as  the  ash  composition  of  yeast: 

« 

Potassium  phosphate 78 . 5 

Magnesium  phosphate 13.3 

Calcium  phosphate 6.8 

Silica,  alumina,  etc 1.4 

100.  o 

Microscopical  Examination  of  Yeast. — Mix  a  bit  of  the  yeast  in  water 
on  the  glass  slip  till  a  milky  fluid  is  formed,  and  stir  in  a  drop  of  a 
very  weak  anilin  dye  solution,  such  as    methyl  violet,   eosin,  or  fuch- 


33'='  FOOD  INSPECTION  AND  yINALYSlS. 

sin.*  Put  on  llie  cover-glass,  and  examine  under  the  microscope. 
Living,  active  cells  resist  the  stain,  if  the  latter  is  dilute  enough,  and 
appear  colorlesf;  or  nearly  so,  while  the  decayed  and  lifeless  cells  are 
stained,  and  can  easily  be  distinguished  by  their  color.  Yeast  cells  are 
circular  or  oval  in  shape,  and  vary  from  0.007  to  0009  mm.  in  diameter. 
They  are  sometimes  isolated,  and  sometimes  grouped  in  colonies;  each 
cell  has  an  outer,  mucilaginous  coating  or  envelope.  The  interior,  granu- 
lar mass  or  substance  of  the  cell  is  the  protoplasm,  and  within  the 
protoplasm  are  frequently  seen  one  or  more  circular  empty  spaces 
kno^^Tl  as  vacuoles. 

Yeast  cells  multiply  by  the  process  of  budding.  The  decadence  of 
yeast  cells  is  marked  by  the  increased  size  of  vacuole,  and  by  the  thicken- 
ing of  the  cell  wall. 


■3 


03^^ 


Fig.  6S. — Sprouting    Yeast-cclls    {Saccharomycas    cerevisice).      {a,   after    Liirssen;     h,  aftei 

Hansen.) 

Yeast-testing. — Available  Carbon  Dioxide. — The  value  of  yeast  in 
bread-making  depends  on  the  amount  of  carbon  dioxide  which  it  is  capa- 
ble of  generating  under  given  circumstances,  hence  the  available  carbon 
dioxide  is  the  chief  factor  in  gauging  a  yeast.  There  are  various  methods 
of  determination,  (i)  either  by  measuring  the  volume  of  gas  set  free  by 
the  action  of  a  weighed  cjuuntity  of  yeast  in  a  sugar  solution  of  known 
strength,  kept  for  a  fixed  time  at  a  fixed  temperature  (say  30°),  or  (2) 
by  conducting  the  gas  from  such  a  fermenting  solution  through  a  weighed 
absorption  bulb,  containing  potassium  hydroxide  and  noting  the  increase 
in  weight,  or  (3)  by  the  more  convenient  method  of  Meissl  as  follows: 

\  mixture  is  made  of  400  grams  pure,  concentrated  sugar,  25  grams 
ammonium  phosphate,  and  25  grams  potassium  phosphate.  A  small, 
wide-mouthed  flask  of  aljout  100  cc.  capacity  is  fitted  with  a  doubly  per- 
forated rubber  stopper,  having  two  tubes  as  shown,  one  of  which  is  bent 
and  passes  nearly  to  the  bottom  of  the  flask,  Ijcing  fitted  at  the  outer 
end  with  a  rubber  tube  and  glass  plug,  while  the  other  is  connected  with 
a  small  calcium  chloride   tube.     Measure  50  cc.  of  distilled  water  into 

*  I  f^am  crystallized  fuchsin  in  i6o  cc.  water  having  i  cc.  alcohol. 


CEREALS,   LEGUMES,    VEGETABLES,  AND  FRUITS. 


331 


I 


this  flask,  and  dissolve  4.5  grams  of  the  above  sugar  phosphate  mixture. 
Finally  add  i  gram  of  the  yeast  to  be  tested,  stir  it  well  t'U  the'-e  are  no 
lumps,  and  cork  the  flask.  Carefully  weigh  on  a 
delicate  balance  the  flask  with  its  contents,  and 
immerse  in  a  water-bath  at  30°  C,  kecjjing  it  at 
that  temperature  for  six  hours.  At  the  end  of 
this  time,  remove  the  flask  from  the  bath,  and 
immediately  immerse  in  cold  water  to  cool  the 
contents.  Remove  the  rubber  tube  with  the  glass 
plug,  and  by  suction  draw  out  the  remaining  carbon 
dioxide.  Replace  the  plug,  and  having  carefully 
wiped  off  the  flask,  again  weigh.  The  loss  in 
weight  is  due  to  carbon  dioxide  set  free  by  the  fer- 
mentation of  the  yeast. 

Starch  in  Compressed  Yeast. — Potato,  com,  or 
tapioca  starch  has  long  been  added  to  yeast  before 
pressing,  on  the  ground  that  the  starch  acts  as  a 
drier,  producing  a  much  cleaner  product,  and  one 
that  can  be  more  readily  and  intimately  mingled 
with  the  materials  of  the  bread,  besides  enhancing 
the  keeping  qualities  of  the  yeast,  especially  in 
warm  weather.  The  quantities  used  vary  from  about  5%  up  to  over 
50%.  Undoubtedly  the  larger  amounts  are  added  as  a  make  weight. 
Some  manufacturers  use  no  starch  whatever. 

The  question  has  frequently  been  raised  whether,  with  improved 
methods  of  manufacture,  w^hereby  yeast  can  be  produced  comparatively 
free  from  slime,  and  thus  capable  of  pressure  without  the  admixture  of 
starch,  the  use  of  the  latter  should  not  be  considered  as  an  adulterant. 

Briant  claims  that  the  admixture  of  starch  up  to  5%  increases  rather 
than  decreases  the  actual  content  of  yeast,  in  that  the  starch  abstracts 
moisture  from  the  yeast  cells  themselves,  the  proportion  of  water  being 
much  smaller,  and  that  of  the  yeast  larger  in  the  starch-mixed  substance. 
T.  J.  Bryan,*  on  the  other  hand,  finds  that  the  addition  of  starch  to  yeast 
reduces  the  carbon  dioxide  value,  and  that  the  percentage  reduction  is 
greater  than  the  percentage  of  starch  present.  His  experiments  further 
indicate  that  the  keeping  qualities  of  starch  yeast  is  not  greater,  but 
actually  less  than  that  of  pure  yeast. 


Fig.  fiQ, — Apparatus  for 
Determining  Leaven- 
ing Power  of  Yeast. 


*  A.  O.  A.  C.  Proc.  1907,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  ii6,  p.  25. 


332  FOOD   INSPECTION  AND   /iN.'. LYSIS. 

U.  S.  Rulings.* — I.  The  term  "compressed  yeast,"  without  qualifica- 
tion, means  distillers'  yeast  without  admixture  of  starch. 

2.  If  starch  and  distillers'  yeast  be  mixed  and  compressed  such 
product  is  misbranded  if  labeled  or  sold  sim])ly  under  the  name  "com- 
]iressed  veast."  Such  a  mixture  or  compound  should  be  labeled  "com- 
pressed yeast  and  starch." 

3.  It  is  unlawful  to  sell  decomposed  yeast  under  any  label. 

CHEMICAL    LEAVENING    MATERIALS. 

Under  this  heading  are  included  the  various  ingredients  that  enter 
into  the  mixtures  commonly  known  as  "baking  powders"  which  have 
no  food  value  in  themselves,  but  are,  strictly  speaking,  instruments  or 
tools  that  by  purely  chemical  reactions  bring  about,  under  certain  con- 
ditions, the  comparatively  quick  liberation  of  gas  and  the  consequent 
aeration  of  biscuit,  bread,  and  cake. 

Baking  Powders  and  their  Classification. — Formerly  the  housewife 
was  accustomed  to  measure  out  in  proper  proportion  a  mixture  of  sour 
milk,  or  cream  of  tartar,  with  saleratus  to  produce  quick  aeration  of  bread. 
The  modem  baking  powder  is  a  natural  outgrowth  of  the  former  practice, 
and  has  almost  wholly  displaced  it,  producing,  as  it  does,  a  mixture  ready 
for  immediate  use  of  an  acid  and  an  alkaline  constituent  in  proper  pro- 
portion for  chemical  combination  to  form  the  gas.  A  third  ingredient 
is,  however,  generally  considered  as  necessary  to  check  deterioration, 
viz.,  a  dry,  inert  material,  which  by  absorbing  moisture  jircvents  the  pre- 
mature chemical  action  between  the  reagents.  Starch  is  nearly  always 
used  for  this  purpose,  though  sugar  of  milk  has  a  limited  use.  The  alkaline 
principle  of  nearly  all  baking  powders  is  bicarbonate  of  soda,  or  saleratus. 
Baking  powders  are  divided  naturally  into  three  main  classes,  with  refer- 
ence to  the  acid  principle: 

(i)  Tartrate  Powders,  wherein  the  acid  principle  is  (a)  bitartrate  of 
potassium  or  (b)  tartaric  acid,  typified  by  the  following  reactions: 

188  84  210  44         18 

(a)  KHC,H,Oo+NaHC03  =  KNaqH,Oo+CO,+  H30 

Potassium  Sodium  Potassium  Carbon      Water 

bitartrate  bicarbonate  and  sodium  dioxide 

tartrate 

150  168  230  S8 

(b)  n,cX^6+  2XaHC03  =  Na2C,H,Oe,2H20+  2CO3 

Tartaric  S^jdium  Sodiumtartrate  Carbon 

acid  bicarbonate  f^'oxide 

*  Ffx)(l  Inspection  Decbion,  No.  11 1,  Jan.  7,  igio. 


CERE/iLS,   LEGUMES,    VEGETABLES,   AND  FRUITS.  t^t,^ 

(2)  FhospJiate  Powders,  in  which  calcium  acid  phosphate  is  the  acid 
principle : 

234  168  136  142  88  ^6 

CaH/PO,)2+2NaHC03  =  C'iHPO,+Na2HPO,+  2CO,+  2H,0 

Calcium  Sodium  Calcium  Disodium  Carbon       Water 

acid  phos-  bicarbonate  monohy-  phosphate         dioxide 

phate  drogen  phos- 

phate 

(3)  ''Alum  Powders,''^  wherein  the  acidity  is  due  wholly  or  in  part 
to  sulphate  of  aluminum  ks  it  occurs  in  potash  or  ammonia  alum,  or  in 
the  double  sulphates  of  aluminum  and  sodium.* 

Assuming  burnt  potash  alum  as  the  substance  used,  the  reaction 
would  be  as  follows: 

516  504  156  426  174  264 

K2Al2(SO,),+  6NaHC03  =  Al3(OH),+  3Na2SO,+  K,SO,+  6CO2 

Burnt  pot-  Sodium  Aluminum  Sodium         Potassium      Carbon 

ash  alum  bicarbonate  hydrate  sulphate  sulphate        dioxide 

Naturally  many  baking  powders  of  complex  composition  are  met 
with,  embodying  various  mixtures  of  the  above  classes. 

Composition  of  Various  Baking  Powders. — Following  are  analyses 
of  typical  baking  powders  of  the  above  classes:  f 

I.  Cream  of  Tartar  Baking  Powder: 

Total  carbon  dioxide,  CO2 13 -21 

Sodium  oxide,  NajO 1308 

Potassium  oxide,  K^O „ 14-93 

Calcium  oxide,  CaO .18 

Tartaric  acid,  C4H4O5 41 .60 

Sulphuric  acid,  SO3 .10 

Starch 7.42 

Water  of  combination  and  association  by  difference. . .  8 .  98 


100.00 
Available  carbon  dioxide  12.58%. 

*  It  is  probable  that  v'ery  little  ammonia  or  potash  alum  is  actually  used  at  present 
in  this  class  of  powders.  A  product  largely  used  is  known  in  the  trade  as  S.  A.  S.  (sodiiun 
aluminum  sulphate)  and  is  a  calcined  double  sulphate  of  aluminum  and  sodium. 

t  Div.  of  Chem.,  Bui.  13,  part  5.  pp.  600,  604,  and  606. 


334  FOOD  INSPECTION  AND  ANALYSIS. 

2.  Phosphate  Baking  Powder: 

Total  carbon  dioxide,  CO2 13-47 

Sodium  oxide,  Na_.0  1 2 .  66 

Potassium  oxide,  KjO .31 

Calcium  oxide,  CaO 10. 27 

Phosphoric  acid,  l^JJ^ 21  .S^ 

Starch 26.41 

Water  of  combination  and  association  by  difference.  ..  15.05 

100.00 
Available  carbon  dioxide  12.86%. 

3.  Alum  Baking  Powder: 

Total  carbon  dioxide,  COj 9-45 

Sodium  oxide,  NajO 9.52 

Aluminum  oxide,  AI2O3 3 .  73 

Ammonia,  NH3 i  .07 

Sul jjhuric  acid,  SO3 10.71 

Starch 43-25 

Water  of  combination  and  association  by  difference  . .  22.27 


100.00 
Available  carbon  dioxide  8.10%. 

Mixed  Powders: 

Total  carbon  dioxide,  CO, 10.68 

Sodium  oxide,  NajO 14.04 

Calcium  oxide,  CaO 1.29 

Aluminum  oxide,  AI2O3 4. 59 

Ammonia,  NH3 i .  13 

Phosphoric  acid,  P^Os 3-3^ 

Sulphuric  acid,  SO3 ii-57 

Starch 42-93 

Water  of  combination  and  association  by  difference  . .  10.39 


100.00 
Available  carbon  dioxide  10.37%. 

The    Adulteration    of    Baking   Powder. — No    substance  that    comes 
within  the  domain  of  food  inspection  is  the  subject  of  so  much  controversy 


CEREALS,   LEGUMES,    VEGETABLES,   AND   FRUITS.  335 

as  baking  powder.  Unless  a  specific  law  forbids  the  use  of  a  j)arlicular 
ingredient  or  cla:s  of  ingredients,  or  in  some  manner  regulates  the 
labelling  of  the  package,  no  baking  powder  of  any  kind  can  be  considered 
adulterated  under  the  general  food  law,  unless  it  can  be  proved  to  be 
injurious  to  health,  or  unless  it  contain  inert  and  useless  mineral  matter. 

As  a  matter  of  fact,  the  residue  left  in  the  bread  by  all  classes  of  baking 
powder  consists  of  one  or  more  drugs  recognized  in  the  Pharmacopoeia, 
all  of  which  in  large  quantity  exercise  well-marked  toxic  effects  on  the 
human  system.  Artificial  digestion  experiments,  and  physiological  tests 
on  the  lower  animals,  using  excessive  doses  of  any  of  the  above  drugs,  do 
not  show  the  effect  of  the  everyday  use  of  baking  powder  in  bread  on  the 
human  system,  and  only  a  systematic  examination  of  the  effect  of  such 
use  on  large  numbers  of  people  can  prove  conclusively  whether  or  not  any 
one  class  of  baking  powders  is  harmful,  and  hence  whether  or  not  it 
should  be  classed  as  adulterated.  Aside  from  the  question  of  the  harm- 
fulness  of  the  acid  ingredients,  which  is  the  subject  of  much  controversy 
among  rival  manufacturers,  there  can  be  no  doubt  that  such  inert  mineral 
substances  as  calcium  sulphate,  terra  alba,  or  clay,  which  arc  entirely 
useless,  and  lower  the  strength  of  the  powder,  are  to  be  considered  in  the 
light  of  adulterants. 

Traces  of  arsenic  derived  from  the  raw  materials  used  in  manufacture 
often  occur  in  both  alum  and  phosphate  powders  while  lead  is  an  acci- 
dental impurity  of  tartrate  powders. 

Cream  of  Tartar. — Its  Nature  and  A  duller ation.-^Crea.m  of  Tartar, 
or  potassium  bitartrate  (KH5C4O6),  is  the  purified  product  obtained  by 
the  recrystallization  of  the  crude  argols  or  lees  deposited  in  the  interior 
of  wine  casks.     It  is  usually  guaranteed  99%  pure. 

The  lees,  or  argols,  consist  chiefly  of  crude  potassium  bitartrate,  which 
is  present  in  the  juice  of  the  grape,  but  is  insoluble  in  the  alcohol  formed 
in  the  fermentation,  and  is  hence  deposited.  If,  for  the  clarification  of 
the  wine,  such  substances  as  gypsum  or  plaster  of  Paris  are  used,  tartrate 
of  calcium  will  be  found  mixed  with  the  bitartrate  of  potassium  in  the 
lees  and  also,  if  not  eliminated,  in  the  cream  of  tartar. 

Other  common  adulterants  of  cream  of  tartar  are  calcium  acid  phos- 
phate, gypsum  or  plaster  of  Paris,  starch,  and  alum. 

Small  amounts  of  lead  from  the  tanks  in  which  the  cream  of  tartar 
is  crystallized  constitutes  a  common  impurity. 

Potassium  bitartrate  is  insoluble  in  alcohol,  sparingly  soluble  in  cold, 
and  readily  soluble  in  hot  water. 


536  FOOD   JNSPECTJON  ^ND   ANALYSIS. 


CHEMICAL   ANALYSIS   OF   BAKING   CHEMICALS   AND    BAKING   POWDERS. 

Cream  of  Tartar. — The  degree  of  purity  of  commercial  cream  of 
tartar  is  best  determined  by  weighing  out  exactly  0.188  gram  of  the 
sample,  dissolving  in  hot  water,  and  titrating  with  tenth-normal  sodium 
hydroxide,  using  phenoljjhthalein  as  an  indicator.  If  the  article  is  pure, 
exactly  10  cc.  of  the  stanthird  alkali  will  be  required  for  the  titration.  All 
the  above-named  adulterants,  with  the  exception  of  alum,  are  either  insol- 
uble, or  sparingly  soluble  in  hot  water,  and  will  indicate  the  impurity  of 
the  sample  even  before  titration.  If  the  adulterant  be  alum,  the  sample 
would  go  into  solution  in  the  water,  but  the  alum  would  be  precipitated 
by  the  sodium  hydroxide,  the  i)recipitate  being,  however,  soluble  in  an 
excess  of  the  alkali. 

Sodium  Bkarboiiatc  on  account  of  its  cheapness  is  rarely  adulterated, 
save  by  the  occasional  presence  of  common  salt,  an  impurity  incidental 
to  its  manufacture.  The  degree  of  purity  of  sodium  bicarbonate  is  best 
ascertained  by  titration  with  standard  acid,  each  cubic  centimeter  of  tenth- 
normal acid  being  equivalent  to  0.0084  gram  of  sodium  bicarbonate. 

Determination  of  Total  Carbon  Dioxide.  Reagents. —  Calcium 
Chloride. — This  can  be  obtained  in  granulated  form  in  pellets  of  abc  ut 
the  size  of  peas,  specially  prepared  for  moisture  absorption. 

Soda  Lime.* — To  a  kilogram  of  commercial  sodium  hydroxide,  500 
to  600  cc.  of  water  are  added,  and  the  mixture  heated  in  an  iron  kettle 
to  form  a  thin  paste.  While  still  hot,  a  kilogram  of  coarsely  powdered  quick- 
lime is  added,  stirring  with  an  iron  rod.  The  lime  is  slaked,  and  the  whole 
mass  heats  and  steams  up.  No  outside  heat  is  necessary  at  this  stage, 
but  the  mass  is  stirred  and  the  lumps  broken  up.  As  soon  as  cool,  place 
the  product  in  wide-mouthed  bottles,  and  seal  with  parafi&n  wax.  The 
product  should  be  slightly  moist  to  give  the  best  results. 

Hydrochloric  Acid. — Specific  gravity  i.i. 

Sulphuric  Acid. — Specific  gravity  1.85. 

Potassium  Hydroxide  Solution. — Specific  gravity  1.55. 

Two  varieties  of  apparatus  are  in  use  for  the  d  termina  ion  of  carbon 
dioxide.  In  one  form  the  amount  of  carbon  dioxide  is  obtained  by  dif- 
ference in  weight  of  the  apparatus,  before  and  after  ehmination  of  the 
gas.  In  the  other,  the  gas  driven  out  of  a  given  weight  of  the  sample  is 
absorbed,  and  its  amount  calculated  from  the  increase  in  weight  of  the 

*  Benedict  and  Tower,  Jour.  Am.  Chem.  Soc,  Vol.  XXI,  p.  396. 


CEREALS,   LEGUMES,    VEGETABLES,    AND  FRUITS. 


337 


absorbent.     Types  of   these    \arielies   are   the    Geisslcr  and    the   Knorr 
apparatus 

The  Geissler  Apparatus. — This  consists  of  a  flask  A,  having  v.  ground 
neck  a,  and  a  ilaring  funnel-top  A'.  B  is  an  elongated  bulb,  closed  at  the 
top  by  the  hollow  stopper  K,  and  terminating  below  in  the  hollow  stem 
B',  which  is  accurately  ground  at  b  to  fit  the  neck  a.  Fused  into  the 
bulb  B  is  the  tube  C,  and  within  this  is  the  small  tube  D,  open  at  the  top 
and  communicating  directly  with  the  hollow  stem 
B'.     gg  are  openings  between  B  and  C. 

£  is  a  fine  glass  tube,  passing  from  the  bottom 
of  the  hollow  stem  B'  and  to  the  height  of  a  small 
protuberance  e  in  the  bottom  of  the  funnel  A',  the 
construction  being  such  that  by  turning  the  bulb 
and  stem  BB'  in  the  neck  a  of  the  flask  A  the 
tube  E  may  be  opened  or  closed  at  the  top.  H 
is  a  side  tube  in  the  flask  A,  closed  by  the  ground 
stopper  h. 

The  bulb  B  and  the  tube  C  are  filled  with 
strong  sulphuric  acid  nearly  to  the  top  of  the  tube 
D,  by  passing  through  the  neck  at  the  top,  which 
is  then  closed  by  the  stopper  K. 

About  0.5  gram  of  the  dried  sodium  bicar- 
bonate, or  I  gram  of  the  baking  powder,  is  in- 
troduced into  the  flask  A  through  the  neck  a 
from  a  weighing-tube  or  otherwise,  so  that  its 
exact  weight  is  known.  The  stem  B^  is  then 
inserted,  and  the  funnel-top  A^  is  nearly  filled 
with    the    hydrochloric   acid,  the    tube  e  being  fig.  r-.-Geissler's  CO,  Ap- 

closed.  paratus  or  Alkalimcter. 

The  entire  apparatus  is  then  weighed,  after  which  the  stem  is  turned 
to  bring  the  protuberance  e  nearly  opposite  the  tube  E,  uncovering  it 
enough  to  allow  the  acid  to  pass  slowly  down  the  tube  into  the  flask  and 
'upon  the  powder  in  the  bottom  of  the  flask.  The  carbon  dioxide  evolved 
passes  through  ;he  opening  /  into  the  hollow  stem  B',  thence  up  through 
he  tube  D.  and  down  and  up  (as  indicated  by  the  arrows)  through  the  sul- 
phuric acid  which  absorbs  the  moisture.  Finally  the  gas  passes  out 
through  the  tube  K. 

After  the  evolution  of  the  gas  has  continued  for  two  or  three  minutes, 
gentle  heat  is  applied  .0  the  flask  from  a  gas  flame,  and  the  solution  is 


13S 


FOOD  INSPECTION  .4ND  ^N^ LYSIS. 


brought  to  boiling,  Avhich  is  continued  for  a  few  minutes,  during  the  latter 
portion  of  which  the  stopper  //  is  removed,  and  the  tubulure  connected 
by  rubber  tubing  with  a  system  of  two  U  tubes,  one  containing  soda 
lime.,  and  the  other  calcium  chloride.  The  tube  k  is  then  connected  with 
the  aspirator,  and  a  curreni  of  dried  air  is  passed  through  the  apparatus  at 
the  rate  of  about  two  bubbles  per  second,  long  enough  to  displace  all 
the  carbon  dioxide.  The  rubber  tubes  are  then  disconnected,  the  stopper 
A'  is  replaced,  and  the  apparatus  cooled  to  room  temperature  and  weighed. 

The  available  carbon  dioxide  in  baking  powder  is  determined  in  the 
same  manner  as  above,  by  simplr  substituting  freshly  boiled,  distilled 
water  for  the  hydrochloric  acid  in  the  funnel-top  A\ 

The  Knorr  Apparatus  [Modified). — The  apparatus  (Fig.  71)  consists 
of  (i)  a  flask,  into  which  is  introduced  an  accurately  w^eighed  amount  of 


Fig.  71. — Modified  Knorr  Apparatus  for  Determining  Carbon  Dioxide. 

the  dr\'  samp'e  (0.5  to  i  gram  of  sodium  bicarbonate  or  i  to  2  grams  of 
baking  powderj;  (2)  a  funnel,  the  tube  of  which,  provided  with  a  stop- 
cock enters  the  stopper  of  the  flask;  (3)  a  soda  lime-  tube,  entering  a 
stopper  at  the  top  of  the  funnel;  (4)  a  Liebig  condenser,  connecting  with 
a  tube  passing  through  the  stopper  of  the  flask;  (5)  a  Geissler  bulb,  filled 
with  the  sulphuric  acid;    (6)  a  potash  absor[)tion-bulb,  and  (7)  a  calcium 


I 


CEREALS,   LEGUMES,   VEGETABLES,   AND  FRUITS.  339 

chloride  tube,  which  may  if  desired  be  replaced  by  a  second  sulphuric 
acid  bulb.  The  potash  absorption  ai)i)aratus  is  accurately  weighed 
before  being  connected  up,  and  the  funnel  is  nearly  filled  with  the  hy- 
drochloric acid  reagent,  after  which  the  soda  lime  tube  is  attached.  The 
calcium  chloride  tube  is  connected  by  a  rubber  lube  with  the  aspirator, 
and  a  current  of  cold  water  is  allowed  to  run  through  the  outer  Liebig 
condenser-tube. 

The  stop-cock  in  the  funnel-tube  is  first  opened  to  allow  the  acid 
to  slowly  run  into  the  flask,  the  How  being  regulated  to  insure  slow  evolu- 
tion of  the  gas. 

The  aspirator  is  then  turned  on  so  that  about  two  bubbles  of  air  per 
second  pass  through  the  apparatus,  and  gentle  heat  is  appHed  to  the 
flask  by  the  gas  flame,  the  solution  within  being  brought  to  boiling,  and 
the  boiling  continued  for  several  minutes  after  the  vapor  has  begun  to 
gather  in  the  condenser. 

Prolonged  boiling  of  the  solution  should  be  avoided,  and  in  a  series  of 
tests  the  time  of  boiling  should  be  precisely  the  same  in  all  cases. 

After  removing  the  flame,  the  flask  is  allowed  to  cool,  the  aspiration 
being  continued.  The  absorption-tube  is  then  removed  and  weighed 
at  room  temperature,  the  increase  in  weight  being  due  to  the  carbon 
dioxide. 

The  Available  Carbonic  Acid  in  Baking  Powder  is  determined  in  the 
same  manner  as  the  total  carbon  dioxide,  except  that  recently  boiled, 
distilled  water  is  substituted  for  the  hydrochloric  acid. 

Detection  of  Tartaric  Acid.* — It  is  often  desirable  to  test  a  "  com- 
pound "  cream  of  tartar,  or  a  "  cream  of  tartar  substitute,"  or  an 
adulterated  sample  made  up  largely  of  foreign  ingredients,  to  see  if  any 
tartaric  acid,  free  or  combined,  be  present.  The  following  test  is 
applicable  in  presence  of  phosphates: 

If  the  substance  to  be  tested  is  found  to  be  free  from  starch,  mix  a 
litde  of  the  dry  powder  in  a  test-tube  with  a  bit  of  dry  resorcin,  add  a 
few  drops  of  concentrated  sulphuric  acid,  and  heat  slowly.  A  rose-red 
color  indicates  tartaric  acid  or  a  tartrate,  the  color  being  discharged  on 
dilution  with  water. 

In  case  of  baking  powder,  or  a  cream  of  tartar  substitute  containing 
starch,   shake  repeatedly  from  3   to   5   grams  of  the  sample  with  about 


*  Wolff,  Rev.  Chim.  Analyl.  ct  appr.  4  (1S99),  p.  2631.    | 


340  FOOD   INSPECTION   JND   AN.-1LYSIS. 

250  cc.  of  colli  water  in  a  large  llask,  allowing  the  insoluble  portion  to 

subside. 

Decant  the  solution  through  a  filter,  and  evaporate  the  filtrate  to  dryness, 

after  which  test  the  dried  residue  or  a  portion  thereof  with  resorcin  and 

sulphuric  acid  as  above  described. 

Determination  of  Total  Tartaric  Acid.  —  Modified  Heidenhain 
Mclhcd* — Apphcablc  only  in  the  absence  of  phosphates  and  salts  of 
aluminum  and  calcium. 

Into  a  shallow  porcelain  dish,  6  inches  in  diameter,  weigh  out  2  grams 
of  the  material  and  sufficient  potassium  carbonate  to  combine  with  all 
tartaric  acid  not  in  the  form  of  potassium  bitartrate.  Mix  thoroughly 
with  1 5  cc.  of  cold  water,  and  add  5  cc.  of  99%  acetic  acid.  Stir  for  half 
a  minute  with  a  glass  rod  bent  near  the  end.  Add  100  cc.  of  95%  alcohol, 
stir  violently  for  five  minutes,  and  allow  to  settle  at  least  thirty  minutes. 
Filter  on  a  Gooch  crucible  with  a  thin  layer  of  paper  pulp,  and  w^ash 
with  95%  alcohol  until  2  cc.  of  the  filtrate  do  not  change  the  color  of 
litmus  tincture  diluted  with  water.  Place  the  precipitate  in  a  small  cas- 
serole, dissolve  in  50  cc.  of  hot  water,  and  add  standard  fifth-normal  potas- 
sium hydroxide  solution,  leaving  it  still  strongly  acid.  Boil  for  one  minute. 
Finish  the  titration,  using  phenolphthalein  as  indicator,  and  correct  the 
reading  by  adding  0.2  cc.  One  cc.  of  fifth-normal  potassium  hydroxide 
solution  is  equivalent  to  0.026406  gram  tartaric  anhydride  (C^H^OJ, 
0.03001  gram  tartaric  acid  (HoC^H^Og),  and  0.03763  gram  potassium 
bitartrate  (KHC,H,Oc)- 

The  standard  of  the  potassium  hydroxide  solution  should  be  fixed  by 
pure  dr)'  potassium  bitartrate. 

The  accuracy  of  this  method  is  indicated  by  the  agreement  of  the 
percentages  of  potassium  bitartrate  in  cream  of  tartar  powders  containing 
no  free  tartaric  acid,  obtained  by  calculation  from  the  tartaric  acid,  with 
those  obtained  by  calculation  from  the  potassium  oxide. 

In  presence  of  phosphates  or  of  aluminum  and  calcium  salts,  the  only 
satisfactory  method  of  arriving  at  the  amount  of  tartaric  acid  present  is 
by  difTerencc,  having  determined  or  calculated  the  other  ingredients. 

Kenrick's  Polariscopic  Methods. — Method  i.  {Applicable  to  Cream 
of  Tartar). — The  method  is  ba.sed  on  the  fact  that  in  the  presence  of 
excess  of  ammonia,  the  rotation  of  the  solution  is  proportional  to  the 


*  Provisional  meihods  of  the  A.  O.  A.  C,  Bur.  of  Chem.,  Uul.  65,  p.  104;   Bui.  107  (rev.), 
p.  175- 


CEREALS,   LEGUMES,    VEGETABLES,  AND  FRUITS.  341 

concentration  of  the  tartaric  acid,  and  is  independent  of  the  other  bases 
and  acids  present, 

(a)  The  Substance  is  Completely  Soluble  in  Dilute  Ammonia. — A 
weighed  quantity  of  the  material  containing  not  more  than  i  gram  tartaric 
acid  is  placed  in  a  25  cc.  measuring  llask,  moistened  with  3  or  4  cc.  of 
water,  and  concentrated  ammonia  (sp.  gr.  0.880)  added  in  quantity  suf- 
ficient to  neutralize  all  acids  that  may  be  present,  and  leave  about  i  cc. 
in  excess.  The  actual  amount  of  the  excess  is  not  of  importance,  but  a 
greater  quantity  than  i  cc.  of  free  ammonia  should  be  avoided.  The 
solution  is  then  made  up  to  25  cc.  with  water,  filtered,  if  necessary, 
through  a  dry  filter,  and  measured  in  a  20  cm.  tube  in  the  polarimctcr. 

The  amount  of  tartaric  acid  (C4HgOg)  in  grams  {y)  in  the  material 
taken  is  given  by  the  formula: 

y  =  0.005 1 9:^, 

where  x  is  the  rotation  in  minutes. 

(6)  The  Substance  is  not  Completely  Soluble  in  Dilute  Ammonia. — In 
this  case  calcium  tartrate  is  probably  present,  and  may  be  determined 
as  follows:  Treat  i  gram  of  the  substance  (or  an  amount  containing 
not  more  than  i  gram  of  tartaric  acid)  in  a  small  beaker  with  15  cc.  of 
water,  and  10  drops  of  concentrated  hydrochloric  acid.  Heat  gently 
till  both  the  potassium  and  calcium  tartrates  have  passed  into  solution, 
and  then,  while  still  hot,  add  2  cc.  of  concentrated  ammonia  (or  enough 
to  produce  an  ammoniacal  smelling  liquid),  and  about  o.i  gram  of  sodium 
phosphate  dissolved  in  a  little  water.  Transfer  to  a  25-cc.  measuring 
flask,  cool,  make  up  to  the  mark  with  water,  filter  through  a  dry  filter, 
and  polarize  the  filtrate  in  a  20-cm.  tube.  The  tartaric  acid  is  calculated 
from  the  formula  given  under  (a). 

The  precipitation  of  the  calcium  by  means  of  sodium  j)hosphate  is 
not  absolutely  necessary,  but  when  this  is  not  done,  in  cases  where  the 
proportion  of  calcium  in  the  sample  is  high,  there  is  a  great  tendency 
for  the  calcium  tartrate  to  crystallize  out  from  the  ammoniacal  solution 
before  the  reading  is  made. 

The  tartaric  acid  present  as  bitartrate  of  potash  may  be  determined 
by  proceeding  as  in  [a],  the  calcium  tartrate  being  practically  insoluble 
in  cold  ammonia  solution. 

The  tartaric  acid  present  as  calcium  tartrate  is  given,  with  sufficient 
accuracy  for  most  purposes,  by  the  difference  between  the  results  of  (a) 
and  (b).     If  more  accurate  results  are  required,  the  residue  insoluble  in 


34- 


FOOD   INSPECTION   /iND   ANALYSIS. 


ammonia  in  [a)  may  be  dissolved  in  a  little  hydrochloric  acid  and  treated 
as  above  with  sodium  phosphate  and  ammonia. 

MetJiod  2.  {Applicable  to  Baking  Powder  and  Cream  of  Tartar  mixed 
with  Substitutes). — Direct  readings  of  rotation  in  ammoniacal  solution 
are  inadmissible  in  analyses  of  the  substances  of  this  class,  on  account 
of  the  inlluence  of  iron  and  aluminum  on  the  rotation  of  tartaric  acid, 
and  on  account  of  the  small  but  unknown  rotation  of  the  trace  of  inverted 
starch. 

Accurate  determinations,  however,  may  be  made  in  the  ])resence  of 
excess  of  ammonium  molybdate  in  neutral  solution.  The  latter  substance 
has  the  property  of  greatly  increasing  the  rotation  of  tartaric  acid,  so 
that  by  its  use  the  small  rotation  of  the  inverted  starch  is  made  insignifi- 
cant. It  is  to  be  noted,  however,  that  this  increased  rotation  is  very 
sensitive  to  the  presence  of  alkali  and  acid,  and  is,  moreover,  modified 
by  phosphates.  It  is  therefore  necessary,  in  the  first  place,  to  remove 
the  j)hosi)horic  acid,  and,  secondly,  to  bring  the  solution  to  a  definite 
state  of  neutrality.  Both  these  results  are  attained  by  the  following 
procedure,  the  details  of  which  must  be  carefully  adhered  to: 

(a)  Reagents. — The  following  solutions  must  be  prepared,  but  need 
not  be  made  up  very  accurately: 

Molybdate  solution:   44  grams  ammonium  heptamolybdate  in  250  cc. 

Citric  acid  solution:    50  grams  citric  acid  in  500  cc. 

Magnesium  sulphate  solution:    60  grams  MgS04  .  7H2O  in  500  cc. 

.\mmonia  solution:  80  cc.  concentrated  ammonia  (sp.  gr.  0.880)  in 
500  cc. 

Hydrochloric  acid :    60  cc.  concentrated  hydrochloric  acid  in  500  cc. 

Methyl  orange  solution: 

(6)  Process. — An  amount  of  material  containing  not  more  than  0.2 
gram  tatraric  acid,  not  more  than  0.3  gram  alum,  and  not  more  than 
0.3  gram  calcium  sujK-rphosphate,  is  accurately  weighed,  and  placed  in 
a  dry  flask.  To  this,  5  cc.  of  citric  acid  and  10  cc.  of  molybdate  solution 
are  added,  and  allowed  to  react  with  the  substance  for  10  or  15  minutes 
(with  an  occasional  shake).  Next,  5  cc.  of  magnesium  sulphate  solution 
are  added,  and  15  cc.  of  ammonia  solution  stirred  in.  After  a  few 
minutes  Tnot  more  than  one  hour),  the  solution  is  fiilered  through  a  dry 
filter,  a  slight  turbidity  of  the  filtrate  being  disregarded.  To  20  cc.  of 
the  filtrate  arc  then  added  a  few  drojjs  of  methyl  orange  and  hydrochloric 
acid,  from  a  burette,  till  the  pink  color  ajjpears  (2  or  3  drops  too  much 
or  too  little  are  of  no  consequence).     Finally,  10  cc.  more  of  the  molybdate 


CEREALS,  LEGUMES,    yEGETABLES,   AND  FRUEFS. 


543 


solution  arc  added  to  the  pink  solution,  whicli  now  becomes  colorless 
or  pale  yellow,  and  water  is  added  to  make  up  the  xolume  to  50  cc. 
This  solution,  after  filtering  if  necessary,  is  polarized  in  a  20-cm.  tube. 
The  amount  of  tartaric  acid  in  grams  (y)  in  the  weight  of  substance 
originally  taken  is  given  by  the  following  formula,  in  which  x  is  the 
rotation  in  minutes: 

y  — o.ooio86x  +  o.ooi6oi\/x. 
But  if  the  rotation  is  not  less  than  40',  the  simpler  formula, 

y  =  0.0075  +  o.ooi  1.68.V, 
may  be  employed. 

The  following  table  gives  the  tartaric  acid  in  grams  for  every  10  mmutes 
rotation : 


Rotation  in  Minutes. 

Grams 

Tartaric 

Acid. 

Rotation  in  Minutes. 

Grams 
Tartaric 

Acid. 

10 

0.016 

0.029 

0.0415 

0-0535 

0.0657 

0.0776 

0-0895 

0-1013 

90 

100 

0.1130 
0.1246 

0-1365 
0.1479 

0.1595 
0.1710 
0.1825 

20              

30 

40 

50 

60 

70 

80 

IIO 

120 

130 

140 

150 

Determination  of  Starch. — McGilVs  Method*  {Modified). — Digest 
I  gram  of  the  sample  with  150  cc.  of  a  cold  3%  solution  of  hydrochloric 
acid  during  twenty-four  hours,  v^ith  occasional  shaking.  Filter  through 
a  tared  Gooch  crucible,  wash  first  with  water  until  neutral,  then  once 
with  alcohol,  and  finally  with  ether.  Dry  at  110°  C.  for  four  hours,  cool, 
and  weigh.  Burn  off  the  starch;,  and  again  weigh.  The  difference  in 
the  two  weights  indicates  the  weight  of  the  starch.  The  purity  of  the 
iitarch  is  insured  by  examination  with  the  microscope. 

Acid  Conversion  Method. f — If  the  sample  contains  lime,  mix  5  grams 
in  a  500-CC.  flask  with  200  cc.  of  3%  hydrochloric  acid,  and  let  the  mixture 
stand  an  hour  with  frequent  shaking.      Fiher  through  a  wetted  ii-cm. 

*  Canada  Inland  Rev.  Bui.  68,  p.  33. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  105;  Bui.  107  rev.,  p.  176. 


344  FOOD  IXSFFCTION   .-IND   /I  \' A  LYSIS. 

filler,  wash  with  water,  and  transfer  the  starch  by  a  wash-bottle  from  the 
filter-paper  back  into  the  original  llask,  using  200  cc.  of  water. 

If  the  sample  be  free  from  lime,  weigh  5  grams  directly  into  the  500-cc. 
llask  with  200  cc.  of  water.  In  either  case  add  20  cc.  of  hydrochloric 
acid  (specific  gravity  1.125)  and  heat  the  flask  in  boiling  water  for  2^ 
hours,  the  flask  being  provided  with  a  reflux  condenser.  Determine  the 
dextrose,  and 'fro in  this  the  starch  in  the  regular  manner. 

Detection  of  Aluminum  Salts.* — (a)  In  Baking  Powder. — Appli- 
cable in  presence  of  phosphates.  Burn  to  an  ash  about  2  grams  of  the 
samj)le  in  a  platinum  dish.  Extract  with  boiling  water  and  filter.  Add 
to  the  filtrate  sufticient  ammonium  chloride  solution  to  produce  a  distinct 
odor  of  ammonia.     A  flocculent  precipitate  indicates  aluminum. 

In  igniting,  as  above  directed,  sodium  aluminate  results  from  the 
more  or  less  complete  fusion.  The  reaction  which  occurs  may  be  repre- 
sented as  follows: 

Na,Al30,-f  2NH,Cl-f  4H,0  =  Al2(OH)e-f  2NH,OH+  2NaCl. 

Sodiurc  Ammonium  Aluminum  Ammonia  Salt 

aluminate  chloride  hydroxide 

If  any  phosphate  of  Hme  be  present,  it  wiU  be  insoluble  in  the  solution 
of  the  ash.  If  phosphate  of  sodium  or  potassium  be  present,  it  will  go 
inio  solution,  but  will  only  precipitate  out  when  an  aluminum  salt  is  also 
present  on  the  addition  of  the  ammonium  chloride  reagent. 

(b)  In  Cream  oj  Tartar. — Mix  about  i  gram  of  the  sample  with  an 
equal  quantity  of  sodium  carbonate,  burn  to  an  ash,  and  proceed  as  in 
the  case  of  baking  powder  (a). 

Determination  of  Alumina. — The  above  fjualilativc  method  with  am- 
monium chloride  may  be  made  quantitative  in  presence  of  phosphates 
as  follows:  .-Mtcr  carr^-ing  out  the  qualitative  method  as  above  directed, 
filter  off  the  final  precipitate,  dissolve  it  in  nitric  acid,  and  test  it  for  phos- 
phate with  ammonium  molybdate.  If  phosphates  are  found  absent, 
proceed  as  before  with  a  weighed  amount  of  the  sample  and  wash,  ignite, 
and  weigh  the  residue  as  AljOg. 

If  phosphate  is  found  present  in  the  ammonium  chlorirle  precipitate, 
proceed  as  before,  igniting  and  weighing  the  total  residue.  Then  deter- 
mine the  P2O5  in  the  latter  and  subtract  from  the  total.  The  difference 
will  be  the  AI2O3. 

♦Leach,  31st  An.  Kep.  Mass.  State  Hoard  of  Ueallh,   1899,  p.  638. 


CEREALS,   LEGUMES,    yEGETABLES,   AND  FRUITS.  345 

Determination  of  Lime. — 5  grams  of  the  sample  arc  treated  in  a 
500  cc.  graduated  llask  with  50  cc.  of  water  and  25  cc.  of  concentrated 
hydrochloric  acid.  Add  water  to  the  mark,  shake,  and  allow  the  starch 
to  settle.  Decant  through  a  dry  filter,  and  to  50  cc.  of  the  filtrate 
add  ammonia  nearly  to  neutralization,  an  excess  of  ammonium 
acetate  solution,  and  4  cc.  of  80%  acetic  acid,  and  heat  at  50°  C. 
Filter  if  necessary,  and  precipitate  the  lime  with  an  excess  of 
ammonium  oxalate.  Filter,  wash,  and  ignite  over  a  blast-lamp.  Weigh 
as  CaO. 

Determination  of  Potash  and  Soda.* — Weigh  out  5  grams  into  a 
platinum  dish,  and  incinerate  in  a  muflle  at  a  low  heat.  The  charred 
mass  is  wxll  rubbed  uj)  in  a  mortar,  then  boiled  fifteen  minutes  with 
about  200  cc.  of  water,  to  which  has  been  added  a  little  hydrochloric 
acid.  The  whole  is  transferred  to  a  500-cc.  ilask,  and,  after  cooling, 
made  up  to  the  mark  and  filtered.  Of  the  filtered  liquid  100  cc, 
representing  i  gram  of  the  sample,  are  measured  out,  heated  to  boiling, 
and  a  slight  excess  of  barium  chloride  solution  added;  then  without 
filtering  barium  hydroxide  is  added  in  slight  excess,  the  precipitate 
filtered  off,  and  washed.  To  the  filtrate  is  added  a  little  ammonium 
hydroxide,  and  ammonium  carbonate  solution  until  the  barium  is  pre- 
cipitated. This  precipitate  is  filtered  and  washed,  the  liltrate  evapo- 
rated to  dryness,  and  carefully  ignited  below  redness  until  all  volatile 
matter  is  driven  off.  The  residue  is  dissolved  in  a  few  cc.  of  water,  and 
a  few  drops  of  ammonium  carbonate  solution  added.  The  precipitate, 
if  any,  is  removed  by  filtering  and  washing,  and  the  filtrate  evaporated 
in  a  small  tared  platinum  dish,  ignited  below  redness,  and  weighed. 
This  gives  the  weight  of  the  mixed  chlorides.  The  residue  is  taken  up 
with  hot  water,  from  5  to  10  cc.  of  a  10%  solution  of  platinic  chloride 
added,  and  the  whole  evaporated  to  a  sirupy  consistency  on  the  water- 
bath;  it  is  then  treated  with  80%  alcohol,  the  precipitate  washed  with 
80%  alcohol  by  decantation,  transferred  to  a  Gooch  crucible,  dried  at 
Too°  C,  and  weighed.  The  weight  of  the  precipitate,  multiplied  by 
0.10308,  gives  the  weight  of  K2O,  and  by  0.3056  the  equivalent  amount 
of  KCl.  The  weight  of  KCl  found  is  subtracted  from  the  weight  of 
the  mixed  chloride,  the  remainder  being  NaCl,  which,  multiplied  by 
0.5300  gives  the  weight  of  Na20  in  the  sample. 

*  U.  S.  Dept.  of  Agric,  Div.  of  Clicm.,  Bui.  13,  part  5,  p.  593. 


346  FOOD  INSPECTION  AND  ANALYSIS. 

Determination  of  Phosphoric  Acid. — Method  oj  Ihe  A,  O.  A.  C.*— 
Mix  5  grams  of  the  material  with  lo  cc.  of  magnesium  nitrate  solution,t 
dr}',  ignite,  and  dissolve  in  hydrochloric  acid.  Take  an  aliquot  part  of 
the  solution  prepared  above,  corresponding  to  0.25  gram,  0.50  gram,  or 
I  gram,  neutralize  with  ammonia,  and  clear  with  a  few  drops  of  nitric 
acid.  In  case  hydrochloric  or  sulphuric  acid  has  been  used  as  solvent, 
add  about  15  grams  of  dr\'  ammonium  nitrate,  or  a  solution  containing  that 
amount.  To  the  hot  solution  add  50  cc.  of  molybdic  solution!  for  every 
decigram  of  PoOj  that  is  present.  Digest  at  about  65°  for  an  hour,  filter, 
and  wash  with  cold  water,  or  preferably  ammonium  nitrate  solution.§ 
Test  the  filtrate  for  phosphoric  acid  by  renewed  digestion  and  addition 
of  more  molybdic  solution.  Dissolve  the  precipitate  on  the  filter  with 
ammonia  and  hot  water  and  wash  into  a  beaker  to  a  bulk  of  not  more 
than  100  cc.  Nearly  neutralize  with  hydrochloric  acid,  cool,  and  add 
magnesia  mixture  from  a  burette;  add  slowly  (about  i  drop  per  second), 
stirring  vigorously,  .\fter  fifteen  minutes  add  30  cc.  of  ammonia  solution 
of  density  0.96.  Let  stand  for  some  time;  two  hours  is  usually  enough. 
Filter,  wash  with  2.5%  NH3  until  practically  free  from  chlorides,  ignite 
to  whiteness  or  to  a  grayish  white,  and  weigh. 

Determination  of  Sulphuric  Acid. — Provisional  Method  A.  O.  A.  C.\\ — 
Boil  5  grams  of  the  powder  gently  for  one  and  one-half  hours  with  a  mix- 
ture of  300  cc.  of  water  and  15  cc.  of  concentrated  hydrochloric  acid. 
Dilute  to  500  cc,  draw  off  an  aliquot  portion  of  100  cc,  dilute  considerably, 
precipitate  with  barium  chloride,  filter  through  a  Gooch  crucible,  ignite, 
and  weigh.  Direct  solution  of  the  material  without  burning  the  organic 
matter  was  proposed  by  Crampton.^ 

Determination  of  Ammonia  (present  in  the  form  of  ammonia  alum 
or  ammonium  carbonate).  Mix  5  grams  of  the  sample  with  200  cc.  of 
water,  and  add  an  excess  of  sodium  hydroxide.  Distil  into  standard 
acid,  and  determine  the  ammonia  by  titration. 

Detection  and  Determination  of  Arsenic. — Proceed  according  to  ths 
Marsh  or  Sanger-Black-Gutzeit  method  without  preliminary  treatment 
(page  75)- 


♦  U.  S.  Dept.  of  A'?ric.,  Div.  of  Chem.,  Bui.  46,  p.  12;   Bui.  107  (rev.),  p.  4- 

t  Prepared  as  follows:  Dissolve  80  grams  calcined  magnesia  in  nitric  acid,  avoiding  an 
excess  of  acid,  then  add  a  little  calcined  magnesia  in  excess,  boil,  filter  from  the  excess  of 
magnesia,  ferric  oxide,  etc.,  and  dilute  with  water  to  500  cc. 

X  Reagent  No.  53. 

§  Prepared  by  dissolving  100  grams  of  ammonium  nitrate.  Reagent  No.  54,  in  i  liter  of 
"Water, 

D  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  107;  Bui.  107  (rev.),  p.  178. 

ir  U.  S.  Dept  of  Agric,  Div.  of  Chem.,  Bui.  13,  part  5,  p.  596. 


CERE  A  Lb-,   LEGUMES,    VEGETABLES,   AND   FRUITS. 


347 


SEMOLINA,  MACARONI,  AND   EDIBLE  PASTES. 

Semolina  is  the  coarse  meal  ground  from  certain  varieties  of  hard 
or  "  durum  "  wheats,  grown  originally  in  Italy,  Sicily,  and  Russia,  but 
at  present  in  France  and  certain  parts  of  the  United  States  and  Canada. 
This  hard  wheat  is  high  in  gluten,  and  especially  adapted  for  the  pre[)ara- 
tion  of  macaroni  and  the  various  j)astes.  A  peculiar  process  is  employed 
in  preparing  the  wheat,  whereby  the  husk  is  removed  by  wetting,  heating, 
grinding,  and  sifting,  the  resulting  meal  or  semolina,  being  in  the  form 
of  small,  round,  glazed  granules. 

Italian  Pastes.  —  Semolina  furnishes  the  basis  of  the  Italian  edible 
pastes,  being  mixed  with  warm  water,  kneaded,  and  molded  into  various 
forms,  either  by  pressure  through  holes  in  an  iron  plate,  or  otherwise, 
and  finally  dried.  In  parts  of  Italy  juices  of  carrots,  onions,  and  other 
vegetables  are  said  to  be  mingled  with  the  paste,  but  for  local  consumption 
only.  Saffron  is  sometimes  added  to  pastes  for  the  purpose,  so  it  is 
claimed,  of  imparting  a  spicy  flavor,  although  the  quantity  used  is  often 
so  small  as  to  be  apparent  only  to  the  eye,  thus  indicating  that  the  real 
object  of  its  addition  is  to  impart  a  color  in  imitation  of  an  egg  paste. 

Macaroni  is  the  larger  of  the  slender-tube  or  pipe-shaped  products; 
vermicelli  is  the  worm-shaped  variety,  produced  when  the  holes  in  the 
plate  are  very  small;  spaghetti  is  the  term  applied  to  the  cord -like  paste 
intermediate  in  size  between  the  others.  A  variety  of  Italian  pastes  or 
pates  is  made  by  rolling  the  kneaded  semolina  into  thin  sheets,  and  cutting 
out  in  shapes  of  animals,  letters  of  the  alphabet,  etc. 

The  composition  of  some  of  these  products  is  as  follows: 


No.  of 
Samples. 


Water. 


Protein. 


Fat. 


Total 
Carbohy- 
drates. 


Crude 
Fiber. 


Ash. 


Fuel 
Value 

per 
Pound. 
Gal's. 


Semolina  * j 

Macaroni  f !        ii 

Noodles  t i  2 

SpagheUi  f I         3 

Vermicelli  f '        15 

*Balland. 


10.50 
10.3 
10.7 
10.6 
II. o 


11.96 

13-4 
II. 7 
12. 1 
10.9 


0.60 

0.9 

i.o 

0.4 

2.0 


75-79 
74-1 


0.50 

0.4 
0.4 


0.65 

1-3 
i.o 
0.6 
4-1 


1665 
1665 
1660 
1625 


t  Atwater  and  Bryant. 


Noodles  are  a  strap-shaped  form  of  paste  made  in  German  house- 
holds as  well  as  in  factories.  True,  or  egg-noodles,  contain  a  certain 
percentage  of  eggs,  while  water-noodles  are  practically  the  same  in  com- 
position as  Italian  pastes.     The  difference  in  composition  between  water- 


:A' 


FOOD   INSPECTION   AND    ANALYSIS. 


noodles  and  noodles  maele  with  different  numbers  of  eggs  or  egg  yolks 
per  German  pound  of  llour,  is  shown  by  the  analyses  of  Juckenack  and 
Pasternack*  given  in  the  following  table:! 


Composition  of  the  Dry  Matter. 

0  0 

Co 

mposition  of  the  Dry  Matter. 

^^ 

j 

"o  = 

1^ 

Ash. 

Total 
Phos- 
phoric 
Acid. 

Lecithin 
Phos- 
phoric 
Acid. 

Ether 
Extract 

Protein 
NX6i 

Ash. 

Total 
Phos.- 
phoric 
Acid. 

Lecithin 
Phos- 
phoric 
Acid. 

Ether  1  Protein 
Extract   NX6i 

2 

Z^i 

% 

% 

% 

% 

% 

% 

% 

% 

% 

% 

o 

0.460 

0.2300 

0.0225     0.66 

12.00 

0 

0.460 

0.2300 

0.0225 

0.66 

12.03 

I 

0.565 

0.2716 

0.0513     1.56 

12.99 

I 

0.488 

0.2720 

0.0518 

1-57 

12.37 

2 

0.664 

O.3110   0.0786     2.42 

13.92 

2 

0.516 

0.3127 

0.0801 

2.47 

12.73 

3 

* 

0-758 

* 

0.3482 
* 

0.1044    3 -24 

*             * 

14.81 
* 

3 
* 

0.542 
* 

0.3520 
* 

0.1075 

* 

3-33  1   13-07 
*            * 

12 

1.426 

0.6123 

0.2875    7-94 

21.09 

12 

0.745 

0.6533 

O.3171 

8.64  \  is-n 

From  these  results  it  appears  that  the  percentages  of  ash,  total  phos- 
phoric acid,  and  protein  are  appreciably  increased  by  the  addition  of 
each  egg  or  egg  yolk,  while  the  j)crcenlagcs  of  lecithin-phosphoric  acid 
and  ether  extract  are  more  than  doubled  by  the  addition  of  the  first  egg, 
and  are  increased  in  corresponding  proportion  by  the  addition  of  two  or 
more  eggs. 

The  German  Association  of  Food  Chemists  require  that  commercial 
egg-noodles  contain  at  least  0.045','^  of  lecithin-phosphoric  acid,  and 
2.oo';'t  of  ether  extract,  corre.s])onding  to  the  minimum  in  noodles  with 
two  eggs  per  half  kilogram  of  flour. 

S[)aethJ  con.siders  that  if  the  ether  extract  of  noodles  has  an  iodine 
number  over  98,  it  is  safe  to  assume  that  they  contain  no  eggs  or  only 
traces. 

In  interpreting  the  results  of  analysis  it  .should  be  remembered  that 
fat  may  have  been  introduced  in  .some  form  other  than  in  eggs,  and  that 
the  lecithin-pho.sphoric  acid  dimini.shes  .somewhat  on  long  standing. 
Allowance  .should  also  be  made  for  the  variation  in  co.mposition  of  the 
eggs  and  flour. 

Of  22  brands  of  American  noodles  examined  by  Winton  and  Bailey§ 
only  5  appeared  to  be  made  with  eggs;    the  lecithin-phosphoric  acid  in 


*  Zeits.  Unters.  Nahr.  Gcnuss.,  3,  1900,  p-  13;    8,  1904,  p.  94. 

t  The  German  pound  is  approximately  468  grams;    the  avoirdupois  pound  is  454  grams. 

X  Forsch.  iiber  Lebensm.,  3,  1896,  p.  49. 

§  Jour,  Am.  Chem.  Soc.  1905,  37,  p.  137;    Rep.  Conn.  Exp.  Sta.,  1904,  p.  138. 


CEREALS,   LEGUMES,    l^EUHTABLES,   AND   FRUITS. 


349 


these  ranged  from  0.036  lo  0.058,  and  the  ether  extract  from  1.83  to  2.33 
per  cent,  while  in  the  other  .samjjles  the  lecithin-phosphoric  ranged  from 
0.015  to  0.032  and  the  ether  extract  from  0.28  to  2.50  per  cent. 

Adulteration  of  Pastes.  — Rice,  corn,  and  potato  flours  have  been 
used  in  the  preparation  of  the  cheaper  varieties  of  .semolina,  but  rarely 
in  this  country.  A  more  common  form  of  adulteration  is  the  substitution 
of  water-noodles  for  egg-noodles,  artificial  colors  being  used  to  carry 
out  the  deception.  Substitutions  of  this  kind  arc  detected  by  determina- 
tions of  lecithin-phosphoric  acid  and  ether  extract,  supplemented  by  tests 
for  artificial  colors. 

Shredded  Wheat  is  a  whole-wheat  preparation,  put  out  in  the  form 
of  light  biscuits  built  up  of  fine  porous  threads,  not  unlike  those  of  vermi- 
celli. The  wheat,  softened  by  boiling,  is  shredded  by  passing  through 
a  peculiar  machine,  after  which  the  biscuits  are  made  by  lightly  putting 
together  the  threads  and  by  final  baking.  The  comparative  composition 
of  shredded  wheat  and  of  typical  whole  wheat  is  thus  shown  by  Wiley:* 


Constituents. 

Shredded 
Biscuit. 
Per  Cent. 

Typical 
Wheat. 
Per  Cent. 

Moisture 

IO-57 
12.06 

1-03 

2.65 

2.58 

71. II 

10.60 

12.25 

1-75 

1-75 

2.40 

71-25 

Ether  extract 

Ash 

Crude  fiber 

Carbohydrates  other  than  fiber 

ANALYSIS    OF    PASTES. 


Determination  of  Lecithin-phosphoric  Acid. — Jnckenack's  Mellwd.f 
— Extract  30  grants  of  the  finely  ground  material  for  10  hours  with  abso- 
lute alcohol  in  a  Soxhlet  extractor  at  a  temperature,  inside  the  extractor, 
not  below  55°-6o°  C.  The  extraction  flask  should  be  provided  with  a 
small  quantity  of  pumice  stone  to  prevent  bumping  during  the  boiling,  and 
the  extractor  enclosed  by  asbestos  paper,  if  the  desired  temperature  is  not 
readily  maintained.  After  the  extraction  is  completed,  add  5  cc.  of  alco- 
holic solution  of  potash  (prepared  by  dissolving  40  grams  of  i)hosphorus- 
free  caustic  potash  in  1000  cc.  alcohol),  and  distil  off  all  the  alcohol. 
Transfer  the  residue  to  a  j)latinum  dish  by  means  of  hot  water,  evaporate 

to  dryness  on  a  water  bath,  and  char  over  asbestos.     Treat  the  charred 

. I 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  13,  p.  1337. 
t  Zeits.  Unters.  Nahr.  Genuss.,  3,  1900,  p.  13. 


35°  FOOD  INSPECTION  AND  ANALYSIS. 

mass  with  dilute  nitric  aciil,  filtrr,  ami  wash  with  water.  Return  the 
residue  with  the  paper  to  the  platinum  dish,  and  Inirn  to  a  white  ash. 
Treat  again  with  nitric  acid,  filter  and  wash,  uniting  the  filtrates. 
Determine  phosphoric  acid  by  the  usual  method. 

Detection  of  Artificial  Colors  in  Pastes. — The  following  colors 
have  been  used  in  noodles  and  other  pastes:  turmeric,  saffron,  annatto, 
naphthol  yellow  (Martius  yellow),  naphthol  yellow  S,  picric  acid,  aurantia, 
\'ictoria  yellow,  tartrazine,  metanil  yellow,  azo  yellow,  gold  yellow,  and 
quinoline  yellow.  Of  these  naphthol  yellow,  picric  acid,  metanil  yellow, 
and  \'ictoria  yellow  are  injurious  to  health,  and  their  use  is  illegal  in 
European  countries  as  wtU  as  in  the  United  States.  Fortunately,  they 
are  rarely  found  in  the  products  now  on  the  market. 

The  detection  of  artificial  colors  is  complicated  by  the  presence  of  the 
natural  coloring  matter  of  the  flour  and  the  lutein  of  eggs.  These  are 
conveniently  extracted  by  ether,  which  does  not  remove  the  artificial 
colors,  although  most  of  them  unmixed  dissolve  freely  in  this  solvent, 

Juckeuack's  Method* — Thoroughly  shake  two  portions  of  the  finely 
ground  material,  each  of  about  lo  grams,  in  test  tubes  with  15  cc,  of 
ether  and  15  cc.  of  70%  alcohol  respectively,  and  allow  to  stand  12  hours. 

(a)  If  the  ether  remains  uncolored  or  only  slightly  tinted  and  the 
material  below  it  remains  yellow,  while  the  alcohol  is  distinctly  colored 
and  the  material  is  decolorized,  a  foreign  dye  is  indicated. 

(6)  If  both  ether  and  alcohol  are  colored,  either  (i)  lutein  (egg  color) 
alone,  or  (2)  this  with  a  foreign  dye  is  present. 

1.  Treat  a  portion  of  the  ether  solution  with  dilute  nitrous  acid, 
according  to  Weyl.  If  the  ether  is  not  completely  decolorized,  a  foreign 
dye  is  present. 

2,  If  the  deposit  of  material  below  the  alcohol  is  decolorized,  while 
that  below  the  ether  is  colored,  tests  should  be  made  for  foreign  dyes  as 
follows:  Shake  the  portion  previously  treated  with  ether  with  three  or 
more  fresh  portions  of  the  same  solvent,  until  no  more  color  is  extracted, 
and  then  shake  the  residue  with  70%  alcohol  and  allow  to  stand  12  hours. 
After  filtering,  concentrate  the  .solution  slightly,  acirlify  with  hydrochloric 
acid,  boil  with  sensitized  wool,  and  identify  the  color  in  the  usual  manner 
(page  801). 

SchlegeVs  Mclhod.'\ — Extract  100  grams  of  the  finely  powdered  material 
with  ether  in  a  continuous  extraction  apparatus,  and  shake  the  residue 

*  Zeits.  Unters.  Nahr.  Genuss.,  3,  1900,  p.  i. 

t  Untcrsuchungsanstalt,  XiJrnberg,  Her.,  1906,  p.  24. 


CEREALS,  LEGUMES,    VEGETABLES,   AND   FRUITS.  351 

at  frequent  intervals  for  half  a  day  with  a  mixture  of  140  cc.  of  alcohol, 
5  cc.  of  ammonia,  and  105  cc.  water.  Filter,  evaporate  to  remove  alcohol 
and  ammonia,  acidify  slightly  with  hydrochloric  acid,  and  again  filter. 
Boil  the  filtrate  with  sensitized  wool,  and  identify  the  color  on  the  dyed 
fiber  by  the  usual  tests  (page  801). 

Fresenius  Method.^ — Extract  20  to  40  grams  of  the  powdered  material 
with  ether  in  a  continuous  extraction  apparatus.  Dry  the  residue  to 
remove  ether,  shake  for  15  minutes  with  120  cc.  of  60%  acetone,  and 
allow  to  stand  12  to  24  hours.  Filter,  evaporate  until  the  acetone  is 
removed,  and  divide  into  two  jjortions,  a  larger  and  a  smaller.  To  the 
larger  portion  add  sufficient  acetic  acid  to  dissolve  Hocks,  and  boil  with 
sensitized  wool.  Remove  natural  coloring  matter  from  the  wool  by 
boiling  in  dilute  acetic  acid.  If  after  this  treatment  the  wool  is  dyed 
the  presence  of  a  foreign  color  is  indicated,  which  may  be  identified  by 
the  usual  tests. 

To  the  smaller  portion  of  the  aqueous  solution,  obtained  after  removal 
of  the  acetone  as  above  described,  add  an  equal  volume  of  alcohol,  heat 
to  dissolve  flocks,  divide  into  four  portions,  and  apply  special  tests  to 
three  of  these,  reserving  the  fourth  for  comparison.  The  natural  color 
of  the  flour  is  decolorized  by  hydrochloric  acid,  intensified  by  ammonia, 
but  not  affected  by  stannous  chloride,  even  on  heating.  Saffron  reacts 
in  a  similar  manner,  but  is  only  slightly  bleached  by  the  acid,  and  is  not 
affected  by  the  other  two  reagents. 

Piutti  and  Bentivoglio  Metliod.-\ — This  method  is  especially  designed 
to  detect  the  four  colors  forbidden  by  Italian  law,  and  to  distinguish  these 
from  naphthol  yellow  S. 

Add  50  grams  of  the  paste  to  500  cc.  of  boiling  water,  made  alkaline 
with  2  cc.  of  concentrated  ammonia  water,  add  60  to  70  cc.  of  alcohol,  and 
continue  the  boiling  40  minutes.  After  filtering,  acidify  the  liquid  with 
2  to  3  cc.  of  dilute  hydrochloric  acid  and  boil  with  5  to  6  strands  of  sensi- 
tized wool,  each  strand  weighing  about  0.5  gram.  Wash  the  wool, 
dissolve  the  color  in  dilute  ammonia,  and  repeat  the  dyeing.  After 
dissolving  a  second  time  in  ammonia,  evaporate  the  solution  of  the  dye 
to  dryness,  avoiding  as  far  as  possible  the  formation  of  a  skin,  and  take 
up  the  residue  in  water.  If  a  skin  has  formed,  filter  and  test  the  insoluble 
matter  for  metanil  yellow  with  dilute  hydrochloric  acid,  and  for  picric 
acid  with  ammonium  sulphide. 

*  Zeits.  Llnters.  Nahr.  Genuss.,  13,  1907,  p.  132. 
t  Gaz.  chim.  Ital.  36,  II,  1806,  p.  385. 


o^- 


Foon  fS'SPEcnow  ^np  .^n^ lysis. 


To  I  cc.  of  the  filtrate  add  stannous  chloride  solution  and  a  little 
sodium  hydroxide,  or  preferably  sodium  cthylate.  If  no  red  color  forms, 
nitro-colors  are  absent;  if,  also,  in  another  portion  dilute  hydrochloric 
acid  proiluccs  no  violet  color,  thus  showing  the  absence  of  metanil  yellow, 
Tio  further  test  is  necessary.  In  the  presence  of  these  colors,  acidify  the 
remainder  of  the  solution  with  acetic  acid,  shake  violently  with  carbon 
tetrachloride,  and  identify  the  color  according  to  the  following  scheme: 

A.  Color  dissolves  in  carbon  tetrachloride  to  colorless  solution. 
Extract  with  very  dilute  ammonia,  concentrate  and  divide  into  two  parts. 

1.  Acidify  with  hydrochloric  acid,  and  add  i  to  2  drops  of  stannous 
chloride  and  ammonia  in  excess.  A  rose  colored  solution  and  precipi- 
tate form NapJithol  yellow. 

2.  Acidify  slightly  with  hydrochloric  acid,  add  a  little  zinc  dust  and 
stir.     Solution  becomes  rose-violet Victoria  yellow. 

B.  Color  is  insoluble  in  carbon  tetrachloride.  Evaporate  to  dryness 
on  water-bath,  take  up  in  water  and  divide  into  three  parts. 

1.  Hvdrochloric  acid  produces  a  violet  coloration Metanil  yellow. 

2.  Ammonium    sulphide    produces   a   red    brown    coloration. 

Picric  acid. 

3.  Stir  on  a  water-bath  with  zinc  dust  and  ammonia,  filler,  treat  with 
zinc  dust  and  hydrochloric  acid  and  again  filter,  (a)  Potassium  hydroxide 
produces  a  yellow  coloration,  and  (b)  ferric  chloride  an  orange  coloration. 

N  a  pill  hoi  yellow  S. 

Schmitz-Dumont  Test  for  Tropeolins* — Moisten  a  small  portion  of 
the  material  with  a  few  drops  of  dilute  hydrochloric  acid.  The  formation 
of  a  reddish  or  bluish  color  shows  the  presence  of  an  azo  color  or  some 
other  coal-tar  color. 

Test  for  Turmeric. — Extract  the  color  from  the  ground  material  by 
alcohol  and  identify  by  the  boric  acid  test  (page  791). 

PREPARED    CEREAL    BREAKFAST    FOODS. 

The  large  number  and  variety  of  these  preparations  now  on  the  market 
testify  to  the  fact  that  the  breakfast  cereal  forms  a  most  important,  as  well 
as  ( onsid(  rable,  portion  of  our  food  supply.  These  foods  are  generally 
prepared  from  wheat,  oats,  and  corn,  and  are,  as  a  rule,  remarkably  pure 
and  free  from  adulteration,  though  the  food  value  of  different  varieties 

*  Zeits.  offent.  Chem.,  8,  1902,  p.  424. 


- 


CEREALS,   LEGUMES,    l^EGETARLES,  AND  FRUITS,  355 

is  often  grossly  misstated  by  their  manufacturers.  Formerly  the  break- 
fast food  consisted  entirely  of  the  coarsely  ground,  generally  decorticated, 
raw  cereal  grain,  and  required  a  long  period  of  cooking  to  prepare  it  for 
use.  At  present  many  of  the  oat  products,  and  to  some  extent  also  those 
of  corn,  rice,  and  wheat,  are  subjected  to  a  more  or  less  preliminary  cook- 
ing and  dr}^'ing,  whereby  they  are  capable  of  being  prepared  for  use  in; 
a  much  shorter  time,  and  their  keeping  qualities  are  enhanced.  The 
so-called  rolled  oats  are  prepared  by  softening  the  grains  through  steam- 
ing, after  which  they  are  crushed  between  rollers  and  afterwards  dried. 
The  steaming  process  is  a  typical  one  for  various  other  cereals,  though 
in  some  cases  the  heating  consists  in  baking  or  kiln  drying. 

The  effect  of  the  preliminary  cooking  on  the  finished  product  varies 
somewhat  according  to  whether  dry  or  moist  heat  has  been  applied,  and 
is  chiefly  noticeable  in  the  altered  character  of  the  carbohydrates.  In 
all  cases  the  starch  is  rendered  more  soluble,  whether  by  the  conversion  of 
a  portion  into  dextrin  and  dextrose,  or  by  a  simple  breaking  dowrt 
of  the  starch  grains,  as  in  the  case  of  bread  in  baking. 

In  spite  of  the  seemingly  endless  variety  of  the  package  cereals,  they 
divide  themselves  as  a  matter  of  fact  into  a  very  few  well-defined  classes, 
the  members  of  which  differ  but  little  from  each  other  except  in  name. 

First  there  are  the  raw  cereal  grains  of  the  oat,  wheat,  and  corn,  pre- 
pared by  simple  crushing  to  various  degrees  of  fineness,  after  decorticating  j 
next  comes  the  classes  of  partially  cooked  preparations  of  each  of  these 
grains,  appearing  in  various  forms  of  "flakes,"  "granules,"  "grits," 
etc.,  and  again  a  class  known  as  malted  cereals,  in  which  the  moist,  ground 
grain  is  mixed  with  malted  barley,  and,  by  controlling  the  temperature, 
a  portion  of  the  starch  is  converted  to  maltose  and  dextrin,  after  which, 
the  mixture  is  crushed  between  hot  rollers  and  dried. 

In  the  preparation  of  most  of  the  com  breakfast  products,  such  as 
samp  and  hominy,  it  is  customary  to  remove  the  germ,  which  contains, 
the  oil  and  fat,  lest  the  tendency  of  the  latter  to  become  rancid  should! 
result  in  the  deterioration  of  the  food.  In  wheat  foods  the  germ  Ls  less-, 
often  removed,  and  rarely,  if  ever,  in  oat  preparations.  The  amount 
of  fat  found  in  the  prepared  cereal  food  as  compared  with  that  in  the 
whole   grain   is   of  interest   in   this   connection. 

Composition  of  Some  of  the  Common  Breakfast  Cereals. — The  follow- 
ing analyses  will  servT  to  typify  the  various  classes  of  these  preparations 
as  they  appear  on  the  market: 


354 


FOOD  INSPECTION   ylND  /IN A  LYSIS. 


Will  "AT.* 

Whcatena 

IVttijohn's  breakfast  food 

Farina 

Cracked  wheat 

Ralston's  breakfast  food 

Fould's  wheat  germ 

Oats* 

Quaker 

Hornby's 

Buckeve 

Corn. 

Ccrcalinc  * 

Wlvot  meal  * 

Hecker's  hominy  t 

Nichols'  snow-white  sampf. . . 

MlSCELLANTOUS.f 

Brittle  bits 

Force 

Grape-nuts 

Ralston's  health  barley  food. . 


6.65 

9-51 
10.94 

9-30 

9-'/ 

10.13 

7.40 
7-63 
7-54 


Carboh  ydrates. 


2.2»  14.1775.62 
1.4510  5676.96 
1.56  IC. 90  75.91 
2.22  12.6094.42 
I. Qo'lS. 1071.75 
1.46  13.30  73.93 

6.08  17.20  66.65 
7.35I17.8265.47 
8.30  16.89165.55 


1.24 
2.32 

0-3 
0-3 


6.9 

5-4 

4-2 

10.8 


9.9078.75 
6-7S!8o.53 
9.4    78-6 
8.2    80.5 


0.5  14. 

1.4  II. 6 

I.I  |l2.6 

1.0  110.7 


76.0 
76.8 
78.4 
75-8 


3    TO 

1^ 


3-9 


1.6 
1-3 
2,-2, 

7-1 


<U  V 


70.50 

72-15 
72.12 
69.63 
65.60 
69-35 

64.65 
62.74 
60.90 

70-93 

77-77 


2£ 


1.22 
2.01 

0.59 
1.49 

1-55 
o. 

1.40 
1-43 
1-35 

0.72 
0.96 
0.4 
0.4 


1.9 
0.6 


1.28 

1-52 
0.69 
1 .46 

1-53 
I.I 

1.67 

1-73 
1.72 

0.56 
0.60 


1-5 
2.8 


3S3 
0.231 

■153 
•333 
■343 
.326 

-341 
0-443 
0.416 

0.192 
0.185 


3  E  ^ 


4343 
4174 
4051 
4236 
4158 
4087 

4673 
4756 
4526 

4542 
3660 


♦  Analyses  made  by  Slossun,  WyomiriK  Exp.  Sta.,  Bui.  33. 

t  Analyses  made  by  Merrill  and  Mansfield,  Maine  Exp.  Sta.,  Bui.  84. 

The  mcthod.s  of  analy.sis  employed  for  these  preparations  are  the 
same  as  for  ordinary  cereals  (p.  277),  the  sample  being  ground  fine 
enough  to  pass  through  a  i-mm.  sieve. 


PREPARED    FOODS    FOR    INFANTS    AND    INVALIDS. 

In  dealing  with  the  composition  and  analysis  of  this  cla.ss  of  proprie- 
tan,'  foofls  more  than  ordinary  care  is  necessary,  in  view  of  the  fact  that 
one  or  another  of  these  preparations  are  frecjuently  prescribed  for  the 
exclusive  diet  of  tho.se  whose  very  life  may  depend  on  the  character  and 
.suitability  of  the  food  to  the  ca.se  in  hand.  Many  of  these  foods  do,  as 
a  matter  of  fact,  honestly  fulfil  the  claims  of  their  manufacturers,  but 
others  fall  far  .short  of  .so  doing,  .so  that  it  is  hardly  safe  to  u.se  them  unless 
some  intelligent  idea  cjf  their  comjK)siti(jn  can  be  gained.  It  is  not,  as 
a  rule,  within  the  jjrovince  of  the  analyst  to  furnish  an  opinion  regarding 
the  adaptability  of  a  certain  food  to  the  requirements  of  an  infant  or 
invalid,  but  rather  to  j^rovide  the  necessary  data  whereon  such  an  opinion 
may  be  intelligently  ba.sed. 


CEREALS,   LEGUMES,    VEGETABLES,  AND   FRUITS.  355 

A  simple  statement  of  moisture,  fat,  protein,  carbohydrates  (by  dif- 
ference), and  ash,  which  in  the  case  of  ordinary  foods  would  often  be 
sufficient,  would  be  obviously  inadequate  in  expressing  the  analysis  of 
an  infant  food,  since  it  is  of  much  more  vital  importance  than  in  other 
foods  to  know  the  solubility  of  the  food  itself,  and,  to  as  great  an  extent 
as  possible,  the  character  of  the  carbohydrates. 

The  chief  ingredients  of  many  of  these  preparations  are  wheat,  or 
mixed  cereals  high  in  starch.  Many  of  the  foods  are,  according  to  the 
directions,  to  be  used  practically  without  cooking,  but  by  simply  mixing 
with  milk  or  water,  and,  in  some  cases,  bringing  to  the  boiling-point. 
Hence  the  degree  of  conversion  which  the  raw  starch  has  undergone  in 
the  process  of  manufacture  of  the  food  should,  if  possible,  be  ascertained 
as  a  prime  factor  in  judging  of  its  character  and  adaptability  to  the  needs 
of  the  young  child  and  of  the  sick.  Incidentally  it  should  be  said  that 
few  if  any  of  the  infant  foods,  even  those  whose  high  character  has  long 
been  established  by  continued  trial,  conform  very  closely  to  the  composi- 
tion of  woman's  milk,  which  was  long  accepted  as  the  true  standard  on 
which  to  base  their  efficiency.  Hence  it  is  no  easy  task  to  pass  judgment 
on  a  particular  food  from  its  chemical  composition  alone  without  trial, 
nor  is  it  right  to  unqualifiedly  condemn  in  all  cases  food  high  in  insoluble 
carbohydrates,  since  there  are  undoubtedly  many  instances  in  which 
such  foods  are  successfully  used. 

Classification  and  Preparation  of  Infants'  Foods. — These  foods  may 
for  convenience  be  divided  into  two  main  classes,  \\z.,  farinaceous  foods, 
or  those  which  are  prepared  wholly  or  chiefly  from  one  or  more  cereal 
grains,  and  lactated  foods,  or  those  in  which  cow's  milk  forms  the  basis, 
but  which  may  contain  in  addition  thereto  various  other  substances,  such 
as  cereals,  sugars,  etc. 

The  farinaceous  foods,  which  are  usually  directed  to  be  mixed  with 
milk  before  using,  may  be  further  subdivided  into  {a)  those  that  consist 
chiefly  of  unconverted  starch,  (b)  those  whose  starch  has  been  nearly 
all  hydrolyzed  to  soluble  form  in  the  process  of  manufacture,  and  (c)  those 
which  contain  much  unconverted  starch,  but  in  addition  thereto  diastase 
or  some  other  ferment,  which,  when  the  food  is  mixed  with  warm  water 
or  milk,  is  supposed  to  convert  all  the  starch  to  soluble  form. 

The  unconverted  starch  foods  are  nearly  all  made  up  of  baked  dry 
flour,  chiefly  that  of  wheat,  but  sometimes  a  mixture  of  cereals  (as  oats, 
barley,  and  wheat)  and  sometimes  oats  or  barley  alone.     The  baking 


;56 


FOOD    INSPECTION  ASD   ANALYSIS. 


breaks  down  to  some  exicni  the  starch  grains,  as  in  the  case  of  bread 
or  crackers,  but  does  not  actually  convert  much  of  it  to  sugar. 

The  soluble  farinaceous  foods  are  usually  prepared  somewhal;  as 
follows:  A  mixture  of  ground  wheat  and  barley  malt  (with  sometimes  a 
little  wheat  bran)  is  mixed  with  water  to  form  a  paste,  and  a  little  bicar- 
bonate of  potash  added.  The  mixture  is  heated  at  65°  C.  for  sufficient 
time  to  convert  the  starch,  after  which  it  is  exhausted  with  w\arm  water, 
the  extract  being  strained,  and  the  liltrate  evaporated  to  dryness  to  form 
the  food.  The  sugars  of  such  foods  consist  largely  of  maltose  mixed 
with  dextrin. 

The  farinaceous  foods,  which  depend  for  the  conversion  of  their  starch 
on  the  method  of  cooking  or  heating  before  serving,  are  usually  mixtures 
of  wheat  or  other  cereal  flour  with  malt  or  pancreatic  extract. 

The  milk  foods  are  variously  prepared,  cither  by  the  simple  desicca- 
tion of  cow's  milk  (usually  previously  skimmed)  or,  when  whole  milk 
is  used,  by  mingling  the  desiccated  milk  with  sugars  or  baked  cereal  flour. 
Sometimes  desiccated  milk  is  used  in  mixture  with  a  dried  extract  of 
malted  cereals.  In  fact  all  sorts  of  mixtures  are  found  on  the  market, 
involving,  however,  in  nearly  all  cases,  one  modification  or  another  of 
the  above  general  ])roccsses  of  preparation. 

Composition. — Few  complete  analyses  of  these  classes  of  foods  have 
recently  been  made.  Among  the  best  are  those  of  McGill,*  from  whose 
work  the  following  figures  have  been  selected,  illustrating  typical  examples 
of  foods  on  the  market: 


C  O 

l< 


farinaceous  foods: 

Imjicrial  granum 

Ridge  8  foor] 

Mother's  forjd 

Robinson's  barlcv 

Mixcfl  fofxJs: 

H'-'-'      --.Itcdmilk 

I  A 

M    .  , ! 

Nestle  s  milk  foofl 

Rcid  <t  Camrick's  baby  food  . . 


9 

12 

8 

9 
2 


ci 

t^ 

■5; 

(SS 

"3 

r' 

3 

0 

OS"" 

2o 

0 
0 

S 

fc. 

h3 

)-) 

6.04 

0.72 

3-94 

8.12 

0.48 

0.34 

4.67 

9-99 
9.41 

0.13 

0.41 

0.65 

2.26 

2-55 
5-77 

1. 41 
0.48 

28.24 

4.27 

4.72 

0.30 

2.18 

4-45 

39-54 

4-30 

5-69 

2.18 

•i.   C  Oi 

1-23 

02 


3-94 

t;.02 
8.83 
2.91 

63.87 

32.90 

82.0 

43-84 

38.21 


gx 


13-77 

13-83 

8.60 

7.46 

14.00 
10.01 
10. 10 
10.72 
16. 6c 


0.49 

0-53 
2.08 
0.94 

3-57 
2-57 
3-50 
1.60 
2.78 


Canatlian  Dept.  of  Inlantl  Rev.,  Bui.  59. 


CEREALS,  LEGUMES,    VEGETABLES,   AND  FRUITS. 


357 


Starch, 

Fiber, 

etc.,  by 

Differ- 
ence. 

Maltose. 

L-tose.  ^Ca^- 

Remarks. 

Farinaceous  foods: 

Imperial  granum 

76.60 
72.01 
69.24 
78.66 

15.68 
47-72 

Ridsje's  food 

Mother's  fooci 

3.00 

Corn  and  wheat  starch 
Barley  starch 

Robinson's  barley 

Mi.xed  foods: 

Horlick's  malted  milk 

49.00 
50  to  60 

8    on 

Lactatcd  food 

30.00 

Trace 

Mellin's  food 

Nestle's  milk  food 

35-34 
34-54 

8.96 
30.00 

36-34 
8  to  9 

Reid  &  Caxnrick  's  baby  food . . . 

Diabetic  Foods.. — Gluten  flour  and  similar  preparations  are  primarily 
intended  for  the  use  of  diabetics,  from  whose  dietary  carbohydrates  must 
be  excluded. 

The  following  analyses  of  commercial  gluten  preparations  were  made 
by  Woods  and  Merrill.* 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


"Cooked  gluten" 

Whole-wheat  gluten  . . 

"Glutine" 

Breakfast  cereal  gluten 
Plain  gluien  flour  .  . . , 
Self-raising  flour 


16.88 
17.89 

15-31 
43-70 
53-60 
31-50 


3-86 
5.20 
0.99 
1.60 
1.20 
1.40 


76.80 

73-85 
82.52 
44-40 
34.50 
53 -20 


2.46 
3.06 
1. 17 
0.70 
0.60 
3.80 


Many  brands  of  gluten  flour  are  put  on  the  market  by  dealers  in  so- 
called  "health  foods,"  and  in  many  cases  are  represented  to  be  practically 
free  from  starch.  Thirteen  samples  of  gluten  flour  were  analyzed  by 
the  author  in  1899,  varying  in  price  from  11  to  50  cents  per  pound.  Of 
these,  3,  the  product  of  one  manufacturer,  contained  less  than  1%  of 
starch,  3  contained  from  10  to  20  per  cent,  while  7  contained  from  56  to 
70  per  cent  of  starch,  the  substance  which,  of  all  others,  the  diabetic  patient 
tries  to  avoid.  Some  of  these  preparations  were  little  better  than  whole- 
wheat flour.  An  analysis  of  one  of  them,  known  as  "  Pure  Vegetable 
Gluten,"  and  sokl  for  50  cents  per  pound,  and  of  two  similar  diabetic 
flours  reported  by  Winton  follow: 


*  Maine  E.xp.  Sta.  Buls.  55  and  75. 


35S                                    FOOD  INSPECTION  AND  ANALYSIS. 

"  Pure  Vegetable  "  Diabetic 

Gluten"  Food." 

Moisture 10.78  12.67 

.\sh 2.20  0.43 

Fat 3.25  0.90 

Protein 14-25  ii-37 

Crude  Fiber 0.25 

Sugars I  -  70  1 

De.xtrin 2.55  I  71.51 

Starch 5^-55  J 

Undetermined 8.72  2.87 


100.00 


"  Diabetic 
Flour." 

9.26 
1.30 
2.21 
14.25 
1.03 

66.63 

5-32 
100.00 


Winton  has  reported  the  following  analyses  of  flours  and  meals  well 
suited  for  the  preparation  of  diabetic  biscuit,  and  of  the  biscuit  made 
from  two  of  these  by  a  cook  in  the  family  of  a  diabetic  patient: 


3 

4 
< 

.si 

u 

2 
0 

I. 

si 

Mi: 
9.  X 

Is 

f. ,           ,^                  '  In  original 

Glu.en  (lour    .  . .  |  j.^,^    water-free. . . 

10.12 

0.22 
0.24 

2.35 
3.16 

4.38 
4-75 
5-33 
7-37 
2.46 

2-73 
6.42 
7.02 

85-38 
95.00 

50-91 
68.41 
39-87 
43.22 
16.71 
23.10 
85-56 
95.08 
50.62 
55-32 

0.03 
0.03 

0.64 

0.86 

3-85 

4-17 

1-55 
2.14 

3-69 

4. II 
3.18 
4.27 
25.09 
27.20 
12.84 
17-75 

0.56 

0.62 

17-34 

23-30 
19.06 
20.66 

35-91 

49.64 

0.50 

0.56 

15-63 
17.09 

4.46 
4.96 

G,..enbi.uh...{jj-ttr;.;ee:;; 

25-58 

Soja  bean  ,,,eal.{^-"Sr.'r;fVee;::L':" 

0  •    .          .•       .,[  In  original 27.66 

Soia  bean  biscuit  {  r-  i          .      t            \ 

'                           \  Calc.  water-free 

^       .,  a                  f  In  original 10.01 

C^'^  ^°"^ (  Calc.  water-free 

.,         J          ,          f  In  original S.?! 

Almond  meal  .  .  .  |  ^^^^  tater-free 

8-95 
9.70 

none 

none 

2.86 
3.12 

15-96 
17-45 

7.18 
7.85 

In  the  analysis  of  diabetic  foods,  the  determination  of  starch,  sugar 
and  dextrin  together  is  of  greater  value  than  of  starch  alone,  since  all 
three  clas.scs  of  carbohydrates  are  about  equally  injurious  to  diabetics, 
the  starch  and  fle.xtrins  being  converted  into  sugars  by  the  digestive 
fluids.  The  nitrogen-free  extract  of  cereal  preparations  corresponds 
clcsely  with  the  sum  of  the  starch,  sugar  and  dextrin,  but  in  the  case 
of  .soja  bean  meal,  almond  meal  and  other  products  of  legumes  and  oil 
seeds,  as  well  as  vegetables,  it  is  considerably  greater,  as  it  includes 
pentosans  and  other  .substances. 


CEREALS,  LEGUMES,   yEGETABLES,   AND   FRUITS.  359 

METHODS    OF    ANALYSIS. 

The  sample  is  prepared  for  analysis  by  grinding  it  sufTicicntly  fine  in 
a  mortar  or  mill  to  jjass  through  a  i-mm.  sieve.  Moisture,  fat,  ash,  and 
nitrogen  arc  determined  as  in  the  regular  methods  for  cereals  (pp.  276-278). 

In  determining  loss  of  weight  due  to  solubility  of  the  sample  in  alcohol 
and  water,  proceed  as  follows:*  The  fat-free  residue  left  in  the  Soxhlet 
apparatus,  after  extraction  with  ether  or  petroleum  ether,  is  subjected 
to  further  extraction  with  <:)$%  alcohol,  till  all  soluble  matter  has  been 
extracted.  If  5  grams  of  the  sample  were  originally  taken  for  the  fat 
extraction,  this  operation  would  require  about  five  hours.  Evaporate  the 
alcoholic  extract  to  dryness,  and  weigh  the  residue  as  in  the  case  of  the 
ether  extract.  Dry  the  residue  left  in  the  Soxhlet  from  the  alcoholic 
extract,  or  a  portion  thereof,  in  a  platinum  dish  over  the  water-bath, 
cool,  and  weigh.  Transfer  to  a  Gooch  crucible,  provided  with  asbestos 
and  previously  tared,  a  portion,  the  relation  of  which  to  the  original  weight 
taken  is  calculated  from  the  moisture,  ether,  and  alcohol  extracts  as  pre- 
viously determined.  Pass  through  the  contents  in  the  Gooch  by  suction 
from  200  to  300  cc.  of  cold  water  at  room  temperature,  dry  the  Gooch 
and  its  contents  at  100°  to  constant  weight,  cool  and  weigh,  thus  deter- 
mining the  solubility  of  the  sample  in  water. 

According  to  McGill,  five  hours'  extraction  with  alcohol  under  the 
above  conditions  removes  all  cane  sugar,  but  probably  not  all  the  lactose, 
maltose,  and  dextrose,  if  a  considerable  quantity  of  these  sugars  is  pres- 
ent. Water  dissolves  the  dextrin  and  gum  and  such  of  the  sugar  as 
escapes  solution  in  the  alcohol,  hence  the  sum  of  the  alcohol  and  water 
extract  is  of  value.  In  the  calculation  of  the  starch,  fiber,  etc.,  by  differ- 
ence, it  should  be  borne  in  mind  that  the  result  is  only  approximate,  by 
reason  of  the  fact  that  the  small  amount  of  soluble  albuminoids  (which 
McGill  states  never  exceeds  2|%)  are  reckoned  in,  hence  a  small  error 
is  introduced,  which  could  be  corrected,  if  considered  worth  w^hile,  by 
determining  the  amount  of  soluble  albuminoids. 

Separation  of  the  Carbohydrates  can  be  effected  by  Stone's  method 
(pp.  295,  296),  but  a  very  satisfactory  idea  of  the  solubihty  of  these 
foods,  which  is  of  chief  importance,  can  be  gained  by  the  much  simpler 
modified  method  of  McGill,  as  described  in  the  preceding  paragraphs. 

*  McGill,  Canada  Inland  Rev.  Dept.,  Bull.  58. 


360  FOOD  INSPECTION  /4ND  ^N.^ LYSIS 

Starch,  Sugar,  and  Dextrin  arc  dclcrmincfl  together  in  diabetic 
preparations  by  the  diastase  method  (p.  283)  omitting  the  prehminary 
washing  with  dilute  alcohol. 

Cold-water  Extract. — The  equivalent  of  10  grams  of  the  moisture-free 
substance,  finely  ground,  is  weighed  in  a  tared  flask,  and  water  added  irt 
several  portions  with  gentle  shaking  till  the  contents  of  the  flask  weigh 
110  grams.  The  flask  is  then  corked  and  vigorously  shaken  at  intervals 
during  six  or  eight  hours  and  allowed  to  stand  over  night.  The  super- 
natant liquid  is  then  decanted  into  the  large  tubes  of  a  centrifuge,  and 
whirled  till  the  sediment  settles  out.  The  conij)aratively  clear  liquid  may 
then  be  readily  Altered.  20  cc.  of  the  filtrate,  corresponding  to  2  grams. 
of  the  original  sample,  are  then  transferred  to  a  tared  dish,  evaporated  to 
dr)'ness,  and  dried  to  constant  weight,  as  in  the  determination  of  the 
total  solids. 

Additional  information  may  be  gained  from  the  speciflc  gravity  of 
the  10%  solution  of  the  cold-water  extract,  best  obtained  by  means  of  a 
pycnometer. 

Reducing  Sugars  are  determined  in  an  aliquot  part  of  the  above  10% 
solution,  diluted  to  j)roper  strength. 

Effects  of  Subsequent  Heating. — It  is  hardly  fair  in  the  case  of  those 
farinaceous  foods  w^hicli,  according  to  directions,  arc  to  be  subsequently 
subjected  to  heating,  or  boiling  with  water  or  milk,  to  condemn  them  as 
containing  much  insoluble  matter,  without  comparing  the  figures  express- 
ing results  of  the  analyses  of  the  raw  foods,  calculated  to  the  water-free 
basis,  with  those  obtained  on  analyzing  the  food  after  boiling  or  otherwise 
cooking  with  pure  distilled  water,  for  a  length  of  time  specified  in  the  direc- 
tions, and  afterwards  drying.  It  is  possible  that  the  presence  in  the  food 
of  diastase,  or  other  ferment,  may  be  depended  on  to  hydrolyze  a  whole 
or  a  portion  of  the  starch,  and  only  by  such  comparison  will  this  be  shown. 

Microscopical  Examination  of  the  food  is  of  value  in  determining 
its  general  character,  showing  especially  whether  or  not  starch  is  present 
in  its  original  form,  or  has  been  converted  in  whole  or  in  part.  The  par- 
ticular varieties  of  cereal  grain  employed  are  generally  evident,  as  well 
as  the  presence  and  proportion  of  the  different  tissues  of  the  grain. 


CEREALS,  LEGUMES,   VEGETABLES,  AND  FRUITS.  36 1 


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Snyder,  H.,  and  Voorhees,  AI.  A.     Studies  on  Bread  and  Bread-Making.     Exp.  Sta. 

Bui.  67. 
Stone,  W.  E.     Carljohydrates  of  Wheat,  Maize,  Flour,  and  Bread.     Action  of  Enzymes 

on  Starches.     Exp.  Sta.  Bui.  24. 
■ The  Quantitative  Determination  of  Carbohydrates  in  Food  Stuffs.     Jour.  Am. 

Soc,  19,  1897,  p.  347. 
Thatcher,  R.  W.     A  Comparison  of  \'arious  Methods  of  Estimating  the  Baking 

Qualities  of  Flour.     Jour.  Am.  Chcm.  Soc,  29,  1907,  p.  910. 

Wheat  and  Flour  Investigations.     Washington  Agric.  Exp.  Sta.  Bui.  84. 

TscHiRCH,   A.,    und    Oesterle,    O.     Anatomi-scher  Atlas   der  Pharmakognosic   und 

Nahrungsmittdkunde.     Leipzig,  1893. 
VOGL,  A.   E.     Verfalschungen  und  Verunreinigungen  des  Mehles  und  dercn   Xach- 

weisung.     Wien,  1880. 

Die  vvichtigsten  vegetabilischen  Nahrungs-u.  Genussmittcl.  Wleri  u.  Leipzig,  1899. 

Wanklyn,  J.  A.,  and  Cooper,  W.  J.     Bread  Analysis.     London,  1886. 

Wiley,  H.  W.     Sweet  Casava.     Div.  of  Chem.,  Bui.  44. 

Analysis  of  Cereals  Collected  at  the  World's  Columbian  Exposition.     Div.  of 

Chem.,  Bui.  45. 

Composition  of  Maize.     Div.  of  Chem.,  Bui.  50. 

Wiley,  H.  W.,  et  al.    Cereals  and  Cereal  Products.     Div.  of  Chem.,  Bui.  13,  Part  IX. 
Winton,  a.  L.     The  Microscopy  of  Vegetable  Foods.     New  York,  1906. 

Diabetic  Foods.     An.  Rep.  Conn.  Exp.  Sta.  1906,  p.  153. 

A  Modification  of  the  Bamihl  Test  for  Detecting  Wheat  Flour  in  Rye  Flour. 

A.  O.  A.  C.  Proc,  1908,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  p.  217. 
• The  Color  of  Flour  and  a  Method  of  Determining  the  Gasoline  Color  \'alue. 

A.  O.  A.  C.  Proc,  1910. 
Winton,  A.  L.,  and  Bailey,  E.  M.     On  the  Composition  of  American  Noodles  and 

Methods  for  the  Analysis  of  Noodles.     An.  Rep.  Conn.  Exp.  Sta.,  1904,  p.  138; 

Jour.  Am.  Chem.  Soc,  37,  1905,  p.  137. 
Winton,  A.  L.,  and  Ogden,  A.  W.     Macaroni,  Sphaghetti,  Vermicelli,  and  Noodles. 

An.  Rep.  Conn.  Exp.  Sta.,  1901,  p.  196. 
Winton,  A.  L.,  and  Shanley,  E.  J.     Simple  Tests  for  Detecting  Bleaching  in  Flour. 

A.  O.  A.  C.  Proc,  1908,  p.  216. 
Woods  and  Merrill.     Digestibility  and  Nutritive  Value  of  Bread.     Exp.  Sta.  Bui.  85. 
Arkansas  E.xp.  Station  Bui.     42.     W'heat  and  its  Mill  Products. 
California     "  "        "      93.     Oranges  and  Lemons. 

"  "  "        "loi.     Prunes,  Apricots,  Plums,  Nectarines. 

"     102.     Figs. 
"  "  "      An.  Reports,  1892  et  seq. 

Maine  Exp.  Station  Bui.  54.     Nuts  as  Food. 

"         "         "  "55.     Cereal  Breakfast  Foods. 

**         "         "  "    75.     Analyses   of    Self-raising    Flours,    Pea    Flours,    Gluten 

Foods,  Chestnuts,  Malted  Nuts. 


364  FOOD  IXSPHCTIO.W  AND    .-IX.-i LYSIS. 

Maine  Exp.  Station  Bui.  84.     Cereal  Breakfast  Foods. 

Minnesota  Exp.  Station  Bui.  74.     Digestibility  and  Food  Value  of  Beans. 

Pcnn.  Depl.  of  .\griculture  Bui.  10.     Special  Report  on  Prepared  Foods  for  Infants 

and  Invalids. 
Wyoming  Exp.  Sta.  Bui.  ^^3.     Coni{x)sition  of  Prejiared  Cereal  Foods. 
Great  Britain.     Local  Govt.  Board  of  Public  Health,  Report  on  Bleaching  of  Flour 

and  "Improvers.."  n.  ser.   iqii.  No.  40.     Ilaniil,   |.  M.,  pp.  1-33.     Monier- 

Williams,  G.  \V.,  pp.  34-65. 
U.  S.  Dept.  of  Agric,  Notices  of  Judgment,  Nos.  382  and  722.     New  Orleans  and 

Kansas  Citv  Bleached  Flour  Trials. 


REFERENCES  ON  LE.WEXIXCi   >r.\TFRI.\LS. 

Bryan,  T.  J.     The  Carbon   Dioxide  \'alue  of  Pure  Comprc.-i.sed  Yeast  and  Starch 

Compounds.    A.  O.  \.  C.  Proc,  1907,  U.  S.  Dept.  of  -Vgric,  TUir.  of  Chem.,  Bui. 

116,  page  25. 
C.ATUN,  C11.A.S.  A.     Baking  Powders,  with  Special  Reference   to    Phosphate   Powders. 

Providence,  1899. 
Cr.\mpt()N.  C.  a.     Baking  Powders.     Div.  of  Clum.,  Hul.  13,  Pt.  5. 
Green.  J.  R.     Die  Enzyme.     Berlin. 

The  Soluble  Ferments  and  Fermentation.     1901. 

H.ANSF.N,  E.  C.     Practical  Studies  in  Fermentation.     London,  i8g6. 
JORGENSEN,  A.     Die  Mikro-organismen  der  Garungsindustrie.     Berlin. 

Micro-organisms  and  P'ermentation.     London,  igoo. 

Kenrick,  G.  B.,  and  F.   B.     The  .Application  of  Polarimetry  to    the  Estimation  of 

Tartaric  Acid    in    Commercial    Products.     Jour.    .\m.    Chem.    Soc,    24,    1902, 

page  928. 
Klocker,  a.     Fermentation  Organisms.     1903. 

Lintner,  p.     Mikroskopische  Betricbskontrolle  in  den  Garungsgewerben.    Berlin,  1895. 
McGili.,  a.     Baking  Powders.     Canada  Inl.  Rev.  Dept.,  Buls.  10,  26,  68. 

Cream  of  Tartar.     Canada  Inl.  Rev.  Dej^t.,  Buls.  12,  26,  71. 

Matthews,  Chas.  G.     Manual  of  Alcoholic  Fermentation.     London,  1901. 
Oppenheimer,  C.     Trans,  by  Mitchell,  C.  A.     Ferments  and  their  .Vction.     London, 

1901. 
Plummer,  R.  IL  a.     Chemical  Changes  and  Products  Resulting  from  Fermentation, 

I>«ndon,  1903. 
Wl.NTON,   A.   L.     Baking  Powders.     Bur.   of  Chem.    Jiul.   65,   Part  XV.     Bui.    107, 

Part  XXVI. 

Conn.  Exp.  Sta.  An.  Rep.,  1900,  page  15. 

Michigan  Dairy  and  F<K)fl  ('ommission,  Bui.  2,  page  12;   Bui.  3,  page  7. 

Penn.  Board  of  .Agriculture  .An.  RejKjrt,  1897,  page  166. 

North  Carolina  Exp.  Sta.,  Bui.  155. 


CHAPTER   XI. 

TEA,    COFFEE,    AND    COCOA. 
TEA. 

Nature  and  Classification. — Tea  consists  of  the  prepared  leaves  or 
leaf  buds  of  Camellia  Thea  also  known  as  Thca  chinensis. 

The  best  teas  are  made  from  young  leaves  only,  the  Chinese  teas 
being  classified  with  reference  to  the  age  and  position  of  the  leaf  on  the 
young  shoot.  Thus,  the  very  choicest  Chinese  tea,  rarely  found  outside 
of  China,  is  prepared  from  the  youngest  or  end  leaves  of  the  shoot,  which 
are  scarcely  more  than  buds,  and  form  the  tea  known  as  pekoe  tip,  or 
flowery  pekoe.  The  next  leaves  are  the  orange  pekoe  and  pekoe,  which 
produce  a  very  high  grade  of  tea,  while  next  in  order  as  to  age,  size,  and 
grade  of  leaf  are  the  souchong  ist  and  2d,  and  the  congou,  producing 
teas  called  by  the  same  names. 

More  than  50%  of  the  tea  consumed  in  the  United  States  comes  from 
China,  and  over  40%  from  Japan,  the  remainder  being  derived  largelv 
from  India,   Ceylon,  and  other  East  Indian  ports. 

In  the  manufacture  of  tea  the  fresh  leaves,  which  are  nearly  80%  water, 
are  rolled,  withered  by  exposure  to  light,  heat,  and  air,  and  finally  dried 
or  "fired"  by  treatment  with  artificial  heat  over  charcoal  fires,  or  in 
properly  constructed  furnaces. 

Teas  are  divided  into  two  groups,  black  and  green,  which  differ  from 
each  other,  not  as  formerly  supposed  in  being  derived  from  different  plants, 
but  in  their  process  of  manufacture,  the  same  species  of  plant  furnishing 
both  varieties.  Genuine  green  tea  is  prepared  by  first  steaming  and 
afterwards  drying  the  leaves  while  still  fresh,  thus  retaining  the  brif^ht 
color.  Black  tea  is  allowed  to  undergo  oxidation  or  fermentation  bv 
exposure  to  the  sun,  which  gradually  turns  the  leaves  black.  Less  tannin 
is  present  in  black  tea  than  in  green. 

36s 


^56 


FOOn  ISSFECTION  y^ND   ANALYSIS. 


Composition  of   Tea. — Konig  gives  the  following  composition  of  fully 
devclopcil  lea  leaves,  being  the  mean  of  50  to  70  analyses: 


1  Nitroge- 
Water.  nous  Sub-  1   Theine. 
1  stances. 

Essential 
Oil. 

Fat.Chlo- 

rophyl. 

and  Wax. 

Gum, 
Dextrin,     Tannin, 
etc.       1 

Pectin, 
etc. 

Crude 
Fiber. 

Ash. 

9.51         24.50         3-58 

0.68 

6-39 

6.44 

15-65 

16.02 

11.58 

5-65 

Though  the  nitrogenous   substances  of  tea  predominate   in  amount 
over  any  other  class  of  constituents,  yet,  with  the  exception  of  theine  or 


Fig.  72. — a,  Flowery  Pekoe;  b,  Orange  Pekoe;  c,  Pekoe;  d,  Souchong,  ist;  e,  Souchong,  2d; 
),  Congou;  a,  b  (when  mixed  together).  Pekoe;  a,  b,  c,  d,  e  (when  mixed  together),  Pekoe 
Souchong.  If  there  be  another  leaf  below  /,  it  is  termed  Bohea.  At  base  of  leaves 
arc  buds  i,  2,  3,  4,  from  which  new  shoots  spring.     (After  Money.) 

caffeine,  they  have  been   little   studied,     Theine,    tannin,    and   essential 
oil  give  to  the  infusion  of  tea  its  chief  characteristics. 

Zollin.ski  *  gives  the  following  summarized  results  of  analyses  of  a 
number  of  the  cheaper  grades  of  Chinese  black  tea: 


*  2^-lts.  anal.  Chcm.,  1898,  37,  365. 


TEA,    COI-F^iB,    AND    COCOA. 


367 


Water. 


Total 
Nitrogen. 


Albumin- 
oid and 
Amido- 

nitrogen. 


Protein, 
NX6.25. 


Thcine. 


Ash. 


Soluble 
Ash. 


Insoluble 
Ash. 


Maximum. . , 
Minimum  .  ., 
Average . . 


11-57 

9.96 

10.58 


4.12 
3-76 
3-93 


3.78 
3-37 
3-52 


23-83 
21.06 


2.06 
1. 14 
1-55 


6.78 
4-79 
5-94 


31-17 
28.13 
29.67 


61. oj 
57-74- 
59-75. 


A  very  complete  series  of  analyses  of  tea  was  made  by  Joseph  F.  Geiss- 
ler  in  1884,*  from  which  the  following  summaries  are  taken: 


It 

II 

■s 
■3 

u     ■ 

n 

0 

§ 

C 

+j  in 

e2< 

0 
3  . 

1-6 

Co 

Indian: 

Maximum.  . 

6 

6.19 

39.66 

45-64 

53-07 

18.86 

3-3 

5-79 

3.68 

2.22 

.296 

Minimum . . 

5. 56, 37. 80141.3248. 53, 13. 04 

1.8 

5-42 

3-24 

1-93 

■m 

Average.  . . . 

S.81 

38.77I42.94 

51-24 

14-87 

2-7 

5.62 

3-52 

2.12 

.178 

Oolong: 

Maximum. . 

13 

6.88 

44.02  48.87 

53-15 

20.07 

3-5° 

6. II 

3-71 

3-17 

.838 

Minimum  .  . 

5-09 

34.10 

40.6 

44.8 

11-93 

1-15 

5-44 

2.60 

1.84 

.266 

Average . 

. .  • 

5-89 

37-88 

43-32 

50.7 

16.38 

2.32 

5-81 

3-2 

2.68 

-507 

Congou: 

Maximum. . 

II 

9-15 

32.1437.06I63.85 

13.89 

2.87 

6.48 

3-52 

3-86 

1-31 

Minimum  .  . 

7-65 

23-48,27.48 

54-5 

8.44 

1.70 

5-52 

2.28 

1.90 

-32 

Average 

•• 

8-37 

28.40134.35 

57-2 

11-54 

2-37 

5-75 

3.06 

2.68 

-425 

Kenrick  f  gives  the  following  averages  of  a  series  of  analyses  of  tea 
made  by  him  in  1891: 


Congou  tea.  — 

Assam  tea 

Ceylon  tea  . 

Unclassed  black 

Japan  

Gunpowder  .  . . 
Young  Hyson. . 


eg 


Substances  Extracted 

by  10  Minutes' 

Infusion. 


13 
18 


23-37 
38-53 
27-45 
23.76 
30.07 

28-55 
34.22 


5.18 
7-49 
7-85 
5-40 
9-38 
8.00 
10.98 


2.65 


2.82 
2-45 
2-39 
2.52 


7.60 

5-75 
6.31 

6.54 
4.00 
4.72 
5-40 


3-55 
3-69 
3-34 
3-53 
3-62 
3-36 
3-83 


2.28 
2.16 
1.88 
2-37 
2-73 
3-70 
2.1C 


4-51 
3-81 
3-50 
4.40 
3.20 

3-57 
3.12 


The  ash  of  many  genuine  teas  has  been  examined  by  Battershal  % 
with  the  following  results: 

*  Am.  Grocer,  Oct.  23,  1884. 

•j-  Canada  Inland  Rev.  Dep.  Bui.  24. 

%  Food  Adulteration  and  its  Detection. 


30i 


hOOD  INSPECTION  AND  ANADStS 


Oolong. 

Average  of  50 

Samples. 


Japan. 


Spent 
Black  Tea. 


Total  ash 

Soiubii-  in  wattT 
Per  cent  soluble. 


Silua 

ChK>rinc 

Potash 

Stxla 

Ferric  oxiile 

Alumina 

Manganic  oxide. 

Lime 

Magnesia 

Phosphoric  acid. 
Sulphuric  acid  . . 
Carbonic  acid.  .  . 


COMPOSITION. 


6.04 

3-44 
57.00 


11.30 

1-53 

37-46 

1.40 

1.80 

5-13 
2.10 

9-43 
8.00 
12.27 
4.18 
5-40 


100.00 


5-5.=; 

3.60 

64-55 


9-30 

1.60 

41.63 

I.  12 
I. 12 

4-26 

I.  -50 

8.18 

16.62 
3-64 
5-90 


2-5: 


27-75 
0.79 


16.00 


19.66 
11.20 

15.80 

1. 10 

6.70 


99.00 


Kozai  *  gives  the  following  as  the  results  of  analyses  made  by  him  of 
Japanese  teas: 


Unprepared 
Leaves. 


Caffeine  or  theine 

Ether  e.xtract 

Hot -water  extract 

Tannin  (as  gallotannic  acid) 
Other  nitrogen-free  extract  . 

Crude  protein 

Crude  6ber 

Ash 

Albuminoid  nitrogen 

Caffeine  nitrogen 

Amido-nitrogcn 

Total  nitrogen 


2,-?,° 
6.49 

50.97 
12.91 
27.86 

37-33 
10.44 

4-97 
4. II 
0.96 
0.91 
5-97 


Green 
Tea. 


3.20 

5-52 

53-74 

10.64 

31-43 
37-43 
10.06 
4.92 
3-94 
0-93 
1-13 
5-99 


Black 
Tea. 


3-30 

5.82 

47-23 

4.89 

35-39 
38.90 
10.07 

4-93 
4. II 
0.96 
1. 16 
6.22 


PROXIMATE    COMPONENTS    AND    ANALYTICAL   METHODS. 

Preparation  of  Sample, — Grind  the  material  .so  as  to  pass  a  sieve 
with  holes  0.5  mm.  in  diameter. 

Moisture,  Ether  Extract,  and  Crude  Fiber  are  determined  in  the 
same  weigher]  portion  of  2  grams,  following  the  methods  described  under 
cereals  (p.  276). 


*  liul.  7,   Imperial  College  of  Agriculture,  Japan. 


TEA,   COFFEE,  AND    COCOA.  369 

Protein. — Determine  total  nitrogen  by  the  Kjeldahl  or  Gunning 
method;  from  this  subtract  the  nitrogen  clue  to  caffein  (obtain  by  dividing 
by  3.464)  and  multiply  the  difference  by  6.25. 

Total  Ash.  —  Burn  2  grams  of  the  material  to  a  white  ash  in  a 
platinum  dish  at  a  faint  red  heat.  The  total  ash  of  pure  tea  should  not 
be  less  than  4  nor  more  than  7%. 

Soluble  and  Insoluble  Ash.* — The  total  ash,  as  obtained  above,  is 
transferred  to  a  beaker  with  liot  water  and  boiled  for  some  time,  after 
which  it  is  poured  u])on  a  filler  and  the  residue  washed  with  hot  water. 
The  residue  is  then  dried,  ignited  at  a  faint  red  heat  in  a  platinum  dish, 
cooled,  and  weighed,  thus  giving  the  amount  of  insoluble  ash.  The 
soluble  ash  is  calculated  by  difference  from  the  total  and  insoluble  ash. 

Ash  Insoluble  in  Acid.* — The  portion  of  the  ash  insoluble  in  water 
is  washed  ujwn  a  tared  lllter  with  hot  lo^'o  hydrochloric  acid  and  further 
washed  with  the  latter  reagent  till  the  acid-soluble  matter  is  dissolved 
out,  after  which  it  is  washed  with  water,  dried,  and  weighed. 

Alkalinity  of  Ash.* — This  is  expressed  in  terms  of  cc.  of  tenth- 
normal acid  required  for  the  ash  of  i  gram  of  sample. 

Soluble  Ash. — Cool  the  filtrate  from  the  determination  of  insoluble 
ash,  as  described  above,  and  titrate  with  tenth-normal  hydrochloric  acid, 
using  methyl  orange  as  an  indicator. 

Insoluble  Ash. — Add  excess  of  tenth-normal  hydrochloric  acid  (usually 
10  to  15  cc.)  to  the  ignited  insoluble  ash  as  obtained  above  in  the  j)latinuni 
dish,  heat  to  the  point  of  boiling  over  an  asbestos  plate,  cool,  and  titrate 
excess  of  hydrochloric  acid  with  tenth-normal  sodium  hydroxide,  using 
methyl  orange  as  an  indicator. 

Essential  Oils. — Distil  100  grams  of  the  tea  with  800  cc.  of  water, 
and  shake  out  the  distillate  with  several  portions  of  ether.  The  residue 
from  the  combined  ether  extracts  contains  the  volatile  oil. 

Insoluble  Leaf.j — Boil  2  grams  of  the  tea  in  a  500-cc.  Erlenmeyer 
flask  over  a  low  flame  with  200  cc.  of  water,  replacing  from  time  to  time 
by  addition  of  hot  water  the  loss  from  evaporation.  Filter  through  a 
tared  filter,  and  wash  the  residue  until  the  filtrate  measures  500  cc, 
stirring  the  contents  of  the  filter  throughout  the  process  to  facilitate 
filtering.  Reserve  filtrate  for  determination  of  tannin  and  theine.  Dry 
the  fiher  and  residue  until  dry  to  the  touch,  transfer  to  the  weighing 
bottle,  and  dry  to  constant  weight  at  100°  C.     If  the  amount  of  insoluble 

*  A.  O.  A.  C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  69. 
t  Doolittle  and  Woodruff,  A.  O.  A.  C.  Proc.  1906,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem., 
Bui.  105,  p.  48.     Winton,  Ogden  and  Mitchell,  Conn.  Exp.  Sta.  An.  Rep.,  1898,  p.  132. 


373 


FOOD  INSPECTION  /tND  ANALYSIS. 


leaf  is  above  60*^-,  the  presence  of  spent  or  exhausted  leaves  may  be 
suspected. 

Extract. — By  this  term  is  meant  the  total  amount  of  water-soluble 
matter  in  tea,  including  such  compounds  as  tannin,  caffeine,  albuminous 
matter,  dextrin,  gum,  certain  parts  of  the  ash,  etc. 

The  value  of  a  tea  from  a  food  standpoint  depends  obviously  upon 
the  character  and  amount  of  the  extract,  rather  than  on  the  composition 
of  the  dry  tea.  The  relative  composition  of  the  extract  and  of  the  insoluble 
leaf,  as  found  by  Eder,  is  given  in  the  following  table. 


Extract. 

Insoluble 
Leaf. 

Dry  matter 

Per  Cent. 

40. 

12. 

2. 

0.6 

10. 
12. 

1-7 

0.94 
0.04 

0-13 
0.21 

Per  Cent. 
60. 
12.7 

7.2 

10. 

2.3 

0.29 

0.58 
1.03 
0.68 

Nitrogenous  substances 

Theine 

Tea  oil 

Resin,  chlorophyll,  etc 

Tannin 

Extractives 

Ash 

Potash 

Lime 

Phosphoric  anhydride 

Silica 

Determination. — The   sum  of  the  percentages  of   insoluble   leaf  and 
moisture  subtracted  from  100  gives  the  percentage  of  extract. 
Tannin. — Proctor's  Modification  of  LoiventhaV s  MetJiod.* 
Reagents:    (i)  Potassium    permanganate    solution    containing    about 
1.33  grams  per  liter. 

(2)  Tenth-normal  oxalic  acid  solution  (6.3  grams  per  liter). 

(3)  Indigo  carmine    solution,  containing    6  grams    indigo 

carmine  (free  from  indigo  blue)  and  50  cc.  concen- 
trated sulphuric  acid  per  liter. 

(4)  Gelatin  solution,  preparcfl  by  soaking  25  grams  gela- 

tin for  an  hour  in  a  saturated  sodium  chloride  solu- 
tion, heating  till  the  gelatin  is  dissolved,  and  mak- 
ing up  to  a  liter  after  cooling. 

(5)  Mixture  of  975  cc.  saturated  sodium  chloride  solution 

and  25  cc.  concentrated  sulphuric  acid. 

(6)  Powdered  ka(jlin. 

Obtain  the  value  of  the  potassium  permanganate  solution  in  terms 
of  the  tenth  normal  oxalic  acid  solution. 

*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  part  7,  p.  890;  Bui.  107  (rev.),  p.  150. 


TEA,   COFFEE,  AND   COCOA.  37  r 

Boil  5  grams  of  the  powdered  lea  for  half  an  hour  with  400  cc.  of  water, 
cool,  transfer  to  a  graduated  500-cc.  flask,  and  make  up  to  the  mark. 
To  ID  cc.  of  the  infusion  (filtered  if  not  clear)  add  25  cc.  of  the  indigo 
carmine  solution  and  about  750  cc.  ,of  water.  Then  add  from  a  burette 
the  potassium  permanganate  solution,  a  little  at  a  time  while  stirring, 
till  the  color  becomes  light  green,  then  cautiously  drop  by  drop  till  the 
color  changes  to  bright  yellow,*  or  further  to  a  faint  pink  at  the  rim. 
The  volume  in  cubic  centimeters  of  permanganate  furnishes  value  a  of 
the  formula. 

Mix  100  cc.  of  the  clear  infusion  of  tea  with  50  cc.  of  gelatin  solution, 
100  cc.  of  salt  acid  solution,  and  10  grams  of  kaolin,  and  shake  several 
minutes  in  a  corked  flask.  After  settling,  decant  flrst  the  clear  super- 
natant liquid  through  a  Alter,  and  finally  bring  the  precipitate  upon  the 
filter.  Mix  25  cc.  of  the  filtrate  (corresponding  to  10  cc.  of  the  original 
infusion)  with  25  cc.  of  the  indigo  carmine  solution,  and  about  750  cc. 
of  water,  and  titrate  with  permanganate  as  before.  The  volume  in  cubi^ 
centimeters  of  permanganate  used  gives  value  h. 

a  =  quantity  of  permanganate  solution  required  to  oxidize  all  oxidiz- 
able  substances  present. 

6  =  quantity  of  permanganate  solution  required  to  oxidize  substances 
other  than  tannin. 

.'.  a  —  b  =  c,  permanganate  required  for  the  tannin.  Assuming  that 
0.04157  gram  tannin  (gallotannic  acid)  is  equivalent  to  0.063  gram  oxalic 
acid,  the  tannin  in  the  tea  is  readily  calculated. 

As  recommended  by  Doolittle  and  Woodrufff  the  determination 
may  be  conveniently  made  on  aliquot  portions  of  the  solution  obtained 
in  the  determination  of  insoluble  leaf. 

Method  of  Fletcher  and  Allen. ^ — This  method  depends  upon  the  pre- 
cipitation of  the  tannin  and  other  astringent  matters  in  tea  infusion  by 
lead  acetate,  the  point  of  complete  precipitation  being  indicated  by  an 
ammoniacal  solution  of  potassium  ferricyanide. 

Five  grains  of  neutral  lead  acetate  are  dissolved  in  water,  made  up  to 
I  liter,  and  after  standing  the  solution  is  filtered. 

As  an  indicator,  0.05  gram  of  pure  potassium  ferricyanide  is  dis- 
solved in  50  cc.  of  water,  and  an  equal  volume  of  concentrated  ammonia- 

*  Various  shades  of  color  may  be  produced,  but  the  same  shade  should  obviously  be 
adopted  as  an  end-point  by  the  operator  as  when  standardizing. 

t  A.  O.  A.  C.  Proc.  1906,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  105,  p.  49. 
X  Chem.  News,  XXIX,  169,  189. 


372  FOOD  INSPECTION  AND  ANALYSIS. 

water  is  added.  This  indicator  produces  a  red  coloration  with  tannin, 
gallic  acid,  or  gallotannic  acid  in  solution,  being  so  sensitive  that 
a  droj)  of  the  indicator  will  detect  i  jiart  of  tannin  in  10,000  parts  of 
water. 

Three  separate  tjuaniiiies  of  10  cc.  each  of  the  standard  lead  acetate 
solution,  as  above  prepared,  arc  measured  into  as  many  beakers,  and  each 
diluted  to  100  cc.  with  boiling  water.  Two  grams  of  powdered,  tea  are 
boikd  in  250  cc.  of  water,  and  var}-ing  quantities  of  this  decoction  are 
measured  from  a  burette  or  pipette  into  the  beakers  containing  the  lead 
solution,  the  first  beaker  receiving,  say,  12  cc,  the  second  15  cc,  and 
the  third  18  cc,  in  the  case  of  black  tea,  and,  with  green  tea,  8,  10,  and 
12  cc,  respectively. 

About  I  cc  of  each  of  these  trial  quantities  is  removed  from  the 
various  beakers  by  means  of  a  pipette,  passed  through  small  filters,  and 
tested  with  the  ammoniacal  ferricyanide  indicator,  the  drops  of  filtered 
solution  being  allowed  to  fall  directly  on  spots  of  the  indicator,  previously 
placed  on  a  white  slab  or  plate. 

It  is  thus  easy  to  ascertain  the  approximate  amount  of  tea  solution 
which  it  is  necessary  to  add  to  produce  a  pink  coloration  with  the  indi- 
cator, so  that  by  repeated  tests,  nearly  the  right  amount  may  be  added 
at  once.  If  no  coloration  in  a  given  case  is  produced  when  a  drop  of 
the  filtrate  from  the  solution  in  the  beaker  is  allowed  to  fall  on  the  drop 
of  indicator  solution,  a  little  more  of  the  tea  decoction  is  added,  and  this 
process  is  repeated  until  the  pink  color  is  apparent. 

It  should  be  noted  how  much  of  the  tea  decoction  is  necessary  to  add 
to  100  cc.  of  pure  water,  that  a  drop  of  the  solution  may  produce  the  pink 
coloration  with  the  ferricyanide,  and  this  amount  should  be  subtracted 
from  the  amount  of  decoction  found  necessary  to  add  to  the  known  lead 
solution  in  the  beaker.  It  was  found  by  repeated  exj)criment  that  10  cc 
of  lead  solution  would  precipitate  0.0 1  gram  of  pure  gallotannic  acid; 
hence,  carr)'ing  out  the  process  exactly  as  above  described,  125  divided 
by  the  number  of  cubic  centimeters  of  tea  decoction  required  gives  the 
percentage  of  tannin  in  the  sample.* 

Theine  or  Caffeine  (C8H10N4O2). — This  alkaloid  when  pure  exists 
in  white  silky  needles.     It  is  odorless  and  .sparingly  soluble  in  cold  water, 

♦  This  process  estimates  the  total  astringent  matter,  all  of  which  is  counted  in  as 
tannin. 


TE^,    COFFEE,   AND   COCOA.  373 

but  more  so  in  hot.  It  is  less  soluble  in  alcoliol,  and  almost 
insoluble  in  ether.  It  readily  dissolves  in  chloroform.  It  is  present 
in  tea,  coffee,  and  kola.  Graf*  has  shown  that  the  amount  of  caf- 
feine present  in  tea  is  in  most  cases  proportional  to  the  commercial 
value  and  quahty. 

Detection. — Caffeine  may  be  detected,  if  present  in  a  suspected  residue, 
by  the  so-called  "  murexid  test,"  which  is  made  with  the  material  in  a 
solid  state,  or  with  the  residue  from  the  evaporation  of  a  licjuid.  A  small 
quantity  of  the  solid  or  powdered  material  is  heated  in  a  white  porcelain 
dish  and  covered  with  a  few  drops  of  strong  hydrochloric  acid,  after  which 
a  fragment  of  potassium  chlorate  is  immediately  added.  The  mixture 
is  then  evaporated  to  complete  dryness  on  the  water-bath,  whereupon, 
if  caffeine  is  present,  a  reddish-yellow  or  pink  color  is  produced.  After 
cooling,  the  residue  is  treated  with  a  very  little  ammonia  water 
applied  on  the  point  of  a  stirring-rod.  In  the  presence  of  caffeine,  a 
purple  color  (that  of  murexoin)  is  produced  on  application  of  the 
ammonia. 

Determination  of  Theine  or  Cafie'me.  —  Dvorkovitsch  Method. ■] — 
Digest  10  grams  of  the  powdered  tea  with  200  cc.  of  boiling  water  for 
5  minutes  and  decant  the  solution;  repeat  the  treatment  twice,  and  boil 
the  residue  with  200  cc.  of  water.  Make  up  the  combined  solutions  to 
1000  cc.  and  extract  a  portion  with  petroleum  ether  to  remove  fat,  etc. 
To  600  cc.  of  the  fat-free  solution  (equivalent  to  6  grams  of  tea)  add  100 
cc.  of  4%  barium  hydroxide  solution,  mix  and  filter.  To  583  cc.  of  the 
filtrate  (equivalent  to  5  grams  of  tea)  add  100  cc.  of  a  20*^^  solution  of 
sodium  chloride,  and  extract  three  times  with  chloroform.  Distil  the 
greater  part  of  the  chloroform  from  the  combined  extracts,  pdace  the 
residue  in  a  tared  dish,  evaporate  the  remainder  of  the  chloroform,  dry 
at  100°  C,  and  weigh.  The  caffeine  is  usually  of  sufficient  purity  to 
render  a  nitrogen  determination  unnecessary. 

Doolittle  and  WoodruffX  proceed  as  follows:  Extract  in  a  separating 
funnel  with  petroleum  ether  225  cc.  of  the  filtrate  from  the  determi- 
nation of  insoluble  leaf  (p.  369)  made  up  to  500  cc.  To  the  fat-free 
I)ortion    add    50    cc.    of    a    4%    barium  hydroxide  solution,  shake  well, 


*  Forsch,  Ber.,  4,  1897,  pp.  88,  89. 

t  Ber.  d.  chem.  Ges.,  24,  1891,  p.  1945;  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107 
(rev.),  p.    150. 
%  loc.  cit. 


374 


FOOD  INSPECTION  JND  ANALYSIS. 


and  filter.     To  tlic  filtrate  add  50  cc.  of  a  20%  sodium  chloride  solution 
and  proceed  as  above  described. 

Modi/iiation  of  Siahlsclimidfs  Method. — Six  grams  of  finely  powdered 
tea  are  boiled  in  a  flask  with  several  successive  portions  of  water  for  ten 
minutes  each,  and  the  combined  aqueous  extracts  thus  obtained  are  made 
up  to  Doo  cc.  with  water.  Four  grams  of  powdered  lead  acetate  are 
added  to  the  decoction,  which  is  then  boiled  for  ten  minutes,  using  a 
reflux  condenser,  or  making  up  the  loss  by  occasional  addition  of  water. 
The  solution  is  then  poured  upon  a  ch-y  filter,  and  500  cc.  of  the  filtrate, 
corresponding  to  5  grams  of  the  tea,  are  evaporated  to  about  50  cc.  and 
enough  sodium  phosi)hate  added  to  precipitate  the  remaining  lead.  The 
solution  is  then  filtered,  and  the  })recipitate  thoroughly  washed,  the 
filtrate  and  washings  being  evaporated  to  about  40  cc.  Finally,  the 
solution  thus  concentrated  is  extracted  with  chloroform  in  a  separatory 
funnel  for  at  least  four  times,  and  the  chloroform  extract  evaporated 
to  drvncss,  leaving  the  caffeine,  which  is  dried  to  constant  weight  at 
75°  and  weighed. 

ADULTERATION    OF    TEA. 

Facing. — The  most  common  form  of  tea  adulteration,  if  such  it  may 
be  called,  is  the  practice  of  "facing''  the  dried  leaves,  or  treating  them 
with  certain  pigments  and  coloring  materials  to  impart  a  bright  color 
or  gloss  to  the  tea,  thus  causing  an  inferior  grade  to  appear  of  better 
quality  than  it  really  is.  This  practice  is  more  often  applied  to  green 
lea.  The  materials  for  facing  include  such  substances  as  Prussian  blue, 
indigo,  plumbago,  and  turmeric,  often  accomjjanied  by  such  minerals 
as  soapstone,  gyj^sum,  etc.  Only  a  small  amount  of  foreign  material  is 
actually  added  to  the  tea,  but  the  adulteration  consists  in  the  deceptive 
appearance  imparted  thereto. 

Battcrshal  has  examined  various  samples  of  the  preparations  used 
in  Japan  for  facing  lea.  He  found  in  one  case  the  following  compo- 
sition: Soapstone,  47.5%;  gypsum,  47.5%;  Prussian  blue,  5%.  An- 
other sample  consisted  of  soapstone,  75%;  indigo,  25%.  A  third  was 
composed  of  .soapstone,  60%,  and  indigo,  40%.  In  applying  the  facing 
to  the  tea,  the  latter  is  first  heated  in  an  iron  pan  over  the  fire,  the  facing 
mixture  is  then  added  while  still  hot,  and  the  whole  is  stirred  briskly  till 
the  desired  color  is  imparted.  The  Chinese  and  Japanese  do  not  face  the 
tea  which  they  themselves  consume,  but  only  that  intended  for  export  trade. 


TE/1,  COFFEE,  AND  COCO  A.  375 

Detection  of  Facing. — Tlie  most  delicate  test  for  facing  is  to  examine 
under  the  microscope,  or  lens,  the  dust  obtained  by  sifting  the  leaves  or 
the  sediment  obtained  after  shaking  them  with  water.  Plumbago  appears 
glossy  black,  soapstone  gray,  gypsum  white,  Prussian  blue,  ultramarine 
and  indigo  shades  of  blue,  and  turmeric  yellow.  Prussian  blue  is 
decolorized  by  sodium  hydroxide  solution.  Ultramarine  is  not  affected 
by  alkali  but  is  decolorized  by  hydrochloric  acid.  Indigo  is  not  decol- 
orized by  either  reagent. 

Read  *  rubs  the  siftings  with  a  spatula  on  sheets  of  white  and  black 
paper  and  removes  the  loose  dust.  The  colors  after  this  treatment  are 
recognized  under  the  lens  as  streaks  on  the  paper.  West  f  detects  Prus- 
sian blue  by  the  blue  spots  formed  by  sprinkling  the  ground  tea  on  filter 
paper  moistened  with  oxalic  acid  solution  and  drying. 

Prussian  blue  if  present  in  considerable  amount  may  be  detected  in 
the  sediment,  as  above  obtained,  by  the  blue  precipitate  vi^hich  forms 
after  dissolving  in  hot  alkali,  filtering,  acidifying  with  hydrochloric  acid, 
and  then  adding  a  drop  of  ferric  chloride.  If  the  residue  on  the  paper  after 
treatment  with  hot  alkali,  on  removal  to  a  porcelain  dish  and  treatment 
with  concentrated  sulphuric  acid,  yields  hydrogen  sulphide  (recognized 
by  its  odor  or  by  the  blackening  of  lead  acetate  paper)  ultramarine  is 
indicated. 

Such  minerals  as  gypsum  and  soapstone  are  readily  separated  as  a 
sediment  by  shaking  the  leaves  in  water,  and  the  sediment  is  examined 
by  the  appropriate  cjualitative  methods  for  these  substances. 

Spent  or  Exhausted  Leaves. — These  consist  of  leaves  of  tea  that  have 
been  previously  steeped  or  infused,  and  afterwards  rerolled  and  dried. 
Such  leaves  are  sometimes  mixed  with  tea  as  an  adulterant.  Any  con- 
siderable admixture  of  spent  leaves  is  evident,  both  by  the  extremely  low 
ash,  and  the  abnormally  small  proportion  of  water-soluble  ash  in  the 
sample.  It  is  rare  that  the  total  ash  of  genuine  tea  is  under  5%,  while 
the  soluble  ash  is  seldom  less  than  3%. 

The  ash  of  spent  tea  leaves  sometimes  runs  as  low  as  2.5%,  of  which 
generally  not  more  than  0.3  to  0.8  per  cent  is  soluble.  Spent  leaves  are 
also  naturally  low  in  tannin  and  in  extract. 

If  the  extract  is  much  below  32%,  spent  leaves  may  be  suspected. 
Allen  determines  the  per  cent  of  spent  leaves  by  subtracting  the  per  cent 
of  extract  from  32,  multiplying  by  100  and  dividing  by  30. 


*  U.  S.  Treasury  Decision,  No.  32322. 
t  Jour.  Ind.  Eng.  Chem.,  4,  1912,  p.  528. 


376 


FOOD  INSPECTION  AND  ANALYSIS. 


The  use  of  spent  or  cxhau>tcd  loaves  as  an  adulterant  is  very  rare 
at  present,  though  formerly  of  common  occurrence. 

Foreign  Leaves  as  a  Substitute  for  Tea. — This  sophistication  is  not 
common,  but  the  detection  of  leaves  other  than  tea  is  readily  accom- 
plished by  a  careful  examination  of  the  shape  and  character  of  the  leaves. 
For  this  purpose  the  dried  leaves  are  opened  out  by  soaking  a  short  time 
in  hot  water,  after  which  they  are  spread  upon  a  glass  plate,  and  examined 
by  the  aid  of  a  magnifying-glass. 

The  genuine  tea  leaf  (Fig.  73)  is  ver>^  characteristic,  and  is  readily 
distinguished  from  other  leaves.     It  is  oval  or  lanceolate,  5  to  8  cm.  long 

and  2  to  3  cm.  wide.  It  is  short-stemmed, 
somewhat  thick  and  fleshy,  attenuated  at  the 
bottom  and  usually  pointed  at  the  top.  At  a 
certain  height  from  the  base,  from  a  third  to 
a  quarter  up,  the  smooth  or  w^avy  border  be- 
comes peculiarly,  though  not  deeply,  serrated  in 
a  regular  manner,  the  serrations,  which  arc 
hook-shaped,  continuing  to  the  tip  of  the  leaf. 
Mature  leaves  always  show  these  serrations, 
but  they  are  somewhat  obscure  in  young  leaf 
buds.  The  latter,  however,  are  rarely  found 
in  this  country.  The  veins  extend  outward 
from  the  central  rib  nearly  parallel  to  each 
other,  but  before  reaching  the  border,  each 
bends  upward  to  form  a  loop  with  the  one 
above. 

Foreign  leaves,  said  to  be  used  as  aduher- 
ants,  are  those  of  the  willow,  poplar,  elder, 
birch,  elm,  and  rose,  but  the  writer  has  never 
found  any  of  these  in  tea.  All  of  them  differ 
materially  from  the  genuine  tea  leaf,  and  if 
foreign  leaves  are  apparent  in  a  sample  under 
examination,  they  should  be  compared  with  various  leaves  collected  by 
the  analyst  for  the  purpose. 

Stems  and  Fragments.— These,  as  well  as  "tea  dust,"  are  apparent 
by  an  examination  of  the  leaves,  opened  out  in  hot  water  as  explained 
above.  The  ash  of  tea  stems  and  dust  is  abnormally  high.  The 
term  "lie  tea"  is  applied  to  an  imitation  of  tea,  consisting  of  fragments, 
stems,  and  tea  dust,  mixed  with  foreign  leaves,  mineral  matter,  gum,  etc. 


Fig.  73.— The  Leaf  of 
Genuine  Tea. 


TEA,  COFFEE,  AND   COCOA.  377 

The  ash  of  such  "tea"  has  been  found  as  high  as  50%.  Such  imita- 
tions are  now  almost  unknown.  Alake-weight  substances,  such  as  brick- 
liust,  iron  saUs,  metalHc  iron,  sand,  etc.,  have  been  found  in  tea.  If 
present,  they  are  to  be  found  in  the  sediment,  obtained  on  shaking  out 
the   tea  in  water. 

Added  Astringents. — Catechu  is  sometimes  said  to  be  added  to  tea 
to  give  it  increased  astringency,  especially  to  such  tea  as  has  been  adulter- 
ated by  the  addition  of  exhausted  tea.  Hagar's  method  for  detecting 
catechu  is  as  follows: 

A  hot-water  extract  of  the  tea  (i  to  100)  is  boiled  with  an  excess  of 
litharge  and  filtered.  To  a  part  of  the  filtrate,  which  should  be  perfectly 
clear,  nitrate  of  silver  is  added.  If  catechu  be  present,  a  yellow  iloc- 
cidcnt  precipitate,  rapidly  becoming  dark-colored,  is  formed.  Pure  tea 
treated  in  hke  manner  gives  a  gray  precipitate. 

Spencer  *  adds,  instead  of  silver  nitrate,  a  drop  of  ferric  chloride  to 
the  clear  filtrate.     With  catechu  a  green  precipitate  is  formed. 

As  a  matter  of  fact  the  worst  forms  of  tea  adulteration,  such  as  the 
actual  substitution  of  foreign  leaves,  once  so  commonly  practiced,  are 
now  extremely  rare  in  this  country  and  have  been  for  some  years,  by  reason 
of  the  careful  system  of  government  inspection  in  force  at  the  various 
ports  of  entry.  The  greater  portion  of  the  tea  on  our  market  to-day  is 
genuine,  but  fraud  is  practiced  to  r.  considerable  extent  by  the  substitu- 
tion of  inferior  grades  for  those  of  good  quality.  This  form  of  deception 
is  in  many  cases  beyond  the  power  of  the  analyst  to  detect,  and  properly 
comes  within  the  realm  of  the  professional  tea-taster. 

Tea  Tablets. — Finely  ground  tea  of  var}dng  quality  is  sometimes 
pressed  into  tablets,  to  be  used  by  travelers  and  campers  for  preparing 
a  beverage,  by  simply  dissolving  in  hot  water. 

The  composition  of  one  of  these  preparations  sold  under  the  name 
of  Samovar  Tea  Tablets,  analyzed  by  the  ISIass.  State  Board  of  Health, 
is  as  follows:     . 

Water 8.7 

Theine 2.25 

Extract 54-4 

Ash 5.4 

Soluble  ash 2.8 

Insoluble  ash 2.6 

*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  p.  S85. 


378 


FOOD  INSPECTION  ^ND  ^N^ LYSIS. 


Microscopical  Structure  of  Tea. — The  powdered  tea  may  be  examined 
directly  in  water-niount.  Schimper  recommends  treating  the  powdered 
tea  with  cliloral  hydrate  or  potash  lye,  to  render  it  more  transparent. 

By  far  the  most  characteristic  clement  is  the  peculiarly  shaped 
sclercnchyma,or  stone  cell,  st,  Fig.  74,  entirely  unlike  anything  to  be  found 
in  other  leaves.  These  cells  are  very  irregular  in  form,  being  sometimes 
star-shaped,  sometimes  branched,  almost  always  with  deeply  wrinkled  sides, 


Fig.  74. — ^Powdered  Tea  under  the  Microscope.  X160.  g,  end  of  leaf  nerve;  p,  chloro- 
phyll parenchyma;  st,  stone  cells;  h,  hairs.  The  tissues  were  warmed  in  potash  to 
render  transparent.     (After  Moeller.) 

and  often  with  sharp  points.  In  most  foreign  leaves  such  sclerenchyma 
cells  are  lacking,  but  they  arc  abundant  in  all  genuine  tea  leaves,  excepting 
rarely  in  the  very  young  leaves,  where  they  are  sometimes  not  fully  devel- 
oped. They  are  especially  numerous  in  the  main  vein  and  in  the  stem. 
They  may  be  seen  to  best  advantage  in  a  section  of  the  stem,  or  midrib, 
made  parallel  to  the  surface  of  the  leaf.  To  make  such  a  section,  soak 
the  leaf  first  in  water,  and  afterward.^  dry  in  alcohol.  The  interior  of 
the  leaf  is  composed  chiefly  of  ground  tissue,  having  rounded  cells  full 
of  chlorophyll  grains  and  the  fibro-vascular  bundles  of  the  veins. 

Other  imjjortant  characteristics  are  the  peculiar  hair  growth  on  the 
under  epidermis,  B,  which  is  apj^arcnl  in  nearly  all  teas,  also  crystal 
rcscttes  of  calcium  oxalate,  which  are  nearly  always  present,  even  in 
fragments  of  tea  leaves,  but  not  in  all  foreign  leaves.  The  peculiar 
structure  of  the  lower  epidermis,  B,  with  its  numerous  stomata  is  also  to 
be  noted.     See  Figs.  189  and  \()0,  PI.  XVIII. 


TEA,  COFFEE,  AND  COCOA.  379 


COFFEE. 


Nature  of  Coffee. — Coffee  is  the  seed  of  the  Cofiea  arabica,  a  tree 
which,  when  under  cultivation,  is  not  allowed  to  exceed  twelve  feet  in 
height,  but  when  wild  sometimes  reaches  a  height  of  twenty  feet.  It  is 
indigenous  in  Southern  Abyssinia,  and  was  cultivated  in  Arabia  in  the 
sixteenth  century,  and  in  the  East  Indies  in  the  seventeenth,  afterward 
being  introduced  into  the  West  Indies  and  South  America.  The  coffee- 
beans  are  usually  inclosed  in  pairs  in  the  berry,  being  plano-convex  with 
their  fiat  sides  together  but  in  "  pea  berry  "  coffee  only  a  single,  rounded 
bean  is  present. 

When  the  ripe  fruit  is  gathered,  it  is  first  dried  and  then  freed  from 
the  hulls,  usually  by  machinery,  or,  in  the  West  Indies,  the  green  berries 
are  "pulped"  or  "hulled"  under  water  by  a  peculiar  macerating  machine. 
The  raw  beans  are  roasted,  and  afterwards  ground  for  preparing  the 
infusion. 

Brazil  furnishes  more  than  half  the  world's  supply  of  coffee,  and 
nearly  75%  of  that  consumed  in  the  United  States. 

Composition  of  Coffee. — Alost  of  the  coffee  in  the  retail  market  is 
roasted,  being  sold  either  in  the  whole  bean  or  ground.  Comparatively 
little  raw  coffee  is  sold  at  retail. 

The  constituents  of  raw  coffee,  besides  water,  are,  in  the  order  of  their 
comparative  amounts,  cellulose  or  crude  fiber,  fat,  protein,  caffetannic 
acid,  sugar,  caffein,  gum,  dextrin,  and  ash.  The  effect  of  roasting  coffee, 
besides  driving  off  most  of  the  water,  is  to  caramelize  a  large  part  of  the 
sugar,  to  make  the  bean  less  tough  and  more  brittle,  and,  most  important 
of  all,  to  develop  an  empyreumatic,  oily  substance,  known  as  cafjeol 
(CgHjoOo),  to  which  the  characteristic  flavor  and  aroma  of  coffee  are 
largely  due.  Caffeol  may  be  obtained  by  distilling  an  infusion  of  roasted 
coffee,  and  extracting  the  distillate  with  ether.  It  is  a  brown  oil,  almost 
insoluble  in  water. 

According  to  Genin,  there  are  in  raw  coffee  small  amounts  of  two 
essential  oils,  one  soluble  in  water,  the  other  insoluble.  During  the 
roasting,   these  are  partially   transformed   into   the   substance   cafl'eol. 

The  fat  in  coffee  forms  a  considerable  constituent,  amounting  in 
some  cases  to  15%. 

Caffetannic  Acid  (CisHigOg)  is,  when  pure,  a  colorless,  crystalline 
compound.  It  exists  in  coffee  either  as  a  salt  of  calcium  or  magnesium, 
or,  according  to  Payen,  as  a  caffctannate  of  potassium  and  caffeine. 


;^ 


FOOD  INSPECTION  AND  .ANALYSIS. 


The  following  siiniman-  of  analyses  of  coffee  of  xarious  kinds  made  by 
Konig  show  in  general  its  composition: 


Raw  Coffee. 

Roasted  Coffee. 

Minimum. 

Maximum. 

Minimum. 

Maximum. 

8.0 

12.0 

0.4 

4.0 

0.8 

1.8 

0.8 

1.8 

II. 4 

14.2 

10. t^ 

16.5 

5-8 

7-8 

0.0 

I.I 

16.6 

4-' -3 

26.3 

51-0 

I.I 

2.2 

1-3 

2-7 

3-5 

4.0 

4.0 

5-0 

WaiiT 

CatTcinc 

Fat 

Reducing  sugar 

Cellulose 

Total  nitrogen. 
Ash 


The  change  in  composition  that  takes  place  in  roasting  coffee  is  well 
shown  l)y  the  following  figures,  which  gi\e  the  mean  of  analyses  by  Konig 
of  four  samples  of  coffee  before  and  after  roasting: 


Water 

CatTeine 

Fat 

Sugar 

Cellulose 

Nitrogenous  substances 

Other  non-nitrogenous  matter 
Ash 


Raw  Coffee. 


11.23 

1 .21 

12.27 

8-55 
18.17 
12.07 
32-58 

3-92 


Roasted  Coffee. 


I-I5 

1.24 
14.48 

0.66 
io.8q 
13.98 
45-09 

4-75 


'COMPOSITION  OF  THE  ASH  OF  COFFEE.* 


Constituents. 


Mocha. 


Maracaibo. 


Java. 


Sand 

Silica  fSiOj) 

Ferric  oxide  (FcjO,).  . 

Lime  rCaO) 

Magnesia  (MgO) 

Pota.sh  (K.O) 

Soda  rNa.,0) 

Phosjjhoric  acid  fP^Oj) 
Sulphuric  acid  (SO-,).  . 
Chlorine  (CI) 


1-44 


7.18 
10.68 
59-84 

0.48 

12.93 
4-43 
1-25 


0.72 

0.88 

0.89 

5.06 

II.  30 

61.82 

0.44 

13.20 

5.10 

0-59 


0.74 
0.91 
1. 16 
4.84 

11-35 
62.08 

14.09 
4. 10 
0-73 


100.00 


100.00 


1-34 
0.69 

1-77 

4-94 

10.60 

63.60 

C.17 

11-53 
4. 88 
0.48 


The   following  are   analyses  of  common   varieties  of  roasted   coffee, 
also  of  coffee  sub.stitutes  and  adulterated  coffee  made  by  Lythgoe:t 

•  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  p.  904. 

t  An.  Rep.  Mass.  State  Board  of  Health,    1904,  p.  3.-70.     U.  S.  Depl.  of  Agric,  Bur.  of 
Chem.,  Bui.  90,  pp.  43-45- 


TEA,   COFFEE,  AND   COCOA. 


381 


COMPOSITION   OF   ROASTED   COFFEE. 


Alka 

inity 

(cc. 

M/io 

«4.| 
0 

< 

Acit 

1)  of 

3 

B6 

J3 

c 

Variety 

oi 
u 

« 
'0 

< 

_3 
"0 
W 
u 

•0 
c 

a 

'C 

.2 

0 

0  2 

< 

"o 

E 

u 

a 

6 

Ji 

j3 
"o 

0 

V 

"c 
c 

Petroleum  Et 
Extract. 

Index  of  Ref 
Extract  at 

2 

0 

'  h 

1.40 

4.16 

3-46 

0.00 

0.023 

2-97 

71-4 

0.319 

0.346 

14-58     I 

4754 

2.26 

Santos 

B 

1.87 

4-31 

3.62 

.00 

.023 

3 

36 

75-7 

.286 

-295 

13.84     I 

4754 

2.26 

X 

I-3I 

3.80 

3.OG 

.00 

.019 

3 

35 

85.6 

-273 

-295 

13.86     I 

4750 

2-39 

Porto 

A 

1.29 

4-05 

3-30 

.00 

.016 

3 

53 

87.2 

•305 

-337 

13.00     I 

4752 

2.28 

Rico     1 

a 

1.26 

4.06 

3-27 

.00 

.020 

3 

72 

92.6 

.226 

-351 

13-34     I 

47.50 

2.26 

c 

1.48 

4.12 

3-32 

.00 

.016 

3 

66 

88.8 

-333 

.328 

14.12     I 

4760 

2-33 

A 

1.76 

■4.06 

3-40 

.oc 

.020 

4 

16 

102.3 

.213 

.166 

13-38     I 

47.58 

2.14 

Rio           \ 

B 

2.34 

3-91 

3-24 

.DC 

.021 

3 

17 

81.2 

.35() 

.227 

13-71      I 

4753 

2.18 

\ 

C 

2.10 

3-74 

3.06 

.DC 

.023 

3 

22 

86.6 

.3<^3 

.236 

13-53     I 

47  5& 

2.26 

A 

2.05 

4.0=; 

3-25 

.00 

.016 

3 

94 

97-4 

.282 

-351 

14.84  *i 

4737 

2.28 

Mocha 

B 

2-95 

3-H5 

3-07 

.00 

.021 

3 

26 

84.7 

•333 

-364 

14-47  *i 

4743 

2.00 

^L 

2.40 

3.80 

3.00 

.00 

.012 

3 

54 

93-3 

-337 

-545 

15.18  *i 

4740 

2.02 

A 

3-34 

4.09 

3-27 

.oc 

.016 

3 

88 

95-0 

-\5« 

.421 

12.61      I 

4752 

2.48 

Java 

B 

3-35 

4-3« 

3-5& 

.00 

.019 

3 

54 

80.8 

.194 

.388 

12.28     I 

4758 

2-35 

C 

3-44 

3-9*3 

3.10 

.00 

•  Oil 

2 

95 

74.5 

-235 

-3«3 

13-54     I 

4752 

2-56 

Highest.. 

.. 

3-44 

4-3« 

3.62 

.00 

.023 

4 

16 

102.3 

-424 

-.545 

15.18     I 

.476c 

2.56 

Lowest.  . 

r.26 

3-74 

3.00 

.00 

.011 

2 

95 

71-4 

.194 

.166 

12.28     I 

-47.50 

2.00 

Average. . 

2.16 

4-03 

3.26 

.00 

.018 

3 

55 

87.1 

.285 

-329 

13-75     I 

•4754 

2.27 

0 

6 
d 

Ten  Per  Cent  Extract. 

>. 

1      0 

Variety. 

1 

a! 

w 

"0 
0 

to 

M 
_C 
'0 

3 
•0 

(5 

S 

•a 

3 

6 
c 

is 

0  10 

0  oj 

c  d  0 

0  g  0 

X3     , 

0 

< 

Pi 

C/2 

U 

0 

M 

m 

< 

'A 

20.80 

16.83 

0.52 

2.28 

13-41 

1-25 

I. 0107 

26.7 

1-33770 

2.64 

0.40 

Santos      \ 

B 

22.72 

17. II 

.68 

I.  00 

11.02 

1. 10 

I. 0108 

26.9 

1-33777 

2.66 

•39 

,C 

21.70 

17.80 

-75 

2.32 

14.71 

1.20 

I.OIOI 

26.0 

1-33743 

2.46 

-30 

Porto 

A 

22.48 

15-70 

■50 

2.17 

13. II 

1-38 

I. 0107 

26.6 

1.33766 

2.60 

-37 

Rico 

B 

21.76 

16.36 

-b3 

1-58 

12.93 

I. 21 

I. 0104 

26.3 

1-33754 

2-50 

-30 

.  ^ 

24.44 

16.91 

-54 

2.62 

12.50 

I. 32 

I.OII3 

27.6 

1.33804 

2-77 

-30 

A 

22.66 

17.00 

.68 

2.82 

14.08 

I. II 

I. 0103 

25-5 

1-33724 

2.48 

.40 

Rio           \ 

^ 

22.61 

17-34 

-78 

1-47 

13.10 

I. 10 

I.OIOI 

25-8 

1-33735 

2.46 

-36 

<- 

22.75 

17-37 

.61 

2.62 

II. 91 

I. 17 

I.OIOI 

26. c 

1-33743 

2.46 

-30 

A 

24.00 

18.01 

1.78 

2.30 

11.22 

I. 16 

I. 0106 

26.4 

1-33758 

2.65 

.40 

Mocha     ■ 

B 

20.27 

17.96 

-94 

1.85 

12.34 

I. 10 

I.OIOI 

26.3 

1-33754 

2.47 

-36 

[<^ 

24.18 

19-55 

1.42 

2.90 

13.20 

I. 18 

I.OIII 

27-3 

1-33793 

2.72 

.40 

A 

23-85 

15-95 

-32 

2-95 

13-43 

1-34 

I.OIIO 

29.6 

1-33777 

2.63 

.39 

Java         ] 

B 

22.19 

15-45 

.42 

2-32 

13-77 

1.30 

I. 0107 

26.5 

1-3376: 

2-58 

-38 

C 

23.20 

16.21 

.66 

3-34 

14-75 

1.27 

I. 0108 

26.6 

1.33766 

2.62 

-38 

Highest.  . 

.  . 

24.44 

19-55 

1.78 

3-34 

14-75 

1-34 

I.0II3 

27.6 

1.33804 

2-77 

.40 

Lowest.  . 

20.27 

16.45 

-32 

1. 00 

11.02 

1. 10 

I.OIOI 

26.0 

1-33743 

2.46 

-30 

Average. 

•- 

22.63 

17-03 

-75 

2-30 

13-03 

1 .20 

I. 0105 

26.6 

1.33766 

2.72 

-37 

*  Omitted  from  average. 


3^2  FOOD  INSPECTION  y4ND  ANALYSIS. 

COMPOSITION  OF  COFFEE  SUBSTITUTES  AND  OF  ADULTERATED  COFFEE. 


3 

s 

< 

< 

1 

•6 

1 

lU 

c 

0 

Alkalinity 
(cc.  N  '10 
Acid)  of 

6 

3 

c5 
1 

u 
<u 

SS 

"0 
c 
.9 

a°o 
rt  w5 

Ort 

•cW 
c 

Variety. 

^  3 

OCfl 

-So 

43 
< 

E 
2 
a 

c 

£ 

"rt 
0 

Roasted  wheat. 
Roasted  chicory 
CotTec          and 

chicory 

Coffec.chicory 

and  pea  hulls 

5.60 

5-55 

5.08 
3-64 

5-71 
4.37 

3-96 

4-97 

2.82 
2.27 

3-14 

4-05 

O-OO 

.81 
.06 
-24 

0-080 

.026 

*.2S4 

0-34 

-95 

3-05 
2.60 

6.0 
21.8 

77-0 
65.6 

0.640 
.277 

.286 

.472 

1.460 
■314 

-323 
.740 

2.40 
.88 

8.32 

9-.s6 

1-4745 

1.84 
1. 10 

1.89 

2.17 

w 

u 
rt 

•a 
■3 
0 

u 

W 
"o 

X! 
p 

< 

rt 
60 

3 

M 
C 

"0 

3 
•T3 
V 

a 
£ 

3 
0 

0 

c 
(A 

0 

Ten  Per  Cent  Extract. 

Variety. 

d  . 

Immersion  Re- 
fractometer 
Reading  at  20°. 

Index  of  Re- 
fraction at 
20°. 

•3 
1 

43 
< 

Roasted  wheat 

25-88 
72.92 

31-79 
25.00 

10.72 

34-39 
21.66 

14-25 

4.10 

19-34 
5.06 
3.00 

28.58 
2.10 

2.21 

3-78 

6.23 
5-91 

14.31 
17.87 

0.00 

Roasted  chicory 
Coffee          and 

chicory 

Coffee,  chicor>' 

and  pea  hulls 

.00 

-95 
1 .00 

1.0307 

I. 0142 

45-0 
30-5 

1-34463 
I-33915 

7-44 
3.62 

0.26 
.29 

*  Admixture  of  salt. 


METHODS    OF    ANALYSIS. 

The  .sample  i.s  prepared  for  analy.si.s  by  grinding  so  as  to  pa.ss  a  sieve 
with  holes  0.5  mm.  in  diameter. 

Moisture,  Ether  Extract,  Crude  Fiber,  Protein,  and  Ash  (including 
total,  water-.solublc,  water-insoluble,  acid-insolubic  and  alkalinity)  arc 
determined  as  in  the  ca.se  of  tea  (pp.  368  and  369).  Starch,  Reducing 
Matters  by  Ac'd  Conversion,  Sucrose,  and  Reducing  Sugars  may  be  esti- 
mated by  the  methods  de.scribed  under  cereal  ];roducts. 

Ten  Per  Cent  Extract.     (See  page  389.) 

Caffetannic  Acid.  —  Krug's  Method* — Two  grams  of  the  coffee  are 
digested  for  thirty-six  hours  with  10  cc.  of  water,  after  which  25  cc.  of 

♦  U.  S.  Dept.  of  Agrir.,  Div.  of  Chem.,  Bui.  13,  p.  908. 


TEA,   COFFEE,   AND    COCOA. 


3^3 


90%  alcohol  are  added,  and  ihc  digestion  continued  for  twenty-four 
hours  more.  The  liquid  is  then  filtered,  and  the  residue  washed  with 
90%  alcohol  on  the  filter. 

The  filtrate,  which  contains  tannin,  caffeine,  fat,  etc.,  is  heated  to 
boiling  and  a  boiling  concentrated  solution  of  acetate  of  lead  is  added, 
which  precipitates  out  a  caffetannate  of  lead,  Pb3(Ci5H  1508)2,  containing 
49%  of  lead.  When  this  has  become  flocculent,  it  is  separated  by  filtra- 
tion, and  washed  on  the  filter  with  90%  alcohol,  till  the  washings  show 


Mk 


II. 

Fig.  75. — Coffee.  I.  cross-section  of  berry,  natural  size.  Pk  outer  pericarp;  Mk  endocarp; 
£ife  spermoderm;  5a  hard  endosperm;  5/*  soft  endosperm.  II.  Longitudinal  section  of 
berry,  natural  size;  Dis  bordered  disc;  Se  remains  of  sepals;  Em  embryo.  III.  Embryo 
enlarged;  co/ cotyledon;  rad  radicle.     (TscHiRCH  and  Oesterle.) 

no  lead  with  ammonium  sulphide,  and  afterwards  with  ether,  till  free 
from  fat.     It  is  dried  at  ioo°  and  weighed. 

The  weight  of  caffetannic  acid  is  obtained  by  multiplying  the  weight 
of  the  precipitate  by  652,  and  dividing  by  1263.63. 

Woodman  and  Taylor's  Modification* — To  2  grams  of  finely  ground 
coffee  (passing  0.5  mm.  sieve),  add  10  cc.  of  water,  and  shake  for  an 
hour  in  a  mechanical  shaking  device.  Add  25  cc.  of  90%  alcohol  and 
shake  again  for  half  an  hour.  Filter  and  wash  with  90%  alcohol.  Bring 
the  united  filtrate  and  washings,  about  50  cc,  to  boiling,  and  add  6  cc. 
of  saturated  lead  acetate  solution.  Separate  the  precipitated  lead  caffe- 
tannate by  means  of  a  centrifuge,  decanting  the  supernatant  liquid 
through  a  tared  filter.  Repeat  the  centrifugal  treatment  twice  with  90% 
alcohol,  decanting  each  time  through  the  filter.  Transfer  the  precipitate 
to  the  filter,  and  wash  free  from  lead.  Wash  with  ether,  dry  at  100°,  and 
weigh.  The  weight  of  the  precipitate  multiplied  by  0.516  gives  the  weight 
of  caffetannic  acid. 


*  A.  O.  A.  C.  Proc.  1908,  U.  S.  Dept.  of  Agric,  Bur.  of  Cham.,  Bui.  122,  p.  82. 


3S4  FOOD  IhSP3.CTlON  AND   ANALYSIS. 

Cafifeine. — Gortcr  Miiliod* — Moisten  11  grams  of  the  finely  powdered 
coffee  with  3  cc.  of  water,  allow  to  stand  for  half  an  hour,  and  extract  for 
three  hours  in  a  Soxhlet  or  Johnson  extractor  with  chloroform.  Evaporate 
the  extract,  treat  the  residue  of  fat  and  caffeine  with  hot  water,  filter  through 
a  cotton  plug,  and  wash  vnth.  hot  water.  Make  up  the  filtrate  and  wash- 
ings to  55  cc,  pipette  off  50  cc,  and  extract  four  times  in  a  separatory 
funnel  with  chloroform.  Evaporate  this  chloroform  extract  in  a  tared 
flask,  dry-  the  catTeine  at  100°  C,  and  weigh. 

Calculate  the  caffeine  also  from  the  nitrogen  content. 

ADULTER.\TrON    OF    COFFEE. 

According  to  the  U.  S.  Standard  roasted  coffee  is  coffee  which,  by 
the  action  of  heat,  has  become  brown  and  developed  its  characteristic 
aroma,  and  contains  not  less  than  10%  of  fat  and  not  less  than  3%  of  ash. 

Imitation  Coffee.  —  Formerly,  artificial  coffee-beans  containing  no 
coffee  whatever,  but  cleverly  molded  to  imitate  the  original,  were  occa- 
sionally to  be  found,  mixed  with  genuine,  whole  coffee. f 

"  Coffee  pellets  "  are  occasionally  sold  in  bulk  to  dealers  as  an  adulter- 
ant of  whole  coffee.  These  do  not  closely  resemble  the  real  berries  in 
appearance,  but  are  approximately  of  the  same  size,  and  are  not  apparent 
to  the  purchaser  when  the  whole  coffee  is  ground  at  the  time  of  purchase. 
A  sample  of  these  "  pellets  "  examined  recently  was  found  to  consist  of 
roa.^tcd  ^^heat  mash,  colored  with  red  ocher. 

Coloring  Coffee  Beans. — The  practice  of  treating  raw  coffee  beans 
in  a  manner  somewhat  analogous  to  the  facing  of  tea  leaves  has  been 
sometimes  practiced,  with  a  view  to  giving  to  cheaper  or  inferior  grades 
the  apjx.-arance  of  high-priced  coffee.  For  this  purpose  various  pigments 
have  been  employed,  such  as  yellow  ocher,  chrome  yellow,  burnt  umber, 
Venetian  red,  Scheele's  green,  iron  oxide,  tumeric,  indigo,  Pru.ssian 
blue,  etc,  the  coffee  beans  being  first  moi.stened  with  water  containing 
a  little  gum,  and  .shaken  with  the  pigment.  As  a  rule  .such  pigments, 
especially  when  inorganic,  are  best  .sought  for  either  in  the  ash,  or  in  the 
sediment  obtained  by  .shaking  the  coffee  beans  in  cold  water,  using  the 

♦  Aimalcn,  358,  1908,  p.  327.  I'.  S.  lk])l.  oi  Agrit  .,  Hur.  of  Chcm.,  Bui.  132,  jj.  135. 
A.  O.  A.  C.  method. 

t  A  sample  of  suth  imilation  whole  ((jfTec  in  the  possession  <jf  the  writer  consists  almost 
cntiirly  of  roasted  wheat  molded  into  hx;ans  with  difficulty  to  be  distinguished  in  appear- 
anrr  from  those  of  genuine  rf^ffee,  so  closely  do  they  resemble  the  f)riginal,  even  to  the  cleft 
in  the  sides.     The  chafi  in  the  cleft  Is,  however,  lacking. 


TEA,   COFFEE,   AND   COCOA.  385 

ordinary  qualitative  chemical  methods.  Organic  coloring  matters  can 
be  best  extracted  with  alcohol.  Prussian  blue  and  indigo  are  tested 
for  as  in  the  case  of  tea  leaves  (p.  375). 

Glazing. — This  is  a  more  recent  form  of  treatment  of  the  whole  bean, 
which  consists  in  coating  the  beans  by  dipping  in  egg  or  sugar,  or  a  mix- 
ture of  the  two,  sometimes  using  various  gums.  Such  glazing  is  alleged 
to  improve  the  keeping  qualities  of  the  coffee,  as  well  as  to  aid  in  clarify- 
ing the  infusion,  and  if  this  is  the  sole  purpose,  the  practice  cannot  be 
condemned  as  a  form  of  adulteration.  If,  however,  it  is  done  to  give 
inferior  varieties  of  coffee  a  better  appearance,  in  order  to  deceive  the 
consumer,  it  clearly  constitutes  adulteration  within  the  meaning  of  the 
law. 

Adulterants  of  Ground  Coffee. — Of  the  adulterants  used  in  ground 
coffee  the  following  have  been  found  in  Massachusetts:  Roasted  peas, 
beans,  wheat,  rye,  oats,  chicory,  brown  bread,  pilot  bread,  charcoal, 
red  slate,  bark,  and  dried  pellets,  the  latter  consisting  of  ground  peas, 
pea  hulls,  and  cereals,  held  together  with  molasses. 

Methods  of  Detecting  Adulterants. — These  methods  are,  as  a  rule,, 
physical  rather  than  chemical.  A  rough  test  of  the  genuineness  of  ground' 
coffee  consists  in  shaking  some  of  the  sample  in  cold  water.  Pure  coffee^, 
under  these  conditions,  usually  floats  on  the  surface,  while  the  ordinarjr 
adulterants,  such  as  cereals,  chicory,  mineral  ingredients,  etc..  sink^ 
th;  grains  of  chicory  coloring  the  water  a  brownish-red  as  they  subside.. 

Macfarlanc  recommends  the  use  of  a  saturated  solution  of  common 
salt,  in  which  a  portion  of  the  suspected  sample,  divided  in  small  grains, 
is  shaken  in  a  test-tube.  If  the  liquid  is  colored  pale  amber,  while  all 
or  nearly  all  the  material  floats,  the  coffee  is  pure.  Any  considerable 
sediment  at  the  bottom  of  the  tube,  accompanied  by  a  dark-yellow  to 
brown  color  imparted  to  the  liquid,  indicates  adulteration  by  roasted 
cereals,  or  chicory,  or  both. 

A  careful  examination  of  the  coarsely  crushed  grains  of  a  ground 
sample  with  the  naked  eye  will  often  serve  to  detect,  and  in  some  cases 
identify,  certain  adulterants,  such  as  chicory  and  ground  peas  or  bcans- 
A  magnifying-glass  will  aid  in  such  an  examination,  and  the  observer 
can  often  separate  the  various  ingredients  of  a  coffee  mixture,  first  spread- 
ing a  small  portion  of  the  sample  on  a  sheet  of  w^hite  paper.  The  chicory 
grains  are  apparent  from  their  dark  and  somewhat  gummy  appearance, 
and  can  usually  be  recognized  by  crushing  them  between  the  teeth.  Their 
soft  consistency  and  sweetish  bitter  taste  are  very  distinctive.     The  dull 


3S6  FOOD  INSPECTION  AND  ANALYSIS. 

outer  surface  of  the  crushed  coffee  grains  is  in  marked  contrast  to  the 
polished  appearance  of  the  surface  of  the  broken  peas  or  beans,  often  to 
be  found  as  aduherants,  while  fragments  of  broken  cereal  grains  are 
readily  distinguished  from  cotTee  with  a  low-power  magnifier,  though 
perhaps  not  easily  identified  by  the  eye  alone. 

Determination  of  Added  Starch, — Starch  is  determined  in  the  finely 
powdered  samj)le  as  directed  on  page  28:;. 

Microscopical  Examination  of  Coffee. — By  far  the  best  means  of 
detecting  adulteration  is  furnished  by  the  microscope.  The  individual 
grains  of  coarsely  ground  coffee  and  adulterants,  separated  by  the  cold 
water  test  or  by  picking  over  the  mixture,  are  identified  by  microscopic 
examination  either  after  sectioning  with  a  razor  or  crushing  to  a  powder. 
In  addition,  examination  is  made  of  a  small  portion  of  the  sample  pulver- 
ized in  a  mortar  to  a  degree  fine  enough  to  allow  the  cover-glass  to  lie 
flat  on  the  wetted  powder,  yet  not  so  fine  that  it  ceases  to  feel  granular 
when  rubbed  between  the  fingers.  The  writer  finds  it  sufficient  to 
examine  this  powder  in  water  without  further  treatment,  although 
Schimper  recommends  maceration  for  twenty-four  hours  with  ammonia, 
in  order  to  render  the  tissues  more  transparent,  using  this  reagent  also 
as  a  mountant. 

In  general  the  interior  of  the  coffee  tissue  or  endosperm  consists  of 
polygonal  cells  with  highly  characteristic,  knotty,  thickened  walls,  which 
are  best  seen  in  razor  sections,  Fig.  76,  2.  These  cells  contain  brilliant, 
colorless,  spherical  oil  drops,  and  also  proteins. 

The  seed  coat  is  also  very  characteristic,  showing  in  the  powder  as 
occasional  delicate  silver-like  patches,  with  peculiar,  spindle-shaped, 
thick-sided  cells,  some  of  which  are  loosened  from  the  tissue. 

Plates  XIV  and  XV  illustrate  photomicrographs  of  pure  and  adulter- 
ated coffee.  Fig.  174  shows  genuine  coffee,  with  its  loose  mesh  of  irreg- 
ularly polygonal  cells,  thick-walled,  and  inclosing  oil  drops  with  amor- 
phous material.  It  is  not  to  be  expected  that  every  pulverized  sample  of 
genuine  coffee,  mounted  as  above,  will  show  in  every  microscopic  field  the 
even,  continuous  structure  that  Fig.  174  illustrates,  but  careful  examination 
will  show  in  nearly  every  field  fragments,  and  more  or  less  disjointed  por- 
tions of  the  polygonal  cells,  grouped  in  the  form  so  characteristic  of  coffee. 
See  Fig.  176. 

Chicory  under  the  Microscope. — Fig.  77,  after  Moeller,  shows  struc- 
tural features  of  chicory.  The  most  striking  elements  are  the  fine,  thick- 
walled,  long-celled,  parenchyma  of  the  bark  rp  and  bp  with  its  delicate 


TE/I,   COFFEE,   AND    COCOA. 


387 


Fig.  76.— Powdered    Coffee    under    the    Microscope.     X125.     (After    Moeller.)       i,  seed 
coat  (surface).     2,  endosperm   parenchyma. 


Fig.  77. — Chicory  Root  in  Tangential  and  Radial  Sections.  X160.  g,  reticulated  ducts 
with  perforations  qu;  hp,  wood  parenchyma;  /,  wood  fibers;  rp,  bark  parenchymn; 
sch,   milk  ducts;    bp,   bast   parenchyma;    m,   medullary   rays.     (After  Moeller.) 


3SS  FOOD   INSPECTION  AND   ANALYSIS. 

tracery,  and  the  vessels  or  tkicts  g  of  the  wood  fibers.  These  ducts  are 
tubular,  resembling  jointed  cylinders,  often  with  overlapping  joints. 
Less  distinct,  but  very  characteristic  of  certain  roots  of  the  composite 
family,  are  the  narrower  branching  milk  ducts  sch  which  do  not  exist 
in  beets  and  turnips,  which  are  sometimes  substituted  for  chicory. 

Fig.  178,  PI.  XV,  is  a  photomicrograph  of  an  adulterated  sample  of 
coffee,  showing  in  this  particular  field  chicory  alone.  It  is  a  mass  of  con- 
fused cellular  tissue,  traversed  by  two  broad  bands  of  the  vessels,  Vi^ith 
their  striking,  transverse,  dotted  markings. 

Fig.  177,  PI.  XV,  shows  a  sample  of  coffee  adulterated  with  roasted 
peas  and  pea  hulls.  No  genuine  coffee  appears  in  this  field.  The  chief 
masses  in  the  center  are  characteristic  aggregations  of  the  round  starch 
granules  of  the  roasted  pea.  The  rectangular  billets,  like  bunches  of 
matches,  are  from  the  outer  or  palisade  layer  of  the  pea. 

Fig.  164,  PI.  XI,  and  Fig.  154,  PI.  IX,  show  the  close  resemblance 
between  the  starches  of  the  pea  and  bean,  both  of  which  are  commonly 
used  in  coffee. 

The  palisade  structures  of  the  hulls  of  these  legumes  also  bear  a  close 
resemblance,  but  the  cells  of  the  next  layer  in  the  pea  are  hour-glass 
shaped,  while  in  the  bean  they  are  not  remarkable  for  their  shape,  but  for 
the  single  crystal  of  calcium  oxalate  contained  in  each. 

The  elTect  of  roasting  on  starches  used  as  adulterants  of  coffee  is  to 
twist  and  distort  the  granules,  in  some  cases  destroying  largely  the  even 
structure  of  the  raw  starch.  Starch  granules  of  wheat,  barley,  and  rye, 
for  example,  are  almost  perfect  circular  disks  in  the  case  of  the  raw  starch, 
while  in  roasted  products,  such  as  pilot  biscuit  and  stale  bread,  the 
granules  are  twisted  and  distorted,  sometimes  almost  forming  the  letter 

<l    C    >» 

Use  of  Chicory  in  Coffee. —  Chicor}^  is  a  perennial  herb  (CicJioriiim 
intyhus)  of  the  same  family  {ComposilcB)  as  the  dandelion.  The  roasted 
and  pulverized  chicory  root  is  so  much  used  in  ground  coffee  to  impart 
a  peculiar  flavor  thereto,  that  by  many  it  is  considered  as  not  strictly 
an  adulterant.  The  taste  imparted  to  coffee  by  a  small  admixture  of 
pure  chicor)'  Ls  to  some  desirable,  ])Ut  if  its  unrestricted  use  is  sanctioned 
in  this  manner,  the  door  would  soon  be  opened  to  a  more  unlimited  form 
of  adulteration,  wherein  the  chicory  might  predominate.  It  is,  therefore, 
best  to  regard  chicory  as  an  adulterant,  and  to  require  the  package  con- 
taining a  mixture  of  coffee  and  chicor)',  if  sold  legally,  to  have  plainly 
printed  thereon  the  percentage  of  chicory  in  the  mixture. 


TEA,    COFFEE,   AND   COCOA. 


389 


Chicory,  when  roasted,  consists  of  gum,  partly  caramelized  sugar, 
and  insoluble  vegetable  tissue.  Common  adulterants  of  chicory  are 
dried  beets  and  other  roots,  also  cereal  matter. 

Villiers  and  Collin  *  give  the  following  analyses  of  two  samples  of 
chicory : 


In  Large 
Granules. 


In  Powder. 


Soluble  in  water: 


Insoluble  in  water: 


'  Water  (loss  at  100°  to  103°) 

Weight  of  total  matter  soluble  in  water. 

Reducing  sugar 

■   Dextrin,  gum,  inulin 

Albuminoids 

Mineral  matter 

^  Coloring  matter 

f  Albuminoids 

I  Weight  of  the  total  insoluble  matter.  .  .. 

Mineral  matter 

Fat 

[  Cellulose 


16.28 
57-96 
26.12 

9-63 

3-23 

2.58 

16.40 

3-iS 
25.76 

4-58 

5-71 

12.32 


16.96 

56.90 

23-79 

9-31 

3-66 

2-55 
17-59 

2.98 
26.14 

5-87 

3-92 
13-37 


See  also  analysis  of  roasted  chicory  on  page  382. 

Detection  and  Estimation  of  Chicory. — ^Various  chemical  tests  for 
detection  of  chicory  in  coffee  infusions  have  been  suggested,  depending  on 
color  reactions,!  but  these  are,  as  a  rule,  unreliable.  By  far  the  best 
means  for  detecting  chicory  in  coffee  is  furnished  by  the  microscope. 

In  mixtures  containing  coffee  and  chicory  only,  the  approximate  amount 
of  the  latter  can  be  calculated  from  the  specific  gravity  of  a  10%  decoc- 
tion, using  conveniently  the  method  of  McGill.J  A  quantity  of  the  pul- 
verized sample,  corresponding  to  10  grams  of  the  dry  substance,  is  weighed 
in  a  counterbalanced  flask,  and  water  added  till  the  weight  of  the  contents 
is  no  grams.  Fit  the  flask  with  a  reflux  condenser,  and  after  so  regulat- 
ing the  heat  that  boiling  begins  in  ten  to  fifteen  minutes,  continue  the 
boiling  for  an  hour.  Remove  the  flame,  and  after  fifteen  minutes  pass 
through  a  dry  filter,  cool,  and  determine  the  specific  gravity  at  15°. 
McGill  found  the  average  specific  gravity  of  a  10%  decoction  as  above 
carried  out  to  be,  in  the  case  of  pure  coffee,  1.00986  and  in  the  case  of 
chicory   i. 02821,  the  difference  being  0.01835. 

The  specific  gravity  of  the   10%  decoction  of  the  suspected  sample 


*  Falsifications  et  .\herations  des  Substances  Alimentaires,  p.  234. 

t  See  Allen's  Commercial  Org.  .Analysis,  4  Ed.,  Vol.  VI,  pp.  671,  672. 

%  Trans.  Royal  Soc.  of  Canada,  1887. 


3?o 


FOOD  INSPECTION  AND  ANALYSIS. 


at  15°  being  d,  the  per  cent  of  chicor}',  c,  can  be  calculated  roughly  by 

the  formula 

(1.02821  —d)\oo 


c  =  ioo  — ■ 


0.01835 


This  method  is  of  course  inapplicable  when  other  substances  than 
chicor}'  are  present. 

Date  Stones,  roasted  and  ground,  have  been  used  to  some  extent  as  a 
cotlee  adulterant.     Fig.  78  shows  the  structural  features  of  date  stones 


Fig.  78. — Powdered  Date  Stones  under  the  Microscope,  end,  endocarp;  c,  episperm; 
a,  albumen  in  cross-section;  a',  albumen  in  longitudinal  section.  (After  Villiers  and 
Collin.) 

under  the  microscope.  End  represents  a  fragment  of  endocarp  with  its 
elongated,  thick-walled  cells,  peculiarly  arranged  as  shown,  adjacent  cells 
often  lying  with  axes  at  right  angles  to  each  other.  The  more  evenly 
formed  episperm  cells,  e,  are  thin-walled  and  of  a  brown  color.  The 
albumen,  a,  is  made  up  of  very  thick-walled,  somewhat  regularly  arranged 
cells,  indented  from  within  with  deep  channels.  Date  stones  are  readily 
distinguished  from  coffee  by  these  features. 

Hygienic  Coffee. — Various  processes  have  been  devised  for  removing 
the  cafTeine  from  colTee.  One  of  the.sc,  patented  in  Germany,  has  recently 
come  into  extensive  use,  as  the  flavor  of  the  beverage  is  not  greatly  injured 
by  the  treatment.  In  following  out  this  process  the  whole  beans  are  first 
exhausted  with  water  in  a  vacuum,  and  the  infusion  extracted  with  a 
suitable  .solvent  for  caffeine.  The  exhausted  beans  are  then  impregnated 
with  the  decaffeinated  infusion  and  dried  in  a  vacuum.     This  treatment. 


TEA,  COFFEE,  AND   COCOA. 


391 


as  shown  by  the  investigations  of  Lcndrich  and  Murdfield,*  does  not 
completely  remove  all  the  caffeine,  the  quantity  remaining  being  from 
0.14  to  0.26%,  or  about  one-sixth  of  that  in  the  untreated  coffee.  Further 
effects  of  the  treatment  are  a  decrease  in  the  water  extract  and  an  increase 
in  the  fat.  The  following  are  the  average  of  analyses,  made  by  these 
authors,  of  caffeine-free  and  untreated  coffee: 


>. 

c 

< 

Analysis  of  the  Dry  Substance. 

.2 
2 

y  of  Ash 
/I    HCl 
0  grams 
ee). 

0 

In 

.S  "• 

'So 

oX 

"0 

_2 

« 

u 

Co 

is 

1 

E 

3 
'o 

< 

CO 

r 

Alkalinit 
(cc.   N 
per  10 
of  Cof^ 

w 

u 

S  J;  » 
U 

.5  2 
a. 

% 

% 

% 

% 

% 

% 

% 

"Caffeine-free  Coffee".  .. 

14 

2.13 

4-23 

3.22 

47-72 

21.30 

17-13 

0.22 

11.83 

Untreated  coffee 

9 

1.46 

4.71 

3-77 

56-43 

26.  17 

15-73 

1. 19 

"-75 

Several  brands  of  coffee,  advertised  to  be  free  from  tannin  and  in 
some  cases  also  from  caffeine,  have  been  placed  on  the  market  in  the 
United  States,  Some  of  these  consist  merely  of  ground  coffee  from 
which  the  chaff  (which  is  represented  to  contain  not  only  the  tannin  but 
also  most  of  the  caffeine)  has  been  removed  by  mechancial  means.  The 
absurdity  of  the  claims  of  the  manufacturers  is  shown  by  the  following 
analyses  made  in  New  Hampshire  by  C.  D.  Howard,  f 


CafiFe- 
tannic 
Acid. 


Tanninless  coffee  No.  i 
Tanninless  coffee  No.  2 
Tanninless  coffee  No.  3 

Java  and  Mocha 

Coffee  chaff 


Water. 

Ash. 

Fat. 

Fiber. 

Caffeine. 

2.70 

4.10 

13.18 

18.46 

1. 17 

2.70 

4-05 

14.12 

15-70 

I-.  3 

2.26 

3.61 

12.55 

22.70 

0.87 

3-13 

4.13 

14.10 

15-50 

1.29 

2.60 

5-65 

9-30 

26.50 

0.40 

10.76 

11.04 

7.61 

II .  17 

5-98 


The  following  analyses  made  at  the   Connecticut   Station  by   E.   J. 
Shanleyl  corroborate  those  of  Howard : 


*  Zeits.  Unters.  Nahr.  Genuss.,   15,   1908,  p.  705. 

t  A.  O.  A.  C.  Proc.  1906,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  105,  p.  41. 

%  An.  Rep.  Conn.  E.xp.  Sta.,   1907,  p.  141. 


3^- 


FOOD    INSPECTION  y4ND   ANALYSIS. 


Caffeine  ir.  the 
Coffee. 


Caffetannic 

Aci:i  in  the 

Coffee. 


Caffetannic 

Acid  in  the 

Chaff. 


Per  Cent  of 

Chaff  in  the 

Coffee. 


Tanninlestf.  cotTee  A 
Tanninless  cotTee  B 
Tanninlc>s  coffee  C 

Java  coffee 

Mocha  coffee 

Rio  coffee 


1. 14 
i.ii 
1 .12 

1.26 
1-13 


5-46 

7-55 
6.79 


1.80 
2.38 
1-77 


Coffee  Substitutes. — A  large  number  of  preparations  sold  as  "  coflfee 
substitutes  "  or  "  cereal  colTee  "  are  now  on  the  market  in  the  United 
States,  most  of  which  are  composed,  as  alleged  on  the  labels,  of  cereals, 
ground  peas,  etc.  Some  contain  roasted  wheat,  malt  or  some  other 
cereal  aLne,  others  are  mixtures  of  cereals  or  cereal  products  and  peas, 
and  a  few  contain  chicory.  Some  of  these  preparations  have  labels 
calling  attention  to  the  evil  effects  of  coflfee,  and  one  of  the  latter  class, 
extensively  advertised,  md  purporting  to  contain  nothing  but  the  entire 
wheat  kernel  roasted  and  ground,  was  found  to  contain  peas,  and  about 
30^1  of  that  "  most  harmful  ingredient  "  coffee  itself.  Various  substitutes 
are  also  made  from  dried  fruits  such  as  figs,  prunes  and  bananas. 

In  addition  to  the  materials  named  the  following  have  been  used  in 
Europe:  beans,  lupine  seeds,  ca.s.sia  seeds,  a.stragalus  seeds,  Parkia  seeds, 
chick  peas,  soja  beans,  dried  pears,  carob  bean  pods,  date  stones,  ivory 
nuts,  acorns,  grape  seeds,  fruit  of  the  wax  palm,  cola  nuts,  false  flaxseed, 
dandelion  roots,  beets,  turnips  and  carrots.* 

As  in  the  case  of  coffee  the  analyst  must  depend  chiefly  on  the  micro- 
scope in  identifying  the  constituents  of  coffee  substitutes.  Coffee  itself 
should  properly  be  considered  in  the  light  of  an  adulterant. 

COCOA  AND  COCOA  PRODUCTS. 

Nature  of  the  Cocoa  Bean.  —  The  various  chocolate  and  cocoa 
jjreparations  are  made  from  the  bean  of  the  tree  Thcohroma  cacao,  of  the 
family  of  ByUneriacecc.  This  tree  averages  13  feet  in  height,  and  its  main 
trunk  is  from  5  to  8  inches  in  diameter.  It  is  a  native  of  the  American 
crofjics,  being  esi>ecially  abundant  and  growing  under  best  conditions  in 
Mexico,  Central  America,  Brazil,  and  the  West  Indies. 

The  cocoa  beans  of  commerce  are  derived  chiefly  from  Ariba,  Bahia, 
Caracas,   Cayenne,   Ceylon,    Guatemala,   Haiti,   Java,   Machala,    Mara- 


*  Winton's  Microscopy  of  Fofxls,  p.  435. 


TEA,   COFFEE,  AND   COCOA.  393 

caibo,   St.   Domingo,   Surinam,   and  Trinidad.     Besides  these,   the   Sey- 
chelles  and   Martinique   furnish    a   small   amount. 

The  plant  seeds,  or  beans,  grow  in  ]X)ds,  varying  in  length  from  23  to 
30  cm.,  and  are  from  10  to  15  cm.  in  diameter.  The  beans,  which  are 
about  the  size  of  almonds,  are  closely  packed  together  in  the  pod. 
Their  color  when  fresh  is  white,  but  they  turn  brown  on  drying. 

The  gathered  pods  are  first  cut  open,  and  the  seeds  removed  to  undergo 
the  process  of  "  sweating  "  or  fermenting,  which  is  carried  out  either 
in  boxes  or  in  holes  made  in  the  ground.  This  process  rcc[uires  great 
care  and  attention,  as  upon  it  depends  largely  the  flavor  of  the  seed. 
The  sweating  operation  usually  takes  two  days,  after  which  the  seeds 
are  dried  in  the  sun  till  they  assume  their  characteristic  warm  red  color, 
and  in  this  form  are  shipped  into  our  markets. 

Manufacture  of  Chocolate  and  Cocoa. — For  the  production  of 
chocolate  and  cocoa  the  beans  are  cleaned  and  carefully  roasted,  during 
which  process  the  flavor  is  more  carefully  developed,  and  the  thin,  paper- 
like shell  which  surrounds  the  seed  is  loosened,  and  is  very  readily 
removed.  The  roasted  seeds  are  crushed,  and  the  shells,  which  are 
separated  by  winnowing,  form  a  low-priced  product,  from  which  an 
infusion  may  be  made,  having  a  taste  and  flavor  much  resembling  chocolate. 

The  crushed  fragments  of  the  kernel  or  seed  proper  are  called  cocoa 
nibs,  and  for  the  preparation  of  chocolate  they  are  flnely  ground  into 
a  paste  and  run  into  molds,  either  directly,  or  after  being  mixed  with 
sugar  and  vanilla  extract  or  spices,  according  to  whether  plain  or  sweet 
chocolate  is  the  end  product. 

For  making  cocoa,  however,  a  portion  of  the  oil  or  fat  known  as  the 
cocoa  butter  is  first  removed,  by  subjecting  the  ground  seed  fragments 
to  hydrauhc  pressure,  usually  between  heated  plates,  after  which  the 
pressed  mass  is  reduced  to  a  very  fine  powder,  either  directly,  or  by  treat- 
ment with  ammonia  or  alkalies,  to  render  the  producL  more  soluble.  It 
is  held  that  the  large  amount  of  fat  contained  in  the  cocoa,  seeds  (vary- 
ing from  40  to  54  per  cent)  is  difficult  of  digestion  to  many,  such  as  invahds 
and  children,  and  hence  the  desirability  of  removing  part  of  the  fat. 

Composition  of  Cocoa  Products. — The  chief  constituents  of  the 
raw  cocoa  bean,  named  in  the  order  of  their  relative  amount,  are  fat, 
protein,  starch,  water,  crude  fiber,  ash,  theobromine,  gum,  and  tannin. 
During  the  roasting  there  is  reason  to  believe  a  volatile  substance  is 
developed  much  in   the  nature  of  an  essential  oil,  which  gives  to  the 


394 


FOOD  INSPECTION   AND   ANALYSIS. 


product  its  peculiar  tlavor,  and  is  somewhat  analogous  to  the  caffeol  of 
coffee.  -  . 

Tannin,  the  astringent  principle  of  cocoa,  exists  as  such  in  the  raw 
bean,  but  rapidly  becomes  oxidized  to  form  cocoa  rcd^  to  which  the  color 
of  cocoa  is  due. 

Wcigmann  gives  the  following  results  of  analyses  of  cocoa  nibs  and 
shells : 


COMPOSITION  OF  COCOA  NIBS. 


Commercial  Varieties. 


^«  3  O 


u 


M 


Caracas 7-77 

Trinidad 7.87 

Surinam 7-53 

Port  au  Prince 7.77 

Machata S.17 

Puerto  Cabello 8.08 

Ariba 8.27 


I-31 
1.66 


I-5I 


45-54 
44.62 

44-74 
46-35 
45-93 
46.61 

45-15 


19.40 
25-30 
26.45 
5-97 
5-69 
22.9 

S-83 


15-53 
17-50 


16.96 


6.19 

4-55 
4-30 
5-19 
4-36 
4-43 
4-48 


4.91 
3-48 
3.16 

4-15 
4-09 
4.28 
3.88 


2.06 
o.io 
0.13 
1.48 
0.22 
0.18 
0.14 


COMPOSITION  OF  COCOA  SHELLS. 


M  ui 

0 
a 

h 

0 

^^ 

E 

C  u 

V 

Commercial  Varieties. 

Mtn 

S 

&,« 

0 

'Z 

U) 

S-^ 

0 

pis 

3 

•d 

"(3  c 

c 

S 

gco 

H 

gW 

0) 

0 

< 

.^ 

Caracas 

12.49 
14.64 

13-93 
14.89 

13.18 
14.62 

0.58 
0-74 
0.78 

0.75 

2.38 

40.30 

^^•33 

9.06 

6.26 

2. II 

Trinidad 

3-45 
2-54 
2.01 

44-89 
42.47 
43-32 

15-79 
17.04 

i5-25 

6.19 
6.63 

0.42 

2-34 
2.60 

Surinam  

16.25 
16.18 

0.85 
0.27 

Puerto  Cabello 

8.08 

2-59 

The  following  arc  the  summarized  results  of  the  analyses  of  seventeen 
varieties  of  cocoa  seeds  and  shells,  made  by  Winton,  Silverman,  and 
Bailey.* 


*  An.  Rep.  Conn.  Agric.  Exp.  Sta.,  1902,  p.  ■770. 


TEA,   COFFEE,  AND   COCOA. 


395 


Water 

Total  ash 

Water-soluble  ash 

Ash  insoluble  in  acid 

Alkalinity  of  ash 

Theobromine 

Caffeine 

Other  nitrogenous  substances 

Crude  fiber 

Crude  starch  (acid  conversion) 

Pure  starch  (diastase  conversion) 

Other  nitrogen-free  substances  - 

Fat 

Total  nitrogen 

Constants  of  fat  (ether  extract) : 

Melting-point,  degrees  C 

Zeiss  refractometer  reading  at  40°  C 

Refractive  index  at  40°  C 

Iodine  number 

Per  cent  of  nibs  in  whole  bean 

"       "     "shells  "       "         "      


Roasted  Cocoa  Nibs. 


Air-dry  Material. 


Maxi- 
mum. 


3.18 

4-15 
1.86 
0.07 

3-35 
1 .32 

0-73 
13.06 

3.20 
12.37 

8-99 
21.07 

52-25 
2-54 

35-0 
48.00 

1-4579 
37-89 
92.90 
13.88 


Mini- 
mum. 


2.29 
2.61 

0-73 

0.00 

I.  SO 

0.82 

o.  14 

II  .00 

2.21 

9-30 

6.49 

17.69 

48.11 


32-3 
46.00 

1-4565 

33-74 

86.12 

8.83 


Mean. 


2.72 

3-32 
1. 16 
0.02 

2-SI 
I  .04 
0.40 

12.12 
2.64 

II. 16 
8.07 

19-57 

50.12 

2.38 

47-23 

T-4573 

34-97 

88.46 

11-54 


Water-  and  Fat-free 
Material. 


Maxi- 
mum. 


8.81 

3-96 
0.14 
7.12 
2.92 

1-55 
28.05 

6.56 
25.68 
18.61 
44.08 

5-41 


Mini- 
mum, 


5-76 
1.60 
0.00 

3-29 
1.66 
0.31 

23-37 
4.70 
19.80 
13.82 
38.78 

4-74 


Mean. 


7.04 
2.46 
0.05 

5-32 

2.21 

0.86 

25.69 

5.61 

23.66 

17.10 

41.49 

5-05 


Roasted  Cocoa  Shells. 

Air-dry  Material. 

Water-  and  Fat-tree 
Material. 

Maxi- 
mum. 

Mini- 
mum. 

Mean. 

Maxi- 
mum. 

Mini- 
mum. 

Mean. 

Water 

6-57 

20.72 

5-67 
11.18 

5-92 

0.90 

0.28 

18.06 

19.21 

13.89 

5.16 

51.86 

5-23 

3-17 

S-71 

7.14 

2.02 

0.05 

5.02 

0.20 

0.04 

10.69 

12.93 

9-87 

3-36 

43-71 

1.66 

1-74 

4-87 
10.48 

3-67 
2-51 
5-52 
0.49 
0.16 

14-54 

16.63 

11.62 

4.14 

46.40 

2-77 

2.34 

21-97 

6. II 

11.86 

6.47 

0.97 

0.31 

19.40 

20.72 

15-42 

5-59 

55-84 

3-41 

5-63 
2.16 
0.05 

5-32 

0.22 

0.04 

11-34 

13-71 

10.47 

3-65 

47.04 

1.87 

Total  ash 

11.33 

Water-soluble  ash 

3-97 

Ash  insoluble  in  acid 

2.70 

Alkalinity  of  ash 

5-97 

Theobromine 

0.52 

Caffeine 

0.17 

Other  nitrogenous  substances 

15.70 

Crude  fiber.                                   

18.01 

Crude  starch  (acid  conversion) 

12.59 

Pure  starch  (diastase  conversion) 

Other  nitrogen-free  substances 

Fat 

4-47 
50.08 

Total  nitrogen  ., 

2-54 

I 


I 


396  FOOD  INSPECTION  ^ND  ANALYSIS. 

According  to  Bell*  the  ash  of  cocoa  nibs  has  the  following  composi- 
tion: 

Per  Cent. 

Sodium  chloride o-57 

Soda 0-57 

Potash 27.64 

Magnesia 19.81 

Li"^^' 4-53 

Alumina 0.08 

P'erric  o.xide 0.15 

Carbonic  acid 2.92 

Sulphuric  acid 4-53 

Phosphoric  acid 39  -  20 


100.00 


Theobromine  (C^HgN^O,),  the  chief  alkaloid  of  cocoa,  when  pure, 
forms  a  white,  cr)'stallinc  powder,  having  a  bitter  taste.  It  is  slightly 
soluble  in  water  and  alcohol,  very  slightly  soluble  in  ether,  insoluble 
in  })etroleum  ether,  but  readily  soluble  in  chloroform.  It  sublimes  at 
290°  to  295°  C.  It  is  a  weak  base,  and  much  resembles  caffeine.  A  small 
amount  of  caffeine  has  also  been  found  in  cocoa,  but  in  most  analyses 
is  reckoned  in  with  the  theobromine. 

The  Nitrogenous  Substances  of  Cocoa,  aside  from  the  alkaloids,  have 
been  little  studied.  Stutzer  has,  however,  separated  them  roughly  as 
in  the  following  analyses  of  four  samples,  of  which  A  was  manufactured 
without  chemicals,  B  with  potash,  and  C  and  D  with  ammonia: 


B. 


D. 


Total  nitrogen 

Theobromine 

Ammonia 

Amifio  romfKjunds 

Digestible  albumin 

Indigestible  nitrogenous  substances  . . . 

Containing  nitrogen 

ProjKjrtion  of  total  nitrogen  indigestible 


3.68 
1.92 
0.06 

1-43 

10.25 

7.18 

31.2 


3-30 
1-73 
0.03 

1-25 
7.68 
9.19 
1-47 
44-5 


3-95 
1.98 
0.46 
0.31 


.68 
•23 


3-57 
1.80 

0-33 
I-3I 
7.81 
8.00 
1.28 
35.8 


Pentosans. — Several  authors  have  called    attention    to  the  value  of 

these  substances  as  a  means  of  detecting  added  shells  in  cocoa  products. 

Liihrig  and  Seginf  found  in  cocoa  nibs  from   2.51  to  4.58  per  cent 


*  Analysis  and  Adulteration  of  Foods. 

t  Zeits.  Unters.  Nahr.  Genuss.,  12,  1906,  p.  161. 


TEA,   COFFEE,   AND    COCOA. 


397 


of  pentosans  calculated  to  llic  dry,  fat-frcc  substance,  and  in  the  shells 
from  7.59  to  11.23  P'^'"  cent  calculated  to  the  dr}'  substance. 

Milk  Chocolate,  a  product  of  comparatively  recent  introduction, 
consists  of  a  mixture  of  chocolate,  sugar,  milk  powder,  and  cocoa  butter. 
It  is  especially  prized  by  travelers  and  others  who  desire  a  concentrated, 
and  at  the  same  time  palatable  food. 

The  following  analyses  by  Dubois  *  show  the  com[)Osition  of  three 
of  the  leading  brands  on  the  market,  and  also  illustrate  the  accuracy  of 
Dubois'   method  of  determining  sucrose  and  lactose  given  on  page  399. 


Polarization. 


Direct. 


After 
Inver- 
sion. 


Temp. 
°C. 


At  86° 


Su- 

Lac- 

crose, 

tose, 

Per 

Per 

Cent. 

Cent. 

40.90 

8.24 

45-73 

9.12 

46.78 

8.24 

35-99 

8.52 

35 -«2 

8.82 

39-84 

6.03 

39.80 

5.88 

Reich-     Approx. 

ert-      Per  Cent 
Meissl       Butter 
Num-  '    Fat  in 
ber  of  '    Total 

Fat.     i     Fat. 


Commercial  milk  chocolate: 

A 

B 

C 

Milk  chocolate  made  in  the 
laboratory: 

j^   /  Found 

\  Calculated 

Found 


-j-  21.00 
-|-  23.22 
-t- 23.88 


4-19.00 


24 
23 
23 


+  1 
+  1 
+  1 


1-50 


+  1.40 


Calculated. 


+  19.70 


-1-0.99 


5-3 
5-5 
5-8 


4-; 


3-48 


22.1 
22.9 
24.2 


14.5 


Various  Compounds  of  chocolate  or  cocoa  with  other  materials  have 
been  placed  on  the  market.  Zipperer  f  gives  formulas  or  analyses  of 
seventy-four  such  preparations,  containing  one  or  more  of  the  following 
ingredients:  oatmeal,  barley  meal,  malt,  malt  extract,  wheat  flour,  potato 
flour,  rice,  peas,  peanuts,  acorns,  cola  nuts,  sago,  arrowroot,  Iceland 
moss,  gum  Arabic,  salep,  dried  meat,  meat  extract,  peptones,  milk  powder, 
plasmon  (a  preparation  of  casein),  eggs,  saccharin,  vanilla,  spices,  and 
inorganic  salts.  Certain  medicinal  preparations  also  contain  cocoa 
products. 

Cocoa  Butter. — See  page  529. 


*  Jour.  Am.  Chem.  Soc,  29,  1907,  p.  556. 

t  The  Manufacture  of  Chocolate  and  Cacao  Preparations,  2d  ed.,  1902. 


39« 


FOOD   INSPECTION  AND  ANALYSIS. 


METHODS   OF   ANALYSES. 

Preparation  of  the  Sample. — Cocoa  is  usually  in  a  fine  powder, 
and  needs  merely  lo  be  put  through  a  sieve,  to  break  up  lumps,  and  mixed. 
Chocolate  should  be  grated  or  shaved  so  as  to  permit  mixing.  It  can 
not  be  ground,  as  the  heat  of  grinding  reduces  it  to  a  ])aste. 

Moisture. — Dry  two  grams  of  the  material  to  constant  weight  at  ioo° 
C.  in  a  current  of  dry  hydrogen.  Somewhat  lower  results  are  obtained 
by  drying  in  a  dish  in  air. 

Ash. — Proceed  as  described  under  tea  (page  369)  in  the  determination 
of  total,  water-soluble  and  acid-soluble  ash,  and  the  alkalinity  of  the  ash. 


Fig.  79. — Cocoa.  7  entire  fruit,  Xi;  77  fruit  in  cross-section;  777  seed  (cocoa  bean) 
natural  size;  IV  seed  deprived  of  seed  coat;  V  seed  in  longitudinal  section,  showing 
radicle  (germ);   VI  seed  in  cross-section.      (Wixton.) 

Protein.  —  Determine  total  nitrogen  by  the  Kjeldahl  or  Gunning 
method.  From  the  percentage  of  total  nitrogen  subtract  the  nitrogen 
of  the  theobromin  and  caffeine,  obtained  by  multiplying  the  percentages 
found  by  0.31 1  and  0.289  respectively,  and  multiply  the  remainder  by 
6.25. 

Fat  (Ether  Extract). — Extract  two  grams  of  the  material  in  a  con- 
tinuous extractor  until  no  more  fat  is  removed.  Grind  the  residue  and 
repeat  the  extraction.     Dry  the  combined  extract  at  100°  C.  and  weigh. 

Constants  of  Fat. — Sec  chapter  on  PMible  Oils  and  Fat.s. 

Crude  Fiber. — Proceed  as  in  the  analysis  of  cereal  products  (page 
277),  using  the  residue  from  the  ether  extraction. 


TEA,  COFFEE    AND   COCOA.  399 

Reducing  Matters  by  Acid  Conversion  (Crude  Starch).* — Weigh 
four  grams  of  the  material  into  a  small  Wcdgewood  mortar,  add  25  cc.  of 
ether,  and  grind  with  a  pestle.  After  the  coarser  material  has  settled 
out,  decant  off  the  ether  with  the  fine  suspended  matter  on  a  11  cm.  paper. 
Repeat  this  treatment  until  no  more  coarse  material  remains.  After  the 
ether  has  evaporated,  transfer  the  fat-free  residue  from  the  filter  to  the 
mortar  by  means  of  a  jet  of  cold  water,  and  rub  to  an  even  paste.  Filter 
the  liquid  on  the  paper  previously  emi)loyed.  Repeat  the  process  of 
transferring  from  the  filter  to  the  mortar,  grinding,  and  filtering,  until 
all  sugar  is  removed.  In  the  case  of  sweetened  cocoa  products,  at  least 
500  cc.  of  water  should  be  u.sed. 

Transfer  the  residue  to  a  500-cc,  flask  by  means  of  200  cc.  of  water, 
and  convert  the  starch  into  dextrose  by  Sachsse's  method  (page  283). 

Cool  the  acid  solution,  nearly  neutralize  with  sodium  hydroxide  solu- 
tion, add  5  cc.  of  lead  sub-acetate  solution  (page  586),  make  up  to  250 
cc.  and  filter  through  a  dry  filter.  To  100  cc.  of  the  filtrate,  add  i  cc. 
of  60%  sulphuric  acid,  shake  thoroughly,  allow  to  settle,  and  filter  through, 
a  dry  filter. 

Determine  reducing  matters  by  Allihn's  method  (page  608). 

Duhois,'\  instead  of  treating  with  ether  as  above  described,  shakes  four 
grams  of  the  unsweetened  product  or  eight  grams  of  the  sweetened  with 
100  cc.  of  gasoline,  and  whirls  in  a  centrifuge  to  separate  from  the  insoluble 
matter.  After  decanting  off  the  gasoline  layer,  sweetened  products  are 
treated  in  like  manner  with  two  portions  of  100  cc.  of  water  to  remove 
the  bulk  of  the  sugar,  and  finally  washed  on  the  paper. 

Starch. — Diastase  Method. — Remove  the  fat  and  sugar  from  four  grams 
of  the  material  by  treatment  with  ether  and  water,  as  described  in  the 
preceeding  section,  and  determine  starch  in  the  residue  by  the  diastase 
method  (page  283). 

Pentosans.     See  page  285. 

Determination  of  Sucrose  and  Lactose. — Dubois  Method. % — Place 
26  grams  of  the  material  in  an  8-ounce  nursing  bottle,  add  about  100  cc. 
petroleum  ether  and  shake  for  five  minutes.  Whirl  in  a  centrifuge  until 
the  solvent  is  clear,  draw  off  the  same  by  suction  and  repeat  the  treat- 
ment with  petroleum  ether.  Keep  the  bottle  containing  the  defatted 
residue  in  a  warm  place  imtil  the  petroleum  ether  is  practically  expelled. 

*  Winton,  Silverman  and  Bailey,  An.  Rep.  Conn.  E.xp.  Sta.,  1902,  p.  275. 

t  A.  O.  A.  C.  Proc.  1908,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  p.  214. 

%  A.  O.  A.  C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  66,  p.  15. 


400  FOOD  INSPECTION  AND   ANALYSIS. 

Add  lOO  cc.  water  and  shake  until  all  the  chocolate  is  loosened  from  the 
sides  and  bottom  of  the  bottle  and  continue  the  shaking  for  three  minutes 
longer.  Adci  lo  cc.  of  lead  subacetate  solution  (p.  586),  mix  thoroughly 
and  filter  through  a  folded  filter.  Make  the  direct  polariscopic  reading 
{a)  in  a  200-mm.  tube,  then  precipitate  the  excess  of  lead  by  dry  potassium 
o.xalate.  Invert  by  one  of  the  methods  given  on  page  5S8,  polarize,  and 
multiply  the  invert  reading  by  2  to  correct  for  dilution  (/;).  Calculate 
the  approximate  percentages  of  sucrose  {S)  and  lactose  (Z)  by  the  follow- 
ing formulas: 

(g-^)Xiio  (aXi.io)-5 

o  —  L,=  . 

142.66—- 

2 

From  the  sum  of  S  and  L  calculate  the  approximate  number  of  grams 
of  total  sugar  G  present  in  the  26  grams  of  sample  taken  and  determine 
the  factor  X  thus: 

A:=iio  +  (GXo.62), 

in  which  0.62  is  the  volume  in  cc.  displaced  by  i  gram  of  sugar  in  water 
solution.     Applying  this  correction, 

SX        ^,  ,  LX 

irue  per  cent  sucrose  =  — .        Irue  per  cent  lactose  = . 

no  no 

The  following  method  of  solution  may  !)e  substituted  for  that  given 
above : 

Transfer  26  grams  to  a  flask,  add  100  cc.  water,  cork,  and  heat  in 
steam-bath  for  twenty  minutes,  releasing  the  pressure  occasionally  during 
the  first  five  minutes.  Twice  during  the  twenty  minutes  shake  thor- 
oughly so  as  to  emulsify  completely.  Finally  cool  to  room  temperature, 
add  10  cc.  lead  subacetate  solution,  mix,  and  filter. 

Theobromine  and  Caffeine  (Decker-Kunze  Method)  * — Boil  10  grams 
of  the  jjowdered  material  and  5  grams  of  calcined  magnesia  for  30 
minutes  with  300  cc.  of  water.  Filter  by  the  aid  of  suction  on  a  Buchncr 
funnel,  using  a  round  disk  of  filter  })aj)er.  Transfer  the  material  and 
paper  to  the  same  flask  used  for  the  first  boiling,  add    150  cc.  of  water, 

*  Schweiz.  Wchschr.  Phar.,  40,  1902,  pp.  527,  541,  553;  Abstract  Chem.  Centr.,  74,  1903, 
p.  62;  An.  Rep.  Conn.  Elxp.  Sta.,  1902,  p.  274. 


TEA,   COFFEE,    AhID   COCOA.  4°i 

and  boil  15  minutes.  Filter  as  before,  and  repeat  the  operation  of  boiling 
with  150  cc.  of  water  and  filtering.  Wash  once  or  twice  with  hot  water. 
Evaporate  the  united  filtrates  (with  quartz  sand  if  sugar  be  present), 
to  complete  dryness  in  a  thin  glass  dish  of  about  300  cc.  capacity.* 

Grind  to  a  coarse  powder  in  a  mortar  provided  with  a  suitable  cover 
to  prevent  loss  by  flying.  Transfer  to  the  inner  tube  of  a  continuous 
fat  extractor,  and  dry  thoroughly  in  a  water  oven.  Extract  with  chloro- 
form for  8  hours,  or  until  the  theobromine  and  caffeine  arc  completely 
removed,  into  a  weighed  flask.  It  is  important  that  the  material  be 
thoroughly  dry,  that  an  extractor  be  used  that  permits  of  a  hot  extraction, 
and  that  a  considerable  volume  of  chloroform  passes  through  the  material. 
Distil  off  the  chloroform,  and  dry  at  100°  C.  to  constant  weight. 

If  the  material  be  pure  chocolate  or  cocoa,  the  extract  thus  obtained 
is  practically  pure  theobromine  and  caffeine,  but  if  the  material  is  cocoa 
shells  or  a  cocoa  product  mixed  with  a  large  amount  of  shells,  the  extract 
may  be  brown  in  color,  due  to  the  presence  of  considerable  amounts  of 
impurities. 

In  either  case,  separate  the  caffeine  by  treating  the  extract  in  the  flask 
at  the  room  temperature  for  some  hours  with  50  cc.  of  pure  benzol. 
Filter  through  a  small  paper  into  a  tared  dish,  evaporate  to  dryness,  and 
dry  to  constant  weight  at  100°  C,  thus  obtaining  the  amount  of  caffeine. 

Determine  theobromine  by  Kunze'sf  method,  as  follows: 

Add  to  the  residue  and  paper  150  cc.  of  water,  enough  ammonia  water 
to  make  the  liquid  slightly  alkahne,  and  an  excess  of  decinormal  silver 
nitrate  solution.  Boil  to  half  the  original  volume,  add  75  cc.  of  water, 
and  repeat  the  boiling.  The  solution  should  be  perfectly  neutral.  If  it 
contains  the  slightest  amount  of  free  ammonia,  add  water  and  boil  until 
it  is  completely  removed. 

Filter  from  the  insoluble  silver  theobromine  compound,  and  wash  with 
hot  water.  In  the  filtrate  determine  the  excess  of  silver  nitrate  by 
Volhard'sJ   method   as  follows: 

Add  5  cc.  of  cold  saturated  solution  of  ferric  ammonium  sulphate 
(ferric-ammonium  alum),  and  enough  boiled  nitric  acid  to  bleach  the 
liquid.  Titrate  with  decinormal  ammonium  sulphocyanide  solution 
until  a  permanent  red  color  appears. 

*  A  "  Hoffmeister  Schalchen  "  ni;iy  be  used,  or  dishes  may  be  made  from  broken  flasks 
by  making  a  scratch  with  a  diamond  and  leading  a  crack  from  this  scratch  about  the  flask 
by  means  of  a  glowing  springcoal. 

t  Ztschr  f.  anal.  Chem.,  2>iy  1894,  p.  i. 
*-      J  Ibid.,  13,  1874,  p.  171. 


403  FOOD  INSPECTION  AND   ANALYSIS. 

One  cc.  of  decinormal  AgXOs  solution  is  equivalent  to  0.01802  gram 
of  theobromine.  If  the  mixed  alkaloids  were  colorless,  the  theobromine 
obtained  by  subtracting  the  weight  of  caffeine  from  the  weight  of  the 
mixed  alkaloids  will  usually  agree  closely  with  that  obtained  by  silver 
titration. 

ADULTERATION  OF  COCOA  PRODUCTS  AND  STANDARDS  OF  PURITY. 

The  following  are  the  U.  S.  standards:*  Standard  chocolate  should 
contain  not  more  than  t^^'/c  of  ^sh  insoluble  in  water,  3.5%  of  crude  fiber, 
and  9'  0  of  starch,  nor  less  than  45 '^,'0  of  cocoa  fat. 

Standard  sweet  chocolate  and  standard  chocolate  coating  are  plain 
chocolate  mixed  with  sugar  (sucrose),  with  or  without  the  addition  of 
cocoa  butter,  spices,  or  other  flavoring  material,  containing  in  the  sugar- 
and  fat-free  residue  no  liigher  percentage  of  either  ash,  fiber,  or  starcli 
than  is  found  in  the  sugar-  and  fat-free  residue  of  plain  chocolate. 

Standard  cocoa  should  contain  percentages  of  ash,  crude  fiber,  and 
starch  corresponding  to  those  of  plain  chocolate,  after  correcting  for  fat 
removed. 

Standard  sweet  cocoa  is  cocoa  mixed  with  sugar  (sucrose)  containing 
not  more  than  60%  of  sugar,  and  in  the  sugar-  and  fat-free  residue  no 
higher  percentage  of  either  ash,  crude  fiber,  or  starch  than  is  found  in 
the  sugar-  and  fat-free  residue  of  plain  chocolate. 

The  removal  of  fat,  or  the  addition  of  sugar  beyond  the  above  pre- 
scribed limits,  or  the  addition  of  foreign  fats,  foreign  starches,  or  other 
foreign  substances,  constitutes  adulteration,  unless  plainly  stated  on  the 
label. 

The  most  common  adulterants  of  cocoa  are  sugar  and  various  starches, 
especially  those  of  wheat',  com,  and  arrowroot.  Starch  is  sometimes 
added  for  the  alleged  purpose  of  diluting  the  cocoa  fat,  instead  of  remov- 
ing the  latter  by  pressure,  thus,  it  is  claimed,  rendering  the  cocoa  more 
digestible  and  more  nutritious.  Unless  its  presence  is  announced  on 
the  lalx,-l  of  ihe  package,  starch  should  be  considered  as  an  adulterant. 
Cocoa  shells  arc  also  commonly  employed  as  a  substitute  for,  or  an 
adulterant  of,  cocoa.  Other  foreign  substances  found  in  cocoa  are  sand 
and  ground  w(X)d  fiber  of  various  kinds.  Iron  oxide  is  occasionally 
used  as  a  coloring  matter,  especially  in  cheap  varieties. 

*  U.  S.  Dept.  of  Agric,  OfT.  of  Sec,  Circ.  19. 


TEA,    CJFFHF,  AND    COCOA..  403 

Such  adulterants  as  the  starches  and  cocoa  shells  arc  best  detected  by 
the  microscope.  The  presence  of  any  considerable  admixture  of  sugar 
is  made  apparent  by  the  taste.  Mineral  aduUerants  are  sought  for  in 
the  ash. 

Addition  of  Alkali. — The  amount  of  water-soluble  matter  in  cocoa 
is  very  small  (about  20  to  25  per  cent),  and  in  preparing  the  beverage, 
the  desideratum  aimed  at  is  to  produce  as  perfect  an  emulsion  as  possible. 
The  legitimate  means  of  accomplishing  this  is  by  pulverizing  the  cocoa 
very  fine,  so  that  particles  remain  in  even  suspension  and  form  a  smooth 
paste.  Another  means  sometimes  resorted  to  for  producing  a  so-called 
** soluble  cocoa"  is  to  add  alkali  in  its  manufacture,  the  effect  bcin"-  to 
act  upon  a  part  of  the  fat,  and  produce  a  more  perfect  emulsion  with  less 
separation  of  oil  particles.  Such  treatment  with  alkali  is  regarded  with 
disfavor,  even  if  not  considered  as  a  form  of  aduheration.  Cocoa  thus 
treated  is  generally  darker  in  color  than  the  pure  article. 

The  use  of  alkah  is  usually  rendered  apparent  by  the  abnormally  high 
ash,  and  by  the  increased  alkalinity  of  the  ash,  the  latter  constant  being 
expressed  in  terms  of  the  number  of  cubic  centimeters  of  decinormal 
acid  necessary  to  neutralize  the  ash  of  i  gram  of  the  sample.  In  pure, 
untreated  cocoa,  the  ash  rarely  exceeds  5.5%,  and  the  alkahnity  of  the 
ash  is  generally  not  more  than  3.75.  In  cocoa  treated  with  alkali,  the 
ash  sometimes  reaches  8.5%,  with  the  alkahnity  running  as  high  as  6 
or  even  8. 

Microscopical  Structure  of  Cocoa. — Fig.  80  shows  elements  of  the 
powdered  cocoa  bean,  both  of  the  shell  and  of  the  kernel.  The  powder 
of  the  latter  should  constitute  pure  cocoa,  with  occasional  fragments 
only  of  the  shell.  The  irregular  lobes  constituting  the  kernel  are  each 
inclosed  in  a  membrane  made  up  of  angular  cells,  filled  with  granular 
matter.  (4),  (5),  and  (6)  show  elements  of  the  powdered  cotyledons, 
or  seed  kernels.  The  polygonal  tissue  of  the  cotyledon  is  shown  in  cross- 
section  at  (4).  In  the  powder  one  finds  also  dark  granular  matter,  bits 
of  debris,  and  fragments,  with  masses  of  yellow,  reddisli-brown,  and 
sometimes  violet  coloring  matter,  together  with  numerous  starch  granules 
and  aleurone  grains. 

The  starch  granules  are  nearly  circular,  with  rather  indistinct  central 
nuclei,  and  range  in  size  from  0.0024  to  0.0127  mm.,  averaging  about 
0.007  n""^''-  They  are  more  often  found  in  single  detached  grains,  but 
sometimes  in  groups  of  two  or  three.  Occasional  spiral  ducts,  sp,  are 
seen,  but  these  are  not  abundant  in  the  pure  cocoa. 


404 


FOOD   IKSVECTION   AND   ANALYSIS. 


The  masses  of  color  pigment  are  shown  iij)  wiih  striking  clearness, 
according  to  Schimjier,  by  applying  a  drop  of  sulpluiric  acid  to  the  edge 
of  the  cover-glass  and  allowing  it  to  penetrate  the  tissue.  The  bits  of 
coloring  matter  are  for  a  short  time  colored  a  brilliant  red,  which,  how- 
ever, soon  fades.      Ferric  chloride  colors  them  iii(liL:;()  l)lue. 

Schimper  recommends  mounting  the  ])owder  in  a  drop  of  chloral 
hvdrate,  which  soon  renders  most  of  the  tissues  transparent.  It  is  some- 
times necessary  to  allow  the  chloral  to  act  on  the  powder  in  a  closed 


qu— 


Fig.  8o. — Cocoa  under  the  Microscope. 
A.  Powdered  Cocoa  under  the  Microscope.    X125.    (After  Moeller.)      i,  cross-section 
through   shell  parenchyma;    2,  thick-walled    cells;    3,  epidermis  of  shell  (surface  section); 
4,  cross-section  of  cotyledon  tissue;    5,  6,  cotyledon  parenchyma;  7,  starch. 

B.  Cocoa  Shell  in  Surface   Section.      X  160.     e^,  epicarp;  />,  parenchyma   of   the   fruit; 
qu,  layer  of  transverse  cells.     (After  Moeller.) 


vessel  for  twenty-four  hours,  before  all  the  elements,  of  pure  cocoa  are 
rendered  transparent.  If  after  that  lime  opaque  masses  are  still  found, 
these  are  due  to  foreign  material. 

Ammonia  rnay  be  used  instead  of  chloral  with  even  better  results, 
but  this  reagent  requires  longer  treatment,  soaking  for  several  days  or 
a  week  being  sometimes  necessary. 

Fig.  185,  PI.  XVII,  shows  the  microscopical  appearance  of  genuine 
powdered  cocoa  with  its  variously  sized  starch  grains  and  the  debris  of 
the  ground  cotyledons.     Fig.  186  shows  cocoa  adulterated  with  arrowroot. 


TEA,  COFFEE,  AND  COCOA.  405 

Cocoa  Shells. — A  cross-section  of  the  shell  ])arenchyma  and  the  stone- 
cell  layer,  also  some  of  the  numerous  spiral  ducts,  all  characteristic  of  the 
ground  shell,  are  shown  at  i,  Fig.  80. 

The  thick-walled  stone-cells  are  shown  in  surface  view  at  2,  and 
the  spongy,  outer  seed-skin,  composed  of  two  layers,  with  elongated 
cells  running  crosswise  to  each  other  in  striated  fashion,  and  with  the 
underlying  hairs  or  so-called  " Mitscherlich  bodies,"  is  shown  at  3. 
The  presence  of  an  abnormally  large  number  of  yellow  and  brown  frag- 
ments in  the  water-mounted  cocoa  specimen,  even  under  small  magnifi- 
cation, arouses  suspicion  of  the  presence  of  shells,  the  most  distinctive 
elements  of  which  are  the  spongy  tissue,  the  stone  cells,  and  the  abundant 
spiral  ducts,  the  latter  being  scarce  in  pure  cocoa  powder. 

Cocoa  shells  are  indicated  on  chemical  analysis  by  the  abnormally 
high  ash,  crude  fiber  and  pentosans. 

Added  Starch. — This  can  only  be  approximately  determined  by  a 
careful  examination  with  the  microscope.  Long  experience  will  enable  the 
analyst  to  familiarize  himself  with  the  appearance  and  abundance  of 
starch  grains  of  various  kinds  in  a  series  of  fields,  so  that  he  can  roughly 
estimate  the  amount  of  each  starch  present  in  the  mixture,  by  careful 
comparison  with  mixtures  of  known  percentage  composition. 

If  the  amount  of  starchy  adulterant  is  considerable,  evidence  may  be 
secured  by  determinations  of  starch  by  the  diastase  method  and  reducing 
matters  by  acid  conversion. 

Added  Sugar. — Any  appreciable  amount  of  added  cane  sugar  is  shown 
by  the  sweet  taste.  The  amount  of  cane  sugar  may  be  determined  by 
means  of  the  polariscope,  as  described  on  page  399. 

An  abnormally  low  ash  is  indicative  of  the  addition  of  starch  or  sugar 
or  both. 

Foreign  Fat. — Certain  manufacturers  have  found  it  i)rolitablc  to 
remove  a  portion  of  the  cocoa  butter  from  chocolate  and  substitute  for 
it  a  cheaper  fat,  such  as  cocoanut  oil,  tallow  or  even  i)arafrme.  Such 
adulteration  is  detected  by  determination  of  the  physical  and  chemical 
constants  of  the  fat  obtained  by  extraction  with  ether. 

Dyes  and  Pigments,  such  as  Bismark  brown  and  Venetian  red,  have 
been  employed  to  hide  the  |)resence  of  diluents.  They  are  detected  by 
dyeing  tests,  and  by  examination  of  the  ash. 


4o6  FOOD  INSPECTION  AND   ANALYSIS. 


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Steinmann,  a.     Ueber  die  Bestimmung  des  Zuckers  in  Schokolade.     Schw.   Woch. 

Chem.  Pharm.,  40,  1902,  p.  581;  41,  1903,  p.  65. 
Trillich,    H.     Die    Kaffeesurrogate,    ihre    Zusammensetzung    und    Untersuchung. 

Munich,  1889. 
Wanklyn,  J.  A.     Tea,  Coffee,  and  Cocoa.     London,  1883. 
Welmans,  p.     Zur  Priifung  von  Schokolade  auf  den  Gehalt  an  Zucker.     Z.  offent. 

Chem.,  9,  1903,  pp.  93  and  115. 

Kakao  und  Schokolade.     Ibid.,  p.  206. 

Wigner,  G.  W.     Nitrogenous  Constituents  of  Cocoa.     Analj'st,  4,  1879,  p,  8. 
WiNTON,  A.  L.,  Silverman,  M.,  and  Bailey,  E.  M.     Cocoa.     An.  Rept.  Conn.  E.^p. 

Sta.,  1902,  p.  248.     Chocolate.     Ibid.,  1903,  p.  123. 
Wolff,  J.     Ueber  die  Zusammensetzung  und  die  Untersuchung  der  Cichorienwurzel. 

Zeits.  Unters.  Nahr.  Genuss.,  3,  1900,  p.  593. 
Yapple,  F.     Analyses  of  Cocoa.     Amer.  Jour.  Pharm.,  67,  1895,  p.  318. 
ZiPPERER.     The  Manufacture  of  Chocolate  and  Other  Cacao  Preparations.     2d  ed. 

Berlin,  1902. 
Conn.  Exp.  Sta.  Annual  Reports,  1896  et  seq. 
Maine  Exp.  Sta.  Bui.  65.     Analysis  of  Coffee  Substitutes. 
Massachusetts  State  Board  of  Health  Reports,  1882  et  seq. 
N.  H.  Sanitary  Bui.,  Jan.,  1906,  p.  168. 

North  Carolina  Exp.  Sta.  Bui.  154.     Adulteration  of  Coffee  and  Tea. 
Penn.  Dept.  of  .\gric.  An.  Rept.,  1897,  p.  178.     Substitutes  for  Coffee. 
"  "  "  1898,  pp.  75  and  548.     Coffee  and  its  Adulterations. 

"  "  "  1898,  pp.  90  and  652.     Chocolate  and  Cocoa. 


CHAPTER  Xll. 
SPICES. 

These  aromatic  vegetable  substances  are  classed  as  condiments,  and 
depend  for  their  use  on  the  pungency  which  they  possess  in  giving  flavor 
or  relish  to  food.  As  such  seasoning  or  zest-giving  substances,  they  are 
of  considerable  importance  dietetically,  but  from  the  fact  that  they  are 
used  in  comparatively  insignificant  amount,  the  determination  of  their 
chemical  composition  or  actual  value  as  nutrients  per  se  is  of  httle  im- 
portance to  the  food  economist. 

Spices  are,  however,  of  chief  interest  to  the  public  analyst,  because 
of  all  food  materials  they  constitute  from  their  nature  a  class  more  sus- 
ceptible than  others  to  fraudulent  adulteration  of  the  most  skilled  variety. 

In  many  cases  not  only  the  megascopic  appearance  and  taste  of  the 
skillfully  adulterated  article  are  made  to  counterfeit  the  genuine  spice, 
but  even  the  microscopical  appearance  is  intended  to  deceive,  since  it 
is  the  microscope  that  is  most  useful  in  the  detection  of  adulteration,  and 
in  many  cases  in  the  determination  of  the  approximate  amount  of  the 
adulterants. 

Indeed  it  is  ver\'  rare  that  the  microscope  will  fail  to  detect  the  presence 
of  any  foreign  substance  in  spice,  and  hence  its  use  is  indispensable  in 
the  study  of  this  class  of  foods  by  the  analyst.  Chemical  methods,  as 
a  rule,  while  of  secondar}'  importance,  are,  however,  very  helpful,  both 
as  confirmatory  of  the  microscopical  research,  and  in  some  cases  show- 
ing instances  of  adulteration  not  readily  apparent  with  the  microscope, 
such,  for  example,  as  in  the  case  of  exhausted  spices,  or  those  deprived  of 
a  whole  or  a  part  of  their  volatile  oil.  Sophistication  of  this  kind  is  best 
shown  by  the  ether  extract. 

General  Methods  of  Proximate  Analysis. — Tlie  following  methods 
common  to  all  the  spices  are  for  the  most  part  those  adopted  provisionally 
by  the  A.  O.  A.  C*     Methods  peculiar  to  special  spices  will  be  treated 

•*  U.  S.  I;cj)t.  of  Agric,  Uur.  of  Chem.,  Bui.  65  and  Hul.  107  (rev  j. 


SPICES.  409 

under  the  discussion  of  the  spice  in  fjuestion.  For  these  de'i.erminations 
the  spices  should  be  powdered  line  enough  lo  pass  through  a  60-mesh 
sieve. 

Determination  of  Moisture. — Richardson's  Method* — Two  grams  of  the 
sample  are  weighed  in  a  tared  i)latinuni  dish  and  dried  in  an  air-oven 
at  110°  to  a  constant  weight,  which  generally  requires  about  twelve  hours. 
The  loss  in  weight  includes  the  moisture  and  the  volatile  oil.  The  latter 
is  determined  from  the  ether  extract,  as  described  on  page  410,  and 
deducted  from  the  total  loss  to  obtain  the  moisture. 

McGill  t  determines  the  moisture  by  exposure  of  a  weighed  portion 
of  the  sample  in  vacuo  over  perfectly  colorless  sulphuric  acid.  The  spice 
gives  up  its  moisture  before  the  volatile  oil  comes  off,  and  any  appreciable 
amount  of  the  volatile  oil,  when  absorbed  by  the  acid,  causes  the  latter 
to  be  discolored,  so  that  by  carefully  observing  the  beginning  of  the  dis- 
coloration, and  removing  the  sample,  the  loss  due  to  moisture  may  be 
obtained  by  weighing  at  the  proper  stage.  The  abstraction  of  the  mois- 
ture in  this  manner  requires  about  twenty-four  hours. 

Determination  of  Ash. — Two  grams  of  the  spice  are  burned  in  a 
platinum  dish  heated  to  faint  redness  on  a  piece  of  asbestos  paper  by 
means  of  a  Bunsen  burner.  The  burning  is  best  finished  in  a  muffle 
furnace.  If  the  ash  contains  an  appreciable  amount  of  carbon,  it  is 
exhausted  on  a  filter  with  hot  water,  and  the  filter  with  the  residue  is 
burnt  in  the  dish  previously  used.  After  adding  the  aqueous  extract 
and  a  few  drops  of  ammonium  carbonate  solution,  the  whole  is  evaj)orated 
to  dryness  and  ignited  at  a  faint  red  heat. 

The  Water-soluble  Ash  J  is  found  by  boiling  the  total  ash  as  above 
obtained  with  50  cc.  of  water,  and  filtering  on  a  tared  Gooch  crucible, 
the  insoluble  residue  being  washed  with  hot  water,  dried,  ignited,  and 
weighed.  The  insoluble  ash,  subtracted  from  the  total,  leaves  the  water- 
soluble  ash. 

Sand. — This  is  assumed  to  be  the  percentage  of  ash  insoluble  in 
hydrochloric  acid.  The  ash  from  2  grams  of  the  substance,  obtained  as 
above  described,  is  boiled  with  25  cc.  of  to%  hydrochloric  acid  (speci.'c 
gravity  1.050)  for  five  minutes,  the  insoluble  residue  is  collected  on  a 
tared  Gooch  crucible,  thoroughly  washed  with  hot  water,  and  finally 
dried  and  weighed. 

*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  pt.  2,  p.  165. 

t  Canada  Dept.  of  Inland  Rev.  Bui.  73,  p.  9. 

X  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  55;    Bui.  107  (rev.),  p.  162. 


410  FOOD  INSPECTION  ^ND  ^N^ LYSIS. 

Lime  h  determined  from  the  ash  as  directed  on  page  303,  having  first 
separated   the   iron   and  phosphates. 

The  sulphuric  acid  due  to  calcium  sulphate  (added  as  an  adulterant) 
is  determined  by  precijMtation  with  barium  chloride  of  a  ven;  weak  hydro- 
chloric acid  solution  of  the  ash,  the  separated  barium  sulphate  being 
washed,  dried,  ignited,  and  weighed. 

Ether  Extract. — Total,  Volatile,  and  Non-volatile* — Two  grams  of  the 
air-dry,  powdered  substance  are  ])laced  in  some  form  of  continuous 
extraction  apparatus,  such  as  Soxhlet's  or  Johnsc>-i's  (pp.  64  and  65), 
and  are  subjected  to  extraction  for  sixteen  hours  with  anhydrous,  alcohol- 
free  ether.f  The  ether  solution  is  then  transferred  to  a  tared  evaporating- 
dish,  and  allowed  to  evaporate  spontaneously  at  tlic  tcmj:)erature  of  the 
room.  After  the  disappearance  of  the  ether,  tlu-  evaporating-dish  is 
placed  in  a  desiccator  over  concentrated  sulphuric  acid  and  left  over 
night,  or  for  at  least  twelve  hours,  after  which  it  is  weighed,  the  residue 
in  the  dish  being  regarded  as  the  total  ether  extract. 

The  dish  and  its  contents  are  then  subjected  to  a  heat  of  about  100°  C. 
for  several  hours,  taking  a  long  time  to  bring  the  temperature  up  to  that 
point  so  as  to  avoid  oxidation  of  the  oil.  Finally  heat  at  110°  C.  till  the 
weight  is  constant.  The  fmal  residue  is  the  non- volatile,  and  the  loss 
in  weight  the  volatile  ether  extract. 

Alcohol  Extract. — Method  of  Winton,  Ogden,  and  Mitchell.^ — Two 
grams  of  the  powdered  sample  are  placed  in  a  loo-cc.  graduated  flask, 
which  is  filled  to  the  mark  with  95%  alcohol.  The  flask  is  stoppered  and 
shaken  at  half-hour  intervals  during  eight  hours,  after  which  it  is  allowed 
to  stand  for  sixteen  additional  hours  without  shaking,  and  the  contents 
poured  upon  a  dr}-  filter.  Of  the  filtrate,  50  cc.  are  evaporated  to  dry- 
ncss  in  a  tared  platinum  dish  on  the  water-bath,  and  heated  at  iio°C. 
in  an  air-oven  to  constant  weight.  This  method,  while  only  approxi- 
mate, is  so  much  simpler  than  the  tedious  operation  of  continuous  extrac- 
tion, considering  the  long  time  required,  that  it  is  regarded  as  preferable 
for  ordinnr}'  work,  and,  unless  great  care  is  taken,  is  nearly  as  accurate. 

Determination  of  Nitrogen.— This,  in  spices  other  than  pepper,  is 
best  done  by  means  of  the  Gunning  or  Kjeklahl  method  (p.  69). 

•  Richardson,  U.  S.  Dcpt.  of  Agric,  Div.  of  Chem.,  Bui.  13,  p.  165. 

t  Petroleum  ether  may  Ijc  userJ,  yielding  results  whicli  differ  but  slightly  from  those 
obtained  with  ethyl  ether.  As  the  latter  has  been  used  in  the  analyses  of  a  large  number 
of  samples  of  spices,  if  these  analyses  are  to  be  taken  for  standards  of  i  (jmparison  it  is  evi- 
dent that  the  same  solvent  should  be  used. 

X  U.  S.  Dcpt.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  ]>.  56;   Bui.  107  (rev.),  p.  163. 


SPICES.  41 1 

Determination  of  Starch. — In  si)iccs  like  white  pepper,  ginger,  and 
nutmeg  that  normally  contain  a  high  content  of  starch  and  very  little 
other  copper-reducing  matter,  the  direct  acid  conversion  process  of  starch 
determination  is  satisfactory'. 

In  spices  normally  free  from  starch,  such  as  cloves,  mustard,  and 
cayenne,  where  a  starch  determination  indicates  the  amount  of  a  foreign 
starch  present  as  an  aduherant,  it  is  safer  to  use  the  diastase  process. 

Four  grams  of  the  powdered  sample  are  extracted  on  a  filter-paper 
(fine  enough  to  retain  all  starch  particles)  first  with  five  successive  por- 
tions of  10  cc.  of  ether,  then  with  150  cc.  of  10%  alcohol.  Owing  to 
difficuhy  of  filtering  in  the  case  of  cassia  and  cinnamon,  Winton  recom- 
mends that  all  washing  in  the  determination  of  starch  in  these  substances 
be  omitted.  The  residue  is  washed  from  the  filter-paper  by  means  of 
a  stream  of  water  into  a  500-cc.  flask,  if  the  direct  acid  conversion  method 
is  used,  using  200  cc.  of  water;  20  cc.  of  hydrochloric  acid  (specific 
gravity  1.125)  are  added,  and  the  method  from  this  point  on  followed, 
as   detailed  on  page  283. 

If  the  starch  is  to  be  determined  by  the  diastase  method,  wash  the 
residue  from  the  fiher-paper  into  a  beaker  with  100  cc.  of  water,  and 
proceed  as  on  page  283. 

Determine  the  dextrose  in  either  case  by  the  Defrcn  or  Allihn  method, 
or  volumetrically,  and  convert  dextrose  to  starch  by  the  factor  0.9. 

Determination  of  Crude  Fiber.  —  Two  grams  of  the  substance  are 
extracted  with  ordinar>^  ether  (or  the  residue  left  from  the  determination 
of  the  ether  extract  may  be  taken)  and  subjected  to  the  regular  method 
for  determining  crude  fiber,  by  boiling  successively  with  acid  and  alkali 
(page  277). 

McGill  recommends  the  use  of  the  centrifuge  in  separating  the  crude 
fiber,  after  boihng  with  the  alkaline  solution. 

Determination  of  Volatile  Oil. — Method  0}  Girard  and  Dupre.^ — 
The  spice  is  mixed  with  water  and  subjected  to  distillation,  receiving 
the  distillate  in  a  graduated  cylinder.  The  volume  occupied  by  the 
essential  oil  (which  is  immiscible  with  water)  can  be  thus  read  off  and 
its  content  roughly  determined.  If  the  volatile  oil  is  slightly  soluble 
in  water,  separate  out  the  water  layer,  having  first  read  the  volume  cf 
the  oil  layer,  and  extract  the  aqueous  solution  with  petroleum  ether. 
Evaporate  the  petroleum  ether  extract  to  dryness  at  room  temperature 


*  Analyse  des  Maticres  Alimentaires,    2nd  ed.,   p.   7S7. 


41:;  FOOD  INSPECTION  y4ND  .4N  A  LYSIS. 

in  a  tared  dish,  and  add  the  volume  due  to  the  weight  of  the  residue  to 
the  vohime  read  olY  in  the  graduate. 

Microscopical  Examination  of  Powdered  Spices.  —  As  a  rule  few 
micrcscopical  roagenls  are  necessary  in  the  routine  examination  of 
jx)wdered  spices  for  adulteration,  unless  a  more  careful  study  of  the 
structure  than  is  necessary  to  prove  the  presence  of  adulterants  is  desir- 
able. The  simple  water-mounted  specimen  is  usually  sufficient  to  show 
the  purity  or  otherwise  of  the  sample.  If  in  doubt  as  to  the  presence  of 
s'.arch  in  small  quantities,  iodine  in  potassium  iodide  should  be  applied 
to  the  specimen,  well  rubbed  out  under  the  cover-glass. 

The  tissues  may  be  cleared  by  adding  to  the  water  mount  a  small 
drop  of  5'^^i  sodium  hydroxide,  or  by  soaking  a  portion  of  the  si)ic  >  for  a 
day  in  chloral  hydrate  solution.  A  valuable  means  of  clearing  dense 
tissues  is  to  boil  about  2  grams  of  the  material  successively  with  dilute 
acid  and  alkali  as  in  the  crude  fiber  process  (p.  277),  decanting  (not 
filtering)  the  solution  after  each  boiling. 

The  presence  of  occasional  traces  of  a  foreign  substance,  when  viewed 
under  the  microscope,  is  hardly  sufficient  to  condemn  the  sample  as 
adulterated,  since  such  traces  are  apt  to  be  accidental. 

Composition  of  Miscellaneous  Spice  Adulterants. — The  chemical 
analyses  of  various  spice  adulterants  commonly  met  with  are  given  on 
page  413. 

CLOVES. 

Nature  and  Composition. — Cloves  are  the  dried,  undeveloped  flowers 
of  the  clove  tree  (Caryophyllus  aromaiicus  or  Euge^iia  caryophyllaia), 
which  belongs  to  the  myrtle  family  {Myrtaccd).  The  tree  is  an  evergreen, 
from  twenty  to  forty  feet  in  height,  cultivated  extensively  in  Brazil,  Cey- 
lon, India,  IMauritius,  the  West  Indies,  and  Zanzibar.  Its  leaves  are 
irom  7.5  to  13  mm.  long,  and  its  flowers,  of  a  ])urplish  color,  grow  in 
clusters.  The  green  buds  in  the  process  of  growth  change  to  a  reddish 
color,  at  which  stage  they  are  removed  from  the  tree,  spread  out  in  the 
sun,  and  allowed  to  dr}-,  the  color  changing  to  a  deep  brown.  Each 
whole  clove  consists  of  a  hard,  cylindrical  calyx  tube,  having  at  the  top 
four  branching  sepals,  surrounding  a  ball-shaped  casing,  which  consists 
of  the  tightly  overlapping  petals,  and  within  which  are  the  stamens  and 
pistil  of  the  flower.  In  taste  the  clove  possesses  a  strong  and  peculiar 
pungency.  One  of  its  most  valuable  ingredients  is  the  volatile  clove 
oil.     Thi';  is  composed  largely  of  eugenol  {Cj^Yiyfi^)^  which  forms  70  to 


SP/CES. 


413 


COMPOSITION    OF   SPICK   ADULTERANTS. 


Ash. 

Ether  Extract. 

'■J 

i 

1 

> 

W 

"5 

u 

English-walnut  shells  * 

Brazil-nut  shells  * 

7 
9 

7 
7 
8 
8 

5 
8 
10 
4 
9 
7 

69 

08 
80 
36 

24 
77 
73 
71 
44 
42 

50 

63 

1.40 
1.59 
2.86 

0.54 
1.24 
0.23 
1.22 

5-72 
8.40 
0.70 
0.88 
1.84 

0.77 
1 .06 

2-39 
0.50 
0.76 
0.16 
0.32 

1-74 
4.66 
0.28 
0.24 
I.  "1 

0.00 

0.17 

0.05 
0.00 
0.04 
0.00 
0.02 

o->5 
0.S3 
0.07 
0.44 

0.  '  T 

0.12 
0.07 
0.16 
coo 
0.36 
0.07 
0.07 
0.04 
1.00 

I. 21 
0.06 

0.07 

0-S5 
0-57 
0.64 
0.25 
8-38 
0.77 
0.84 
6.58 

2-99 

11.47 

0.24 

0.38 

1.84 

Almond  shells  * 

5.16 

Coroanut  shells  * 

Date  stones  * 

16.72 

1.50 
6.25 

9.46 

4-77 
19-37 

2.17 

Linseed  meal  * 

Cocoa  shells  * 

Red  sandalwood  * 

Ground  olive  stones  f   

Buckwheat  hulls 

English-walnut  shells*. 

Brazil-nut  shells  * 

Almond  shells  * 

Cocoanut  shells  * 

Date  stones  * 

Spruce  sawdust  * 

Oak  sawdust  * 

Linseed  meal  * 

Cocoa  shells  * 

Red  sandalwood  * 

Ground  olive  stones  f  • 
Buckwheat  hulls 


■C2„.2 


19.30 
12.96 
22.72 
20.88 
20.88 
15.48 
17.10 
21.15 

8.68 
6.79 


20.51 


iSQS 


0-73 
0.84 

0-73 
2.19 

I-13 

1.68 

14.06 

3-15 
1. 12 

1-73 
1.46 


X 

c 

Oxypen  Ab- 
sorbed   by 
Aqueous 
Extract. 

1       c 

S(>-5& 

1.69 

0-53 

2.08 

50.98 
49.89 
56.19 

4.19 
1-75 
I -13 

0-33 
0.40 
0.47 

1.30 
1.56 
1.82 

5-72 
64.03 

5-31 
0.^6 

0.61 
0.30 

2.34 
1. 17 

47-79 

1.63 

3-13 

12.22 

8.30 

31.81 

1. 00 

3-90 

14.12 

16.19 

1.26 

4-94 

52-30 
57-46 
43-76 

3.06 
1.06 

3.06 

0-59 

2.29 

P.  60 


0.27 
0.67 
0.28 
0.18 
0.85 
0.09 
0.26 
5-09 

2-59 
C.49 

0.17 
0.49 


75  per  cent  of  the  oil,  and  a  sesquiterpene  known  as  caryophyllene. 
There  are  also  in  cloves  a  notable  amount  of  fixed  oil  and  resin,  and  also 
a  pecuHar  form  of  tannin. 

Very  few  complete  analyses  of  cloves  are  on  record.  Richardson  % 
seems  to  have  been  the  earliest  worker  in  the  field  to  give  anything  at 
all  satisfactory  in  the  way  of  a  number  of  determinations  of  value. 

The  following  are  maximum  and  minimum  figures  from  the  tabu- 
lated results  of  Richardson's  analyses: 

*  Winton,  Ogden,  and  Mitchell,  Conn.  Exp.  Sta.  An.  Rcji.,  1P98,  p.  210. 
t  Doolittle,  Mich.  Dairy  and  Food  Dept.  Bui.  94,  1903,  p.  12. 
X  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13. 


414 


FOOD   INSPECTION  /iND  ANALYSIS. 


c 

u 

0  «i 

c 

u> 

^"^ 

u  S 

S  ,A 

♦J 

rt-4 

o-O 

•0^ 

^•a 

<A 

A 

X  c 

3;- 

.0!^ 

^ 

< 

>^ 

E<^ 

^U. 

^'^ 

10.67 

13-05 

18.89 

10.24 

9-75 

7- 

2. go 

5  -  50 

10.23 

7.12 

6.1S 

4-73 

10.18 

6.96 

4.40 

4-03 

i3-5« 

5-7« 

9.38 

IO-73 

13-93 

7-44 

13.80 

6.48 

5-93 

5-79 

3-94 

4.02 

9-3H 

4.20 

^ 

c 

OJ 

c? 

M3 

>>  cr 

><W 

0 

^'2 
05 


Whole  cloves  (7  samples): 

Maximum 

Minimum 

Stems  (  I  sample") 

Ground  cloves  (9  samples) 

Maximum 

Minimum 


:.i2 

.76'  3.00 
.92    5.96 


5.43I22.13 
11.70 
23.24 


1-04 

.70 


6.20 


24. 1  i 
11.2J 


McGill  *  gives  tables  of  analyses  of  pure  and  adulterated  samples  of 
cloves.  Analyses  of  upwards  of  twenty  samples  of  genuine  cloves,  both 
whole  and  ground,  from  these  tables  show  the  following  maximum  and 
minimum  figures: 


Moisture 

Volatile  oil 

Total  volatile  matter 

Fixed  oil 

Total  extraction .... 
Ash 


Maximum. 


Minimtim. 


11.80 
19.63 
30.68 
10.23 
31.40 
7.00 


5-05 

9.24 
16.25 

0.94 
22.23 

5-03 


McGill  also  made  analyses  of  whole  cloves  of  several  varieties,  the 
following  table  being  a  summary  of  his  results: 


Moisture. 


Total 
Volatile 
Matter. 

Volatile 
Oil. 

Total 
Extract- 
ive 
Matter. 

24-3 

17.2 

28.2 

20.7 

14.8 

24.4 

22.4 

16.2 

27.0 

25-9 

19.2 

29.2 

23-5 

18.0 

26.5 

24.6 

18. 5 

27-5 

23.6 

18.3 

28.1 

18.6 

12. 1 

21-3 

21.7 

16.0 

25-5 

Fixed 
Oil. 


Pcnang  cloves:       Maximum 

Minimum. 

Mean. . . . 
Amboyna  cloves:   Maximum 

Minimum. 

Mean. . . . 
Zanzibar  cloves:     Maximum 

Minimum. 

Mean .... 


9-5 
10.8 
10. o 

8.2 

9.0 
10.7 

8.0 


Maximum  and  minimum  figures  of  thirteen  samples  of  unadulterated 
cloves,  as  purchased  from  retail  dealers  in  Connecticut  and  analyzed 
by  Winton  and  Mitchell, f  are  as  follows: 


*  Canada  Inland  Rev.  Dept.  Bui.  73. 

t  Conn.  Exp.  Sta.  Rep.,  1898,  pp.  176-177 


SPICES. 


415 


Maximum. 

Minimum. 

Ash,  total 

7-92 

18.25 

7.19 

5-99 
11.03 

4-87 

Ether  extract,  volatile 

"           "        non-volatile 

Winton,  Ogden,  and  Alilchcll  '■=  give  more  complete  analyses  of  eight 
sam[)lcs  of  whole  cloves  of  known  purity,  representing  Penang,  Amboyna, 
and  Zanzibar  varieties,  and  two  samples  of  clove  stems,  as  follows: 


Moisture. 

Ash. 

Ether  Extract. 

Alcohol 
Extract. 

Total. 

Soluble  in 
Water. 

Insoluble 
in  HCl. 

Volatile. 

Non- 
volatile. 

Maximum 

8.26 

7-03 
7.81 

8.74 

6.22 
5.28 
5-92 
7-99 

3-75 
3-25 
3-58 
4.26 

0-13 
0.00 
0.06 
0.60 

20-53 
17.82 
19.18 

5.00 

6.67 
6,24 
6.49 

15-58 
13-99 
14.87 

6-79 

Minimum 

Mean 

Clove  stems,  mean 

Reducing 
Matters 
by  Acid 
Conver- 
sion, as 
Starch. 

Starch  by 
Diastase 
Method. 

Crude 
Fiber. 

Nitrogen, 
X6.25. 

Oxygen 
Absorbed 
by  Aque- 
ous Ex- 
tract. 

Querci- 
tannic 
Acid. 

Total 
Nitrogen. 

Maximum 

9-63 
8.19 

8-99 
14-13 

3-15 

2.08 

2-74 
2.17 

9.02 

7.06 

8.10 

18.71 

7.06 
5.88 
6.18 
5-88 

2.63 
2.0S 

2-33 
2.40 

20.54 
16.25 
18.19 
18.79 

I-13 
0.94 
0.99 
0.94 

Minimum 

Mean 

Clove-stems,  mean 

The  Tannin  Equivalent  in  Cloves. — The  amount  of  tannin  in  cloves 
was  shown  by  Ellis  to  be  so  constant  as  to  be  of  valuable  assistance  as  a 
guide  to  their  purity.  The  actual  determination  of  tannin  is,  however, 
a  long  and  difficult  proceeding,  and  Richardson  f  has  pointed  out  that 
it  is  not  necessary,  but  that  simply  using  the  first  part  of  the  Lowenthal 
tannin  process,  and  noting  the  "oxygen  absorbed"  as  expressed  by  the 
oxidizing  power  of  permanganate  of  potash  on  the  material  after  extrac- 
tion with  ether,  is  quite  as  useful  as  determining  the  tannin,  and  is  in 
effect  proportional  to  the  tannin  present.  The  result  is  sometimes 
expressed  as  in  Richardson's  figures  above,  as  the  oxygen  equivalent,  or 
as  quercitannic  acid. 

Determination  of  Tannin  Equivalent.^ — Reagents:  Indigo  Solution. — 
Six  grams  of  the  indigo  salt  §  arc  dissolved  in  500  cc.  of  water  by  heat- 

*  Conn.  Exp.  Sta.  Rep.,  1898,  pp.  206,  207. 

t  U.  S.  Dept.  of  Agric,  Div.  of  Cham.,  Bui.  13,  p.  167. 

X  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  60;    Bui.  107  rev.,  p.  164. 

§  The  quality  of  the  indigo  used  is  of  great  importance  since  with  inferior  brands  it  is 


4i6  FOOD  INSPECTION  AND  ANALYSIS. 

ing.  Afier  cooling,  50  cc.  of  conccnlralcd  sulphuric  acid  are  added, 
ihe  sokuion  made  up  to  a  liter  and  filtered. 

Standard  Permanganate  Solution. — Dissolve  1-333  grams  of  pure 
potassium  permanganate  in  a  liter  of  water.  This  should  be  standardized 
by  titrating  against  10  cc.  of  tenth-normal  oxahc  acid  (6.3  grams  pure 
crystallized  oxalic  acitl  in  1,000  cc),  diluted  to  500  cc.  with  water,  heated 
to  60°  C,  and  mixed  with  20  cc.  of  dilute  sulphuric  acid  (i :  3  by  volume). 
The  permanganate  solution  is  added  slowly,  stirring  constantly,  till  a 
pink  color  appears. 

Two  grams  of  the  material  arc  extracted  for  twenty  hours  with  pure 
anhydrous  ether.  The  residue  is  boiled  for  two  hours  with  300  cc.  of 
water,  cooled,  made  up  to  500  cc,  and  hltcred. 

Twenty-five  cc.  of  the  filtrate  arc  pipetted  into  a  1200-cc.  flask,  750  cc. 
of  distilled  water  are  added  and  20  cc.  of  indigo  solution. 

The  standard  permanganate  solution  is  then  run  in  from  a  burette 
a  drop  at  a  time  with  constant  shaking,  until  a  bright  golden  yellow  color 
appears,  which  indicates  the  end-point.  Note  the  number  of  cubic  cen- 
timeters required,  represented  by  (a). 

In  a  similar  manner  determine  the  number  of  cubic  centimeters  of 
standard  permanganate  solution  consumed  by  20  cc.  of  the  indigo  solu- 
tion alone,  represented  by  (b),  and  subtract  this  from  (a). 

The  oxygen  equivalent,  or,  as  it  is  sometimes  called,  the  "oxygen 
absorbed,"  is  calculated  from  the  equivalent  in  tenth-normal  oxalic  acid 
of  the  number  of  cubic  centimeters  of  standard  permanganate  repre- 
sented by  a — b.  10  cc.  of  tenth-normal  oxalic  acid  are  equivalent  to 
0.008  gram  of  oxygen  absorbed,  or  0.0623  gram  of  quercitannic  acid. 

Microscopical  Examination  of  Cloves. — Unless  the  finely  powdered, 
water-mounted  sample  is  well  rubljcd  out  under  the  cover-glass,  many 
oi  the  masses  of  cellular  tissue  will  be  too  dense  to  recognize.  With  a 
little  care,  however,  it  is  possible  to  make  a  very  satisfactory  water  mount, 
though  by  soaking  for  twenty-four  hours  in  chloral  hydrate  solution  the 
more  opaque  masses  are  rendered  very  translucent. 

Fig.  81,  from  Moeller,  shows  some  of  the  characteristics  of  p-^wdered 
cloves.  The  outer  skin  of  the  calyx  tube  is  shown  at  (i)  with  itL  polyg- 
onal cells  and  large  oil  spaces  showing  through  them;  (2)  shows  the 
epidermis  of  the  outer  part  of  the  lobes  or  wings  of  the  calyx,  with  stomata 

impossible  to  get  a  sharp  end-point.  The  infligo  solution  should  be  made  from  the  very 
Vxrst  variety  of  sulphindigotate,  which  may  be  obtained  from  C;rueber&  Co.,  of  Leipzig,  or 
Gehe  &  Co.,  of  Dresden,  under  the  name  of  carminium  cceruleum. 


SPICES. 


417 


surrounded  by  irregularly  shaped  cells;  (3)  represents  the  epidermis 
of  the  petals,  with  crystals  of  calcium  oxalate;  a  cross-section  of  the  ei)i- 
dermis  of  the  calyx  is  shown  at  (4);  (5)  shows  the  parenchyma,  with 
calcium  oxalate  crystals  and  with  one  of  the  slender  spiral  ducts;  (6) 
and  (7)  represent  in  cross-section  and  longitudinal  section  respectively 
the  parenchyma  of  the  middle  layers  of  the  ovary,  one  of  the  rounded, 
triangular  pollen  grains  being  shown  at  (12). 


Fig.   Si. — Powdered  Cloves  under  the  Microscope.      X125.     (After  Moeller.) 


Characteristics  of  clove  stems,  which  are  frequently  used  as  adulter- 
ants of  cloves,  are  found  in  (8),  (9),  (10),  and  (11).  Stone  cells  of 
the  outer  skin  and  the  inner  portion  of  the  clove  stem  are  shown 
at  (8)  and  (9)  respectively;  (10)  shows  one  of  the  vascular  ducts, 
and  (11)  two  of  the  bast  fibers.  Both  the  vascular  ducts  and  the 
stone  cells  are  very  characteristic  of  clove  stems.  Pure  cloves  have  no 
stone  cells  and  comparatively  few  bast  fibers.  Slcnn;  under  the  micro- 
scope show  a  large  number  of  bast  fibers  and  frequent  stone  cells,  the 
latter  being  of  a  distinctly  yellow  color. 

A  plain  water-mounted  slide  rarely  shows  all  the  structural  details 
depicted  in  Fig.   8r,   but  is  nearly  always  sufficiently  characteristic   to 


41 S  FOOD  INSPECTION  AND  ANALYSIS. 

prove  I  ho  purity  of  the  sample.  Fig.  220,  PI.  XXV,  shows  the  actual 
appearance  of  powdered  cloves,  mounted  in  water  and  examined  under 
a  magnification  of  130.  The  general  appearance  of  the  cellular  tissue 
is  that  of  a  loose,  spongy  mass  filled  with  brown,  granular  material. 
Througlicuit  the  masses  of  tissue  are  to  be  seen  small  oil  globules. 

Clo\es  have  no  starch  whatever.  Aside  from  the  stems,  cloves  are 
sometimes  adulterated  with  clove  fruit  or  "mother  cloves,"  which  have 
a  small  amount  of  a  sago-like  starch,  and  also  contain  some  stone  cells. 

Adulteration  of  Cloves. — The  U.  S.  standard  for  pure  cloves  is  as 
follows:  \'olatile  ether  extract  not  less  than  10%;  quercitannic  acid,  cal- 
culated from  the  total  oxygen  absorbed  by  the  aqueous  extract,  should 
not  be  less  than  12%;  total  ash  should  not  exceed  8%;  ash  insoluble  in 
hydrochloric  acid  should  not  exceed  o-sSc,  '^^^  crude  fiber  should  not 
be  more  than  io9c. 

Clove  Stems  are  v?ry  frequent  aduherants  of  cloves  and  possess  some 
slight  pungency.  They  are  commonly  identified  under  the  microscope 
by  the  large  number  of  bast  fibers  and  stone  cells,  and  should  not  be 
found  in  pure  cloves  in  excess  of  5%. 

Allspice,  being  considerably  cheaper  than  cloves,  is  sometimes  used 
as  an  adulterant.  It  is  readily  recognized  by  the  characteristics  described 
on  page  422. 

Other  Adulterants  commonly  found  are  cereal  starches  (especially 
corn  and  wheat)  and  ginger  (for  the  most  part  "exhausted").  Besides 
the  above,  pea  starch,  rice,  turmeric,  charcoal,  sand,  pepper,  ground  fruit 
stones,  and  sawdust  have  been  found  in  samples  of  cloves  examined  in 
Massachusetts. 

Exhausted  Cloves,  both  whole  and  in  powdered  form,  are  not  infre- 
quently found  on  the  market.  These  have  been  de])rivcd  of  a  portion 
of  the  volatile  oil,  and  are  much  less  pungent  than  the  pure  article,  so 
that  the  difference  in  taste  between  the  two  varieties  is  quite  marked.  It 
is,  however,  rare  that  powdered  cloves  are  sold  consisting  entirely  of 
the  exhausted  variety,  the  more  common  practice  being  to  mix  from 
10  to  25  per  cent  of  exhausted  cloves  with  the  pure  powder,  so  that  the 
sophistication  is  less  apparent. 

A  determination  of  the  volatile  oil  is  the  only  reliable  means  of  show- 
ing whether  or  not  the  material  has  been  wholly  or  in  part  exhausted, 
though  Villier  and  Collin  claim  that  under  the  microscope  an  exhausted 
sample  of  cloves  shows  the  oil  glands  to  be  nearly  empty,  or  to  inclose 
much  smaller  droplets  of  oil  than  the  pure  variety. 


SPICES. 


419 


With  the  exception  of  exhausted  cloves,  the  presence  of  nearly 
every  foreign  ingredient  is  best  and  most  quickly  shown  by  the  use  of 
the  microscope,  though  much  information  as  to  the  purity  of  the  sample 
can  be  gained  by  the  ether  extract,  the  percentage  of  ash,  and  of  crude 
fiber.* 

Cocoanut  Shells, — Figs.  226  and  227,  PI.  XXVII,  show  samples  of  cloves 
adulterated  with  ground  cocoanut  shells.  The  long,  spindle-shaped,  yellow- 
brown  and  deeply  furrowed  stone  cells  of  the  adulterant  with  their  thick 
walls  and  central  branching  pores  are  unmistakable.  The  dark-brown 
contents  of  the  cells  turn  reddish  brown  when  treated  with  potassium 
hydroxide.  The  anatomy  of  the  cocoanut,  including  the  shell,  has  been 
carefully  studied  by  Winton.f 

Fig.  82,  after  Winton,  shows  elements  of  powdered  cocoanut  shell 
under  the  microscope,     st  are  the  daik,  elongated,  yellow,  porous  stone 


<^ 


Fig.  82. — Cocoanut-shell  Powder.  sf,  dark-yellow  stone  cells  with  brown  contents; 
/,  reticulated  trachea;  sp,  spiral  trachea;  g,  pitted  trachea;  w,  colorless,  and  br, 
brown,  parenchyma  of  mesocarp;  /,  bast  fibres,  with  stegmata  {ste).  Xi6o.  (After 
Winton.) 

cells  with  their  brown  contents,  these  stone  cells  being  the  most  dis- 
tinctive characteristic  of  the  ground  shells.  /,  sp,  and  g  are  the  various 
forms  of  trachea;  w  and  br  are  respectively  colorless  and  brown  paren- 
chyma of  the  mesocarp  or  outer  coat,  portions  of  which  always  adhere 
to  the  nutshell  and  are  ground  with  it. 

*  Note  especially  the  sharp  distinction  between  these  values  in  the  case  of  pure  cloves 
and  of  clove  stems  in  Richardson's  table. 

t  The  Anatomy  of  the  Fruit  of  the  Cocoanut.     Conn.  Exp.  Sta.  Rep.,  1901,  p.  208. 


42o 


FOOD   INSPECTION  /1ND   ANALYSIS. 


Fig.  264,  PL  XXW'I.  shows  a  photomicrograph  of  powdered  cocoanut 
shells,  mounted  in  gelatin.  The  long,  spindle-shaped  stone  cells  are 
especially  apparent. 

Ground  cocoanut  shells  ha\'e  been  used  in  various  spices  besides 
cloves,  especially  allspice  and  ])ei)per.  In  the  following  tabulated 
results  of  analyses  by  Winton,  Ogden,  and  ]\Iitchcll  *  are  shown  the  wide 
deviation  between  the  chemical  constants  of  cocoanut  shells  and  several 
of  the  spices  in  which  they  appear  as  adu.lterants. 


Cocoanut 
Shells. 


Water 

Total  ash. 

Ash  soluble  in  water 

Ash  insoluble  in  hydrochloric  acid 

\'olatile  ether  extract 

Non-volatile  ether  extract 

Alcohol  extract 

Reducing  matters,  as  starch,  acid  conversion 

Starch  by  diastase  method 

Crude  fiber 

Total  nitrogen 

Ox>gen  absorbed  by  aqueous  extract 

Qucrcitannic  acid  equivalent 


Black 
Pepper. 

Cloves. 

Allspice. 

Nutmeg. 

11.96 

7.81 

9.78 

3.63 

4.76 

5-92 

4-47 

2.28 

2.54 

3-58 

2.47 

0.86 

0.47 

0.06 

0.03 

C.Ob 

I.  14 

19.18 

4.05 

3.02 

8.42 

6.49 

5.84 

36.70 

9.62 

14.87 

11.79 

10.77 

38.63 

8.99 

18.03 

25 .  56 

34-15 

2.74 

3.04 

23.72 

13.06 

8.10 

22.39 

.     2.51 

2.26 

0.99 

0.92 

1.08 

2.33 

1.24 

18.19 

9.71 

736 
0.54 

o.  50 
0.00 
0.00 

0.25 

I  .  12 

20.88 

0.73 
56.19 
0.18 
0.23 
1.83 


ALLSPICE,    OR  PIMENTO. 

Nature  and  Compositicn.^ — Allspice  is  the  dried  fruit  of  the  Eugenia 
pimeuta,  an  e\ergrecn  tree  belonging  to  the  same  family  {Myrlacecc) 
as  the  clove.  It  is  indigenous  to  the  West  Indies,  and  is  especially  cul- 
tivatefl  in  Jamaica. 

The  allspice  berry  is  grayish  or  reddish  brown  in  color,  and  is  hard 
and  globular,  measuring  from  4  to  8  mm.  in  diameter,  being  surmounted 
by  a  short  style.  This  is  imbedded  in  a  depression,  and  around  it  are 
the  four  lobes  of  the  calyx,  or  the  scars  left  by  them  after  they  have  fallen 
ofT.  The  berry  has  a  wrinkled,  ligneous  ])ericar]),  with  many  small 
excrescences  filled  with  es.sential  oil.  The  pericarp  is  easily  broken 
between  the  fingers,  showing  the  Ijcrry  to  br  formetl  of  two  cells  with  a 
single,  brown,  kidney-shaped  seed  in  each,  covered  with  a  thin,  outer 
coating,  inclosing  an  embryo  rolled  up  in  a  si)iral. 

The  berries  are  gathered  when  they  have  attained  their  largest  size, 
but  before  becoming  fully  ripe.  If  allowed  to  mature  beyonrl  this  stage, 
some  of  the  aroma  is  lost. 


*  Conn.  Ag.  Kxp.  Sta.  Rcj).,  1901,  p.  225. 


SPICES.  421 

Though  considerably  less  pungent  than  other  spices,  allspice  possesses 
an  aroma  not  unlike  cloves  and  cassia.  In  chemical  composition  it  most 
resembles  cloves,  containing  both  volatile  oil  and  tannin;  but,  unlike 
cloves,  it  contains  much  starch,  the  starch  being  contained  in  the  seeds. 
The  volatile  oil  of  allspice  is  very  similar  to  clove  oil.  It  is  shghtly  laevo- 
rotary,  and  is  composed  of  eugenol  and  a  sesquiterpene  not  determined. 
It  is  present  in  allspice  to  the  extent  of  3  to  4.5  per  cent.  The  boiling- 
point  of  the  oil  is  255°  C. 

Authoritative  full  analyses  of  allspice  are  even  more  meager  than 
of  cloves.  Analyses  of  one  sample  of  whole  allspice  and  five  samples 
of  the  ground  spice,  made  by  Richardson,*  are  thus  summarized: 


la 

< 

16 

V  0 

•O.Q 

si 

S 

_5 
C  > 

■£'3 

■6 

£■5 

Mo* 
>■  v 

Whole 

6.19 

4.01 

5-15 

6-15 

59.28 

14.83 

4.38 

.70 

10.97 

2.81 

Ground: 

Maximum 

8.82 

5-53 

3-32 

6.Q2 

58.24 

18.98 

5-42 

.87 

12.74 

?,-?,(^ 

Minimum 

5-51 

3-45 

2.07 

3-77 

56.86 

13-45 

4-03 

.64 

8.27 

2.  12 

Seventeen  samples  of  unadulterated  allspice,  as  sold  on  the  Connect- 
icut market,  were  analyzed  by  Winton  and  Mitchell,t  with  maximum 
and  minimum  results  as  follows: 


Ash. 

Maximum. 

Minimum. 

Total 

7-51 

-95 

3-50 

6.22 

4-34 

.40 

1-34 

3-78 

Insoluble  in  hydrochloric  acid  (sand) . . 

Ether  extract,  non-volatile 

Three  samples  of  pure  whole  allspice  were  more  fully  analyzed  by 
Winton,  INIitchell,  and  Ogden  with  the  results  given  on  page    42 2. J 

The  Tannin  Equivalent  in  Allspice.— ^Tannin  is  present  in  allspice, 
though  to  a  less  extent  than  in  cloves.  The  exact  amount  present  is 
rarely  determined,  but  rather  the  "oxygen  equivalent,"  or  quercitannic 
acid,  as  explained  on  page  415,  the  determination  being  carried  out  as 
there  detailed. 


*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  p.  229. 
t  An.  Rep.  Conn.  Exp.  Sta.,  1898,  pp.  178,  179. 
\,  Ihid.,  pp.  208,  209. 


422 


FOOD  INSPECTION  /IND  ANALYSIS. 


Moisture. 


Maximum '      10.14 

Minimum j       Q  -  45 

Average 9. 78 


Ash. 


Total. 


Soluble 
in  Water. 


4.76 
4.15 
4-47 


2.69 
2.29 
2.47 


Insoluble 
in  HCl. 


0.06 
0.00 
0.03 


Ether  E.xtract. 


Volatile.         Non- 
volatile. 


3-38 
4-05 


7.72 
4 -.3^ 
5-84 


Alcohol 
Extract. 


14.27 

7-39 
11.79 


Reducing 
Matters 
by  Acid 
Conver- 
sion, as 
Starch. 


Starch 

.  by 

Diastase. 


Maximum I     20.65 

Minimum 16.56 

.■\veragc 18.03 


3-76 
1.82 

3-04 


Crude 
Fiber. 


Nitrogen, 
X6.2S. 


Oxygen 
Absorbed 
by  Aque- 
ous Ex- 
tract. 


Querci- 
tannic 
Acid. 


23-98 
20.46 
22.39 


<^-37 
5-19 
5-75 


I 

•59 

I 

■03 

I 

.24 

12.48 
8.06 
9.71 


Total 
Nitrogen. 


1 .02 
0.83 
0.92 


Microscopical  Examination  of  Powdered  Allspice. — By  soaking  the 
powder  twenly-four  hours  or  more  in  chloral  liydralc,  many  of  the  harder 
portions  are  rendered  much  more  transparent  than  would  otherwise 
be  possible.  Fig.  83,  after  Moeller,  shows  the  microscopical  structure 
of  various  elements  that  go  to  make  up  allspice  powder. 

The  epidermis,  or  outer  layer  of  the  berry  with  its  small  cells,  is  shown 
in  cross-section  at  iia)  and  in  surface  \iew  at  (2).  Just  beneath  the 
outer  coat  are  the  large  oil  spaces  (16)  and  still  further  below  the  stone- 
cells  (ic).  The  fruit  parenchyma  (3)  has  vascular  tissues  running  through 
it.  (4)  and  (5)  are  the  inner  epidermis  and  stone  cells  of  the  dividing 
partitions  between  the  seeds.  Small  hairs  connected  with  the  outer 
epidermis  arc  shown  at  (6).  (7)  and  (8)  show  in  cross-section  a  portion 
of  the  seed-shell  and  inclo.sed  seed  or  embryo,  with  the  starch  (8a)  and 
the  colored  lumps  of  gum  or  resin  (8i)  of  a  port-wine  color.  These  colored 
cells  exist  in  the  seed  coating,  and,  although  only  one  is  here  shown, 
constitute  a  very  important  and  striking  characteristic  of  allspice.  (9) 
represents  the  spongy  parenchyma  of  the  seed  shell,  and  (10)  shows  its 
epidermis.  In  the  parenchyma  of  the  fruit  and  of  the  partitions  between 
the  cells  are  seen,  but  not  always  plainly,  minute  cr^'stals  of  calcium  oxa- 
late (see  (4)  and  (5)). 

These  details  so  closely  drawn  by  Moeller  are  idealized,  but  serve 
well  to  indicate  what  should  be  looked  for.  In  practice  the  water- 
mounted  specimen  shows  all  the  characteristics  necessary  to  identify 
pure  allspice,  and  most  if  not  all  its  adulterants.  In  fact  pimento  is  one 
of  the  easiest  spices  to  identify  under  the  microscope,  by  reason  of  its 
striking  characteristics. 


SPICES. 


423 


Three  distinctive  features  are  especially  typical,  viz.:  First,  the  starch 
grains,  which  are  very  uniform  in  size,  measuring  about  0.008  mm.  in 
diameter,  being  nearly  circular  as  a  rule,  and  often  arranged  in  groups 
not  unhke  masses  of  buckwheat  starch.  Ordinarily  these  masses  con- 
tain fewer  granules  than   do   those   of  buckwheat.     The   granules    are 


Fig.  83 ^Powdered  Allspice  under  the  Microscope.     X125.     (After  Moeller.) 


smaller  and  more  inclined  to  the  circular  than  to  the  polygonal  form, 
while  in  many  cases  they  have  distinct  central  hila.  The  starch  grains 
are  very  numerous  and  are  found  in  nearly  every  field.  See  Fig.  195,  PI. 
XIX. 

A  second  distinctive  feature  of  allspice  is  the  stone  cells,  of  which  there 
are  many.  These  are  more  often  colorless,  and  in  most  cases  very  large 
and  plainly  marked.  They  are  sometimes  seen  singly  and  at  other 
times  grouped  together.  Frequently  they  are  attached  to  pieces  of  brown, 
parenchyma. 


424  FOOD    INSPECTION  /1ND    /IN  A  LYSIS. 

The  third  and  most  characteristic  feature  of  allspice  powder  under 
the  microscope  is  the  striking  appearance  of  the  lumps  of  gum  or  resin, 
which  are  of  a  more  or  less  deep  port-wine  or  amber  color  and  are  con- 
tained in  the  middle  layers  of  the  seed  coat.  These  cells  are  very 
striking,  occurring  sometimes  in  isolated  bits,  and  in  other  cases  in  aggre- 
gations of  from  2  to  4  or  even  6  to  8  cells.  These  resinous  lumps  appear 
plainly  in  Fig.  194,  PI.  XIX.  Droplets  of  oil  are  occasionally  seen,  but 
noi  in  profusion.  As  a  rule  the  oil  is  forced  out  of  its  large  containing 
cells  and  into  the  surrounding  tissue  by  the  process  of  drying. 

Adulteration  of  Allspice. — According  to  the  U.  S.  standard  for  all- 
spite,  (juercitannic  acid  should  not  be  less  than  8%,  total  ash  not  more 
than  6*^^,  ash  insoluble  in  hydrochloric  acid  not  more  than  0.5%,  crude 
liber  not  more  than  25%.  The  most  common  adulterants  found  in 
p)owdercd  allspice  arc  cocoanut  shells  and  the  cereal  starches.  Besides 
these  the  writer  has  found  in  Massachusetts,  peas,  pea  hulls,  exhausted 
ginger,  cayenne,  olive  stones,  pepper,  and  turmeric.  To  this  Hst  may 
be  added  clove  stems,  which  are  on  record  as  a  not  uncommon  adulterant 
in  some  localities.  All  of  these  are  to  be  readily  recognized  by  a  care- 
ful microscopical  examination. 

CASSIA    AND    CINNAMON. 

Nature  and  Composition.  —  The  terms  cassia  and  cinnamon  are 
interchangeable  in  commerce,  though,  strictly  speaking,  they  represent 
two  separate  and  distinct  species  of  the  genus  Clnnamomum,  belonging 
to  the  laurel  family  {Lauracece).  True  cinnamon  is  the  bark  of  Clnna- 
momum zeylanicum,  a  tree  from  20  to  30  feet  high,  having  horizontal 
or  drooping  branches,  and  native  to  the  island  of  Ceylon,  but  cultivated 
also  in  some  parts  of  tropical  Asia,  in  Sumatra,  and  in  Java.  The  entire 
yield  of  pure  Ceylon  cinnamon  is  extremely  small,  and  but  little  of  it  is 
found  in  this  country.  It  is  the  very  thin,  inner  bark  of  the  tree,  and  is 
of  a  pale,  yellowish-brown  color,  being  found  on  the  market  in  long,  cylin- 
drical, quill-hke  rolls  or  pieces,  the  smaller  rolls  being  inclosed  in  the 
larger.  The  outer  surface  is  marked  by  round  dark  spots,  correspond- 
ing 10  points  of  insertion  of  the  leaves,  and  it  is  also  furrowed  length- 
wnsc  by  somewhat  wavy,  light-colored  lines.  The  inner  surface  of  the 
bark  is  darker  colored,  and  has  no  hnes.  In  thickness  the  bark  varies 
from  1.5  to  3  mm.  Both  the  inner  and  outer  coatings  of  the  bark  of 
Ceylon  cinnamon  are  usually  removed  in  the  process  of  preparation,  so 


SPICES.  425 

that  it  is  of  a  much  cleaner  and  more  even  texture  than  the  cassia  bark,  which 
is  thicker  and  heavier  by  reason  of  the  outer  cork  layer  usually  left  on  it. 

The  cheaper  and  more  common  cassia  is  the  bark  of  the  Cinna- 
momum  cassia,  which  comes  from  China,  Indo- China,  and  India.  It  is 
of  a  darker  color  than  that  of  cinnamon,  of  coarser  texlure,  and  as 
a  rule  about  four  times  as  thick.  Most  varieties  of  cassia  bark  are  less 
tightly  rolled  than  cinnamon,  and  are  not  arranged  one  within  the  other 
in  layers.  The  outer  surface  is  marked  by  elhptical  spots  left  by  the 
leaves,  and  by  small,  dark-brown,  wart-like  protuberances.  Cassia  does 
not  have  the  wavy,  Hght-colored  Hnes  found  in  the  cinnamon.  Both 
cinnamon  and  cassia  barks  are  very  aromatic  in  taste,  somewhat  astrin- 
gent, and  slightly  sweet. 

Cassia  buds  are  the  dry  flower  buds  of  China  cassia,  and  are  found 
in  the  market  both  in  whole  and  in  powdered  form.  Powdered  cassia 
often  consists  of  a  mixture  of  several  varieties  of  bark,  while  the  cheaper 
grades  sometimes  contain  an  admixture  of  the  ground  buds. 

The  best  grade  of  cassia  is  that  from  Saigon,  a  much  cheaper,  from 
Batavia,  while  the  cheapest  is  the  China  cassia. 

The  odor  of  cassia  and  cinnamon  bark  is  due  to  the  volatile  oil,  of 
which  from  i  to  2  per  cent  is  usually  found.  Cassia  and  cinnamon  oil 
greatly  resemble  each  other,  the  principal  constituent  in  either  case  being 
cinnamic  aldehyde,  CgH^CH:  CH.CHO.  Besides  this,  one  or  more  esters 
of  acetic  acid  are  present.     Both  oils  are  very  pungent  and  intensely  sweet. 

Starch  is  present  in  cassia  to  the  extent  of  from  16  to  30  per  cent. 
A  very  small  amount  of  tannin  is  found,  as  well  as  cinnamic  acid  and 
mucilaginous  matters.  Cassia  buds  are  somewhat  similar  in  com- 
position to  the  bark.  They  have,  however,  less  starch  and  crude  fiber, 
and  higher  contents  of  volatile  oil  and  nitrogen  than  the  bark. 

Richardson  *  has  made  analyses  of  a  few  samples  of  pure  whole  cinna- 
mon and  cassia,  from  which  the  following  are  taken: 


1^ 

0 

Cll 

Xi 

^ 

< 

5-40 

4-55 

7-43 

3-40 

4-79 

5-5« 

17-45 

8.23 

9-32 

1 

2.48 

Ccvlon  cinnamon,  i 

2.... 

Cassia  bud- 

Cassia  bark  (4  samples) 

Maximum 

Minimum 


1.05 

.82 

3-59 

3-51 
-55 


1.66 
1-58 
5-21 


-74 


33 

25 

8 

08 

63 
60 

26 

29 

14 

33 

3.80 

7.00 

4.55 
2.63 


51.28 
56.84 
65-23 

65-33 
48.65! 


.48 
.62 


-73 
.42 


*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  p.  221. 


I 


4-6 


FOOD  INSPECTION  AND  ANALYSIS. 


Wimon,  Ogdcn,  ami  Miichcll's*  results  of  analyses  of  whole  samples 
of  cinnamon,  cassia,  and  cassia  buds  are  thus  summarized: 


Moisture. 


Ash. 


Total. 


Sohible 

in 
Water. 


Insoluble 
in  HCl. 


Ether  Extract. 


Volatile. 


Non- 
volatile. 


Ccylun  cinnamon  (6  samples) 

^Iaximum 

Minimum 

Average 

Cassia  bark  (20  samples): 

Maximum 

Minimum 

Average 

Cassia  buds  (2  samples): 

Average 


10.48 

7-79 
8.63 

II. 91 

6-53 
9.24 

7-93 


5-99 
4.16 
4.82 

6.20 
3-01 
4-73 

4.64 


2.71 
1.40 
1.87 


1.68 
2.8S 


0.02 
0.13 

2.42 
0.02 
0.56 

0.27 


1 .62 
0.72 
1-39 

5-15 
0-93 
2.61 

^.88 


1.68 

I-3S 
1-44 

4-13 
1.32 
2.12 

5-96 


Ceylon  cinnamon  (6  samples) 

Slaximum 

Minimum 

Average 

Cassia  bark  (20  samples): 

Maximum 

Minimum 

Average 

Cassia  buds  (2  samples): 

Average 


Alcohol 
Extract. 


Reducing 

Matters 

by  Acid 

Conversion. 

as  Starch. 


13.60 

9-97 
12.21 

16.74 

4-57 
8.29 


22.00 
16.65 
19.30 

32.04 
16.65 
23-32 

10.71 


Crude 
Fiber. 


38.48 
34.38 
36.20 

28.80 

17-03 
22.96 

13-35 


Nitrogen, 
X6.2S. 


4.06 
3-25 
3-7° 

5-44 
3-31 
4-34 

7-53 


Total 
Nitrogen. 


0.65 

0.52 
0-59 

0.87 

0-53 
0.69 


Structure  of  Powdered  Cassia  under  the  Microscope.  —  Fig.  84, 
from  Moeller,  shows  various  elements  of  cassia  bark  as  vciwed  microscop- 
ically. (1)  shows  in  cross-section  a  portion  of  the  cork  and  outer  layer 
of  the  bark  rind,  with  flat  cells  nearest  the  surface,  having  somewhat 
thick  walls  anrl  reddish-brown  contents,  and,  fartlicr  in,  the  cells  5,  with 
mucilaginous  material. 

The  stone  cells  of  the  intermediate  layer  of  bark  are  shown  at  (2). 
Here  the  tendency  of  the  stone  cells  is  to  be  thicker  on  one  side  than  on 
the  other,  as  is  plainly  shown.  (3)  represents  the  structure  of  the  inner 
layer  of  the  bark,  showing  bast  fibers  b  cut  across,  and  more  of  the  so- 
called  mucilaginous  cells  s  of  large  size,  which  normally  contain  the 
ethereal  or  volatile  oil.  The  starch  granules  (4)  are  contained  in  great 
aViundance  in  the  polygonal  cells  of  the  parenchyma  of  the  intermediate 


♦  Twenty-second  Annual  Report  Conn.  Exp.  Sta.,  1898,  pp.  204,  205. 


SPICES. 


427 


and  inner  bark  layers.  (6)  represents  a  fragment  of  a  bast  fiber,  which 
is  often  shown  in  cassia  powder  with  connecting  parenchyma.  The 
stone-cells  of  the  cork  are  shown  in  plan  view  at  (7).  Very  small,  needle- 
like  crystals  of  oxalate  of  calcium  are  occasionally  to  be  seen  if  looked  for 
carefully.  They  occur  in  the  parenchyma  cells  of  the  inner  and  inter- 
mediate layers  of  the  bark. 

The   microscopical   structure   of   Ceylon   cinnamon   much   resembles 
that  of  cassia.     Cassia  starch  grains  measure  from  0.0132  to  0.0222  mm., 


Fig.  84.' — Powdered  Cassia  under  the  Microscope.     X125.     (After  Moeller.) 


being  considerably  larger  and  more  abundant  that  those  of  true  cinnamon. 
As  a  rule  the  bast  fibers  of  cassia  are  larger,  but  shorter,  than  those  of 
cinnamon,   and  provided  with  thicker  walls. 

Figs.  203  and  204,  PI.  XXI,  show  various  phases  of  pure  cassia  bark  as 
photographed  from  water-mounted  specimens  of  the  powder.  Cassia 
starch  somewhat  resembles  that  of  allspice,  but  it  is  not  as  a  rule  found 
in  masses  containing  as  many  granules  as  does  the  allspice  starch.  Vcr\^ 
commonly  two  or  three  of  the  starch  granules  are  arranged  together  in 


42 S  FOOD  INSPECTION  AND  ANALYSIS. 

such  a  manner  that  at  first  sight  they  appear  to  form  a  single  large  granule, 
but  on  more  careful  examination  are  seen  to  Ije  two-  and  three-lobed, 
consisting  of  several  smaller  grains.  Stone  cells,  which  are  veiy  abundant 
in  the  ])owdered  cassia,  do  not  happen  to  be  included  to  any  extent  in  the 
photographed  fields.  Cassia  stone  cells  are  generally  more  oblong  than 
those  of  allspice,  and  are  more  often  brown  in  color,  while  the  allspice 
stone  cells  are  generally  colorless. 

A  distinctive  feature  of  powdered  cassia  consists  in  the  long,  amber- 
colored  wood  fibers,  some  distributed  in  bundles,  and  others  arranged 
singly.     These  are  ver)'  clearly  shown  in  Figs.  204  and  205. 

Yellow  patches  of  cellular  tissue  with  starch  grains  interspersed 
among  them  are  very  abundant  in  the  powder. 

Adulteration  of  Cinnamon  and  Cassia. — The  U.  S.  standards  are 
as  follows:    Total  asii  not  to  exceed  8'/f' ;   sand  not  to  exceed  2%. 

The  commonest  adulterants  are  cereal  products  and  foreign  bark. 
Besides  these,  the  writer  has  found,  in  samples  sold  in  Massachusetts, 
leguminous  starches,  pea  hulls,  nutshells,  turmeric,  pepper,  olive  stones, 
ginger,  mustard,  and  sawdust.  Much  of  the  China  cassia  when  imported 
contains  an  inexcusably  large  amount  of  dirt.  In  one  sample  Winton, 
Ogdcn,  and  Mitchell  found  over  15','  of  sand. 

Ground  Bark  of  the  Common  Trees,  especially  that  of  the  elm, 
resembles  in  physical  appearance  ground  cassia,  and  is  to  be  looked 
for  as  an  adulterant.  Fig.  265,  PI.  XXXVII,  shows  the  appearance  of 
ground  elm  bark.  The  fibers  of  cassia  bark  have  starch  granules  as  a 
rule  interposed  among  them,  while  the  foreign  bark,  usually  of  a  much 
coarser  texture,  shows  no  starch  connected  with  its  structure. 

Fig.  206,  PI.  XXII,  shows  a  water- mounted  specimen  of  adulterated 
cassia  powder,  chosen  from  samples  purchased  in  the  Massachusetts 
market.  Nothing  but  the  adulterant  (a  foreign  bark)  shows  in  the  field. 
The  tissue  is  loose  and  considerably  coarser  than  that  of  cassia  bark. 

PEPPER. 

Nature  and  Composition. — Pepper  is  the  dried  berry  of  the  pepper 
plant  {Piper  nigrum),  a  climbing  shrub  belonging  to  the  family  Pipe- 
racecB,  native  to  the  East  Indies,  but  cultivated  in  many  tropical  countries. 
The  height  of  the  pepper  yjlant  is  from  twelve  to  twenty  feet.  When 
the  fruit  begins  to  turn  red,  it  is  gathered  and  then  dried,  by  which  process 
it  turns  black  and  shrivels  up,  forming  the  black  peppercorns  of  com- 
merce.    They  are  spherical  single-seeded  berries,  about  5  mm.  in  diam- 


SPICES. 


4«9 


etcr,  covered  with  a  brownish-gray  cj)icarp,  and  having  on  the  under 
side  the  remains  of  a  short  stem.  At  the  toj)  of  the  berry  is  an  indistinct 
trace  of  a  style,  and  of  a  lobed  stigma. 

Varieties  of  black  ])ei)[)er  are  named  from  the  localities  in  which  they 
are  grown  or  from  which  they  are  shipped,  as  Singapore,  Lampong, 
Sumatra,  Tellichery,  Malabar,  Acheen,  Penang,  Allcppi,  Trang,  Man- 
galore,  etc. 

White  •pci)per  is  obtained  by  decorticating  the  fully  ripened  black 
peppercorns,  or  removing  tlie  dark  skin.  This  is  accomplished  by  mac- 
erating them  in  w^ater  to  loosen  the  skin,  which  is  then  removed  readily 
by  drying  and  rubbing  between  the  hands.  White  whole  pepper  grains 
are  grayish  white,  and  a  trifle  larger  than  the  black  pej)pcr  berries.  They 
are  nearly  spherical  in  shape,  and  have  a  number  of  light-colored  lines 
that,  like  meridians,  run  from  top  to  bottom.  The  common  varieties 
are  Siam,  Singapore  and  Penang,  the  latter  being  coated  with  lime. 

The  pungent  taste  of  pepper  is  due  in  great  part  to  its  essential  oil, 
a  hydrocarbon  of  the  formula  CioHig,  present  in  amounts  varying  from 
0.5  to   1.7  per  cent.     Pepper  oil  contains  phellandrene  and  a  terpene. 

Other  important  constituents  of  pepper  are  piperidine,  and  the  crys- 
talline base  piperin,  C17H19NO3,  insoluble  in  water,  but  soluble  in  ether, 
and  in  alcohol.     Starch  is  present  in  pepper  to  a  large  extent. 

Burcker  gives  the  following  average  percentage  composition  of  black 
and  white  pepper: 


3 

0 

0 

c 

0 

u 

^h 

f^     c 

.fii3 

< 

_2 
0 

1^ 

1 

4-57 

12.45 

12.50 

11.98 

1.36 

6.85 

42.90 

1.80 

6.08 

13-56 

II. 12 

0.94 

7.  II 

56.04 

C  3 

o  o 

^  C  ^ 


Black  pepper  . 
White  pepper. 


7-39 
3-35 


Richardson's  *   analyses  of  three   samiples  of  wdiole  black  and  two 
samples  of  whole  white  pepper,   all  pure,   are  as  follows: 


Black  pepper:    West  coast. 

Acheen. 

Singapore.  , 

White  pepper:  West  coast. 
Singapore  . 


Volatile 

Piperin 

Alcohol 

Starch 

SVater. 

Ash. 

Oil. 

and 
Resin. 

Extract. 

(Acid  Con- 
version)  . 

8.91 

4.04 

.70 

7.29 

.... 

36-52 

8.29 

4.70 

1.69 

7.72 

6.06 

37-50 

9-«3 

3-70 

1.60 

7-15 

5-74 

37-30 

9-85 

1. 41 

-57 

7.24 



40.61 

10.60 

1-34 

1.26 

7.76 

2-57 

43.10 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  13,  part  2,  p.  206. 


43^ 


FOOD  INSPECTION  AND  ANALYSIS. 


Undeter- 
mined. 


Crude 
Fiber. 


Albumin- 
oids. 


Total 
NX6.2S. 


Total  N. 


Black  pepper:  West  coast 
.\chcen.  . . 
Singapore  . 

White  pepper:  West  coast 
Singapore  . 


24.62 

13-64 
17.66 
23.28 
19-55 


10.23 
10.02 
10.02 

7-73 
4.20 


7-69 
10.38 
10.00 

9-31 
9.62 


9.81 
12.60 
12.08 
11.48 
II  .90 


■57 
.02 

•93 
-83 
.90 


Richardson  gives  the  following  variations  in  the  constituents  of  pure 
pepper : 


I              Black. 

White. 

Water 

8.0    toii.o     i       8.0    toii.o 

\sh              

2.7^  to      ^.0                  TO      to      90 

.50  to    1.75 
7.0    to    8.0 
32.0    to  38.0 
8.0    to  I  I  .0 

.50  to     1.75 
7.0    to    8.0 
40.0    to  44.0 

/I  -  T  T    to       8.0 

Starch 

McGill's  *  analyses  of  six  samples  of  whole  black,  and  five  samples 
of  whole  white  pepper,  all  genuine,  are  thus  summarized: 


Moisture, 
etc.,  Lost 
at  100°  C. 

Ash. 

Soluble 
in  Hot 
Water. 

Insoluble 
in  Water. 

Total. 

Insoluble 
in  Hydro- 
chloric 
Acid. 

Sand 
Expressed 
as  Per 
Cent  of 
Total 
Ash. 

Alcohol 
Extract. 

Black:  Maximum 

Minimum 

Mean 

14.10 
10.62 
12.03 
13.00 
11.30 
12.34 

2.64 
2.07 
2.41 
0.72 
0.14 
0.54 

3.06 
1.46 
2.05 
3 -04 
1-50 
2-46 

5-i6 
3-98 
4-47 
3-65 
1.64 
3.00 

1.08 
.06 
0.36 
0.88 
0.26 
0-55 

21 
2 
8 

42 

9 
21 

9.06 
8.28 
8.71 
8.92 
7.00 
7-73 

White:  Maximum 

Minimum 

Mean 

Winton,  Ogden,  and  Mitchell's,  and  Winion  and  Bailey's  f  analyses 
of  whole  black  pepper  and  whole  white  pepjKT,  rcj;resenting  the  leading 
varieties  imported  into  the  United  States,  also  of  ];epper  .shells  and  long 
pepi>er,  arc  summarized  in  the  following  table: 

*  Canada  Inl.  Rev.  Dcpt.  Bui.  20,   1890. 

t  An.  Rep.  Conn.  Exp.  Sta.,  1898,  pp.  198-199;    1903,  pp.  158-164. 


SPICES. 


431 


M 

fN. 

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vO    1000    M    ■*  iri*!  90  *fS 

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w    0>000    OvW'^OQO 

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r>.  t>.  o^oq    t-.  ro°0  ^O  <3i 

oqooo'^H'^f-oqMppN 

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joBJlxg  jama  ut 

piwddi-<NQoO'^ 

M'-;do>^00'i-"« 

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saj  'uaSojjij^  I^l^X 

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w    M  00    0   r~0  to  i^  50 

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asBjSBtQ  Aq  naJH^g 

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lOM   w   t>,^sof^   opooo 

oqO'O    M    -<   on^'~^^_ 

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n     k-t    OnoO    i^H-iCyNQQOo 

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Tt    Tt   '^rDrorr;v-(.^Er5 

0    miotr);ouj(~,    p«    M    •«r 

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ki 

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w   q   q   Tj-q   qtoON. 

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M     t^rr)t^OO®*i^to 

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<: 

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00   -:J■^q•o■^^-;^o   i^-* 

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N    c<    po  po  0               PO        H 

(U     0     SJ 

bc  bC  tc 

«      0      C      r- 

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1 

43 -' 


FOOD   INSPECTION  AND  .ANALYSIS. 


The  following  table  summarizes  the  results  of  full  analyses  of  pepper 
and  [X'pper  shells  recently  made  by  Doolittle:* 


No.  of    I     No.  of 
Samples.  iVarieties. 


Blark  ptpper: 
Maximum. , 
Minimum  , 
Average 

White  iH'i)])cr: 
Ma.ximum . 
Minimum. 
Average.. . 

Long  pojiper: 
Maximum, 
Minimum. 

Pepper  shells: 
^Iaximum. 
Minimum, 


45 


Mois- 
ture. 


II. q6 
S.09 
9-54 

13-34 
8.04 
9.87 

10.13 
8.43 

II. 01 
7.00 


Ash. 


Total. 


8.04t 

3-43 

4-99 

4.28 
0.86 
1.69 

14.39 
6.12 


Insoluble 
in  HCl. 


2  -  59t 

0.05 

0.58 

0.86 
0.05 
0.19 

5-92 
0-45 


28.81  22.90 

7.82    !    0.79 


Soluble  in 
Water. 


5-32 
1.65 

2-49 
1. 16 

O.  12 
0-34 

4-39 
1.72 

4.66 
I -.53 


Starch  by 
Diastase 
Method. 


41-75 
25.09 
36.69 

63-55 
48.88 

54-37 

45-87 
28.43 

11.70 
9.28 


Black  pepper: 

Maximum. . 

Minimum  . . 

.■\verage 

While  pepj)er: 

Maximum. . 

Minimum  . . 

.'\verage 

Long  pep[)cr: 

Maximum. . 

Minimum  . . 
Pep[K-r  shells: 

Siaximum. . 

Minimum  . . 


Ether  Extract. 


Volatile. 


1.30 

1.66 

0.7S 
1. 17 

1. 01 
0.79 


0.89 


Non-vola- 
tile. 


10.44 
6.60 
7.67 

7.26 

5-65 
6.46 

7-53 
5-71 

4.67 
1-51 


Crude 
Fiber. 


18.89 
10.05 
II. 12 

7-65 
O.IO 

4-17 

10.01 
7.19 

28.22 
21.06 


Nitrogen. 


Total. 


2.38 
1.86 
2. II 

2.14 
1-85 
1.97 

2.04 
2.13 

1.82 
1.72 


In  Non- 
volatile 
Ether 
Extract. 


TcHal  N 
less  N  in 
non-vola- 
tile Ether 
Extract 
X6.2S. 


0-45 
0.25 

0-31 

0-34 
0.24 
0.30 

0.22 


0.12 
0.02 


13.12 

9-25 
11.20 

11.56 

9.69 

10.44 

12.06 
11-37 

11.25 
10.00 


t  Two  samples  of  Acheen  C  pepper  had  a  total  ash  of  H.00%  and  8.04%,  with  "ash  insoluble  in 
HCl"  A  2.50%  and  2.40%  respectively.  Eliminating  these  two  samples,  which  were  evidently 
abnorijiallv  hiwh  in  sand  and  dirt,  the  highest  total  ash  of  the  remaining  43  samples  was  7.00%, 
while  whe  highest  ash  insoluble  in  HCl  was  1.80%. 

Betermination  of  Nitrogen  in  Black  and  White  Pepper. — Winton, 
Ogden,  and  Milchell  have  .shown  that  the  Kjeldalil  and  Gunning  methods 
are  )na[)j)licable  in  the  ca.se  of  pepper,  owing  to  the  jjresence  of  pipcrin, 
bui  that  the  Gunning- Arnold  t  method  gives  accurate  results.  In  accord- 
ance with  this  method,  i  gram  of  the  .sample  is  mixed  with  a  gram  each  of 
copf»cf  sulj)hate  and  red  oxide  of  mercury,  about  i6  grams  of  pota.ssium 

*  Mich.  Dairy  and  Food  Comm.  Bui.  94. 
+  Zeits.  anal.  Chem.,  31,  1892,  p.  525. 


SPICHS. 


433 


sulphate,  and  25  cc.  of  sulphuric  acid  in  a  Kjcldahl  flask,  for  both  diges- 
tion and  distillation,  of  about  600-cc.  capacity.  The  heating  is  conducted 
in  the  usual  manner,  beginning  with  a  gentle  lieat  till  the  frothing  ceases, 
and  gradually  increasing  the  temperature  till  the  mixture  boils.  The 
boiling  is  continued  for  three  or  four  hours,  after  which  the  flask  is 
cooled,  and  to  it  are  added  300  cc.  of  water,  50  cc.  of  potassium  sulphide 
solution,*  and  enough  of  a  saturated  solution  of  sodium  hydroxide  to 
render  the  reaction  alkaline. 

The  flask  is  then  connected  to  the  condenser,  and  the  distillation  con- 
ducted as  in  the  Gunning  method  (p.  69),  using  zinc  dust  to  prevent 
bumping,  receiving  the  distillate  into  standard  acid,  and  titrating  against 
standard  alkali. 

Nitrogen  Determination  in  the  Ether  Extract. f— Ten  grams-  of  the 
sample  are  extracted  with  absolute  ether  for  twenty  hours  in  a  con- 
tinuous-extraction apparatus,  the  extract  being  collected  in  a  tared  Kjcl- 
dahl extraction-  and  distillation-flask,  the  same  as  used  in  the  preceding 
section.  The  ether  is  then  evaporated  off,  the  residue  dried  to  constant 
weight  at  110°  C.  and  its  weight  ascertained.  The  nitrogen  is  then 
determined  in  the  ether  extract  by  the  Gunning-Arnold  method. 

Determination  of  Piperin.l — Fifty  grams  of  the  sample  are  thoroughly 
exhausted  with  hot  alcohol,  and  the  alcohol  extract  evaporated  to  dry- 
ness. The  dry  residue  is  then  treated  with  a  solution  of  potassium 
hydroxide,  and  washed  upon  a  filter.  The  residue  is  washed  several 
times  with  the  caustic  alkali,  which  dissolves  the  resinous  matters,  and 
afterwards  with  water.  It  is  then  dissolved  in  alcohol,  from  which  crystals 
of  crude  piperin  separate  on  evaporation.  These  are  redissolved  in 
alcohol,  and  precipitated  by  the  addition  of  water.  The  cr}'stalline  pre- 
cipitate is  collected  on  a  tared  filter,  washed  with  wacer,  dried,  and 
w'eighed. 

Piperin  may  be  roughly  estimated  by  multiplying  the  nitrogen  in 
the  ether  extract  by  the  factor  20.36. 

The  amount  of  piperin  varies  considerably,  ranging  in  black  pepper 
from  4  to  9  per  cent. 

Microscopical  Characteristics  of  Ground  Pepper. — ]\Ioeller's  repre- 
sentation of  powdered  black  pepper  shows  what  should  be  looked  for 
under  the  microscope  with  the  best  conditions  (Fig.  85).  The  shell  of 
the  peppercorn,  a  cross-section  of  which  is  shown  at  (i),  consists  of  the 

*  Forty  grams  KjS  in  i  liter  or  water. 

t  Method  of  Winton,  Ogden  and  Mitchell. 

X  Villiers  et  Collin,  Substances  Alimcntaires,  p.  371. 


434 


FOOD  INSPECTION  ^ND  yiN^ LYSIS. 


epidermis,   a,    under   which 
while   below    this    laver 


IS 


Fig.   85. — Powdered    Black    Pepper 


under    the    Microscope. 
(.After  Moeller.) 


X   125. 


is  a  ihin  layer  of  brown  parenchyma,  c, 
shown  the  most  characteristic  portion  of 
the  pepper  shell,  viz.:  the  thickened, 
colored,  stone  cells,  b.  These  are  as  a 
rule  inclined  to  be  rectangular  rather 
than  rounded.  At  d  is  shown  a  bit  of 
the  colorless  parenchyma  of  the  fruit 
itself. 

(2),  (3),  and  (4)  show  a  cross-section 

of    the    outer    part    of    the   berry,    (2) 

representing   the    inner  stone- cell    layer, 

a     single    row    of    horseshoe-like    cells, 

(3)  the  thin  seed  coat,  and  (4)  the  white 

perisperm,  with  its  large  cells.     Here  and 

there  through  the  perisperm  certain  yellow 

contents  are  visible,  consisting  largely  of 

resinous  matter.      A  dark  resin    cell   is 

shown  at   (4).     The  ethereal  oil,  starch, 

and   piperin    are  found    in  this  part  of 

the  berry. 

(5)  shows  in  surface  view  the  mostly  rectangular  stone  cells  of  the 

pepper  shell,    resting   upon   the  epidermis    (6).     Groups   of   stone  cells 

are  frequently  thus  found  with  ])ortions  of  the  epidermis. 

The  inner  rounded,  or  cup-shaped  cells  are  show^n  in  plan  view  at 
(7)  and  the  seed  skin  at  (8),  masses  of  starch  and  separate  starch  granules 
are  shown  at  (9),  and  cry^stals  of  piperin  at  (10). 

The  bast-parenchyma  of  the  pepper  stem  is  shown  at  (11), 
pieces  of  which  are  commonly  found  in  powdered  pepper,  and  (12) 
shows  a  fragment  of  one  of  the  many-celled  hairs  which  grow  on  the 
stem. 

The  rounded  cup  cells  (7)  are  readily  distinguished  from  the  more 
rectangular  stone  cells  (5).  The  walls  of  the  cuj)  cells  are  nearly  always 
colorless,  and  the  cells  themselves  empty.* 

A  water-mounted  specimen  of  finely  ground,  black  pepper,  when 
viewed  microscopically,  shows  most  of  the  elements  above  described,  at 
least  in  fragmentar)-  form,  though,  in  the  case  of  the  coarser  particles, 

*  The  harder  portions  of  the  pepper,  especially  of  the  shell,  are  best  examined  by  soak- 
ing for  at  least  twenty-four  hours  in  chloral  hydrate,  and  mounting  in  this  reagent  on  the 
slide. 


SPICES. 


43S 


by  no  means  as  clearly  as  by  the  use  of  chloral  hydrate.  Large  polyg- 
onal masses  of  starch  appear  grouped  as  photographed  in  Fig.  256,  PL 
XXXIV,  if  not  rubbed  out  too  fme  under  the  cover-glass.  Starch,  in- 
deed, is  the  most  conspicuous  element  of  pepper,  being  distributed  more 
or  less  evenly  throughout  the  mass.  The  powder  may,  however,  be  so 
finely  reduced  by  abrasion  under  the  cover-glass  as  to  break  up  these 
starch  masses  wholly  or  in  part,  so  that  the  granules  may  appear  in  much 
smaller  groups  or  even  singly.  Fig.  255  shows  such  a  field  under  a 
higher  magnification.  The  individual  granules  of  pepper  starch  average 
0.003  ^^*  i^  diameter. 

Besides  the  starch,  and  next  to  it  the  most  numerous,  one  finds  in  the 
water-mounted  black-pepper  specimen  many  of  the  dark-yellow,  thick- 
walled  stone  cells,  patches  of  the  colored  parenchyma,  and  epidermis  of 
the  shell.  Other  elements  of  the  perisperm,  besides  the  starch,  are 
seen  in  fragments,  such  as  bits  of  resin,  small  droplets  of  oil,  pieces  of 
stems,  and  occasionally  the  needle-shaped  crystals  of  pipcrin.  Some 
of  the  rounded,   cup-shaped  cells  are  also  usually  found. 

White  pepper  contains,  of  course,  the  same  elements,  but  without 
the  deeply  colored  stone  cells  and  other  characteristics  of  the  shell, 
which  has  been  removed  from  it. 

Adulteration  of  Pepper.— The  following  U.  S.  standards  for  pepper 
have  been  adopted :  For  white  pepper,  non- volatile  ether  extract  should 
not  to  be  less  than  6%;  starch  should  not  be  less  than  50%  by  the  diastase 
method;  total  ash  should  not  be  more  than  4%;  ash  insoluble  in  hydro- 
chloric acid  should  not  exceed  0.5%;  crude  fiber  should  not  exceed  5%. 
One  hundred  parts  of  the  non-volatile  ether  extract  should  contain  not 
less  than  4  parts  of  nitrogen.  For  black  pepper,  which  should  be  free 
from  added  pepper  shells,  pepper  dust,  and  other  pepper  by-products, 
non-volatile  ether  extract  should  not  be  less  than  6%;  starch  by  the 
diastase  method  should  not  be  less  than  25'}^ ;  total  ash  should  not  exceed 
7%;  and  crude  fiber  should  not  exceed  15^/v.  One  hundred  parts  of  the 
non-volatile  ether  extract  should  contain  not  less  than  3.25  parts  of 
nitrogen.     The  adulterants  used  in  ground  pei)i)er  are  many  and  varied. 

Pepper  Shells,  which  have  been  removed  from  the  white  pepper  of 
commerce,  are  not  infrequently  ground  and  added  to  the  cheaper  grades 
of  black  pepper.  When  a  sample  of  black  pepper  is  shown  by  the  micro- 
scope to  contain  more  shells  in  proportion  to  the  other  elements  than 
could  be  possible  in  a  ground  whole  berry,  added  shells  are  indicated. 


436  FOOD  INSPECTION  AND  ANALYSIS. 

The  analyst  should,  for  comparison,  grind  in  a  mortar  single  berries  of 
vai-ious  grades,  and  familiarize  himself  with  the  aj^pearance  of  the  ground 
poAvder  under  the  microscope,  when  the  maximum  amount  of  shells 
jx)ssible  under  natural  conditions  are  present,  noting  es])c'cially  the  appar- 
ent number  of  stone  cells  of  the  outer  coating.  The  famihar  title  of  P.  D. 
(pepper  dust)  originally  given  to  ground  pepper  shells,  stems,  and  "sweep- 
ings "  is  now  applied  in  the  trade  not  only  to  almost  any  cheap  and  appro- 
priate material  for  admixture  with  pepper,  but  also,  in  a  broader  sense, 
to  ground  powder  suitable  as  an  adulterant  for  any  spice. 

The  presence  of  pepper  shells  is  indicated  by  an  excess  of  ash,  sand, 
and  crude  liber,  and  a  deficiency  of  starch. 

Hilger  and  Bauer,  also  Hanus  and  Bien,  advocate  the  determination 
of  pentosans  as  a  means  of  detecting  pepper  shells. 

Ground  Olive-stones  constitute  one  of  the  most  commonly  found  foreign 
materials  used  as  an  adulterant  of  pepper.  The  powder,  sometimes 
called  "poivrette,"  is  very  like  white  pepper  in  appearance,  is  wholly 
inert  in  taste,  and  thus  forms  an  admirable  adulterant.  While  best 
detected  by  their  characteristic  appearance  under  the  microscope,  the 
presence  of  ground  olive  stones  may  be  shown  by  color  tests  with  certain 
chemical  reagents. 

Pabst  has  adopted  for  this  purpose  a  test  first  suggested  by  Wurster 
for  the  detection  of  wood  pulp  in  paper.  The  reagent  is  prepared  as 
follows:  In  a  porcelain  capsule  lo  grams  of  commercial  dimethyl  anilin 
arc  mixed  with  20  grams  of  pure  concentrated  hydrochloric  acid,  and 
at  least  100  grams  of  cracked  ice  are  added.  Then,  while  stirring,  a 
solution  of  8  grams  of  nitrite  of  soda  in  100  cc.  of  water  are  added  little  by 
little,  and  the  mixture  allowed  to  remain  for  half  an  hour,  after  which 
30  or  40  cc.  of  hydrochloric  acid  are  added,  and  20  grams  of  tin-foil. 
The  reduction  is  allowed  to  go  on  for  half  an  hour,  heating  on  the  water- 
bath,  if  neccssar)'.  The  tin  is  then  precipitated  by  granulated  zinc,  the 
liquid  is  filtered,  and  the  filtrate  neutrahzed  with  carbonate  of  potassium 
or  scxiium  to  the  point  of  forming  a  precipitate,  the  precipitate  being 
dissolved  by  a  few  drops  of  acetic  acid.  Finally  the  volume  is  made  up 
with  water  to  2  liters,  adding,  Ijcfore  doing  so,  3  or  4  cc.  of  a  concentrated 
solution  of  sfxlium  bisulphite,  to  prevent  oxidation.  The  reagent  thus 
prepared  will  keep  for  several  years  in  a  brown,  tightly  stoppered  bottle. 

If  a  pinch  of  pepper,  which  contains  ground  olive  stones,  be  heated 
gently  with  a  little  of  the  above  reagent  in  a  test-tube,  the  stone  cells 
of  the  adulterant  will  be  colored  a  bright  red  brown,  and  the  colored 
particles  will  Vx;  seen  lo  settle  to  the  bottom  of  the  tube,  after  shaking, 


SPICES.  437 

more  quickly  than  the  rest  of  the  powder.  Or,  if  the  whole  is  poured 
from  the  test-tube  into  a  porcelain  dish,  the  color  is  more  marked.  Pure 
pepper  is  not  colored  under  this  treatment  with  the  reagent. 

Jumeau  uses  for  a  color  reagent  5  grams  of  iodine  in  100  cc.  of  a  mix- 
ture of  equal  parts  of  ether  and  alcohol.  Enough  of  the  fmely  ground 
pepper  to  be  examined  is  placed  in  a  porcelain  capsule  to  cover  the 
bottom  of  the  dish,  and  suliicient  iodine  reagent  is  added  to  wet  the  entire 
mass,  carefully  avoiding  excess.  The  thick  paste  is  hrst  mixed  till  homo- 
geneous, and  then  allowed  to  dry  in  the  air,  after  which  it  is  broken  up 
by  a  pestle,  and  the  powder  examined,  either  under  the  microscope,  or 
by  the  naked  eye.  With  pure  pepper,  a  more  or  less  deep-brown  color 
is  produced  uniformly  through  the  powder,  but  if  olive  stones  are  presen:^, 
particles  of  these  are  colored  yellow.  With  the  naked  eye  as  small  an 
admixture  as  2%  of  olive  stones  can  thus  be  detected. 

A  solution  of  anilin  acetate  colors  olive  stones  yellowish  browr, 
while  pure  pepper  appears  grayish,  or  white. 

Under  the  microscope  olive  stones  are  readily  apparent,  since  the 
stone  cells  differ  in  size,  form,  and  mode  of  grouping  from  those  of  pepper. 
Fig.  263,  PI.  XXXVI,  is  a  photograph  of  a  water-mounted  specimen  of 
olive  stones.  They  are  for  the  most  part  entirely  devoid  of  color,  being 
long  and  narrow.  In  shape  and  manner  of  grouping  they  much  resemble 
cocoanut  shells  (p.  419),  but  are  distinguished  from  the  latter  from  their 
lack  of  color. 

Fig.  261  shows  under  low  magnification  a  sample  of  pepper,  bought 
on  the  market  in  Massachusetts,  highly  adulterated  with  olive  stones. 
A  large  mass  of  the  stone  cells  of  the  adulterant  appears  in  the  center  of 
the  field.  Many  of  the  stone  cells  are  shown  arranged  end  to  end,  so 
that  what  at  first  sight  appear  to  be  single,  very  long  cells  are  in  reality 
made  up  of  several  shorter  ones.  In  ground  ohve  stones  one  frequently 
finds,  besides  the  stone  cells,  bits  of  the  outer  tegument  of  the  seed,  show- 
ing large  cells  with  sinuous,  rather  thick  walls;  also  bits  of  parenchyma, 
crossed  frequently  by  fibro-vascular  duct  bundles. 

Buckwheat  Products. —  Both  the  hulls  and  tlie  middlings  have  been 
added  to  black  pepper,  and  the  middlings  to  white  pepper.  The  starch 
of  buckwheat  possesses  the  added  advantage,  from  the  point  of  view 
of  the  spice-grinder,  that  it  somewhat  resembles  pepper  starch  in  micro- 
scopical appearance,  not  only  in  the  shape  of  the  starch  granules,  but  also 
in  the  manner  of  grouping  into  masses.  Compare  Figs.  128  and  129, 
Plates  II  and  III,  showing  buckwheat  starch,  with  Figs.  255  and  256, 
PI.    XXXIV,    respectively,    showing    pepj^er   starch  made   under  similar 


43S 


FOOD   INSPECTION  AND   ANALYSIS. 


conditions  of  magnification,  etc.  The  starch  granules  and  masses  are 
coarser  in  the  case  of  buckwheat  than  of  pepper. 

Fig.  2O0,  PI.  XXXV,  shows  a  photograph  of  a  pepper  sample  adulterated 
with  buckwheat,  masses  of  both  starches  appearing  in  the  same  field. 

Other  Adulterants  found  in  Massachusetts  samples  of  pepper  have 
been  wheat  and  corn  products,  nutshells,  cayenne,  charcoal,  turmeric,  rice, 
sand,  and  sawdust.  Charred  cocoanut  shells  were  at  one  time  extensively 
used  (see  pp.  419  and  420). 

Long  Pepper,  according  to  English  analysts,  has  been  used  to  a  con- 
sitlerable  extent  as  an  adulterant.  This  is  the  fruit  of  the  Chavica  Rox- 
burgh ii,  a  wild  plant  growing  in  India  on  the  banks  of  rivers.  The  fruit, 
as  its  name  implies,  is  long  and  cylindrical,  while  of  about  the  same  diam- 
eter as  the  spherical  true  pej^pcrcorns.  Long  pepper  contains,  as  a  rule, 
less  than  half  the  amount  of  piperin  that  true  pepper  docs,  and  rather  more 
starch  than  black  pepper.  Its  taste  is  much  less  pungent  than  that  of 
true  pepper. 

From  its  method  of  growth,  long  pepper  is  found  with  considerable 
dirt  and  sand  adhering  to  the  outer  surface  of  the  dried  grains.  This 
is  due  to  the  fact  that  the  fruit  often  trails  on  the  ground,  and  in  gather- 
ing it  the  natives  are  not  particular  about  removing  the  adhering  soil. 
The  surface  of  the  fruit  grains  being  very  rough  and  irregular,  much 
of  the  dirt  remains  dried  thereon.  The  presence  of  long  pepper  thus 
materially  increases  the  ash. 

Long  pepper  possesses  a  very  disagreeable,  but  peculiar  odor,  devel- 
oped more  especially  when  slightly  warmed.  For  this  reason,  if  for 
no  other,  it  is  not  an  ideal  adulterant,  since  pepper  containing  it  would 
not  be  palatable  with  warm  foofl.  At  the  present  time  it  costs  more  than 
black  pepper,  anri  is  used  chiefly  in  mixed  whole  spices  for  pickles. 

Brown  gives  the  following  analyses  of  samples  of  long  pepper: 


Total 
Ash. 


8.91 
8.98 
9.61 


Sand  and 
Ash  Insfjl- 

uble  in 
Hydrochlo- 
ric Acid. 


1.2 
I.I 
1-5 


Starch  and 

Matters 

C'jnverti- 

ble  into 

Sugar. 


44.04 

49-34 
44.61 


Albumin 

ous  Matter 

SoIuVjIc  in 

Alkali. 


15-47 
17.42 

15-51 


Cellulose. 


'5-7 
IO-5 
10-37 


Alcoholic 
Extract. 


7-7 
7.6 

10-5 


Ether 
Extract. 


5-5 
4.9 
8.6 


Total 
Nitrogen. 


2-3 


According  to  Brown  and  Heisch,  the  granules  of  long  pepper  starch 
under  the  microscope  are  larger  than  those  of  true  pepper,  and  more 
angular.     Stokes,*  however,  finds  no  such  marked  difference  in  the  size 

*  Analyst,  XIII,  p.  109. 


SPICES.  439 

of  starch  granules  and  his  experience  is  shared  by  the  writer.  When 
the  two  specimens  (long  and  true  pepper)  are  viewed  side  by  side  in 
water  mounts  under  the  microscope,  the  average  size  of  the  long  pepper- 
starch  grains  is  a  trille  larger  than  those  of  true  pepper,  though,  unless 
compared  directly,  the  difference  is  not  readily  apparent.  Stokes  sug- 
gests a  method  of  distinguishing  the  two  by  polarized  light.  With  crossed 
Nicols,  so  that  a  dark  field  is  given,  and  with  the  specimen  mounted 
in  glycerin,  true  pej)per  starch  shows  an  evenly  dark  appearance,  using 
a  low  power,  while  with  long  j)epper  a  "ghostly  white"  image  is  shown. 
Long  pepper,  when  present  in  true  pepper  powder,  may  generally  be 
rendered  apparent  by  the  development  of  the  characteristic  odor  on 
heating.  Bits  of  fluffy  fiber  from  the  catkin  of  the  long  pepper  will  always  be 
found  in  the  ground  powder,  and  will  be  aj)parent  under  the  magnifying-glass. 
Microsco])ic  examination  of  the  crude  fiber  discloses  the  highly  char- 
acteristic, large,  beaded  cells  of  the  endocarj),  also  elements  of  the  spindle. 

RED   PEPPER. 

Nature  and  Composition.— According  to  the  U.  S.  Standards  red 
pepper  is  the  red,  dried,  ripe  fruit  of  any  species  of  Capsicum,  a  genus  of 
the  nightshade  family  {SolanacecB),  indigenous  to  the  American  tropics, 
but  now  cultivated  in  nearly  all  warm  and  temperate  countries,  and  is  of 
two  distinct  kinds:  cayenne__pepper  or  cayenne,  the  dried  ripe  fruit  of 
C.  frutescens,  C.  baccaiiim,  or  some  other  small  fruited  species  of  Capsicum, 
and  paprika,  the  dried  ripe  fruit  of  C  annuum,  or  some  other  large-fruited 
species  of  the  genus,  excluding  seeds  and  stems. 

Cayenne  is  characterized  by  its  extreme  pungency  and  the  small  size 
of  the  pods,  which  seldom  exceed  2  cm.  in  length.  The  leading  commercial 
varieties  are  Zanzibar  and  Japan,  the  latter  being  the  more  brilliant  in  color. 

''Capsicums''  or  "Bombay  Chillies''  are  low  grade  peppers  of  a 
brown  color,  with  pods  2  to  3  cm,  long,  which  now  are  said  to  come  from 
the  vicinity  of  the  river  Niger  in  Africa. 

Paprika  is  a  variety  of  C.  annuum  grown  in  Hungary.  The  powder  is 
of  a  deep  red  color  and  has  a  sweetish,  mildly  pungent  flavor. 

Pimiento  is  a  large-fruited  pepper  grown  in  Spain.  The  succulent 
pericarp  is  much  used  for  stuffing  olives  while  the  dried  pod  is  ground  as 
a  spice,  often  being  substituted  for  the  more  valuable  Hungarian  varieties. 
The  kitchen  garden  peppers,  of  which  over  thirty  varieties  are  cultivated 
in  the  United  States,  also  belong  to  the  species  C  annuum. 

The  capsicum  plant  has  solitary  flowers,  with  a  five-cleft  corolla,  and 
the  fruit  is  of  an  elongated,  conical  form.     The  surface  of  the  fresh  fruit 


\ 


4-,o 


FOOD   INS  PEC  HON  AND   ANALYSIS. 


is  smooth  and  very  red,  but  it  loses  some  of  its  brilliance  in  drying,  and 
becomes  shriveled.  The  pericarp  is  thin  and  tough,  and  at  its  base  is 
a  tive-lobed  calyx,  greenish  brown  in  color,  terminating  in  a  thick  stem. 
The  fruit  projier  is  divided  into  two  or  three  cells,  which  are  separate 
and  distinct  at  the  lower  portion,  but  which  unite  and  form  one  at  the 
top.  The  cells  inclose  a  large  number  of  yellow,  wrinkled,  kidney- 
shaped  seeds,  containing  a  fleshy  endosperm,  and  a  curved  embryo. 

Red  pepper  contains  a  fixed,  bland  oil,  found  in  both  pod  and  seed,  but 
more  abundantly  in  the  latter,  considerable  resinous  and  mucilaginous 
material,  a  red  coloring  matter  confmed  to  the  pod,  and  the  active  principle 
capsicin,  a  cr}'stainnc  alkaloid,  to  which  much  of  the  pungency  is  due. 
The  capsicin  is  present  in  both  seeds  and  pod,  but  is  more  abundant  in 
the  latter,  where  it  is  dissolved  in  the  oil. 

Capsicin  may  be  isolated,  according  to  Thresh,  by  extracting  pow- 
dered cayenne  with  petroleum  ether,  mixing  the  red  residue  left  on 
evaporating  off  the  solvent  with  two  or  three  limes  its  weight  of  oil  of 
almonds,  and  exhausting  the  mixture  with  alcohol.  On  evaporating 
the  alcohol  extract,  the  capsicin  crystallizes  out  in  narrow,  thin  plates, 
ver>'  soluble  in  alcohol,  but  insoluble  in  water.  They  volatihze  at  ioo°, 
and  condense  in  small  drops. 

The  red  coloring  matter  is  soluble  in  ether,  petroleum  ether,  carbon 
bisulphide,  and  chloroform,  but  sparingly  soluble  in  alcohol. 

Analyses  of  Cayenne. — Richardson  *  gives  the  following  data  of  analyses 
of  two  pure  samples  of  cayenne: 


'a 

< 

0 
0 

u 

0 

.-St 
^0. 

h 

•S.S 

"(3 

0 

s 

2 

A 

B 

2-35 
5-74 

9.06   0.12 
t:.24   i-=;8 

26.99   16.88 
17.90   18.10 

13-13 
11.20 

41.47 

40.24 

100 
100 

2.10 
1.70 

Maximum  and  minimum  data  of  ash  and  non-volatile  ether  extract 
of  fourteen  samples  of  cayenne,  sold  in  sealed  packages  in  Connecticut, 
:,nd  analyzed  bv  Winton  and  Mitchell  are  as  follows  if 


Ash. 


Maximum. 
Minimum  . 


7.1S 
^.8S 


Nnn-volatile 
Ether  Extract. 


19.14 
15-59 


♦  U.  S.  Dcpt.  of  Afp-ic,  Div.  of  Chem.,  Bui.  13,  p.  211. 
■f  An.  Rep.  Conn.  Exp.  Sta.,  1898,  p.  175. 


SPICES. 


441 


Winton,  Ogden,  and  IMitchcll  *  analyzed  eight  sami)lcs  of  whole 
chillies,  representing  three  varieties,  namely  Zanzibar,  Japan,  and  Bombay, 
the  summarized  results  being  as  follows: 


Moisture. 

Ash. 

Ether  Extract. 

Total 

Soluble  in 
Water. 

Insoluble 
in  HCl. 

Volatile. 

Non-vola- 
tile. 

Maximum 

7.08 
3-67 

5-73 

5-96 

5.08 

5-43 

4-93 
3-30 
3-98 

0.23 
0.05 
0-15 

2-57 
0-73 
1-35 

21.81 

Minimum 

17.17 
2a.  15 

Avcra^'u ........... 

Alcohol 
Extract. 


Reducing 

Matters  as 

Starch, 
Acid  Con- 


Starch  by 
Diastase 

Method. 


Crude 
Fiber. 


Nitrogen, 

X6.2S. 


Total 
Nitrogen. 


Maximum 
Minimum 
Average . . 


27.61 
21.52 
24-35 


9-31 

7-15 

8.47 


1.46 
0.80 


24.91 
20-35 
22.35 


14-63 
13-31 
13-67 


■34 
■13 


The  percentages  of  "  starch  by  the  diastase  method  "  given  in  the 
above  table  represent  errors  of  the  process  as  neither  cayenne  or  paprika 
contain  an  appreciable  amount  of  starch. 

Analyses  of  Paprika  and  Pimiento. — Dooiittle  and  Ogden  f  have  made 
exhaustive  analyses  of  known  samples  of  Hungarian  and  Spanish  red 
pepper,  including  determinations  of  non-volatile  ether  extract,  and  iodine 
number  of  this  extract,  which  are  of  especial  value  in  detecting  added 
oil.     A  summary  of  their  results  is  given  on  page  442. 

Microscopical  Structure  of  Red  Pepper. — Fig.  86,  from  Moeller, 
shows  the  appearance  under  the  microscope  of  various  elements  of  powdered 
paprika,  (i)  is  a  sectional  view  through  the  outer  portion  of  the  fruit 
shell  or  pod,  showing  the  epidermis  a,  and  beneath  this  the  collenchyma 
layer.  The  inner  epidermis  is  shown  at  (2),  with  its  cells  thick-walled 
in  places,  and  inclosing  brilliant,  red  oil  drops  of  coloring  matter.  (3) 
represents  the  outer,  and  (4)  and  (5)  the  inner  epidermis  in  surface  view. 
The  outer  epidermis  of  cayenne,  which  is  the  element  of  chief  value  in 
distinguishing  this  from  paprika,  is  shown  at  (6). 

A  cross-section  through  the  seed  shell  is  shown  at  (7),  a  being  the 
epidermis  of  the  seed,  b  the  parenchyma  layer  directly  beneath,  and  r 
the  tissues  of  the  endosperm.     (8)  shows  in  surface  view  the  peculiar  seed 


*  Am.  Rep.  Conn.  Exp.  Sta.,  1898,  pp.  200-201. 
t  Jour.  Am.  Chem.  Soc,  30,  190S,  p.  14S1. 


44- 


FOOD   INSPECTION  AND  ANALYSIS. 


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SH/CES. 


443 


epidermis,  the  appearance  of  which  Moeller  compares  with  that  of 
intestines.  At  (9)  is  shown  one  of  the  isolated  cells  of  this  epidermis 
more  highly  magnified,  while  (10)  shows  the  epidermis  of  the  calyx. 

Figs.  211  and  212,  PI.  XXIII,  show  photomicrographs  of  powdered 
cayenne.  In  Fig.  211  is  shown  a  large  bit  of  the  outer  epidermis  of  the 
fruit  pod,  while  in  Fig.  212  appears  a  smaller  portion  of  this  same  kind 
of  epidermis,  and  next  to  this  the  characteristic  skin  of  the  seed  shell,  with 
its  striking  markings  suggestive  of  the  convolutions  of  the  intestines. 
Yellow  or  yellowish-red  droplets  of  oily  coloring  matter  are  distributed 
through  the  field.     Starch  grains  are  absent. 


Fig.  86. — Powdered  Red  Pepper  under  the  Microscope.      X125.     (After  Moeller.) 

Adulteration  of  Red  Pepper. — The  U.  S.  standards  for  cayenne  are  the 
following:  Non- volatile  ether  extract  should  be  not  less  than  15%;  total 
ash  should  not  exceed  6.5%;  ash  insoluble  in  hydrochloric  acid  should 
not  exceed  0.5%;  starch  by  the  diastase  method  should  not  exceed 
1.5%,  and  crude  fiber  should  not  exceed  28%. 


444  FOOD  INSPECTION  .'IND   AN/fLYSIS. 

The  most  common  adulterants  ot  cayenne  are  the  starches  of  the 
cereal  grains,  corn  and  wheat.  Ground  pilot  bread  and  crackers  are 
csjX'cially  common.  Besides  these  the  writer  has  found  in  the  routine 
examination  of  cayenne  samples  in  T^Iassachusetts,  ginger,  nutshells, 
turmeric,  rice,  gypsum,  buckwheat,  olive  stones,  mustard  hulls,  ground 
redwood,  red  ocher,  and  coal-tar  dyes.  Fig.  213,  PI.  XXIV,  shows  a 
sample  adulterated  with  wheat,  corn,  and  cocoanut  shells. 

Mineral  Adulterants,  such  as  gypsum,  and  red  ocher  and  other  pigments, 
are  all  to  be  looked  for  in  the  ash  by  methods  of  qualitative  analysis. 
An  abnormally  high  ash  is  suggestive  of  adulteration.  According  to 
\'edrodi,  the  ash  of  genuine  cayenne  should  not  exceed  5.96.  The  presence 
of  red  ocher  is  rendered  apparent  by  the  high  content  of  iron. 

Salts  of  lead  and  mercury  are  rarely  if  ever  now  used  for  color. 

Groirnd  Redwood. — Numerous  varieties  of  redwood  arc  commonly 
used  to  intensify  the  color  of  cayenne,  especially  when  otherwise  highly 
adulterated  with  colorless  materials,  such  as  the  starches.  The  redvv'ood 
is  sometimes  used  alone,  and  sometimes  in  mixture  with  turmeric.  Both 
redwood  and  turmeric  are  readily  recognized  under  the  microscope. 

Fig.  214,  PI.  XXIV,  shows  a  cayenne  sami)lc  adulterated  with  corn 
starch  and  red  sandalwood,  a  mass  of  the  latter  filling  the  center  of  the 
field.  The  wood  fibers  of  the  dyestuflf,  even  when  finely  ground,  are 
ver}'  striking  under  the  microscope,  showing  a  brick-red  color. 

Detection  of  Coal-tar  and  Vegetable  Colors. — Oil-soluble  coal-tar 
and  vegetable  colors  may  be  tested  for  in  cayenne  and  paprika  by  an 
adaptation  of  Martin's  butter-color  method,  shaking  the  ether  extract 
of  the  sample  with  the  alcohol  and  carbon  bisulphide  mixture,  page  535. 
The  carbon  bisulphide  dissolves  the  oil  and  natural  color,  while  the  over- 
lying alcohol  layer  holds  in  solution  many  of  the  artificial  coloring  matters 
that  may  be  cmployerl. 

The  natural  colors  of  cayenne  and  i)aj)rika  are  sparingly  soluble  in 
alcohol,  but  readily  soluble  in  carbon  bisul})hide.  The  separated  alcohol 
is  examined  for  colors  by  methods  given  elsewhere. 

Tests  for  coal-tar  dyes  should  also  be  made  by  Sostegni  and  Carpen- 
ticri's,  or  Arata's  method  (p.  796). 

S/Jgeti  *  treats  the  suspected  samj)le  with  water  acidified  with  acetic 
acid,  and  boils  in  this  solution  a  bit  of  wool,  which,  if  carotin  or  a  coal-tar 
dye  be  present,  is  colored  red.     If  the  color  is  carotin,  it  will  be  removed 

*  2Jeits.  lanrlw.  Versuchs.  Ocsterreich,  5,  1902,  pp.  1208,  1222. 


SPICES.  445 

from  the  wool  by  treatment  with  petroleum  ether,  or  by  heating  at  ioo° 
C.  for  some  hours,  but  if  a  coal-tar  dye,  it  will  still  remain  fixed 
thereon. 

Detection  of  Olive  Oil  in  Red  Pepper. — The  color  of  paprika  and 
pimiento  is  often  intensified  by  grinding  with  olive  oil.  This  form  of 
adulteration  is  detected  by  determination  of  the  iodine  number  of  the  non- 
volatile ether  extract.  The  following  method  elaborated  by  Seeker  has 
been  adopted  by  the  A.  O.  A.  C. : 

Dry  5  grams  on  a  watch-glass  over  sulphuric  acid  for  at  least  twelve 
hours.  Measure  250  cc.  of  anhydrous  alcohol-free  ether  (p.  66)  into  a 
graduated  flask  with  the  mark  near  the  lower  end  of  the  neck,  and  brush 
the  paprika  into  it.  Place  a  mark  on  the  neck  of  the  flask  at  the  meniscus, 
and  allow  to  stand  for  one  hour,  shaking  at  twenty-minute  intervals 
durinw  that  time.  Bring  the  meniscus  back  to  the  mark  either  by  cooling 
if  the  level  has  risen,  or  by  adding  absolute  ether  if  it  has  fallen,  and 
let  settle.  Pipette  off  100  cc.  of  the  supernatant  liquid,  filter  through  an 
ii-cm.  close-textured  paper  into  a  tared,  air-dry  glass-stoppered  250-cc. 
Erlenmeyer  flask  previously  counterpoised  against  a  similar  flask,  wash 
with  a  little  absolute  ether,  and  distil  off  the  solvent  until  the  ether  ceases 
to  come  over.  Lay  the  flask  on  its  side  in  a  water-oven,  heat  for  thirty 
minutes,  cool  the  open  flask  for  at  least  thirty  minutes  in  the  air  and 
weigh.  Repeat  this  heating  and  weighing  until  the  weight  is  constant 
to  within  one  milligram,  two  heatings  usually  being  sufficient,  and  calcu- 
late the  per  cent  of  ether  extract.  If  more  than  i  h  hours'  heating  is  required 
to  obtain  constant  weight  or  if  the  ether  extract  becomes  colorless  it 
should  be  rejected,  and  a  new  determination  started  with  freshly  purified 
ether. 

Dissolve  the  ether  extract  in  the  flask  in  10  cc.  of  chloroform,  add 
30  cc.  of  Hanus  solution,  and  proceed  as  described  on  page  491.  The 
iodine  number  thus  determined  should  not  be  less  than  125. 

GINGER. 

Nature  and  Composition. — Ginger  as  a  spice  is  the  ground  root- 
stock  of  the  Zingiber  officinale,  an  annual  herb  of  the  family  /Angi- 
beracecE,  growing  to  a  height  of  from  3  to  4  feet.  It  is  a  native  of  India 
and  China,  but  is  cuhivated  quite  extensively  in  tropical  America,  Africa, 
and  Australia. 

The  root  is  dug  when  the  plant  is  a  year  old,  and  when  the  stem  has 


440 


FOOD  INSPECTION   AND  ANALYSIS 


•withered.  If  the  root,  when  freshly  dug  and  scalded  to  prevent  sprout- 
ing, is  dried  at  once,  it  forms  the  so-called  black  ginger,  of  which  Calcutta 
and  African  are  the  comnnin  varieties.  When  decorticated,  the  product 
is  known  in  commerce  as  white  ginger,  the  chief  varieties  being  Jamaica, 
Cochin,  and  Japan.  The  best  variety  is  Jamaica  ginger.  The  scraped 
root  is  sometimes  bleached  to  make  it  still  whiter,  or  sprinkled  with 
carbonate  of  lime. 

In  commerce  whole  or  black  ginger  appears  in  "  hands  "  4  to  10  cm. 
long,  and  from  10  to  15  mm.  in  diameter.  These  usually  have  three  or 
four  various-sized,  irregular  branches,  some  short  and  thick,  others 
elongated.  The  epidermis  is  gray  or  yellowish  gray  in  color,  more  or 
less  wrinkled,  and  beneath  it  is  a  reddish-brown  layer.  The  inner  portion 
of  the  dried  root  is  white  or  yellowish.  The  root  is  hard,  and  of  a  com- 
pact, horny  structure. 

While  or  decorticated  ginger  appears  in  "  hands  "  of  smaller  diameter 
than  the' black,  and  yields  a  lighter  colored  powder  on  grinding.  Preserved 
ginger  root  is  prepared  by  boiling  the  root  in  water,  and  curing  with  sugar 
or  honey.     Much  of  the  preserved  ginger  comes  from  Canton, 

The  distinguishing  features  of  ginger  arc  its  large  content  of  starch, 
its  volatile  oil,  and  its  resinous  matter.  Inasmuch  as  the  epidermis  con- 
tains a  large  amount  of  jjungent  resin,  it  is  easy  to  see  how  the  peeled  or 
decorticated  variety  is  inferior. 

Oil  of  ginger  is  very  aromatic,  and  of  a  greenish-yellow  color.  Its 
specific  gravity  ranges  from  0.875  to  0.885.  ^^  ^s  slightly  soluble  in  alco- 
hol.    Of  its  composition  little  is  know'n. 

Richardson's  analyses  in  full  of  five  samples  of  whole  ginger-root  are 
as  follows : 


u 

< 

|5 

•g-d 
.2  5 

CD 

•§.-5 

S  ^5 

.§.-2 

u     . 

s, 
s 

2- 

Cal(  utt;i 

9.60 

9.41 

10.49 

11.00 

10.  II 

7.02 
3-39 
3-44 
4-54 
5-58 

2.27 
1.84 
2.03 
1.89 
2-54 

4.58 
4.07 
2.29 

3-04 
2.69 

49-34 
53-33 
50-58 
49-34 
50-67 

7-45 
2.05 

4-74 
1.70 

7-65 

6.30 
7.00 
10. 8s 
9.28 
9. 10 

13-44 
18.91 

15-58 

19.21 
11.66 

1. 01 

Cfx:hin 

Unbloarhed  Jamaica 

1-74 
1.48 
1.46 

Bleached  Jamaica,  London 

"              "          American 

Summaries  of  W^inton,  Ogdcn,  and  Mitchell's  analyses  of  eighteen 
.samjjles  of  whf)lc  ginger,  representing  the  common  white  and  black 
varieties,  as  well  as  of  two  samples  of  exhausted  ginger,  are  as  follows: 


SPICES. 


447 


Ash. 

0 

"rt 

li 

0 

1) 

0 

^■^ 

c.s 

H 

M 

h3 

9-35 

4.09 

2.29 

3-53 

3.61 

1-73 

0.02 

0.20 

5-27 

2.71 

0.44 

0.80 

2.12 

0-59 

0.18 

5-05 

3-55 

1.50 

Ether  Extract. 


Ginger:    Maximum 11.72 

Minimum 8.71 

Average j  10.44 

Exhausted  ginger  from  English  ginger- 
ale  works 10.61 

Exhausted  ginger  from  extract  works..  8.02 


3-09 
0.96 

1-97      4-10 


.61 
■13 


2  X 


S-42 
2.82 


3.86 
0-54 


_  o 


Ginger:    Maximum j  6.58 

Minimum j  3.63 

Average 5  - 18 

Exhausted  ginger  from   English  gin- 
ger-ale works. 4.88 

Exhausted  ginger  from  extract  works.      1.52 


62.42 
53-43 
57-45 

59.86 


60.31 

5-5° 

49  05 

2-37 

54-53 

3-91 

54-57 

5-17 

9-75 
4.81 

7-74 
6.94 


17-55^  1-55 

10.92  0.77 

13.421  1.23 

6.15  I. II 
16.421 


McGill  *  records  the  analyses  of  ninety-eight  samples  of  ground  ginger 
as  sold  in  the  Canadian  market.  Of  thirty-two  of  these,  pronounced 
pure  on  analyses,  the  following  is  a  summary: 


Maximum . 
Minimum  . 


Moisture 
or  Loss 
on  Dry- 
ing at 
100°. 


Petro- 
leum- 
ether 
E.xtract. 


Cold- 
water 
Extract. 


9-50 


6.13 

2.78 


15.48 
14.04 


Ash. 


Total. 


7.84 
3-67 


Soluble.   ;  Insoluble. 


2.28 


3-99 
1.96 


Alkalin- 
ity of 
Soluble 
Ash  as 
KoO. 


-133 
.103 


According  to  Vogl,  the  proportion  of  ginger  ash  varies  quite  widely 
according  to  the  kind,  but  should  never  exceed  8%, 

Exhausted  Ginger  and  Methods  of  Detection. — There  are  two  kinds 
of  exhausted  ginger  commercially  available  for  admixture  with  ground 
spice,  as  an  adulterant.  One  is  the  product  left  after  extraction  with  strong 
alcohol  in  the  making  of  extract  of  Jamaica  ginger,  and  the  other  the 
residue  from  extraction  with  either  very  dilute  alcohol,  or  with  water. 


*  Dept.  Inl.  Rev.  Canada  Bui.  48,  pp.  10,  11. 


4-»S 


FOOD  INSPECTION  AND  ANALYSIS. 


in  the  manufacture  of  ginger  ale.  Ground,  exhausted  ginger  is  rarely 
substituted  wholly  for  the  pure  variety^  since,  from  its  lack  of  pungency, 
the  sophistication  wmil.l  be  too  apparent.  It  is  rather  used  to  mix  with 
the  latter  in  var}-ing  proportions,  and  as  an  adulterant  of  other  spices. 
Ginger  that  has  been  exhausted  by  extraction  with  alcohol  has  been 
deprived  of  most  of  its  volatile  oil,  which  is  found  in  the  "extract,"  while 
lor  the  manufacture  of  ginger  ale,  a  water  extract,  or  at  most  a  very  dilute 
alcoholic  extract  is  best  adapted.  Such  a  water  extract  does,  as  a  matter 
of  fact,  remove  much  of  the  valued  ])ungency,  so  that  the  residue,  or 
exhausted  ginger,  is  rather  inert. 

Either  the  alcohol-  or  the  water-extracted  variety  of  exhausted  ginger, 
when  present  in  considerable  amount,  would  be  apparent,  one  by  the 
alcohol  and  ether  extract,  and  the  other  by  the  abnormally  low  cold- 
water  extract,  and  water-soluble  ash. 

Dyer  and  GUbard  *  first  called  attention  to  the  water-soluble  ash  as 
a  reliable  means  of  indicating  exhausted  ginger.  Six  samples  of  ginger 
of  known  purity  were  analyzed  by  them,  their  results  being  summarized 
as  follows: 


Total  Ash, 

Water- 
soluble 
Ash. 

Alcohol 

Extract, 

after  Ether 

Extract. 

Pure  ginger  (d  samples) :             Highest 

4-1 
3-1 
3-8 

2-3 

I.I 
1.8 

3- 
1-9 

2.7 

o-S 

0.2 

0-35 

3-8 

Lowest 

Average 

2    8 

Exhausted  ginger  (6  samples) :  Highest 

1-5 
0.8 

Lowest 

Average 

.\lk-n  and  Moor  f  ])ointed  out  the  value  of  the  cold-water  extract 
as  a  help  in  detecting  exhausted  ginger,  especially  when  taken  in  con- 
nection with  the  soluble  ash,  showing  that  the  presence  of  this  adulterant 
is  assured,  when  the  soluble  ash  is  as  low  as  i%,  and  the  cold-water  extract 
is  less  than  8%. 

Determination  of  Cold-water  Extract. — Winton,  Ogden,  and  MilcheWs 
Mtlhod.X — Four  grams  of  the  ground  sample  are  placed  in  a  200-cc. 
graduated  flask,  and  the  latter  is  filled  to  the  mark  with  water,  and  shaken 
at  half- hour  intervals  during  eight  hours,  after  which  it   is  allowed  to 

♦Analyst,  XVHI  (1893),  p.  197. 

t  Analyst,  XIX  (1894),  p.  194. 

X  L".  S.  Dept.  of  Agrii .,  Bur.  of  Chem.,  Bui.  65,  p.  59;   Bui.  107  (rev.),  p.  164. 


SPICES. 


449 


stand  at  rest  for  sixteen  hours  in  addition.  The  contents  are  then  filtered, 
and  50  cc.  of  the  filtrate  evaporated  to  dryness  in  a  platinum  dish.  It 
is  then  dried  at  100°  to  constant  weight  and  weighed. 

Microscopical  Structure  of  Ground  Ginger. — Fig.  87,    from  Moeller, 
shows  elements  of  ginger  root,  from  which  the  epidermis  has  not  been 


Fig.  87. — ^Powdered  Ginger  under  the  Microscope.     X125.     (After  Moeller.) 


removed.  A  bit  of  the  large-celled  cork  (or  dead  protective  tissue  of 
the  epidermis)  is  shown  in  surface  view  at  (i);  at  (2)  is  shown  in  cross- 
section  the  parenchyma  in  which  the  starch  is  contained,  h  being  an  oil- 
cell;  (3)  shows  the  parenchyma  in  longitudinal  section,  with  bast  fibers. 
Fragments  of  spiral  ducts  are  shown  at  (4),  and  starch  grains  at  (5).  (6) 
is  a  cross-section  in  the  extreme  interior  of  the  root. 

The  most  prominent  feature  of  powdered  ginger  is  the  starch  grains 
(5),  which  Moeller  compares  in  shape  to  tied  sacks. 

Fig.  228,  PI.  XXVII,  is  a  photomicrograph  of  pure,  ground  ginger, 
mounted  in  water,  showing  the  starch  grains  inclosed  in  the  cells  of  the 
parenchyma.  Fig.  231  shows  the  starch  grains  alone.  The  granules  of 
ginger  starch  are  ellipsoidal,  and  as  a  rule  very  clear  and  transparent, 
being  for  the  most  part  entirely  devoid  of  either  hilum  or  concentric  rings. 


450  FOOD  INSPECTION  JND  ANALYSIS. 

Occasionally  granules  arc  to  be  found,  however,  with  faint  concentric 
markings,  and  even  with  an  apparent  hilum.  The  characteristic  form  of 
the  ginger  starch  granule  is  more  or  less  egg-shaped,  with  a  small  protu- 
berance near  one  end.  This  protuberance  serves  to  readily  distinguish 
the  starch  granules  of  ginger  from  those  of  wheat,  with  which  ginger 
is  frequently  adulterated.  While  wheat  granules  arc  of  various  sizes, 
the  grains  of  ginger  starch  are  as  a  rule  much  more  uniform. 

Adulteration  of  Ginger. — U.  S.  standard  ginger  should  meet  the  follow- 
ing requir.'ments:  Starch  by  the  diastase  method  should  not  be  less  than 
^2^1;  crude  liber  should  not  exceed  8%;  total  ash  should  not  exceed  8%f 
lime  should  not  exceed  i%;  ash  insoluble  in  hydrochloric  acid  should 
not  exceed  3%. 

Besides  exhausted  ginger,  the  most  common  adulterants  found  in 
powdered  ginger  are  turmeric,  wheat,  corn,  rice,  and  sawdust.  Sawdust 
of  soft  wood  is  a  not  uncommon  adulterant,  and  care  should  be  taken 
to  distinguish  between  the  wood  fiber  natural  to  the  ginger  root,  and  that 
of  the  foreign  variety.  A  careful  study  should  be  made  of  finely  ground, 
soft-wood  sawdust,  with  its  long  spindle  cells  and  lateral  pores,  as  shown 
in  Fig.  266,  PI.  XXXVH,  and  the  wood  fiber  of  the  genuine  ginger  root. 
A  large  admixture  of  sawdust  would  materially  increase  the  percentage 
of  crude  fiber. 

Fig.  234,  PI.  XXIX,  shows  a  sample  of  ginger  adulterated  with  com 
and  wheat.  Fig.  232  shows  a  mass  of  wheat  bran  in  an  adulterated 
sample. 

Fig.   233  shows  ginger  adulterated  with  turmeric* 

TURMERIC. 

Nature  and  Composition. — Turmeric,  while  largely  used  as  an  adul- 
terant of  other  spices  (especially  of  ginger  and  mustard),  possesses  some 
value  as  a  condiment  in  itself,  forming,  for  instance,  the  chief  ingredient 
of  curry  powder.f  Turmeric  {Curcuma  longa)  belongs  to  the  same 
family  (ZingiberacecB)  as  ginger,  having  a  perennial  rootstock,  and  an 
annual  stem.  It  is  a  native  of  the  East  Indies  and  Cochin-China.  Its 
chief  ingredients  are  starch,  a  volatile  oil,  a  yellow  coloring  matter  (cur- 
cuminj,  cellulose,  and  gum. 

*  This  photomicrograph  is  very  disaf>pointing,  in  that  it  fails  to  show  the  intense  yellow 
of  the  central  mass  of  turmeric. 

t  Curry  powder  consists  of  a  mLxtiire  of  tunncric,  cayenne,  and  various  pungent  spices. 


SPICES. 


451 


Curcumin  (CiiHj^OJ  is  insoluble  in  cold  water,  but  readily  soluble 
in  alcohol.  It  is  extracted  from  powdered  turmeric  by  boiling  the  latter 
with  water,  filtering,  and  extracting  the  residue  with  boiling  alcohol. 
The  alcoholic  solution  is  filtered,  evaporated,  and  the  residue  extracted 
with  ether.  The  ether  extract  contains  the  curcumin,  together  with  a 
small  amount  of  volatile  oil. 

Curcuma  oil  is  an  orange -yellow,  slightly  fluorescent  liquid,  its  specific 
gravity  being  0.942. 

The  following  analyses  of  turmeric  were  made  in  the  writer's  labo- 
ratory : 


Variety. 


Mois- 
ture. 


Total 
Ash. 


China.  . 
Pubna.  . 
Alk'ppi. 

Average 


9-03 
9.08 
8.07 

8.73 


6.72 
8.52 
5-99 

7.07 


Ash 

Soluble 

inWater. 


Ash 

Insoluble 

in  HCl. 


5.20 
6.14 
4-74 

5-36 


Total 
Nitrogen. 


1-73 
0.97 

1.56 
1.42 


Protein, 
NX6.2S. 


Total 

Ether 

Extract. 


10.81 
6.06 
9-75 


10.86 
12.01 
10.66 

II. 17 


Variety. 


Volatile 

Ether 

Extract. 


Non-vol- 
atile 
Ether 
Extract. 


Alcohol 
Extract. 


Crude 
Fiber. 


Reducing 
Matter  by 
Acid  Con- 
version ,  as 
Starch. 


Starch  by 
Diastase 
Method. 


China 2.01 

Pubna '  4.42 

Alleppi 3- 16 

Average '  3-^9 


8.84 
7.60 
7-51 

7.98 


9.22 
7.28 
4-37 

6.96 


4-45 
5-84 
5-83 

5-37 


48.69 
50.08 
50-44 

49-73 


40.05 
29.56 
33-03 

34.21 


Microscopical  Structure  of  Turmeric. —  Moeller's  representation  of 
characteristics  of  powdered  turmeric  is  reproduced  in  Fig.  88.  The 
epidermis  is  shown  at  (i)  with  one  of  the  numerous,  one-celled  hairs  that 
grow  from  it,  also  the  scar  left  after  one  of  the  hairs  has  been  removed ; 
(2)  shows  in  plan  view  the  cork  immediately  under  the  epidermis.  The 
tender-celled  parenchyma  is  shown  in  cross-section  at  (3),  and  in  longi- 
tudinal section  at  (4).  In  some  of  the  cells  of  the  parenchyma  are  found 
dark-yellow  lumps  of  resin  (/t),  and  vascular  ducts  {g),  but  by  far  the  most 
numerous  and  striking  contents  of  the  parenchyma-cells  are  the  bright- 
yellow  masses  of  "paste  balls"  {t^o)  and  the  starch  granules,  one  of 
which  is  shown  in  (3).  See  also  Plate  XIII.  The  starch  grains  in  the 
water-mounted  powder  show  under  the  microscope  in  masses,  usually  of 
a  deep-yellow  color,  unless  very  finely  rubbed  out,  when  they  appear  for 
the  most  part  in  fragments. 


452 


FOOD  INSPECTION  AND  ANALYSIS. 


The  whole  starch  granule  appears  somewhat  in  the  fonn  of  a  clam- 
shell, with  \cr\  distinct  markings.  WThcn  fragments  of  the  starch  granules 
are  carefully  examined,  these  distinct  markings  are  so  strongly  charac- 
teristic, even  in  the  smallest  pieces  commonly  found  in  the  powdered 
sample,   as    to   nearly   always    serve   to  identify   them.       See    Fig.    171, 

n.  XIII. 

Turmeric  as  an  Adulterant. — Turmeric  is  a  material  especially  adapted 
bv  its  deep-yellow  color  to  intensify  mustard  and  ginger,  especially  when 


FiC.  88. — ^Powdered  Turmeric  under  the  Microscope.     X125.     (After  Moeller.) 


these  spices  are  adulterated  with  the  lighter-colored  cereal  starches,  hence 
it  is  very  commonly  found  in  these  spices,  both  with  and  without  other 
adulterants. 

It  is  also  frcfjuently  used  in  small  (juanlities  in  adulterated  cayenne 
mace,  and  various  spices,  to  counteract  the  colors  of  other  dyestuffs, 
such  as  ground  redwood,  which  in  itself  would  sometimes  be  too  intense 
if  used  alone. 


SPICES.  453 

Turmeric,  when  present  to  any  marked  extent  in  a  powdered  spice, 
may  be  detected  chemically,  by  extracting  the  material  with  alcohol, 
pouring  off  the  latter,  and  soaking  in  it  a  piece  of  Ulter-paper.  Tur- 
meric, if  present,  will  stain  the  latter  yellow,  turning  red  with  alkali,  espe- 
cially apparent  after  drying.  Soak  the  yellow  paper  in  a  solution  of  borax, 
acidulated  slightly  with  hydrochloric  acid.  When  dry,  a  rose-red  color 
will  indicate  turmeric,  turning  dark  olive  when  dilute  alkali  is  applied. 

MUSTARD. 

Nature  and  Composition. — Mustard  is  the  seed  of  the  mustard  plant, 
an  annual  belonging  to  the  family  CnicljercB,  and  to  the  genus  Sinapis, 
or  Brassica,  as  it  is  sometimes  called.  The  plant  is  an  herb,  native 
throughout  Europe,  and  cultivated  extensively  in  the  United  States.  It 
grows  to  a  height  of  from  3  to  6  feet,  having  yellow  flowers  and  lyrate 
leaves. 

Two  varieties  commonly  used  are  Brassica  or  {Sinapis)  alba,  white 
mustard,  and  Brassica  (or  Sinapis)  nigra,  black  mustard,  the  ground 
spice  being  as  a  rule  a  mixture  of  the  two.  In  the  trade  these  varieties 
are  known  as  bro^m  and  yellow  mustard  respectively.  The  seeds  of 
both  varieties  are  globular,  those  of  the  black  mustard  being  small,  and 
of  a  dark-brown  color  on  the  outside  and  yellow  within.  White  mustard 
seeds  are  considerably  larger  than  the  black,  being  pale  yellow  in  color 
on  the  outside. 

The  surface  of  the  black  mustard  seeds  is  reticular,  and  full  of 
small  depressions,  while  the  white  variety  is  much  smoother.  There  are 
several  layers  forming  the  husk  of  the  seed  of  both  varieties,  and  within 
the  husk  is  the  yellowish-colored  kernel  or  embryo,  with  two  cotyledons. 

Both  black  and  white  mustard  contain  from  31  to  37%  of  fixed 
oil,  a  soluble  ferment  known  as  myrosin,  and  a  sulphocyanate  of 
sinapin.  Mustard  seeds  contain  no  s^^arch,  and  very  little  volatile  oil 
as  such.  Black  mustard  seed  contains  sinigrin,  or  myronate  of  potash 
(not  found  in  the  white  seed),  which,  when  moistened  with  water,  forms 
by  hydrolysis  the  volatile  oil  of  black  mustard,  otherwise  known  as  allyl 
isothiocyanate,  in  accordance  with  the  following  equation: 

KCioHi^NS^O.-f  H,0  =  C«Hj.Pe  +  CgH.CNS  -f  KHSO,. 

Potassium  Glucose  Mustard  Potassium 

myronate  oil  bisulphate 

Mustard  Oil  (volatile)  is  a  colorless,  or  slightly  yellow,  highly  refrac- 
tive liquid  of  a  very  strong  'odor,  and  capable  of  blistering  the  skin  when 


4  54  FOOD  INSPECTION  /iND  ANALYSIS. 

brought  in  contact  \\\\\\  it.  It  is  optically  inactive.  Its  specific  gravity 
varies  between  1.016  and  1.030.  It  boils  between  148°  and  156°.  It 
turns  reddish  brown  by  exposure  to  light. 

Volatile  oil  of  black  mustard  forms  thiosinamine  with  ammonia,  as 
follows : 

C3H,CNS+NH3=CS.NH,.NH.C3H5. 

Thiosinamine  is  soluble  in  hot  water,  from  which  it  crystalhzes  in 
tufts  of  monoclinic  crystals,  having  a  melting-point  of  74°  C.  It  is  pre- 
cipitated by  silver  nitrate,  mercuric  chloride,  and  Mayer's  solution, 

WTiite  mustard  diflers  from  the  black  in  containing  a  sulphur  com- 
pound, sinalhin,  C3oH^2^2S20i5.  This  is  a  glucoside.  Sinalbin  by  hy- 
drolysis forms  an  oil  of  white  mustard,  in  a  somewhat  similar  manner 
to  the  potassium  myronate  of  black  mustard,  and  according  to  the  follow- 
ing equation: 

C3oH«N2S20i5+  H2O  =  C,H,ONCS  ^-C,Yi,,0,  +  CeH^^NO^HSO,. 

Sinalbin  Sinalbin  Glucose  Sinapin  acid 

mustard  oil  sulphate 

Sinalbin  Mustard  Oil  cannot  be  obtained  by  the  distillation  of  white 
mustard,  being  sparingly  volatile  with  steam. 

Sinalbin  mustard  oil  somewhat  resembles  that  from  black  mustard, 
being  quite  as  pungent,  but  less  strong  in  odor  when  cold.  It  is  soluble 
in  dilute  alkali. 

Fixed  oil  of  mustard  is  a  bland,  tasteless,  and  nearly  odorless  oil,  its 
specific  gravity  at  15°  varying  between  the  limits  of  0.914  to  0.918.  It 
is  said  to  be  used  to  some  extent  as  an  adulterant  of  table  oils,  being 
separated  by  pressure  from  the  crushed  mustard  seeds  before  the  latter 
are  ground  into  "flour."  The  chief  use  of  mustard  oil  is  in  mixture 
with  other  oils  as  an  illuminant. 

MUSTARD  FLOUR. — In  the  process  of  preparing  the  ground  spice  com- 
monly known  as  mustard  "flour,"  the  seeds  are  first  crushed  and  sepa- 
rated by  winnowing  from  the  hulls,  the  latter  being  incapable  of  the  fine 
grinding  necessan,'  to  produce  a  smooth  flour.  The  yellow  hulls  are, 
however,  found  in  the  cheaper  grades  ot  ground  mustard,  and  both 
varieties  of  hull  arc  frequently  used  in  the  wet  mustard  preparations, 
sold  in  bottled  form.  In  order  to  produce  an  even,  dry  powder,  free  from 
lumps,  it  is  necessary  to  remove  a  large  portion  of  the  fixed  oil,  which 
is  indeed  of  no  value  in  the  final  product,  and  this  is  done  by  subjecting 
the   crushed  material  to  hydraulic   pressure,   during  which  process  the 


SPICES. 


455 


mustard    is    molded    together  into   thin,   hard   plates,   called   "mustard 
cake."     This  is  then  broken  up  and  reduced  to  fine  powder  by  pounding. 
Richardson's*    analyses    of    whole-seed    flour,    prepared   by    himself 
without  the  removal  of  the  fixed  oil,  are  as  follows: 


White  seed 

White  tlour 

Seed  husk 

California  yellow 
California  brown, 
English  yellow  . . 
Trieste  brown.  .. 


5-57 
3-33 
6.17 

4-83 
4. II 

3-11 
4.62 


4.29 
5-23 
4-99 
5-96 
4.88 
4.07 
5-61 


-97 
1.84 

-55 
1.27 

1-35 

2.c6 

■63 


33-56 
34.83 

28.12 
31.96 
36-63 
31-51 

39-55 


00 

5.40 

00 

9.05 

00 

9.50 

00 

8. so 

00 

16.18 

00 

6.90 

00 

10.84 

28. 
25-56 
23-44 
31-13 

24.69 

30-25 
25.88 


21-331  4-62 

20.16  4.09 

27-23'  3-75 

16.35:  4.98 

12.16;  3.95 

22.10,  4.84 

18.87I  4.14 


Winton  and  Mitchell  made  no  full  analyses  of  mustard  seed  of  known 
purity,  but  the  following  is  a  summary  of  analyses  of  18  samples  of  com- 
mercial mustards,  sold  in  packages  in  Connecticut,  and  not  found  to  be 
adulterated: 


Total 
Ash. 

Ether  Extract. 

Reducing 

Matters 
by  Acid 
Conver- 
sion, as 
Starch. 

Starch 

Diastase 
Method. 

Crude 
Fiber. 

Volatile. 

Non-vol- 
atile. 

X6.a5. 

Maximum ............ 

7.35 
4.81 

5.99 

1.90 
0.00 
0.56 

28.10 
17.14 
20.61 

6.12 

1.85 

4.33 

2.08 
0.28 
1.07 

4.87 
1-58 
2.58 

43-56 
35-63 
39.57 

Minimum  ............ 

Average .............. 

The  following  analyses  of  5  samples  of  mustard  flour,  6  samples  of 
mustard  hulls,  and  6  samples  of  whole  mustard,  were  made  in  the  author's 
laboratory  in  1903: 


*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  part  2. 


4>6 


FOOD   IKSPECT/ON  AND  ANALYSIS. 


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SPICES.  457 

Piesse  and  Stanscii  give  the  following  composition  of  mustard  ash: 


White  Seeds. 

Brown  Seeds. 

Yorkshire. 

Cambridge. 

Cambridge. 

Potash 

21.29 
0.18 

13.46 
8.17 
1. 18 
7.06 

O.I  I 

32-74 
1. 00 
1.82 

12.82 

18.88 
0.21 

9-34 
10.49 

1-03 
7.16 
0. 12 

35-00 
1. 12 

1-95 
15-14 

21.41 

0-35 

13-57 

10.04 

1.06 

5-56 

0-15 
37.20 
1. 41 
1.38 
7-57 

Soda 

Magnesia 

Iron  oxide 

Sulijhurif  acid 

Chlorine 

Phosphoric  acid 

SiUca 

Sand 

Charcoal 

99-85 

100.48 

99.70 

Determination  of  Myronate  of  Potassium  and  Sinapin  Sulphocyanate.* 

— Extract  at  least  50  grams  of  the  powdered  material  with  several  por- 
tions of  a  mi.xture  of  equal  parts  of  water  and  alcohol,  digesting  with  the 
aid  of  heat  in  a  flask  with  a  return-flow  condenser.  Evaporate  the 
alcoholic  extract  in  a  tared  dish  to  dryness,  and  heat  at  105°  to  constant 
weight.  After  weighing,  incinerate  the  residue  at  a  temperature  suf- 
ficiently high  to  transform  to  the  neutral  sulphate  the  potassium  bisulphate 
resulting  from  the  decomposition  of  the  myronate.  The  weight  of 
myronate  of  potassium  is  obtained  by  multiplying  the  weight  of  neutral 
sulphate  (the  final  ash)  by  the  factor  4.77.  This,  deducted  from  the 
total  weight  of  the  dried  alcoholic  residue  as  above,  gives  that  of  the 
sulphocyanate  of  sinapin. 

Determination  of  Mustard  Oil  in  Mustard  Flour. — Roesefs  Method.\ 
— Mix  5  grams  of  the  sample  with  60  cc.  of  water  and  15  cc.  of  60%  alcohol, 
and  let  stand  for  two  hours.  Distil  into  a  flask  containing  10  cc.  of 
ammonia,  and^  after  about  two-thirds  of  the  solution  have  been  distilled 
off,  mix  the  ammoniacal  distillate  with  10  cc.  of  tenth-normal  silver 
nitrate  solution,  and  allow  the  mixture  to  stand  for  twenty-four  hours, 
after  which  make  up  with  water  to  100  cc.  Filter,  and  treat  50  cc.  of 
the  filtrate  with  5  cc.  of  tenth-normal  potassium  cyanide  solution.  Titrate 
the  excess  of  cyanide  with  the  tenth-normal  silver  nitrate,  using  as  an 
indicator  a  5%  solution  of  potassium  iodide,  made  slightly  ammoniacal. 

*  Girard,  Analyse  des  Matieres  Alimentaires,  p.  810. 
t  Abs.  Analyst.  XXVII,  1902,  p.  197. 


45S 


FOOD  INSPECTION  AND  ANALYSIS. 


The  percentage  of  mustard  oW  present  is  found  by  multiply- 
ing by  2  the  number  of  cubic  centimeters  of  silver  nitrate  solution 
taken    up    by    the    oil,    and    multiplying    this    product    by    the    factor 

Microscopical  Characteristics  of  Powdered  Mustard.— The  principal 
features  of  powdered  black  mustard  are  rejircsented  in  Fig.  89*     The 

seed  shell  or  hull  is  shown  in  cross-section 
at  (i),  a  being  the  polygonal-celled  epi- 
dermis, h  a  layer  of  palisade-shaped  cells, 
and  c  a  thin  pigment  layer,  tlie  Ijrown 
coloring  matter  of  which  is  colored  blue  by 
iron  salts;  d  is  the  aleurone  layer  and  ob- 
scure j)arenchyma,  and  c  the  small-celled 
tissue  of  the  c()t}-lcdons,  containing  fixed  oil 
and  albumen. 

(2)  shows  in  surface  view  the  various 
kiyers  of  the  seed  shell,  the  letters  of 
reference  corrcs])onding  to  those  of  (i). 

(3)  shows  in  surface  view  a  bit  of  the 
extreme  outer  mucilaginous  layer  of  the  seed- 
hull. 

Fig.  247,  PI  XXXII,  shows  the  ap- 
pearance in  water-mount  of  pure  ground 
mustard.  This  is  a  ])hotomicrograph  of  the  ground  hulled  seed  with- 
out the  extraction  of  the  oil,  and  should  not  l)e  taken  as  a  standard 
for  commercial  mustard  "flour,"  from  which,  as  a  rule,  a  large  por- 
tion of  the  oil  has  been  removed.  The  cellular  tissue  of  the  mustard 
shows  in  the  form  of  granular  masses  of  loose,  fine  gray  texture;  the 
globular  bodies  are  oil  drops.  Here  and  there  through  the  field  of 
ordinar)^  ground  mustard  are  to  be  seen  patches  of  the  yellowish  layer 
Df  the  seed  skin  of  the  brown  mustard,  a  mass  of  which  is  shown  in 
Fig.  248,  with  dark-brown  spots  distributed  regularly  through  it.  This 
is  the  layer  .shown  at  (2)  b,  Fig.  89.  The  hull  of  the  yellow  seed,  also 
common  in  powdered  mustard,  is  similar  in  appearance,  having  dark- 
brown  .s[X)ts,  but  with  nearly  colorless  or  gray  cell  walls,  in.stead  of  yellow. 
Patches  of  the  outer  hull  layer  represented  by  (3)  in  Fig.  89  are  also 
vcr)'  common  in  the  commercial  mustard  flour.  Mustard  contains  no 
starch. 


Fig.  89.  —  Powdered  Mustard 
under  the  Microscope.  X125. 
(After  Mocller.) 


SPICES.  459 

Adulteration  of  Mustard. — U.  S.  standards  for  mustard  are  a^,  follows: 
Starch,  by  diastase  method,  should  not  exceed  2.5%  and  total  ash  should 
not  exceed  8%. 

It  is  difficult  to  draw  the  line  between  the  amount  of  mustard  hulls 
which  may  naturally  occur  in  ground  mustard,  and  the  excess  amount 
which  is  sometimes  added  as  an  adulterant.  Samples  in  which  the 
patches  of  hulls  predominate  in  number  over  the  regular  cellular  tissue 
of  the  seed,  as  seen  under  the  microscope,  are  undoubtedly  adulterated 
by  the  fraudulent  admixture  of  ground  hulls,  that  have  been  separated 
out  from  the  crushed  mustard  seeds  intended  for  higher  grades.  Samples 
of  mustard  flour  thus  adulterated  are  common.* 

In  determining  starch  in  mustard,  it  should  be  borne  in  mind  that 
mustard  hulls  have  considerable  reducing  matter  by  the  diastase  process. 

The  most  common  adulterants  of  mustard,  other  than  excess  of  hulls, 
are  wheat,  rice,  millet,  turmeric,  charlock  and  other  weed  seeds.  Yellow, 
oil-soluble  azo-dyes  are  also  employed. 

Other  adulterants  found  in  Massachusetts  have  been  potato  starch, 
cayenne,  corn,  and  gypsum  or  "  terra  alba  "  (the  latter  being  found  in 
one  instance  to  the  extent  of  21%). 

Fig.  250,  PL  XXXIII,  shows  a  sample  of  mustard  adulterated  with 
wheat  bran.     Very  little  besides  the  adulterant  appears  in  this  field. 

The  common  practice  of  adulterating  mustard  with  wheat  is  an  out- 
growth of  the  old  notion  that  a  certain  amount  of  wheat  flour  was  neces- 
sary to  prevent  lumping. 

Charlock  or  Wild  Mustard  {Brassica  Sinapistnim)  grows  luxuriantly 
in  the  grain  fields  of  the  Northwest  and  the  seed  is  a  common  impurity 
of  the  uncleaned  wheat  from  that  region.  It  is  an  important 
constituent  of  wheat  screenings,  from  which  it  is  separated  and  placed  on 
the  market  under  such  names  as  "  Dakota  mustard,"  "  Domestic  mustard," 
etc.  This  product  also  contains  other  weed  seeds,  notably  those  of  the 
mustard  family,  and  also  a  certain  amount  of  broken  wheat.  Ground 
charlock  or  charlock  cake    and  charlock  flour  are  common  adulterants 

*  It  is  claimed  by  some  manufacturers  that  the  hulls  thus  removed  are  not  used  as  an 
adulterant  of  cheaper  mustard  flours,  in  view  of  the  fact  that  it  is  difficult  or  impossible  to 
grind  them  finely  enough,  but  that  they  are  used  up  in  the  manufacture  of  compound  mus- 
tard pastes.  A  sample  of  ground  mustard  was  recently  found  by  the  writer,  in  which  it 
was  noticed  that  a  large  number  of  yellow  lumps  were  distributed  through  it.  These  lumps 
were  picked  out,  transferred  to  the  microscope  slide,  and  crushed  and  rubbed  out  under 
the  cover-glass.  E.xamined  under  the  microscope,  they  were  found  to  consist  entirely  of 
a  mixture  of  mustard  hulls  and  turmeric,  which  would  seem  to  show  that  hulls  were  present 
in  this  case  as  an  adulterant. 


460  FOOD    ISSPFCTION    AND   ANALYSIS. 

of  prepared  mustard  and  mustard  llour.  These  rank-tasting  adulterants 
often  contain  an  appreciable  amount  of  starch  derived  from  the  broken 
wheat  and  starchy  weed  seeds.     See  Fig.  249,  PI.  XXXIII. 

Charlock  is  identified  by  the  presence  in  the  palisade  cells  of  a  black 
substance  which  on  heating  in  various  acid  reagents  (such  as  chloral 
hvdratc,  glycerine,  or  zinc  chloride,  acidified  with  hydrochloric  acid, 
svrupy  phosphoric  or  citric  acid),  becomes  bright  carmine.  A  satisfactory 
reagent  is  a  solution  of  16  grams  of  chloral  hydrate  in  10  cc.  of  water  and 
I  cc.  of  concentrated  hydrochloric  acid.  Mount  lo  mg.  of  the  material 
in  a  drop  of  the  reagent,  heat  gently,  and  examine  under  a  lens. 

Detection  of  Coloring  Matter.* — Turmeric  is  best  detected  by  the 
m.icroscope  (see  pp.  451  and  452).  OR-soluble  coal-tar  dyes  should  be 
tested  for  as  in  the  case  of  cayenne.  Nitro  colors,  such  as  naphthol  yellow 
(Martius  yellow)  and  naphthol  yellow  S,  are  detected  by  dyeing  tests,  with 
subsequent  examination  of  dyed  fabric  according  to  the  scheme  on    p.  801. 

Prepared  Mustard. — This  product  consists  of  a  mixture  of  ground 
mustard  seed  or  mustard  flour  with  salt,  spices,  and  vinegar.  The  U.  S. 
standards  require  that  it  should  contain  not  more  than  24%  of  carbo- 
hvdrates  calculated  as  starch,  not  more  than  12%  of  crude  fiber,  and  not 
less  than  35%  of  protein. 

Most  of  the  product  consumed  in  the  United  States  is  of  domestic 
manufacture,  although  until  the  passage  of  the  federal  food  law  it  was 
cusiomarv  to  designate  it  German  or  French  mustard, or  label  it  in  a  foreign 
language. 

Composition  and  Adulteration. — The  common  admixtures  are  wheat 
flour,  maize  flour,  and  other  starchy  matter,  mustard  hulls,  sugar,  chemical 
preservatives,  and  artificial  colors. 

Of  28  brands  examined  in  Connecticut  in  1905  byWinton  and  Andrew ,t 
13    contained    cereal    flour    (wheat   or  corn),    4    salicylic    acid,    and    25 

•  Recently  some  very  yellow  samples  of  powdered  mustard  have  appeared  on  the 
market  that  are  apparently  free  from  foreign  color.  Their  method  of  manufacture  is  kept 
secret.  From  the  fact  that  they  contain  nearly,  if  not  quite,  the  full  content  of  fixed  mus- 
tard oil  that  would  Ik;  present  if  the  oil  had  not  been  previously  expressed,  and  for  various 
other  reasfjns,  it  is  probable  that  the  color  is  due  largely  to  the  presence  of  the  fixed  oil,  which 
has  a  flccp-vellow  color,  and  which  has  hitherto  been  generally  removed  for  purposes  of  fine 
pounding  and  to  avoid  caking. 

In  such  samples,  the  oil,  previously  pressed  out,  is,  after  pounding,  restored,  and  with 
it  much  of  the  color.  Incidentally  in  such  a  process  oil-sfjjubie  coal-tar  dyes  may  conve- 
niently be  dissolved  in  the  mustard  oil,  in  order  to  intensify  the  color,  and  the  analyst  should 
be  on  the  outlook  for  such  foreign  colors. 

t  An.  Rep.  Conn.  Exp.  Sta.,  1905,  p.  123. 


SP/CHS. 


461 


artificial  color  (tarmeric,  nitro-color  or  azo-color).  A  summary  of  the 
analyses  of  those  brands  free  from  cereal  flour  and  those  containing  it 
follows : 


Prepared    mustard    free 
from  cereal  flour; 

Maximum 

Minimum 

Average 

Prepared    mustard    con- 
taining cereal  flour : 

Maximum 

Minimum 


In  the  Material  as  Sold. 


Water. 


83 .  68 

73-OI 
78.59 


8s .  6,3 

70.44 


Acid- 
ity 
Calcu- 
lated 

as 
Acetic 
Acid. 


3.66 
2.74 
3-os 


Total 
Solids. 


23.67 
13-32 
18.36 


27.70 
9.89 


Total 
Ash. 


4-79 

2  .  60 
3.38 


4.21 
2.28 


Com- 
mon 
Salt. 


3-39 

I. SI 


Ash 
other 
than  I 

Salt 


1-31 
0.82 
I  .06 


I. 16 
0.48 


Pro- 
tein. 


6. 12 
3-62 
4.71 


6.38 
I -53 


Crude 
Fiber. 


1.68 

0.77 
1. 17 


1-59 
o.  22 


Reduc- 
ing 
Matters 
by  Acid 
Conver- 
sion, as 
Starch. 


Nitro- 
gen- 
free 
Ex- 
tract. 


2  .92 
1.83 
2  .40 


13-69 


6.H 

4.21 
4.98 


15-35 
3-82 


Fat. 


7.23 
2.12 

4.12 


3-2S 
o.  76 


In  the  Dry,   Fat,   and  Salt-free   Material. 


Ash. 


Protein. 


Crude 
Fiber. 


Reducing 
Matters 
by  Acid 
Conver- 
sion, as 
Starch. 


Nitrogen- 
free 
Extract. 


Prepared  mustard  free  from  cereal  flour: 

Maximum 

Minimum 

Average 

Prepared  mustard  containing  cereal  flour: 

Maximum 

Minimum 

Whole  mustard  seed  (analyses  by  the  author. 
See  page  456) : 

Maximum 

Minimum 

Average 


10 .  66 
7-35 
8-94 


9.68 

4.84 


7-64 
6.28 
6.83 


43-94 
32.01 
39-44 


33-89 
21-37 


48-31 
37-50 
44-31 


14.12 
7.77 
9.89 


18.44 
0.4S 


10.33 

7-24 
8.0s 


24-37 
16.82 
20.11 


59-22 

24.51 


15-91 

11-94 
13-82 


44.76 
34-98 
41.73 

66 .  42 
41-79 


48.5s 
37.84 
40.81 


The  following  methods  for  the  analysis  of  prepared  mustard  were 
used  by  Winton  and  Andrew,  and  afterwards  adopted  by  the  Association 
of  Official  Agricultural  Chemists: 

Solids,  Ash  and  Salt  arc  determined  in  one  portion  of  5  grams  of 
the  thoroughly  mixed  material,  following  the  usual  methods.  The  salt 
is  calculated  from  the  percentage  of  chlorine. 

Ether  Extract.— Ten  grams  of  the  material  and  about  30  grams  of 
sand  are  placed  in  a  capsule,  and  dried  on  a  water  bath  with  stirring. 
The  dried  residue  is  ground  and  extracted  with  anhydrous  ether  in  the 
usual  manner. 


46 J  FOOD  INSPECTION  .^ND   ANALYSIS. 

Reducing  Matters  by  Acid  Conversion  arc  determined  directly  in 
the  material,  without  previously  washing,  as  described  on  page  411. 

Crude  Fiber.— Eit:;ht  grams  of  the  material  (equivalent  to  about  2 
iTxims  of  dr}'  matter)  are  treated  as  described  on  page  277,  except  that 
(^i)  the  boiling  i.2^^q  acid  is  added  directly  to  the  material  without  previous 
extraction,  taking  care  to  introduce  it  in  small  portions  and  shake  thor- 
ouf^hly  until  all  lumps  are  broken  up,  and  (2)  the  fiber  after  collecting 
on  the  weighed  paper  is  washed  twice  with  alcohol  and  finally  with  ether 
until  all  fat  is  removed.  If  these  precautions  are  not  followed  the  results 
will  be  high. 

Protein. — Nitrogen  is  determined  by  the  Kjeldahl  or  Gunning  method, 
and  the  result  multiplied  by  6.25. 

Dyes  and  Preservatives.^See  chapters  XVII  and  XVIII. 

NUTMEG    AND   MACE. 

Nature  and  Composition. — Both  nutmeg  and  mace  occur  in  the  fruit 
of  several  varieties  of  trees  of  the  genus  Myristlca,  especially  of  the  Myri- 
stica  jra grans  or  Myristica  moschata,  belonging  to  the  family  Myristi- 
cacecB.  The  nutmeg  tree  is  a  native  of  the  Malay  archipelago,  and  grows 
from  20  to  30  feet  high,  somewhat  resembling  the  orange  tree  in  appear- 
ance. It  does  not  produce  flowers  till  its  eighth  or  ninth  year,  after  which 
it  bears  fruit  constantly  for  many  years.  The  fruit  is  a  globular,  pendant 
drupe,  about  5  cm.  in  diameter,  of  a  yellowish-green  color,  the  pericarp 
of  which,  when  ripe,  splits  in  two,  showing  within  it  the  kernel,  completely 
surrounded  by  a  fleshy,  fibrous  aril,  or  covering  of  a  crimson  color.  This 
covering,  when  dried,  furnishes  the  mace  of  commerce,  while  the  inner 
kernel,  which  is  a  hard,  brown  seed,  is  the  nutmeg. 

The  jiutmeg  seed  or  kernel,  when  gathered,  is  surrounded  by  a  thick 
tegument,  marked  with  depressions  corresponding  to  the  lobes  of  the 
aril  or  mace,  and  by  a  second  thin,  inner  envelope,  closely  adhering  to 
the  seed.  The  whole  seed  is  dried  in  the  sun  for  about  two  months,  or 
by  the  aid  of  heat,  the  tegument  becoming  separated  from  the  kernel, 
and,  by  breaking  with  a  hammer,  is  readily  removed.  The  kernels 
are  then  commonly  washed  in  milk  of  lime,  and  again  dried,  or  they 
arc  .sf)metimes  treaterl  with  dry,  powdered,  air-slaked  lime.  Liming  is 
alleged  to  prevent  .sprouting  and  ward  off  the  attacks  of  insects.  The 
.so-called  brown  nutmegs  of  commerce  are  those  which  have  not  been 
treated  or  coated  with  lime. 


SPICES. 


463 


Nutmegs  arc  spheroidal,  sometimes  nearly  spherical,  from  20  to  25 
mm.  long  and  15  to  j8  mm.  in  diameter.  The  outer  surface  is  somewhat 
furrowed.  A  cross-section  of  the  kernel  shows  the  grayish-brown,  starchy 
cndosjxTm,  mottled  with  the  dark-brown,  resinous  veins  of  the  j^erisperm. 
These  veins  on  pressure  with  the  fmger  nail  present  an  oily  ajjpearance. 
Near  the  end  of  the  nutmeg  which  is  attached  to  the  stem,  is  a  small 
cavity,  in  which  is  the  undeveloped  embryo  with  two  cotyledons. 

Nutmeg  contains  a  considerable  amount  of  fixed  oil,  a  volatile  oil, 
starch,  and  albuminous  matter.  Its  volatile  oil  is  colorless,  and  is  soluble 
in  three  parts  of  strong  alcohol.  The  specific  gravity  of  nutmeg  oil 
varies  between  0.865  ^.nd  0.920,  and  its  specific  rotary  power  (0)^=14 
to  28. 

Richardson's  analyses  of  three  samples  of  nutmeg  are  as  follows: 


Water. 


Ash. 


Volatile 
Oil. 


Fixed 
Oil  or 
Fat. 


Starch, 
etc. 


Crude 
Fiber. 


Albu- 
minoids. 


Nitro- 
gen. 


Whole  limed. 
Ground  limed 
Ground 


6.08 
4.19 
6.40 


3-27 
2.22 

3-15 


2.84 

3-97 
2.90 


34.37 
37-3° 
30.98 


36.98 
40.12 
41.77 


II 


30 
6.78 

9-55 


5.16 
5-42 
5.25 


.83 
.87 
.84- 


Konig  gives  the  following  minimum  and  maximum  composition  of 
nutmeg : 


Water 

Albuminoids. . 

Volatile  oil 

Fat 

Carbohydrates 

Cellulose 

Ash 


Minimum. 

Maximum. 

4-2 

12.2 

5-2 

6.1 

2-5 

4.0 

31.0 

37-3 

29.9 

41.8 

6.8 

12.0 

2.2 

3-3 

Winton,  Ogden,  and  Mitchell  analyzed  four  samples    of   nutmeg  of 
known  purity,  the  following  being  maximum  and  minimum  results: 


Ash. 


Ether  Extract. 


Moisture. 


Total. 


Soluble  in 
Water. 


Insoluble 
in  HCl. 


Volatile. 


Non-vola- 
tile. 


M2Lximum. 
Minimum  , 


10.83 
5-79 


3-26 
2-13 


1.46 

0.82 


o.oi 
0.00 


6.94 
2.56 


36.94 
28.73 


464 


FOOD  INSPECTION  .-iND  ANALYSIS. 


Alcohol 
Extract. 


Reducing 
Matters  by 
Acid  Con- 
version ,  as 
Starch. 


Starch  by- 
Diastase. 


Crude 
Fiber. 


Nitrogen 
XO.25. 


Total 
Nitrogen. 


Maximum. 
Minimum. 


10.42 


25.60 
17.19 


24.20 
14.62 


3-72 
2.38 


7.00 
6.56 


1. 12 
1.05 


^91 


Microscopical  Structure  of  Nutmeg.  (Fig,  90.) — The  Ihin-walled 
cells   of  ihc  parenchyma  of  the   cndosj)crm  or  albumen   are   shown   at 

(1),  with  starch  grains.  Simple  and  com- 
pound granules  of  the  starch  are  shown  at 
(2).  Aleurone  grains  appear  as  shown  at 
(3),  and  (4)  represents  in  surface  view  the 
epidermis,  or  brown  seed  coat,  with  its 
numerous  layers  of  flat  cells.  Powdered 
nutmeg  under  the  microscope  in  water- 
mount  shows  most  commonly  a  sponge- 
hke,  loose  meshwork  of  bruised  or  broken 
Fig.    90.— Powdered    Nutmeg    cellular  tissue,    with    many    starch    granules, 

underthe  Microscope.  X125.  ,  .         ,    r  .        r  i.u  -j 

-.    ,,    .  and  occasional  fragments  of  the  epidermis. 

(.\fter  Moeller.)  ^      °  ^ 

Fig,  240,  Pi.  XXX,  is  a  photomicrograph 
of  a  water-mounted  sample  of  pure  nutmeg.  The  starch  granules  of 
nutmeg  are  different  from  other  starches  in  appearance,  being  almost 
circular  as  a  rule,  quite  uniform  in  size  (averaging  0.006  mm.  in 
diameter),  and  having  very  distinct  central  hyla. 

Adulteration  of  Nutmeg.  —  The  U.  S.  standards  for  nutmegs 
arc  as  follows:  Xon-\olatile  ether  extract  should  be  not  less  than 
25%;  total  ash  should  not  exceed  5%;  ash  insoluble  in  hydrO" 
chloric   acid  should   not   exceed   0.5%;    crude  fiber   should  not    exceed 

10%. 

This  spice  is  more  often  sold  in  the  whole  form,  since  the  house- 
wife much  prefers  to  grate  the  whole  nutmeg,  rather  than  to  use 
the  ground  material.  It  is  hence  less  liable  to  adulteration  than 
the  other  spices,  though  of  late  more  of  the  ground  nutmeg  is 
being  sold  in  packages.  Samples  of  ground  nutmeg  have  been 
found  in  Massachusetts  adulterated  with  wheat  and  nutshells.  One 
sample  was  found  to  contain  at  least  25%  of  ground  cocoanu' 
shells. 

Nutmegs  which  have  become  mouldy,  or  liave  l)een  eaten  out  by 
in.sccts,  have  Vx-en  imported  for  grinding,  as  .sounfl  nutmegs  are  not  readily 
reduced  to  a  [.K)wder.     Such  a  ijroduct  is  obviouslv  unfit  for  consuniDtion. 


SPICES. 


465 


An  inferior  variety  is  known  as  the  Macassar  nutmeg.  This  lacks 
much  of  the  agreeable  pungency  of  the  better  grades. 

Mace. — The  crimson-colored  aril  that  surrounds  the  nutmeg  kernel 
within  the  pericarp,  as  above  described  (p.  462),  has  many  narrow,  flattened 
lobes.  In  the  process  of  drying  to  form  the  mace  of  commerce,  it  loses 
its  brilUant  red  color,  and  turns  a  yellowish  brown.  When  dried,  it  is 
brittle,  somewhat  translucent,  and  of  a  pungent  odor.  Whole  mace 
appear  on  the  market  in  the  form  of  flat  membranous  masses,  3  to  4  cm. 
long. 

It  contains  no  starch  as  such,  but  has  a  modified  form  of  starch  known 
as  amylodextrin.  This  is  a  carbohydrate,  CsgHfioOai+H^O,  which  pro- 
duces with  iodine  a  red  coloration.  Mace  has  a  large  amount  of  fixed 
oil,  as  well  as  considerable  resinous  and  albuminous  matter,  and  a  vola- 
tile oil  which  much  resembles  that  of  nutmeg. 

The  specific  gravity  of  volatile  oil  of  mace  is  rather  higher  than  that 
of  nutmeg  oil.     Its  specific   rotary   power,  (a)o=iot0  2o. 

Konig's  figures  for  the  composition  of  mace  are  as  follows: 


Minimum. 

Maximum. 

Water     

4.Q                             17.6              1 

Albuminoids 

Volatile  oil 

4-6 
4.0 

6.1 

8-7 
29.1 

44-1 
8.9 

4-1 

55-7 

Fat 

1S.6 
41.2 

4-5 
1.6 

45-1 

Carbohydrates 

Cellulose.  .        

Ash 

Alcoholic  extract 

Richardson  gives   the    following   as   the   results  of  analyses  of  three 
samples  made  by  him: 


Water. 

Ash. 

Volatile     J,     .       1    U"de-       ^^^^ 

Albu- 
minoids. 

Nitro- 
gen. 

Whole  mace 

5-67 

4.86 

10.47 

4.10 
2.65 
2.20 

4.04 
8.66 
8.68 

27.50  i  41.17 
29.08      35.50 
23-33      34-68 

8-93 
4-48 
6.88 

4.55 
6.13 
5.08 

-73 
.98 
.81 

Ground  mace 

Winton,  Ogden,  and  ^Mitchell's  analyses  of  four  samples  of  pure  Banda 
or  Penang  mace,  as  well  as  of  Bombay  and  Macassar  mace,  are  sum- 
marized as  follows: 


466 


FOOD  IS'SPECTION  /IND  .4 N^ LYSIS. 


Moisture. 

Ash. 

Ether  Extract. 

Total. 

Soluble  in 
Water. 

Insoluble 
in  HCl 

Volatile.    'Non-vola- 

True  ni.uo:  Maximum 

Miiiiinum 

.\verage 

^lacassar ..,. 

12.04  2.54 
9. 78             I. 81 

11.05  '        2. or 
4.18             2.01 
0.32              1.98 

1-33 
I -06 

I -13 
I  -  II 

1-37 

0.21 
0.00 
0.07 
0.03 
O-07 

8.65 
6.27 
7-58 
5.89 
4.65 

23.72 
21.63 
22-48 
53-54 
59-81 

Bombay  (adulterant) 

Alcohol 
Extract. 

Reducing 
Matters  by 
Acid  Con- 
version, as 
Starch. 

Starch  by- 
Diastase.* 

Crude 
Fiber 

Nitrogen 
X6.2S. 

Total 

Nitrogen. 

True  mace:  Maximum 

Minimum 

.\veragc 

Macassar 

24-76 
22-07 
23-11 
32-89 
44.27 

34-42 
26-77 

31-73 
10-39 
16.20 

30-43 
23.12 

27-87 
8.78 

14.51 

3-85 
2.94 
3-20 

4.57 
3.21 

7 -00 
6-25 

6-47 
7.00 
5 -06 

I. 12 
1. 00 
1.03 
I  .  12 

Bombay  (adulterant) 

0.81 

♦  The  figures  in  this  column  do  not  express  starch,  but  amylo-dextrin,  which  like  starch  may  be 
determined  by  the  diastase  method. 


Microscopical  Structure   of   Mace. — Fig.    91  shows    characteristics  of 
mace,    (i)   being   a   cross-section   through   it,  (2)  a  surface  view   of  the 

epidermis,  showing  its  elongated,  often 
nearly  rectangular  cells,  and  (3)  the  large- 
celled  parenchyma,  in  which  are  numerous 
oil  globules.  The  contents  of  the  paren- 
chyma cells  are  for  the  most  part  color- 
less, consisting  of  protein,  fat,  and 
granules  of  amylodextrin,  which  are  shown 
at  (4).  At  (5)  are  shown  fragments  of 
vascular  tissue. 

The  water-mounted  powder  of  pure 
mace  shows  no  highly  colored  fragments, 
Fig.  fyi— Powdered  Mace  under  |jut  as  a  mass,  is  white  or  grayish,  and 
the  MicroscoFx.-.  x,25.  (After  ^^^  ^^^^^^  Icxturc.  Occasional  pale,  yel- 
lowish, lumpy  masses  appear,  and  pale- 
brown  fragments  of  the  seed  coating.  The  amylodextrin  granules 
(which  are  colored  red-brown  by  solution  of  iodine)  are  very 
smalL 

Adulteration  of  Mace. — U.  S.  standard  mace  should  contain  not  less 
than  20  nor  more  than  30%  of  non-volatile  ether  extract;  nor  more  than 


SPICES.  467 

3%  of  total  ash;  nor  more  than  0.5%  ash  insoluble  in  hydrochloric  acid; 
nor  more  than  10%  of  crude  fiber. 

Turmeric  and  cereal  starches  are  not  uncommonly  found  in  mace, 
but  by  far  the  most  common  adulterant  is  the  so-called  false,  or  wild 
mace,  otherwise  known  as  Bombay  mace. 

Bombay  Mace  {Myrislica  fatua)  is  almost  entirely  devoid  of  odor 
or  taste,  being  nearly  as  inert  as  so  much  starch.  It  is  most  properly 
regarded  as  an  adulterant  from  its  lack  of  pungency,  even  though  in  a 
sense  it  is  a  variety  of  mace. 

Its  non-volatile  ether  extract  is  twice  as  high  as  that  of  Penang  mace, 
and  at  room  temperature  the  fixed  oil  of  Bombay  mace  is  a  thick  and 
viscous  fat,  while  that  of  Penang  and  other  maces  is  a  thin  oil. 

The  refractive  indices  of  the  fixed  oils  of  various  species  of  pure,  as 
well  as  of  Bombay  mace,  as  determined  by  Lythgoe  in  the  writer's  labora- 
tory, are  as  follows : 

tJD  at  35°  C. 
Banda  Mace  (i) 1.4848 

(2) 1-4747 

(3) 1-4829 

Batavia  Mace  (i) 1-4893 

(2) 1-4975 

Papua  Mace  (i) i  .4816 

(2) 1-4795 

West  Indian  Mace  (i) i  .4766 

Bombay  Mace        (i) 1-4615 

(2) 1.4633 

The  microscope  indicates  at  once  when  Bombay  mace  is  present 
in  a  sample.  The  oil  glands  situated  in  the  outer  layers  of  Bombay  mace 
are  strongly  colored  and  contain  a  reddish  resinous  substance,  while  the 
glands  of  the  more  interior  layers  have  balsam-Hke  contents  of  bright 
yellow  color.  Both  the  red  and  yellow  lumps  are  visible  in  water  mounts, 
but  a  5%  potassium  hydroxide  solution  colors  them  a  brilliant  blood-red, 
making  possible  a  close  percentage  estimation  of  Bombay  mace  in  true 
mace. 

Hefelmann's  Test  for  Bombay  Mace  *  consists  in  saturating  a  strip 
of  filter-paper  with  an  alcoholic  solution  of  the  mace,  and  removing  the 
excess  of  liquid  by  pressure  between  filter-paper.     On  treating  with  a 

*  Pharm.  Zeit.,  1891. 


468  FOOD    IXSPECTION  AND   ANALYSIS. 

drop  of  dilute  sodium  or  potassium  hydroxide  solution,  a  red  color  is 
produced  in  presence  of  the  wild  mace. 

ir(Zt7^f'5  Test. — One  part  of  the  mace  is  extracted  with  ten  parts  of 
alcohol,  and  potassium  chromate  solution  is  added  to  the  extract.  If 
Bombay  mace  is  present,  the  solution  becomes  red,  and  the  precipitate, 
which  is  at  first  yellow,  becomes  red  on  standing.  True  mace  gives  a 
yellow  solution  and  precipitate,  and  the  latter  does  not  change  greatly  on 
standing. 

Turmeric  is  tested  for  chemically  as  on  p.  791. 

Macassar  Mace  is  sometimes  designated  as  wild  mace,  but  it  is  by 
no  means  as  inert  as  the  Bombay  variety,  and  possesses  a  wintergrcen- 
like  odor.  Its  taste,  while  distinctive,  is  not  that  of  true  Penang  mace. 
It  is  distinctly  an  inferior  article,  and  its  volatile  oil  content,  as  shown 
by  the  analyses  on  p.  466,  is  considerably  below  the  minimum  for  true 
mace. 

REFERENCES  ON  SPICES. 
(See  also  References  on  the  Microscope,  p.  98.) 

Arnst,  T.,  and  Hart,  F.     Zusammensetzung  einiger  Gewiirze.     Zeits.  fiir  Angew. 

Chem.,  1893,  p.  136. 
Beythien,   a.     Einige   Paprika-Analysen.     Zeits.   Unters.   Nahr.    Genuss.,    5,    1902, 

p.  858. 
BoHRisCH,  P.     Ueber  den  Nachvveis  einer  Kiinstlichen  Fiirbung  des  Senfs.     Zeits. 

Unters.  Xahr.  Genuss.,  8,  1904,  p.  285. 
BussE,  W.     Ueber  Gewiirze.     I.  Pfeffer.  II.  Muskatniisse.     III.  Macis.     Arbeit,  a.  d. 

Kais.  Gesundheits.,  9,  1894,  p.  509;    11,  1895,  p.  390;    12,  1896,  p.  628. 
NotLz,   betreffend   den   Nachweis  von   Bombay-Macis   im   Macispulver.     Zeits. 

Unters.  Xahr.  Genuss.,  7,  1904,  p.  590. 
Delaite,  J.     Untersuchung  von  Senfmehl.     Rev.  Int.  des  Falsif.,  1897,  pp.  10,  37. 
Denis,  W.     Determination  of  the  Iodine  Number  of  the  Non-volatile  Ether  E.xtract 

of  Paprika.     A.  O.  A.  C.  Proc,  1908.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem., 

Bui.  122,  p.  213. 
DooLiTTi.E  and  Ogden.     Composition  of  Known   .Samples  of  Paprika.     Jour.   .\m. 

Chem.,  Soc.  30,  1908,  p.  1481. 
Dyer  u.  Gilbard.     Unterscheidung  zwi.schen  unverfaLschtem  und  e.xtrahirtem  Ingwer. 

Chem.  Ztg.,  17,  1893,  P-  838. 
FoRSTER,  A.     Ueber  Gewiirze.     Zeits.  f.  ofTentl.  Chem.,  4,  1898,  p.  626. 
Gf.NiN,    V.     Epices   et   .Vromates.     Analy.se    des    Matieres   Alimentaires.     Girard    et 

Dupr<;,  Paris,   1894. 
GlCHARD,  B.     VerfaLschung  von  Zimmetrindenpulver.     Zeits.  f.  Nahr.  Hyg.  Waarenk., 

9,  1895,  p.  281. 
Gladhii.l,   J.   W.     ^Examination  of  Commercial   Peppers.     Am.   Jour.   Pharm.,    76, 

1904,  p.  71. 


SPICES.  469 

H'artel,    F.     Untersuchung    und    Beurteilung    von    gemahlenen    schwarzen    PfefFer. 

Zeits.  Untcrs.  Nahr.  Genuss.,  13,  1907,  p.  665.- 
u.  Wii.i.,  R.     Untersuchung  und  Beurteilung  von  PfcfTer.     Zeits.  Unters.  Xahr. 

Genuss.,  14,  1907,  p.  567. 
Hanausek,  T.  F.     Zur  Charaktcri.stik  dcs  CayenpfelTers.     Zeits.  fur  Nahr.  Unters. 

Hyg.,  7,  1893,  p.  297. 
Verfalschung  von  Gewiirzen.     Zeits.  fiir  Xahrungsm.     Unters.  u.  Hyg.,  8,  1894, 

95- 

GewUrzfalschungen.     Apoth.  Ztg.,  1894,  p.  582. 

• Gefalschte  und  echte  Macis.  Rev.  I"ter.  Fa!s.,  i,   1887,  p.  23, 

Hanus,   J.     Beitrag  zur   Kenntnis  verschiedener  Arten  von  Zimmet.     Zeits.  Unters. 

Nahr.  Genuss.,  7,  1904,  p.  669. 
u.  BiEN,  F.     Zur  Kentniss  der  Zuckerarten  der  Gewiirze.     Zeits.  Unters.  Nahr. 

Genuss.,  12,  1906,  p.  395. 
Hartwich,  C.     Eine  Bemerkungen  iiber  den  Pfeffer.     Zeits.  Unters.  Nahr.  Genuss., 

12,  1906,  p.  524. 

Hebebrand,  a.     Die  Beurteilung  des  PfeflFers  nach  dem  Gehalte  an  Rohfaser  und 

Piperin.     Zeits.  Unters.  Nahr.  Genuss.,  6,  1903,  p.  345. 
Hefelmann,  R.     Zur  Untersuchung  von  Macis.     Pharm.  Ztg.,  36,  1891,  p.  122. 
Held,  F.,  u.  Hilger,  A.     Zur  chemischen  Charakteristik  der  Bombay  Macis.     Forsch. 

iiber  Lebensm.,  i,  1894,  p.  136. 
Jones,  E.  W.  T.     Analysis  of  Ginger.     Analyst,  1886,  p.  75. 
Kr.\mer,  H.     Zur  Priifung  der  Gewurznelken.     Apoth.  Ztg.,  1894,  p.  870. 
Leach,  A.  E.     Microscopical  Examination  of  Foods  for  Adulteration.     Mass.  State 

Board  of  Heatlh  An.  Rep.,  1900,  p.  679. 
Composition  and  Adulteration  of  Ground  Mustard.     Jour.   Am.    Chem.    Soc, 

26,  1904,  p.  1203. 
LuDwiG,  W.,  u.  Haupt,  H.     Zucker  als  Natiirlicher  Bestandteil  der  Macis.     Zeits. 

Unters.  Nahr.  Genuss.,  9,  1904,  p.  200. 
LiJHRiG,   H.,  u.   Thamm,  R.     Beitriige  zur  Kenntniss  der  Gewiirze.     Zeits.   Unters. 

Nahr.  Genuss.,  11,  1906,  p.  129. 
Macfarlane,  T.     Mustard.     Canada  Inl.  Rev.  Dept.,  Bui.  19. 

Mustard.     Canada  Inl.  Rev.  Dept.,  Bui.  50. 

McGiLL,  A.     Cloves.     Canada  Inl.  Rev.  Dept.,  Bui.  73. 

Ground  Ginger.     Canada  Inl.  Rev.  Dept.,  Bui.  48. 

Pepper.     Canada  Inl.  Rev.  Dept.,  Bui.  20. 

Reich,   R.      Ingwer  und  extrahierter    Ingwer.      Zeits.   Unters.   Nahr.   Genuss.,    14, 

1907,  p.  549. 
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13,  part  2,  1887. 

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p.  66. 
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p.  308. 


4 TO  FOOD  INSPECTION  AND  ANALYSIS. 

Spath,  E,      Zur  mikroskop.  Priifung  des  Piments.     Forsch.  iibcr  Lebensm.,  2,  1895, 

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U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  162 


CHAPTER  XIII. 


EDIBLE  OILS  AND  FATS. 


Nature  and  Properties. — The  oils  and  fats  are  the  glycerin  salts  or 
glyceridcs  of  the  fatty  acids,  the  most  important,  on  account  of  their 
occurrence  in  nearly  all  fats  and  oils,  being  the  triglycerides  of  oleic, 
palmitic,  and  stearic  acids,  known  as  olein,  palmitin,  and  stearin, 
respectively. 

Fats  and  oils  are  insoluble  in  water,  and  are  almost  insoluble  in  cold 
95%  alcohol,  though  they  are  somewhat  soluble  in  absolute  alcohol. 
They  are  readily  soluble  in  ether,  petroleum  ether,  chloroform,  amyl 
alcohol,  oil  of  turpentine,  and  carbon  bisulphide. 

Following  is  a  list  of  the  fatty  acids  whose  glycerides  are  found  in 
edible  oils  and  fats,  together  with  their  melting-  and  boiling-points  when 
these  have  been  determined,  and  the  oils  and  fats  in  which  they  occur. 


ACIDS 

OF  THE  ACETIC  SERIES  CnHj^Oj.* 

Name. 

Formula. 

Melting- 
point. 

Boiling- 
point. 

Occurrence  in  Oils  and  Fats. 

Butyrict 

C,H«0, 

-6.5° 

162.3 

Butter,  cocoa  butter. 

Caproicf 

QH12O2 

200 

Butter,  cocoanut  oil. 

Caprylicf 

CsH.eO, 

16.5 

236 

"                 " 

Capricf 

CloH2:,02 

3'^-:i 

268-270 

<  (                 <( 

Laurie 

C,,H,,0, 

43-6 

176 

Cocoanut  oil,  cocoa  butter. 

Mvristic 

CuHjsOj 

53-8 

196.5 

"             sesame  oiL 

Palmitic 

C16H32O2 

62.6 

215 

Nearly  all  oils  and  fats. 

Stearic 

CigHjgOj 

^9-3 

232.5 

Fats    and   nearly  all  oils,  except 
olive  and  com. 

Arachidic 

C20H40O2 

77 

.... 

Peanut,  olive  (trace),  rape  (trace). 

Behenic 

CjjH^^Oj 

83-84 

.... 

Rape,  mustard. 

Lignoceric.  ... 

Cj^H^gOj 

8r 



Peanut. 

*  Lewkowitsch,  Oils,  Fats,  and  Waxes,  3d  ed.  (1Q04),  pp.  63-71. 

t  These  four  acids  are  the  only  ones  that  can  be  distilled  under  ordinary  pressure  without  becom- 
ing decomposed. 

471 


47-' 


['OOD  INSPECTION  AND  ANALYSIS. 


ACIDS 

OF  THE  OLEIC  SERIES 

CnILn-.0,. 

N.i-io. 

Fonnula.              ^Snu" 

Boiling- 
point. 

Occurrence  in  Oils  and  Pats. 

Hvf>oga'ic 

Ok'ic 

Iso-olcic  *  .  - . . 

Ra{)ic .. 

I-'.rucic. . . 

CibHsoO, 
C,sH3^0, 

C,,H,,0. 

33'' 

14° 

44-45° 

33-34'' 

2:;6° 

232-5° 
^6;° 

Peanut. 

Nearly  all  fats  and  oils. 

Rape  and  mustard. 

ACIDS   OF  THE   LINOLEIC   SERIES   C„ILn_,0, 


Name. 

Formula. 

Melting- 
point. 

Boiling- 
point. 

Occurrence  in  Oils  and  Fats. 

Linolcic 

C1SH32O2 

Undcr-iS°C. 

Olive,  cottonseed,  peanut,  sesame, 
cocoa  butter,  poppy  seed,  sun- 
flower. 

*  Solid  oleic  acid. 


Saponification  of  Fats  and  Oils. — By  this  term  is  meant  the  decom- 
posilion  of  the  glyceridcs  composing  the  fats  or  oils,  whereby  the  tri- 
atomic  alcohol  glycerin  and  the  fatty  acids  are  separated.  The  sapon- 
ification process  is  commonly  applied  in  carrying  out  many  determina- 
tions of  value  on  fats  and  oils,  such  as  those  of  the  soluble  and  insoluble 
fatty  acids,  the  Rcichert  value,  etc.  As  commonly  carried  out,  the  tri- 
glycerides are  first  split  up  into  glycerin  and  the  soluble  soaps  of  the  fatty 
acids  by  the  action  of  caustic  alkali,  usually  in  solution  in  alcohol.  This 
part  of  the  process  in  the  case"  of  a  given  oil,  composed,  for  example,  of 
stearin,  olein,  and  palmitin,  is  illustrated  as  follows: 

(i)  C3H,(C,8H350,)3-1-  3KOH  =  C3H,(OH)3+  3K(C,,H3,0,) 

Stearin  or  Glycerin  Potassium 

triglyceryl  stearate 

stcarate 

(2)  C3H3fC,«H3,0,)3+  3KOH  =  C3Hs(OH)3+  3K(C,,H3,0,) 

Palmitin  or  Potassium 

triglyceryl  palmitate 

palmitate 

(3)  C3H,fQ«H330,)-f3KOH  =  C3H5(OH)3-f3K(C,8H3302) 

Olein  or  tri-  Potassium 

glyceryl  oleate  oleate 

These  "soaps, "  or  potassium  salts  of  the  fatty  acids,  are  further  decom- 
posed by  the  action  of  sulphuric  acid  into  the  free  fatty  acids  and  pr/as- 
sium  sulphate,  in  the  case  of  potassium  stearate,  as  follows: 

2KfC„H3,0,)-fH,SO,  =  K,SO,-f2HrC,3H,50J 

Potassium  stearate  Stearic  acid 


EDIBLE  OILS   AND   FATS.  473 

ANALYSIS    OF    EDIBLE    OILS    AND    FATS. 

No  class  of  food  products  presents  more  difficulties  to  the  analyst 
than  the  fats  and  oils,  in  that  the  various  physical  and  chemical  constants 
by  which  one  derives  information  as  to  their  nature  or  jjurity  differ  within 
such  wide  limits  that  it  is  not  easy  to  prescribe  absolute  standards.  ]\Iany 
elements  enter  in  to  cause  this  variation,  chief  among  which  are,  in 
vegetable  oils,  the  large  number  of  varieties  of  fruits  or  seeds  from  which 
each  oil  is  in  different  localities  obtained,  as  well  as  the  vaiious  grades 
of  each  oil  with  respect  to  refining.  In  the  animal  fats,  butter  and  lard, 
the  kind  of  food  fed  to  the  animal  undoubtedly  influences  the  constants 
of  the  fat,  and  in  all  fats  and  oils  much  depends  upon  their  age,  and  the 
conditions  under  which  they  are  kept  as  to  temperature,  exposure  to 
moisture,  light  and  air,  etc. 

Rancidity  should  not  be  confounded  with  acidity,  although  rancid  oils 
usually  are  high  in  acids.  Lewkowitsch  holds  that  fatty  acids  are  liberated 
by  the  action  of  moisture  in  the  presence  of  enzymes.  If  in  addition  the 
oil  is  exposed  to  air  and  light,  the  fatty  acids  are  acted  on  causing  rancidity, 
which  is  detected  by  taste  and  smell,  although  chemically  little  understood. 
As  a  rule  rancidity  develops  more  readily  in  liquid  oils  in  which  olein 
predominates  than  in  solid  fats.  To  avoid  changes  samples  should  be 
kept  in  a  dark,  cool  place  in  tight  containers. 

Judgment  as  to  Purity  of  a  given  oil  or  fat  should  not  be  hastily  given. 
It  is  sometimes  comparatively  easy  to  prove  the  presence  and  approx- 
imate amount  of  an  adulterant,  the  various  constants  all  serving  to  identify 
it  without  fail.  Again,  in  some  cases  it  is  easy  to  pronounce  the  sample 
adulterated,  without  being  able  to  definitely  state  the  exact  nature  of 
the  adulterant.  The  tests  to  be  employed  depend  on  the  particular 
case  in  hand.  Sometimes  the  determination  of  two  or  three  constants 
will  be  sufficiently  definite. 

Again,  a  large  number  of  tests  must  be  made  before  one  can  intel- 
ligently form  an  opinion.  It  should  be  borne  in  mind  that  skilful  manu- 
facturers may  adulterate  the  edible  oils  and  fats  with  mixtures  intended 
to  confuse  the  chemist,  and  yield  on  analysis  constants  that  are  entirely 
misleading. 

Much  information  may  usually  be  gained  by  carefully  noting  the  color, 
taste,  odor,  and  appearance  of  the  sample. 

Filtering,  Measuring,  and  Weighing  of  Fats. — These  manipulations 
naturally  present  some  difficulties  in  the  case  of  solid  fats  not  encountered 
with  liquid  oils. 


474 


FOOD  INSPECTION  /1ND   ANALYSIS. 


A  steam-  or  hot-watcr-jacketed  funnel  as  represented  in  Fig.  92  is  con- 
venient for  filtering  fats,  or,  in  the  absence  of  this  contrivance  for  keeping 
the  fat  in  a  molten  condition,  a  hot  funnel  may  be  employed,  the  filtering 
being  best  conducted  in  a  warm  closet  or  oven. 

Portions  of  the  fat  for  the  various  determinations  may  be  measured 
off  with  a  pipette  while  the  fat  is  still  hot,  but  a  much  better  way  is  to 


Fig.  92. — ^Jacketed  Funnel  for  Hot  Filtration. 

cool  the  fat  (over  ice  if  necessary),  and  to  weigh  the  desired  amounts  in 
the  sohd  state.  This  can  very  readily  be  done  by  placing  a  flat  platinum 
or  other  dish  on  the  scale-pan,  covering  it  with  a  moderately  thick,  cut 
filter-paper  somewhat  larger  in  diameter  than  the  dish  and  designed  to 
lie  flat  upon  it,  and  taking  the  tare  of  both  dish  and  filter.  The  solidified 
fat,  after  mixing  with  a  stirring-rod,  is  transferred  in  one  or  more  por- 
tions to  the  middle  of  the  filler,  and  the  exact  weighed  amount  is  obtained, 
after  which,  by  carefully  handhng  the  edges  of  the  filter  and  folding  in 
the  latter,  the  fat  with  the  filter  may  be  transferred  to  a  flask  or  other 
receptacle. 

Specific    Gravity.   -The    sy^ecific    gravity    of   lifiuid   oils  is  most  con- 
veniently taken  either  at  room  temperature  or  at   15.5°,  being    always 


EDIBLE    OILS    yiND    EATS. 


475 


best  referred  lo  the  latter.  Either  the  hydrometer,  Westphal  balance, 
Sprengel  tube,  or  pycnometer  are  employed,  according  to  the  degree  of 
accuracy  required.  If  taken  at  any  other  temperature  than  15.5°,  say 
at  room  temperature,  T,  the  specific  gravity  may  be  computed  at  15.5° 
by  the  formula 

in  which  G  is  the  specific  gravity  at  15.5°,  G'  the  specific  gravity  at  r°, 
and  K  a  factor  varying  with  the  diflfcrent  oils  as  follows: 

FACTORS  FOR  CALCULATING  SPECIFIC  GRAVITY. 


Oil. 

Correction 
for  1°  C. 

Observer. 

Cod-liver  oil 

0.000646 
.000658 
.000629 
.000655 
.000620 
.000624 
.000629 

A.  H.  Allen 
C.  M.  WetheriU 
C.  M.  StUlwell 
A.  H.  AUen 

« 
<< 

Lard  oil 

Olive  oil 

Peanut  oil 

Rape  oil 

Sesame  oil 

Cottonseed  oil. ............ 

Unless  the  most  accurate  work  is  necessary,  it  is  sufficient  to  assume 
in  all  cases  X'  =  0.00064,  in  which  case  the  formula  becomes  G=G'  + 
o.ooo64(r-i5.5). 

In  the  case  of  soHd  fats,  it  is  most  convenient  to  take  the  specific 
gravity  of  the  melted  fat.  This  may  be  done  at  any  temperature  above 
the  melting-point  by  either  of  the  instruments  above  described,  or  at  the 
temperature  of  boihng  water  by  the  Westphal  balance  or  pycnometer. 

When  the  pycnometer  is  used,  it  is  immersed  in  a  water-bath,  the 
temperature  of  which  is  well  above  the  melting-point  of  the  fat,  say  35° 
or  40°.  While  still  immersed  nearly  to  the  neck,  it  is  carefully  filled 
with  the  melted  fat  and  kept  in  the  bath  till  the  fat  has  acquired  the  same 
temperature,  usually  about  fifteen  minutes.  If  the  pycnometer  is  pro- 
vided with  a  thermometer  stopper,  this  will  serv^e  to  indicate  the  tem- 
perature; otherwise  a  separate  thermometer  is  inserted  in  the  bath. 
The  pycnometer  is  then  removed,  cleaned,  dried,  and  cooled  to  the  room 
temperature,  at  which  it  is  weighed.  The  factors  employed  in  the  above 
formula  for  calculation  of  specific  gravity  of  solid  fats  at  15.5°  are  as 
follows : 


*  Allen,  Com.  Org.  Ana!.,  4  Ed.;  Vol.  II,  p.  49. 


470 


FOOD  INSPECTION  ANr.  ANALYSIS. 
FACTORS  FOR  CALCULATING  SPECIFIC  GRAVITY. 


Fats. 

Correction 
for  i"  C. 

Cotoa  huttir 

0.000717 
.000675 
.000650 
. 0006 1  7 
.000674 
. 00064  2 
. 00065  7 

Tallow 

Laul 

Butter  fat 

Cocoanut  stearin 

Cocoanut  oil 

Palm  nut  oil 

Either  the  Wcstphal  balance  or  the  hydrometer  may  be  used  directly  on 
the  melted  fat,  carefully  recording  the  temperature  and  calculating  as  above. 

For  making  the  determination  with  the  Westphal  balance  at  the  tem- 
perature of  boiling  water,  the  melted  fat  is  contained  in  a  vessel  immersed 
in  a  boiling  water-bath,  and  kept  sufficiently  long  to  acquire  that  tem- 
perature, which  is  carefully  noted. 

.-1.  O.  A.  C.  Method."^ — The  pycnometer,  being  perfectly  clean,  is 
first  weighed  with  the  stopper,  after  which  it  is  filled  with  freshly  boiled, 
hot,  distilled  water  and  i)laced  in  a  bath  of  boihng  water,  where  it 
is  kept  for  half  an  hour,  replacing  any  loss  by  evaporation  in  the  flask 
with  boiling  distilled  water.  The  stopper  of  the  pycnometer,  previously 
heated  at  100°,  is  then  inserted,  and  the  flask  removed  and  wiped  perfectly 
dr)-.  It  is  then  allowed  to  cool  nearly  to  room  temperature,  and  weighed 
on  the  balance  when  the  temperature  is  the  same  as  that  of  the  room. 

The  flask,  being  again  perfectly  clean  and  dry,  is  filled  while  hot  with 
freshly  mehed  and  filtered  hot  fat,  free  from  air-bubbles,  and  kept  for 
half  an  hour  in  a  boiling  water-bath,  after  which  the  stopper,  previousl}' 
heated  as  before  to  100°,  is  inserted,  and  the  flask  taken  from  the  bath 
and  wiped  dry.  It  is  then  allowed  to  cool  and  weighed  when  the  tem- 
perature of  the  room  has  been  reached. 

The  specific  gravity  is  calculated  by  dividing  the  weight  of  the  fat 
by  the  weight  of  the  water  previously  found. 

Having  once  obtained  the  weight  of  the  flask  and  the  weight  of  a 
volume  of  water  contained  therein  when  at  boiling  temperature,  these 
figures  can  be  constantly  used  without  redetermination,  if  the  flask  is 
cleaned  thoroughly  each  time. 

Calculation  of  Proportions  of  Two  Known  Oils  in  Mixture.f — This 
may  Ix;  roughly  accomplished  fr<;m  the  specific  gravity  of  the  mixture 
and  of  the  oils  known  to  comj)ose  it. 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  C5,  p.  21. 
t  ViUiers  et  Collin,  Les  Substances  Alimentaires,  p.  646. 


r.DIBLr.    OILS    .^ND    FATS. 


A77 


Let  G  =  specific  gravity   of  mixture, 
D  and  Z>'  =  specific  gravity  of  the  two  oils, 
and  X  =  %  oil  of  specific  gravity  D. 
loo(G-D') 


Then  X 


D-D' 


EDIliLE  OILS  AND  FATS  ARRANGED  IN  ORDER  OF  SPECIFIC  GRAVITY. 


Cocoa  butter  . 
Mutton  tallow, 
Beef  ' '     . 

Bulter 

Lard 

Poppyseed  oil. 
Sunflower  oil  . 

Corn  oil 

Cottonseed  oil 
Sesame  oil.  . . . 
Peanut  oil.  . . . 
Mustard  oil. . . 

Olive  oil 

Rape  oil 


Specific  Gravity. 


.976 
■953 
•952 
-940 
■938 
.927 
.926 
.926 

-925 
.924 
.921 
.920 
.918 
.917 


-950 
-937 
-943 
.926 

-934 
■924 
.924 
.921 
.922 

-923 
.917 
.916 
.916 
-913 


The  Viscosity,  or  degree  of  fluidity  in  the  case  of  edible  oils,  is  of  less 
importance  than  in  the  case  of  lubricating  oils,  and  gives  little  insight 
into  the  nature  or  purity  of  the  sample. 

Hence  a  discussion  of  various  viscosimeters  and  their  use  will  not 
be  included  here,  but  reference  is  made  to  Lewkowitsch  *  for  information 
regarding  them. 

The  Refractive  Index,  and  the  reading  on  the  arbitrary  scale  of  the 
butyro-refractometer,  express  in  two  different  and  interchangeable  terms  the 
refraction  value,  a  useful  constant  of  fats  and  oils  and  easily  determined. 

For  the  routine  examination  of  fats  and  oils  the  butyro-refractometer 
is  more  convenient  than  the  Abbe  refractometer,  and  the  readings  obtained 
by  the  former  instrument  are  less  cumbersome  than  refractive  indices. 

These  instruments  and  details  with  regard  to  their  manipulation  are 
described  in  Chapter  VI. 

The  readings  on  the  scale  of  the  butyro-refractometer  may  be  readily 
transformed  into  refractive  indexes  and  vice  versa  by  table  or  by  means  of 
the  Leach  and  Lythgoc  slide  rule  (page  107).  Lythgoe'sj  table  on  pp. 
47S  and  479  is  useful  as  showing  readings  on  the  butyro-refractometer  of 
all  the  edible  oils  and  fats  at  various  temperatures. 

*  Chemical  Analysis  of  Oils  and  Fats,  3d  cd.,  1904,  pp.  197-209. 
f  Tech.  Quarterly,  16,  1903,  p.  222. 


47S 


FOOD  INSPECTION  AND  ANALYSIS. 


C.\LCLX.\TED    READINGS    ON   BUTYRO-REFRACTOMETER   OF   EDIBLE 

OILS   AND    FATS. 


Temp. 

Cocoanut 

Butter.* 

Bref 

Cacao 

B»ef 

Lard 

Beef 

Lard.t 

Lard 

C. 

OU. 

Stearin. 

Butter. 

Tallow. 

Stearin. 

Oleo. 

Oil. 

45 -o 

3X-6 

41-5 

41.9 

43-7 

44.1 

44-9 

45-0 

48.2 

44.5 

31-9 

41.8 

42.2 

44.0 

44-3 

45-1 

45-3 

48.4 

44 -o 

32.2 

42.0 

42-4 

44-2 

44-6 

45-5 

45-6 

48.7 

4.V5 

32-4 

42.3 

42.6 

44-5 

44-8 

45-7 

45-9 

49-0 

43 -o 

32-7 

42.6 

42.9 

44.8 

45-1 

46.0 

46.1 

49-3 

42.5 

52-9 

42.9 

43-2 

45-0 

45-4 

46.3 

46-4 

49.6 

42.0 

33-2 

43-1 

43-5 

45-3 

45-6 

46.5 

46.7 

49-9 

41-5 

33-5 

43-4 

43-7 

45-6 

45-8 

46.8 

47.0 

50.1 

41.0 

33-7 

43-7 

44.0 

45-9 

46.1 

47.0 

47-3 

50-4 

40.5 

34-0 

43-9 

44-2 

46.1 

46.3 

47-3 

47-6 

50-7 

40.0 

34-3 

44.2 

44-5 

46-4 

46.6 

47-6 

47-8 

51-0 

51.6 

39-5 

34-5 

44-5 

46.6 

46. 8 

47-8 

48.1 

51-3 

51.8 

39-0 

34-« 

44-8 

46.8 

47-1 

48.1 

48-4 

51.6 

52-1 

38.5 

35-0 

45-0 

47-1 

47-4 

48.4 

48-7 

51-9 

52-4 

38.0 

35-3 

45-3 

47-4 

.17.6 

48.6 

48.9 

52-1 

52.6 

37-5 

35-5 

45-6 

47-6 

47-8 

48-9 

49-2 

52-4 

52.8 

37-0 

35-8 

45-9 

47-9 

48.1 

49-2 

49-5 

52-7 

53-1 

36-5 

36-1 

46.1 

48.2 

48.3 

49.4 

49-8 

53-0 

53-4 

36.0 

36.3 

46.4 

48.5 

48.6 

49-7 

50.0 

53-3 

53.7 

35-5 

36.6 

46.7 

48.7 

48.8 

50.0 

50.3 

53-6 

54-0 

35-0 

36.9 

47.0 

49.0 

49-1 

50.2 

50.6 

53-9 

54-2 

34-5 

37-1 

47-2 



50-9 

54.2 

54.5 

34.0 

37-4 

47-S 

51-2 

54-4 

54-7 

33-5 

37-6 

47-8 

5^-5 

54-7 

55-0 

iZ-o 

37-9 

48.1 



51-7 

55-0 

55-3 

52  5 

38-1 

48.3 

52.0 

55-3 

55-6 

7,2. 0 

38-4 

48.6 

52-3 

55-6 

55-9 

31-5 

^8.6 

48-9 

52.6 

55-9 

56-r 

3J-0 

38-9 

49.2 

52.8 

56.1 

56-4 

30-5 

39-2 

49-5 

53 -r 

56.4 

56.7 

30.0 

39-5 

49-8 

53-4 

56-7 

57-0 

29-5 

39-7 

50.0 

53-7 

57.0 

57-2 

2Q.O 

40.0 

50-3 

53-9 

57-3 

57-5 

28.5 

40.3 

50-5 

54-1 

57-6 

57-8 

28.0 

40.5 

S0.8 

54-4 

57.8 

58.1 

27.5 

40.8 

51-I 

54-7 

58.1 

58-3 

27.0 

41.0 

51-4 

55-0 

58-4 

S8.6 

26.5 

41-3 

51.6 

55-2 

58.7 

58-9 

26.0 

41.5 

51-9 



55-5 

59-0 

59-2 

25-5 

41.8 

52.2 



65.8 

59-3 

59-5 

25.0 

42.0 

52.5 



6(3.1 

59-6 

59-8 

*  Butter  readings  by  Zeiss. 

t  Lard  readings  by  Hefelmana. 


EDIBLE   OILS   AND  FATS. 


479 


CALCULATED  RIL\T>INGS— (Continued). 


Temp. 
C. 

Olive 
OU. 

Peanut 
OU. 

Cotton- 
seed 
Oil. 

Rape- 
seed 
Oil. 

Sesame 
Oil 

Yellow 

Mustard 

Oil. 

Black 

Mustard 
Oil. 

Sun- 
flower 
Oil. 

Com 
Oil. 

Poppy- 
seed 
Oil. 

35-0 

57-0 

59-8 

61.8 

62.1 

62.3 

63.0 

64.2 

64-5 

65.0 

^■5-5 

34-5 

57-2 

60.0 

62.1 

62.4 

62.5 

63-3 

64-5 

64.8 

65-3 

65-8 

34-0 

57-4 

60.^ 

62.3 

62.7 

62.8 

63.6 

64.8 

65.1 

65-6 

66.1 

33-5 

57-7 

60.6 

62.5 

63.0 

63.1 

63-9 

65-1 

65-4 

65-9 

66.4 

33-0 

58-0 

60.9 

62.8 

63-3 

63-4 

64.1 

65-3 

65-7 

66.2 

66.7 

32-5 

58-3 

61. 1 

63.0 

63.6 

63.7 

64.4 

65.6 

66.0 

66.5 

67.0 

32.0 

58.5 

61.4 

63.2 

63.8 

64.0 

64-7 

65-9 

66.3 

66.8 

67-3 

31-5 

59-0 

61.7 

63.6 

64. 1 

64-3 

65.0 

66.2 

66.6 

67.1 

67.6 

31.0 

59-2 

62.0 

64.0 

64.4 

64.6 

65-3 

66.  <5 

66.9 

67-4 

67-9 

30-5 

59-5 

62.2 

64.2 

64.7 

64.9 

65.6 

66.8 

67.2 

67-7 

68.2 

30.0 

59-9 

62.5 

64-5 

65.0 

65.1 

65.8 

67.0 

67-5 

68.0 

68.5 

29-S 

60.1 

62.8 

64.9 

65-3 

65-4 

66.1 

67-3 

47-7 

68.2 

68.7 

29.0 

60.3 

63.1 

65.1 

65.6 

65-7 

66.4 

67.6 

68.0 

68.5 

69.0 

28.5 

60.6 

63-3 

65-3 

65-9 

66.0 

66.7 

67.9 

68.3 

68.8 

69-3 

28.0 

60.9 

63.6 

65-7 

66.1 

66.2 

66.9 

68.1 

68.6 

69.1 

69.6 

27-5 

61. 1 

63-9 

66.0 

66.4 

66.5 

67.2 

68.4 

68.9 

69.4 

69-9 

27.0 

61-5 

64.2 

66.5 

66.7 

66.8 

67-5 

68.7 

69.2 

69.7 

70.2 

26.5 

62.0 

64-4 

67.0 

67.0 

67.1 

67.8 

69.0 

69-5 

70.0 

70-5 

26.0 

62.2 

64-7 

67-3 

67-3 

67.0 

68.0 

69.2 

69.8 

70-3 

70.8 

25-5 

62.4 

65.0 

67-5 

67.6 

67.7 

68.3 

69-5 

70.1 

70.6 

71. 1 

25-0 

63.0 

65-3 

67.9 

67.8 

67.9 

68.6 

69.8 

70.4 

70.9 

71-4 

24.5 

63-3 

65-5 

68.2 

68.1 

68.2 

68.9 

70.1 

70.7 

71.2 

71-7 

24.0 

63.6 

65.8 

68.5 

68.4 

68.5 

69.2 

70.4 

71.0 

71-5 

72.0 

23-S 

63-9 

66.1 

68.8 

68.7 

68.8 

69-5 

70.7 

71-3 

71.8 

72-3 

23-0 

64.2 

66.4 

69.1 

69.0 

69.1 

69.7 

70.9 

71.6 

72.1 

72.6 

22.5 

64-5 

66.6 

69.4 

69-3 

69.4 

70.0 

71.2 

71.9 

72.4 

72.9 

22.0 

64.8 

66.9 

69.7 

69.7 

69.7 

70-3 

71-5 

72.2 

72.7 

73-2 

21-5 

65-1 

67.1 

70.0 

70.0 

70.0 

70.6 

71.8 

72-5 

73-0 

73-5 

21.0 

65-4 

67.4 

70-3 

70.3 

70-3 

70.9 

72.1 

72.8 

73-3 

73-8 

20.5 

65-7 

67.7 

70.6 

70.6 

70-5 

71.2 

72.4 

73-1 

73-6 

74-1 

20.0 

66.0 

68.0 

70.9 

70.8 

70.8 

71.4 

72.6 

73-4 

73-9 

74-4 

19-5 

66.^ 

68.2 

71.2 

71. 1 

71. 1 

71.7 

72-9 

73-6 

74-1 

74-6 

19.0 

66.6 

68.5 

71-5 

71.4 

71-4 

72.0 

73-2 

73-9 

74-4 

74-9 

18.5 

66.9 

68.8 

71.8 

71.7 

71.7 

72-3 

73-5 

74-2 

74-7 

75-2 

18.0 

67..  2 

69.1 

72.1 

72.0 

72.0 

72.6 

73-8 

74-5 

75-0 

75-5 

17-5 

67-5 

69-3 

72.4 

72.3 

72-3 

72-9 

74-1 

74-8 

75-3 

75-8 

17.0 

67.8 

69.6 

72.7 

72.6 

72-5 

73-1 

74-3 

75-1 

75-6 

76.1 

16.5 

68.1 

69.9 

73-0 

72.9 

72.8 

73-4 

74-6 

75-4 

75-9 

76-4 

16.0 

68.4 

70.2 

73-3 

73-2 

73-1 

73-7 

74-9 

75-7 

76.2 

76-7 

15-5 

68.7 

70.5 

73-6 

73-5 

73-4 

74.0 

75-2 

76.0 

76.5 

77.0 

15.0 

68.9 

70.8 

73-8 

73-8 

73-7 

74-3 

75-5 

76-3 

76.8 

77-3 

4So 


FOOD  IWSPHCT/OX  /f\D  /IN  A  LYSIS. 


Melting-point. — A  ])iccc  of  small  glass  tubing  is  drawn  out  to  a  ca- 
pillary o^>t'n  at  both  ends,  and  this  is  inserted  into  a  beaker  of  the  fat,  melted 
at  a  temjx>rature  slightly  above  its  fusing-point.  A  portion  of  the  melted 
fat  being  drawn  up  into  the  capillary,  the  latter  is  removed  and  the  fat 
allowed  to  solidify  spontaneously.  After  an  iniirval  of  not  less  than 
twelve  hours,  the  caj)illary  is  attached  by  a  rubber  band  to  the  stem  of 
a  delicate  thermometer  (preferably  capable  of  being  read  to  tenths  of  a 
degree),  the  portion  of  solidified  fat  being  opposite  the  thermometer  bulb. 
A  test-tube  containing  water  is  held  in  the  neck  of  a  flask  in  such  a  man- 
ner as  to  be  immersed  in  water  contained  in  the  flask,  as  shown  in  Fig. 
93,  the  flask  being  held  on  the  ring  of  a  stand,  with  wire  gauge  inter- 
posed between  flask  and  flame.  The  thermometer  with  attached  capil- 
larv  is  then  held  immersed  in  the  water  of  the   test-tube  and  below  the 


Fig.  93.  Fig.  94. 

Fig.  93, — .\pparatus    for   Determining  Melting-point.      Capillary    tube    with    enclosed 
fat  shown  on  the  right,  enlarged. 

Fig.  94. — Reichcrt  Flask  with  Card  Inserted  for  Quick  Evaporation. 

level  of  the  water  in  the  flask,  as  shown.  The  water  in  the  flask  is  then 
heated  very  gradually,  so  that  the  rise  of  temj^erature  as  shown  by  the 
thermometer  docs  not  exceed  0.5°  C.  per  minute,  the  exact  temperature 
at  which  fusion  of  the  fat  occurs  being  recorded  as  the  melting-point. 

The  flame  is  then  removed,  and  the  temperature  at  which  the  fat 
solidifies  is  noted  as  the  .solidifying-point. 


EDIBLE  OILS    AND   FATS. 


481 


The  mean  of  two  or  three  determinations  is  usually  taken  as  the  true 
melting  and  solidifying-points. 

Reichert-Meissl  Process  for  Volatile  Fatty  Acids. — This  process 
has  undergone  various  modilkations  from  time  to  lime.  Reichert  origi- 
nally used  2.5  grams  of  fat,  but  Meissl,  who  improved  the  process,  used 


Fig.  95. — Apparatus  for  Reichert-Meissl  and  Polenske  Distillation. 


5  grams,  so  that  the  Reichert-Meissl  number  is  now  expressed  on  the 
basis  of  5  grams  of  fat.  The  method  is  conveniently  carried  out  as 
follows : 

Five  grams  of  the  fat  arc  transferred  to  a  dry,  clean  Erlenmeyer  flask 
of  about  300  cc.  capacity,  10  cc.  of  95%  alcohol  are  added,  and  2  cc.  of 
sodium  hydroxide  solution  (prepared  by  dissolving  100  grams  of  sodium 
hydroxide  in  100  cc.  of  water).     The  flask  with  its  contents  is  then  heated 


432  FOOD  INSPECTION  AND  ANALYSIS. 

on  a  water-bath  with  a  funnel  in  the  neck,  which  satisfactorily  replaces 
the  return  flow  condenser  originally  prescribed.  The  heating  is  con- 
tinued with  occasional  shaking  till  saponification  is  complete.  This 
stage  of  the  ])rocess  is  indicated  by  the  appearance  of  the  solution,  which 
is  then  perfectly  clear  and  free  from  fat  globules. 

The  condenser-funnel  being  removed,  the  contents  of  the  flask  are 
next  evaporated  by  continued  heating  over  the  bath  to  dryness.  This 
may  be  hastened  by  inserting  a  card  in  the  neck  of  the  flask,  as  shown 
in  Fig.  g4,  tlius  starting  a  circulatory  movement  to  the  air  through  the 
flask. 

The  dry  soap  thus  formed  is  then  dissolved  by  warming  on  the  water- 
bath  with  135  cc.  of  added  water,  shaking  the  flask  occasionally.  After 
cooling,  5  cc.  of  dilute  sulphuric  acid  (200  parts  sulphuric  acid  in  i  liter 
of  water)  are  added,  and  the  fatty  acid  emulsion  formed  is  melted  by 
heating  the  flask  on  the  water-bath,  the  flask  being  corked  during  the 
heating.  The  fatty  acids  are  completely  melted  when  they  form  an  oily 
layer  on  the  surface  of  the  solution. 

Scraps  of  pumice  stone  joined  by  platinum  ^\ires  are  next  placed  in 
the  flask  to  prevent  bumping,  and  the  flask  is  properly  connected  with 
the  condenser  for  distilling,  as  shown  in  Fig.  95.  A  flask  graduated  at 
no  cc.  is  used  as  a  receiver,  the  funnel  placed  therein  being  provided 
with  a  loose  tuft  of  absorbent  cotton  to  ser\'e  as  a  filter.  The  distilla- 
tion is  conducted  by  so  grading  the  heat  that  the  receiving  flask  is 
filled  with  the  distillate  in  about  thirty  minutes. 

Finally  the  entire  distillate  is  titrated  with  decinormal  sodium  hydrox- 
ide, using  0.5  cc.  of  a  solution  of  phenolphthalein  as  an  indicator.  The 
number  of  cubic  centimeters  of  decinormal  alkali  required  to  neutralize 
the  acidity  of  the  distillate  from  5  grams  of  the  fat  in  the  manner  described 
expresses  what  is  known  as  the  Reichert-Mcissl  number. 

Lefjmann  and  Beam's  Modification.'^ — Five  grams  of  the  fat  placed  in 
the  flask  are  treated  with  20  cc.  of  a  solution  of  soda  in  glycerin  (20  cc. 
of  a  50%  solution  of  sodium  hydroxide  in  180  cc.  of  glycerin),  heating  the 
flask  till  the  contents  are  completely  saponified.  The  solution  becomes 
perfectly  clear,  showing  comjjlete  saponification  in  about  five  minutes, 
after  which  135  cc.  of  water  are  adfled  to  the  clear  soap  solution,  at  first 
drop  by  drop  to  prevent  foaming;  5  cc.  of  the  dilute  sulphuric  acid  are 
then  added,  and  the  distillation  conducted  at  once  without  first  melting 
the  fatty  acids. 

*  Lefifmann  and  Beam,  Select  Methods  of  Food  Analysis,  p.  146. 


HDIBLF   OILS  AND    FATS. 


483 


EDIBLE  OILS  AND  FATS  IN  THE  ORDER  OF  THEIR  REICHERT-MEISSL. 

NUMBER. 


Lowest. 


Highest. 


Average. 


Butter 

Cocoanut  oil. 
Cocoa  butter. 

Corn  oil 

Lard 

Cottonseed  oil 
Sesame  oil.  .. 

Rape  oil . 

Olive  oil 

Beef  tallow.  . , 


1-32 


32 

7- 

0 

8 

.So 

c 

.0 

I 

20 

0 

90 

28.25 
7.2 

0-5 

3.16 
1. 10 
0-95 
0-95 
0.74 
0.60 
0.5 


Polenske  Number.* — This  number  represents  the  volatile  fatty  acids 
insoluble  in  water,  and  is  of  value  in  detecting  cocoanut  oil  in  butter  and 
other  fats.  The  details  of  apparatus  and  manipulation  here  described 
should  be  closely  adhered  to  in  order  to  secure  comparable  results.  Both 
the  Rcichert-Meissl  and  the  Polenske  number  may  be  determined  in 
one  weighed  portion  of  the  fat. 

Place  5  grams  of  the  clear  filtrated  fat  in  a  300-cc.  Jena  flask,  add  20 
grams  of  glycerine  and  2  cc.  of  a  50%  solution  of  sodium  hydroxide. 
Heat  the  flask  on  a  wire  gauze  until  the  contents  are  completely  saponified, 
which  requires  about  5  minutes,  and  is  indicated  by  the  clearing  up  of  the 
liquid.  While  still  hot  add  90  cc.  of  boiled  water,  at  first  drop  by  drop  to 
prevent  foaming,  and  shake  until  the  .soap  is  dissolved.  The  solution 
should  be  completely  clear  and  almost  colorless.  Rancid  or  oxidized  fats 
that  yield  a  brown  soap  solution  should  not  be  examined. 

To  the  soap  solution,  warmed  to  50°,  add  50  cc.  of  dilute  sulphuric 
acid  (25  cc:  i  liter)  and  0.5  gram  of  granulated  pumice  stone  with  grains 
1  mm.  in  diameter,  then  connect  with  the  distilling  apparatus  shown  in 
Fig.  95.  Distil  over  a  0.5  mm.  mesh  copper  gauze,  using  a  Bunsen  flame 
.so  regulated  as  to  give  a  distillate  of  no  cc.  in  19-20  minutes,  and  a  stream 
of  water  that  will  cool  the  distillate  to  about  20-23°.  The  room  should 
have  a  temperature  of  about  18-22°.  As  soon  as  no  cc.  have  come  over, 
replace  the  flask  by  a  25-cc.  measuring  cylinder. 

Without  mixing  the  distillate  place  the  flask  for  10  minutes  in  water 
at  15°,  so  that  the  no  cc.  mark  is  about  3  cm.  below  the  surface  of  the 
water.     After  the  first  five  minutes,  gently  move  the  neck  of  the  flask  in 


*  Polenske,  Zeits.  Unters.  Nahr.  Genuss.,  7,  1904,  p.  274.     Fritsche,  ibid.,  p.  193. 


48 4  FOOD  INSPECTION  AND   ANALYSIS. 

the  water  so  that  tne  fatty  acids  iloating  on  the  surface  come  in  contact 
with  the  glass,  noting  at  the  end  of  lo  minutes  the  condition  of  these  acids. 
If  the  butter  is  jnire,  the  floating  acids  are  either  solid  or  form  a  half  solid 
turbid  mass,  according  as  the  Reichert-Meissl  number  is  high  or  low; 
if  it  is  adulterated  with  io'\'  or  more  of  cocoanut  oil,  ihey  form  transparent 
oil  drops.  Stopper  the  i  lo-cc.  flask,  mix  by  inverting  4  or  5  times,  avoiding 
violent  shaking.  Alter  through  an  8-cm.  dry  filter  fltted  close  to  the  funnel, 
and  titrate  ico  cc.  of  the  licjuid  with  tcuh-normal  barium  hydroxide 
solution,  thus  obtaining  the  Reichert-Meissl  number. 

After  the  last  drop  of  distillate  has  passed  through  the  Alter,  wash 
with  three  15  cc.  portions  of  water,  each  of  which  has  previously  been 
used  to  rinse  the  condenser  tube,  the  measuring  cylinder  and  the  no  cc. 
flask.  Then  repeat  this  treatment,  using  15  cc.  portions  of  neutral  90% 
alcohol.  Titrate  the  united  alcoholic  washings  with  tenth-normal  barium 
hydroxide  solution,  using  phenolphtalein  as  indicator.  The  number  of 
cc.  required  is  the  Polenske  number. 

The  following  results  illustrate  the  value  of  the  method: 

Reichert-Meissl       Polenske 
Number.  Number. 

31  samples  of  buUer  (Polenske) 23.3-30.1  1.5-3.0 

4  samples  of  cocoanut  oil  (Polenske) 6.8-7.7  16. 8-1 7. 8 

Oleomargarine  (.\rnold) 0.5  o. 53 

Lard  (.\rnold) 0.35  0.5 

Tallow  f.\rnold) 0.55  o.  56 

Determination   of    Soluble  and  Insoluble  Fatty  Acids. — A.  O.  A.  C. 

Method.'*' — Soluble  Acids. — P^ive  grams  are  weighed  out  and  trans- 
ferred to  an  Erlenmeyer  flask  of  the  same  size  and  in  the  same  manner 
as  that  u.sed  for  the  Reichert-^SIeissl  jjrocess.  50  cc.  of  alcoholic 
IX)ta.sh  .solution  are  added  (40  grams  of  potassium  hydroxide  in  i  liter 
of  95'^t,  redistilled  alcohol)  and  the  flask,  provided  with  a  return-flow 
conden.scr,  is  heated  on  the  water-bath  till  saj)onification  is  comjjlete, 
a.s  eviflenced  by  the  clear  solution  free  from  fat  globules.  The 
alcoholic  solution  of  potash  is  preferably  measured  from  a  pipette, 
from  which  it  is  allowed  to  drain  for  a  noted  inter\al  of  time,  say  thirty 
seconds. 

.'\fter  comj)lete    saponiflcation,  the  condenser    is  removed    and     the 
alcohol  is  evaporated  by  further  heating.      One  or  more  blanks  are  pre- 

T  ■■  I.  ■  ■  -— ■     ■ 

*  U.  S.  Dcpt.  of  Agric,  Div.  of  Chem.,  Bui.  46,  p.  47;   Bui.  107  (rev.),  p.  138. 


EDIBl.F.    OILS  AND    FATS.  485 

pared  at  the  same  lime,  using  the  same  50-rc.  pipette  for  measuring,  and 
applying  the  same  time  limit  for  draining  the  pipette.  The  blanks  are 
first  titrated,  after  evaporation,  with  half-normal  hydrochloric  acid, 
using  phenolphthalein  as  an  indicator.  Then  add  to  the  flask  contain- 
ing the  fatty  acids  i  cc.  more  of  the  half-normal  acid  than  is  found  neces- 
sary to  neutralize  the  alkali  in  the  blanks,  after  which  the  flask  is  again 
heated  with  a  funnel  in  the  neck  till  the  fatty  acids  have  completely  sepa- 
rated in  a  layer  on  top  of  the  soluLion.  Then  cool  the  flask  in  ice  water 
till  the  fatty  acids  are  solidified,  after  which  decant  the  liquid  portion 
through  a  filter,  previously  dried  in  the  oven  and  weighed,  into  a  liter 
flask,  keeping  the  solid  mass  of  fatty  acids  intact.  Next  add  200  or  300 
cc.  of  hot  water  to  the  flask  containing  the  fatty  acids,  and  again  melt 
over  the  water-bath  till  they  collect  as  before  on  top,  having  again  inserted 
the  funnel  to  act  as  a  condenser,  and  occasionally  shaking  the  contents 
of  the  flask  during  heating.  Cool  as  before  in  ice  water,  after  which 
again  decant  the  liquid  from  the  solid  mass  through  the  same  filter  into 
the  liter  flask.  Repeat  this  process  of  washing,  melting,  cooling,  and 
decanting  three  times,  receiving  all  the  wash  water  through  the  same 
filter  in  the  same  flask.  Make  up  the  washings  with  water  to  the  liter 
mark,  and,  after  mixing,  two  portions  of  100  cc.  each  are  titrated  with 
tenth-normal  sodium  hydroxide,  using  phenolphthalein  for  an  indicator. 
Each  reading  is  multiplied  by  ten  to  represent  the  total  volume,  and  the 
figure  thus  obtained  represents  the  number  of  cubic  centimeters  of  tenth- 
normal alkali  necessary  to  neutralize  the  acidity  of  the  soluble  fatty  acids, 
together  with  the  excess  of  half-normal  acid  used,  amounting  to  i  cc. 
This  I  cc.  of  half-normal  acid  corresponds  to  5  cc.  of  tenth-normal  alkali, 
hence  5  cc.  are  to  be  deducted  from  the  total  number  of  cubic  centimeters 
required  for  the  titration,  the  corrected  figure  thus  obtained  being  multi- 
plied by  the  factor  0.0088,  which  gives  the  weight  of  soluble  fat  acids  in 
the  5  grams  of  the  sample,  calculated  as  butyric  acid. 

Insoluble  Acids. — Transfer  the  fatty  acids  left  in  a  cake  in  the  flask 
from  the  separation  of  the  soluble  acids,  to  a  weighed  glass  evaporating 
dish,  using  strong  alcohol  to  wash  them  out  thoroughly.  Dry  the  filter  used 
in  the  separation,  transfer  it  to  an  Erlenmeyer  flask,  and  thoroughly 
wash  it  with  strong  alcohol,  transferring  all  the  washings  to  the  dish.  The 
alcohol  is  then  evaporated  by  placing  the  dish  on  the  water-bath,  after 
which  it  is  dried  for  two  hours  in  the  air-oven  at  100°,  cooled  in  the  desic- 
cator, and  weighed.  After  once  heating  for  two  hours,  cooling  and  weigh- 
ing, heat  again  for  half  an  hour,  cool,  and  weigh.     If  a  considerable  loss 


-;S6  FOOD  INSPECTION  AND   ANALYSIS. 

in  weight  is  found,  heat  for  an  additional  half-hour.  It  is  best,  "however, 
to  avoid  too  prolonged  heating,  lest  oxidation  of  the  fatty  acids  should 
produce  an  increase  in  weight. 

Hehnirs  Method. — Transfer  the  fatty  acids  left  in  the  original  Erlen- 
meycr  flask  to  the  thoroughly  wet,  tared  filter,  washing  out  the  flask 
with  hot  water,  thus  bringing  all  the  fatty  acids  upon  the  filter,  which, 
if  of  good  quality  and  thoroughly  wet  beforehand,  will  retain  them.  If, 
however,  oily  particles  are  noticed  in  the  filtrate,  they  may  be  solidified 
by  cooUng  in  ice  water,  and  afterwards  removed  by  a  glass  rod  and  trans- 
ferred to  the  filter.  After  draining  dry,  the  funnel  is  immersed  in  cold 
water  to  sohdify  the  fatty  acids,  and  the  filter  containing  them  is  trans- 
ferred to  a  weighed  dish,  which  is  dried  for  two  hours  in  the  oven  at  icxd°, 
cooled  in  the  desiccator,  and  weighed,  subtracting  the  weight  of  the 
dish  and  filter. 

EDIBLE  OILS  AND  FATS  ARRANGED  IN  ORDER  OF  INSOLUBLE  FATTY 

ACIDS. 

Mustard  oil 96.2  to  95.1 

Cottonseed  oil 96      "95 

Corn  oil 96      "93 

Lard 96      "93 

Peanut  oil 95-8 

Sesame  oil 95-7 

Beef  tallow 95-6 

Mutton  tallow 95-5 

Poppyseed  oil 95-2  "94.9 

Rape  oil 95  - 1 

Sunflower  oil 95 

Olive  oil 95 

Cocoa  butter 94-6 

Cocoanut  oil 90       "  88.6 

Butter 89.8  "  86.5 

Saponification  Number.  —  Koettstorjer^s  Method.  —  By  the  saponifi- 
cation number  is  meant  the  number  of  milligrams  of  potassium  hydroxide 
neccssar}'  to  completely  saponify  i  gram  of  the  fat.  Between  i  and  2 
grams  of  the  fat  are  transferred  in  the  usual  manner  (see  p.  474)  to  an 
Erlenmeycr  flask,  and  25  cc.  of  the  alcoholic  potash  solution  (40  grams  of 
.potassium  hydroxide  free  from  carbonates  in  i  liter  of  95%  alcohol 
redistilled  after  standing  for  some  time  with  potassium  hydroxide)  are 
arlded  with  a  grarluaterl  pipette,  which  is  allowed  to  drain  for  a  noted 
fx;riod  of  time,  say  thirty  seconds.     The  determination  should  preferably 


EDIBLE   OILS  AND  FATS 


487 


be  made  in  duplicate.  Conduct  the  saponification  as  in  the  case  of  the 
soluble  fatty  acids  by  heating  on  the  water-bath.  After  saponification, 
remove  from  the  bath,  cool,  and  titrate  with  half-normal  hydrochloric  acid, 
using  phcnoli)lUhalein  as  an  indicator.  Titrate  also  several  blanks  in 
which  25  cc.  of  the  alcoholic  potash  solution  are  measured  out  with  the 
same  pipette  as  before,  and  allow  to  drain  for  the  same  amount  of  time. 
Subtract  the  number  of  cubic  centimeters  of  half-normal  acid  necessary 
to  neutralize  the  alkali  in  the  case  of  the  saponified  fat  from  that  necessary 
to  neutralize  the  blank,  multiply  the  result  by  28.06,  and  divide  the 
product  by  the  number  of  grams  of  fat  taken. 

EDIBLE  OILS  AND  FATS  ARRANGED  IN  ORDER  OF  THEIR  SAPONIFICA- 
TION NUMBER. 


Cocoanut  oil 

Butter 

Cocoa  butter 

Beef  tallow 

Lard 

Lard  oil 

Cottonseed  stearin. 

Poppyseed  oil 

Cottonseed  oil  . . . . 

Peanut  oil 

Sunflower  oil 

Sesame  oil 

Olive  oil 

Corn  oil 

Rape  oil 

Black  mustard  oil  . 
White  mustard  oil. 


Miniimtin. 

Maximum. 

Mean. 

246.2 

268.4 

257-3 

225 

230 

227.5 

192 

202 

197 

193.2 

200 

196.6 

195-3 

196.6 

196 

195 

196 

I95-S 

194.6 

195  .  I 

194.8 

190 

198 

194 

191 

196.6 

193.8 

190 

197 

193-5 

193 

194 

193-5 

187.6 

192.4 

192.6 

185 

196 

191-5 

188 

193-4 

190.7 

170.2 

179.2 

174.6 

174 

174-6 

174-3 

170.3 

174.6 

172.4 

The  Iodine  Absorption  Number. — This  determination  is  based  on 
the  well-known  property  of  the  unsaturated  fatty  acids  to  absorb  a  fixed 
amount  of  iodine  under  given  conditions  of  time,  strength  of  reagent,  etc. 

Hiibl's  Method.* — The  following  reagents  are  necessary: 

(i)  Iodine  Solution,  made  by  dissolving  26  grams  of  pure  iodine  in 
500  cc.  of  95%  alcohol,  and,  separately,  30  grams  of  mercuric  chloride 
in  500  cc.  of  the  same  strength  of  alcohol.  Filter  the  latter  solution, 
if  necessary,  and  mix  the  two  together,  allowing  the  mixture  to  stand 
at  least  twelve  hours  before  using. 

(2)  Decinormal  Thlosulphate  Solution,  made  by  dissoKang  24.6  grams 
of  the  freshly  powdered,  chemically  pure  salt  in  water,  and  making  up 
to  I  liter. 


*  A.  O.  A.  C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  24;    Bui.  107 
(rev.),  p.  136. 


4SS  FOOD  INSPECTION  AND  ANALYSIS. 

(3)  Starch  paste,  prcparotl  by  boiling  i  gram  of  starch  in  200  cc.  of 
water  for  ten  minutes,  then  cooHng. 

(4)  Potassium  Iodide  Solution,  made  by  dissolving  150  grams  of  the 
salt  in  water,  and  making  up  the  volume  to  i  liter. 

(5)  Potassium  Bichromate  Solution  for  standardizing  the  thiosulphate, 
made  by  dissolving  3.874  grams  of  chemically  ])ure  potassium  bichromate 
in  distilled  water,  and  making  up  the  volume  to  i  liter. 

The  sodium  thiosulphatc  solution  is  standardized  as  follows:  20  cc. 
of  the  potassium  bichromate  solution  are  introduced  into  a  glass-stoppered 
flask  together  wiih  10  cc.  of  potassium  iodide  and  5  cc.  of  strong  hydro- 
chloric acid.  Then  slowly  add  from  a  burette  the  sodium  thiosulphatc 
solution,  till  the  yellow  color  of  the  solution  has  nearly  disappeared,  after 
which  a  little  of  the  starch  paste  is  added,  and  the  titration  carefully  con- 
tinued to  just  the  point  of  disappearance  of  the  blue  color.  The  reaction 
which  takes  place  is  as  follows: 

K3Cr20,+ i4HCH-6KI  =  2CrCl3-f8KCl+6H- 7H2O. 

The  equivalent  of  i  gram  of  iodine  in  terms  of  the  thiosulphatc  solu- 
tion is  found  by  multiplying  the  number  of  cubic  centimeters  of  the  latter 
solution  required  for  the  above  titration  by  5. 

If,  for  example,  16.4  cc.  of  the  thiosulphatc  solution  are  required 
for  20  cc.  of  the  bichromate  solution,  then  i  gram  of  iodine  is  equivalent 
to  16.4X5  =  82.0  cc.  of  sodium  thiosulphatc  solution,  or  i  cc.  of  the  thio- 
sulphatc solution  =^^Tf  =  0.0122  gram  of  iodine,  i  cc.  of  exactly  deci- 
normal  thiosulphatc  is  theoretically  equivalent  to  0.0127  gram  of  iodine. 

The  thiosulphatc  solution  may  also  be  standardized  by  means  of 
iwline.  A  short  tube  closetl  at  one  end  is  tared,  together  vvitli  another 
tube  of  such  a  size  as  to  fit  over  the  first.  Into  tlie  inner  tube  are 
introduced  about  0.2  gram  of  resublimed  iodine  and  the  tube  heated 
until  the  iodine  melts,  after  which  it  is  closed  by  the  second  tube  and  the 
■whole  cooled  in  a  desiccator  and  weighed.  The  iodine  is  dissolved  in 
10  cc.  of  10%  potassium  iodide  solution,  ihe  solution  diluted  with  water, 
and  the  thiosulj^hate  solution  added  wiili  constant  stirring  until  only  a 
yellow  color  remains.  Starch  jjaste  is  then  added,  and  the  titration  con- 
tinued until  the  blue  color  disappears. 

Manipulation.  Place  0.4  to  1  gram  of  the  solid  fat,  or  from  0.2  to 
0.4  gram  of  oil,  in  a  glass-stoppered  flask  or  bottle  of  300  cc.  capacity. 


RDIRLR   Oils   AND   FATS.  4B9 

In  the  case  of  oils,  this  may  conveniently  be  done  by  (liffercncc,  weigh- 
ing I'lrst  a  small  (juantity  of  the  oil  in  a  beaker  with  a  short  piece  of  glass 
tubing  to  serve  as  a  pipette,  transferring  a  number  of  drops  of  the  oil 
from  the  beaker  to  the  bottle,  and  again  weighing  the  beaker  and  contents. 
The  numl)er  of  drops  of  oil  re(|uired  for  the  desired  weight  is  first  ascer- 
taine(l  experimentally. 

The  material  may  also  be  conveniently  and  accurately  weighed  in 
small,  Hat  bottomed  cylinders  of  glass  about  10  mm.  in  diameter  and  15 
mm.  high,  which  may  be  made  by  cutting  off  so-called  "  .shell  vials." 
Fats  are  introduced  while  melted,  the  weight  being  taken  after  cooling. 
The  cylinder  and  fat  are  transferred  together  by  means  of  forceps  to 
the  glass-stoppered  bottle. 

Dissolve  the  oil  in  10  cc.  of  chloroform,  and  after  solution  has  taken 
place,  add  30  cc.  of  the  iodine  solution,  shake,  and  set  in  a  dark  place 
for  three  hours,  shaking  occasionally.  The  excess  of  iodine  should  be  at 
least  as  much  as  is  absorbed.  When  ready  for  the  titration,  add  20  cc. 
of  the  potassium  iodide  solution  (the  purpose  of  which  is  to  keep  in 
solution  the  mercuric  iodide  formed,  which  would  otherwise  precipitate 
on  dilution)  and  100  cc.  of  distilled  water.  Titrate  the  excess  of  iodine 
by  the  thiosulphate  solution,  which  is  slowly  added  from  a  burette  till 
the  yellow  color  has  nearly  disappeared,  then  add  a  little  starch  paste, 
and  finally  thiosulphate  solution  drop  by  drop  until  the  blue  color  of 
the  iodized  starch  is  dispelled.  Near  the  end  of  the  reaction  the  flask 
should  be  stoppered  and  vigorously  shaken,  in  order  that  all  the  iodine 
may  be  taken  up,  and  sufficient  thiosulphate  should  be  added  to  prevent 
a  reappearance  of  any  blue  color  in  five  minutes. 

Two  blanks  are  conducted  at  the  same  time  and  in  similar  flasks  or 
bottles,  in  exactly  the  same  manner  as  in  the  case  of  the  above  titration, 
except  that  the  fat  is  omitted.  This  is  to  get  the  true  value  of  the  iodine 
solution  in  terms  of  the  thiosulphate  solution. 

Suppose,  for  example,  in  the  case  of  the  blanks,  30  cc.  of  the  iodine 
solution  recjuired  in  one  instance,  46.2  cc.  of  sodium  thiosulphate  solution 
and  in  the  other  46.4  cc.  The  mean  is  46.3.  Suppose  30.7  cc.  of  thio- 
sulphate solution  were  required  for  the  excess  of  iodine  remaining  over 
and  above  that  absorbed  by  0.5  gram  of  the  fat  in  the  above  process. 
Then  the  thiosulphate  equivalent  to  the  iodine  absorbed  by  the  fat  would 
Jh>e  46.3-30.7  =  15.6  cc,  and  the  per  cent  of  iodine  absorbed  would  be 

1 5.6X0.0122X100       „    ^ 

-^ =  38.06. 

0-5 


490 


FOOD   INSPECTION   AND   ANALYSIS. 


EDIBLE  OILS  AND  FATS  ARRANGED  IN  ORDER  OF  THEIR  HUBL  NUMBER. 


Lowest. 


Highest. 


Average. 


Poppyseed  oil. . . . 
Sunflower  oil  .  .  .  . 

Corn  oil 

Cottonseed  oil  .  . . 

Sesame  oil 

Rape  oil 

Black  mustard  oil 
White  mustard  oil 

Peanut  oil 

Cottonseed  stearin 

Olive  oil 

Lard  oil 

Lard 

Beef  tallow 

Mutton  tallow  . . . 
Cocoa  butter  .  .  . . 

Butter 

Cocoanut  oil 


iiS 

1  I  I  .  2 
1 08 
103 

94 
96 
92.1 

83 
88.7 

79 
56 
46 

35-4 
32.7 
32 
2S-7 
8 


143-3 

'33-3 
130 
1 10 

115 
105 
1 10 

97-7 
103 
103.8 

88 

85 
70 

47 
46 

41 

37 

9 


138 

125-7 
120.6 
109.5 
109 

99-5 
103 

94-9 

93 

91.2 

n-5 

70-5 

58 

41.4 

39-5 

34.9 

ii-i 
8.7 


The  Hiibl  method  ha.s  long  been  ahnost  universally  u.sed  for  esti- 
mating the  per  cent  of  iodine  absorbed,  but  is  open  to  serious  objections, 
chief  of  which  are  the  tendency  of  the  iodine  solution  to  lose  strength, 
and  the  length  of  time  required  to  insure  saturation  of  the  oil  with  ihe 
iodine. 

Of  late  two  other  methods  have  come  into  prominence,  viz.,  the 
Wijs  and  the  Hanus.  The  reagents  in  both  these  methods  hold  their 
strength  for  months  without  change,  and  the  time  required  for  carrying 
out  the  reaction  in  the  case  of  most  of  the  edible  oils  and  fats  is  very 
short. 

Of  the  three  methods,  that  of  Hanus  has  the  advantage  of  greatest 
simplicity  in  the  composition  and  preparation  of  the  chief  reagent. 

Tolman  and  Munson  *  have  shown  that  with  oils  and  fats  having 
iodine  numbers  below  100,  the  three  methods  give  practically  identical 
figures,  while  with  oils  having  high  iodine  numbers,  the  Wijs  and  Hanus 
methods  give  higher  results  than  the  Iliibl,  but  are  doubtless  more  nearly 
correct. 

The  following  are  comparative  results  of  the  three  methods:* 


*  Jour.  .\m.  Chcm.  Soc,  25  (1903),  p,  244. 


:  EDIBLE  OILS  /fND  FATS. 


491 


O   CO 

2;< 


U    Ifl 


.52.  §  o 


3E« 
c  3  o 

J52xZ2 


o  C  g 

u  >  t/)  -^i 


•a 


9) 


o  C  rt 
C  u  CO 

<LI   J*    3  J 


0*  ^ 


Q 


I 
2 

I 

4 

2 
36 

3 
5 

2 

I 

3 

I 
3 


Cocoanut  oil 

Butter —               minimum 
maximum. 
Oleo  oil 

Oleomargarine — minimum 

maximum. 
Lard  oil —  minimum 

maximum, 
Olive  oil —  minimum 

maximum, 

average  . . 
Peanut  oil —         minimum 

maximum, 
Mustard  oil —      minimum 

maximum, 
Rape  oil —  minimum 

maximum, 

Sunflower  oil 

Cottonseed  oil —  minimum 

maximum, 

Sesame  oil 

Com  oil —  minimum 

maximum 
Poppyseed  oil —  minimum 

maximum 


8. 

34- 

35- 
42. 

52. 
66. 
69, 

73' 
79 
89 
84 
94 
107 
98 

"3 
100 
101 
106 
103 
106 
106 
119 
123 

134 


9-05 
3.^-9 
36.2 

43-5 
52-9 
66.0 

70.5 
74.5 
79-9 
91.4 

^■?, 

95-2 

109.5 

104 -3 
118. 2 
104. 1 

105-7 
109.2 

105-3 
107-3 
107.0 
122.2 
129.2 
135-2 
139-1 


8.60 
35-4 
35-3 
43-3 
52.0 
64.8 
69.8 

73-9 
80.6 
90.0 
84.6 

94 -r 
107.7 
103.8 
116. 8 
102.8 
105.2 
107.2 
105.2 
107.8 
106.5 
119. 6 
126.0 
132.9 
138.4 


-fo.12 
-f  I.I 
-f  0.9 
-fo.9 
-1-0.4 

-0.3 

+  1.2 
+  0.7 
4-0.7 
4- 1.6 

+  1-3 
-f  0.7 
4-1.8 

+  5-9 

4-5.2 

+  3-9 
+  4.4 
4-2.8 

+  1-5 
4-1. 1 
4-0.6 
+  i-o 
4-5.8 
4-1.8 
+  4.2 


-0-33 

4-0.6 

4-0.0 

4-0.7 

-o-S 

-1-5 

+  0.5 

4-0.2 

+  1-4 
-f  0.2 
4-0.6 
—  0.1 

4-0.0 
+  5-4 
+  3.8 
4-2.6 
4-3-8 
4-0.8 

4-1.4 
-f  1.6 
+  0.1 
4-0.4 
+  2.7 
-0-5 
+  3-5 


Hanus'  Method.* — Reagents. — Iodine  Solution. — Dissolve  13.2  grams 
of  pure  iodine  in  i  liter  of  pure  glacial  acetic  acid  (99%),  and  to  the  cold 
solution  add  3  cc.  of  bromine,  or  sufficient  to  practically  double  the  halo- 
gen content  when  titrated  against  the  thiosulphate  solution,  but  with 
the  iodine  slightly  in  excess. 

Decinormal  Thiosulphate  Solution,  Starch  Paste,  and  Potassium  Iodide 
Solution,  as  in  Hiibl's  method. 

Method  oj  Procedure. — Proceed  as  in  Hiibl's  method,  substituting 
30  cc.  of  the  Hanus  iodine  reagent  for  that  of  Hiibl,  stirring  the  solu- 
tion before  adding  the  water,  and,  instead  of  adding  20  cc.  of  the 
potassium  iodide  solution,  use  only  10  cc.  The  excess  of  iodine  should 
be  at  least  60%  of  that  added. 


*  Zeits.  Unters.  Nahr.  Genuss.,  4,   1901,  p.  913.     Also  Hunt,   Jour.  Soc.  Chem.  Ind., 
21,  1902,  p.  454;   U,  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  136. 


452  FOOD  INSPECTION  AND   ANALYSIS. 

Only  half  an  hour  is  required  for  full  saturation  of  the  oil  by  the 
iodine  in  the  Hanus  method,  as  against  three  hours  in  the  Hiibl.  In 
case  of  the  non-dPi-ing  oils  and  fats,  the  reaction  takes  place  in  from 
eight  to  fifteen  minutes,  though  it  is  best  to  let  the  flask  set  for  half  an 
hour  at  least,  in  all  cases.  With  oils  having  an  iodine  number  in  excess 
of  IOC,  Tolman  and  ^lunson  recommend  one  hour's  standing. 

On  account  of  the  high  coefhcient  of  expansion  of  acetic  acid,  care 
should  be  taken  that  the  temperature  is  the  same  when  the  iodine  solu- 
tion is  measured  for  the  blank  and  for  the  determination,  as  otherwise 
a  serious  error  may  be  introduced. 

Wijs's  Method.* — Reagents. — Iodine  Solution. — Dissolve  13.2  grams 
of  pure  iodine  in  i  liter  of  pure  glacial  acetic  acid,  and  pass  through  the 
larger  portion  of  this  solution  a  current  of  carefully  washed  and  dried 
chlorine  gas  f  until  the  solution  is  practically  decolorized.  Finally  add 
enough  of  the  original  solution  of  iodine  in  acetic  acid  to  restore  the 
iodine  color,  so  that  there  is  a  slight  excess  of  iodine. 

Hunt's  Modified  Iodine  Solution. — Dissolve  10  grams  of  iodine  tri- 
chloride in  I  liter  of  pure  glacial  acetic  acid,  and  finally  add  and  dissolve 
10.8  grams  of  pure  iodine. 

Other  Reagents,  as  in  the  Hiibl  and  Hanus  methods. 

Method  of  Procedure. — Proceed  as  in  the  Hanus  method,  observing  the 
same  precautions,  the  only  difference  being  in  the  use  of  the  Wijs  iodine 
reagent. 

Wijs  recommends  the  following  periods  of  time  for  absoq^tion  of 
the  iodine  in  the  case  of,  various  oils:  For  non-drying  oils  and  fats,  such 
as  peanut  and  olive  oil, J  fifteen  minutes;  for  semi-dr}dng  oils,  such  as 
cottonseed,  rape,  sesame,  corn,  and  mustard,  thirty  minutes;  for  drying 
oils,  such  as  sunflower  and  ])oppyseed,  one  hour. 

The  Bromine  Index  or  Bromine  Absorption  Number. — The  measure 
of  the  amount  of  bromine  absorbed  by  the  oils  and  fats  is  a  useful  factor. 
B\-   the  bromine  index  is  understood  the  weight  of  bromine  which    is 


*  Ber.  d.  chem.  Ges.,  31  (1898),  p.  750. 

t  The  chjorine  is  conveniently  prepared  by  treatment  of  likathing  powder  with  dilute 
sulphuric  acid,  using  gentle  heat,  and  washing  the  gas  by  jjassing  through  strong  sulphuric 
acid. 

X  For  butter,  oleo  oil,  lard  oil,  and  cocoanut  oil,  Gftcen  minutes  is  sufficient. 


EDIBLE    OILS    AND  FATS. 


493 


absorbed   by    i   gram  of  a  given  oil.     The  bromine  index  of  various  oils 
has  been  determined  as  follows: 


Bromine  Index. 

Observer. 

Poppvseed 

0.835 
0.763 
0.69s 
0.645 
0.632 

0-530 
0.500  to  0.544 

Levallois 

Girard 

Levallois 

Girard 
Levallois 

1 

Mustard 

Sesame. 

Cottonseed 

Rape 

Olive 

Method  oj  Levallois. — Five  grams  of  the  oil  are  saponified  with  alcoholic 
potash  in  a  50-cc.  graduated  flask  by  the  aid  of  a  gentle  heat.  At  the  end 
of  the  saponification  and  after  cooling,  the  flask  is  filled  to  the  mark  with 
alcohol,  and,  after  shaking,  5  cc.  are  removed  by  means  of  a  pipette  and 
transferred  to  a  flask.  A  slight  excess  of  hydrochloric  acid  is  added 
to  set  free  the  fatty  acids,  and  from  a  burette  a  standardized  solution 
of  bromine  water  is  run  in  till  with  constant  shaking  a  permanent  yellow 
color  persists.  The  bromine  is  previously  standardized  with  potassium 
iodide  and  sodium  thiosulphate.  The  weight  of  bromine  fixed  by  i  gram, 
of  the  fat  is  then  calculated. 

MllVs  Method. — ModIfied.-\ — Dissolve  o.i  gram  of  the  filtered  and 
dried  fat  in  50  cc.  of  carbon  tetrachloride  or  chloroform  in  a  loo-cc.  stop- 
pered bottle.  From  a  burette  a  standard  solution  of  bromine  in  carbon 
tetrachloride,  approximately  tenth- normal  (8  grams  to  a  liter),  is  slowly 
added  to  the  oil  solution  till,  after  fifteen  minutes,  a  permanent  coloration 
remains.  The  amount  of  bromine  absorbed  is  calculated  by  comparing 
with  the  color  similarly  produced  in  a  blank  experiment,  or  an  excess 
of  bromine  solution  may  be  run  in  and  the  solution  titrated  back  with  a 
standard  solution  of  thiosulphate,  using  potassium  iodide  and  starch. 

Thermal  Tests.— The  rise  in  temperature  produced  by  the  action 
of  certain  reagents  on  various  oils  and  fats,  when  applied  in  a  defi- 
nite manner,  has  been  found  to  be  of  considerable  value,  especially  in  the 
case  of  sulphuric  acid  and  of  bromine. 


*  Villiers  et  Collin,  Les  Substances  Alimentaires,  p,  680. 
t  Jour.  See.  Chem.  Ind.,  2,  p.  435;   3,  p.  366. 


494  FOOD  INSPECTION  AND   ANALYSIS. 

The  Maumene  Test,*  or  thermal  reaction  with  sulphuric  acid,  is  most 
readily  carried  out  in  a  beaker  of  say  150  cc.  capacity,  which  is  set  into  a 
larger  beaker  or  vessel  of  any  kind,  the  space  between  the  two  being  packed 
with  felt  or  cotton  waste.  The  inner  beaker  is  removed,  and  into  it  is 
weighed  50  grams  of  the  oil.  It  is  then  rei)laced  and  the  packing  adjusted, 
if  necessar}',  after  which  the  temperature  of  the  oil  is  noted  with  a  ther- 
mometer. From  a  burette  containing  the  strongest  sulphuric  acid  of 
the  same  temperature  as  the  oil,  10  cc.  are  run  into  the  beaker,  at  the 
same  time  stirring  the  mixture  of  acid  and  oil  with  the  thermometer. 
The  temperature  rises  somewhat  rapidly,  and  remains  for  an  appreciable 
time  at  its  maximum  point,  which  should  be  noted.  The  difference 
in  degrees  centigrade  between  the  initial  temperature  of  the  oil  and  the 
maximum  temperature  of  the  mixture  expresses  the  Maumene  number. 

With  certain  oils,  as  cottonseed,  considerable  frothing  ensues  when 
concentrated  acid  is  employed,  making  an  accurate  determination  of  the 
Maumene  number  somewhat  difficult.  In  this  case  it  is  better  to  employ* 
a  somewhat  weaker  acid,  and  to  expre&s  results  in  terms  of  what  is  called 
the  "specific  temperature  reaction."  This  is  the  result  obtained  by 
dividing  the  rise  of  temperature  in  the  case  of  the  oil  by  the  rise  of 
temperature  in  the  case  of  water,  using  the  same  strength  of  acid,  and 
multiplying  the  quotient  by  100.  Indeed,  it  is  of  importance  in  all 
cases  to  compare  results  on  oils  with  those  obtained  by  carrying  out 
the  same  test  on  water. 

Bromination  Test. — This  test  depends  upon  the  avidity  with  which 
the  oils  and  fats  absorb  bromine,  the  rise  in  temperature  caused  by  the 
reaction  being  measured  in  this  case  rather  than  the  actual  amount  of 
bromine  absorbed,  as  in  the  case  of  the  iodine  absorption.  Indeed,  there 
is  such  a  close  relation  between  the  iodine  number  and  the  heat  of 
bromination,  that  when  one  is  determined  the  other  may  be  calculated 
quite  closely  by  multijjlying  by  a  factor.  In  view  of  the  fact  that  the 
heat  of  bromination  is  much  more  readily  determined  than  the  iodine 
numlx-r,  it  is  often  convenient  to  calculate  the  latter  from  the  former, 
the  result  in  the  case  of  the  edible  oils  and  fats  being  quite  sure  to  fall 
within  the  limits  of  variation  of  the  iodine  number  of  different  oils  of  the 
same  class.  The  bromination  test  was  devised  by  Hehner  and  Mitchell,t 
who  emplfjyed  a  vacuum  jacketed  tube  for  a  calorimeter  in  which  to 
make  the  test.      X'arious  modifications  have  been  suggested  both  in  the 


*  Maumen^,  Compt.  Rend.,  XXXV  (1852),  p.  572. 
t  Analyst,  XX  (1895),  p.  146. 


EDIBLE   OILS  AND  FATS. 


495 


apparatus  employed  and  in  the  manner  of  diluting  the  oil  and 
applying  the  reagent.  The  calorimeter  employed  by  Gill  and  Hatch,* 
;  Fig.  96,  is  conveniently  made  and  is  very  satisfactory.  It  consists  of  a 
long,  narrow,  flat-bottomed  tube,  held  by  a  cork  in  a  small  beaker,  in 
such  a  manner  that  it  is  surrounded  by  an  air  jacket.  The  small  beaker 
is  set  into  one  of  larger  size,  the  space  between  the  two  being  packed  with 
cotton    waste.     Five    grams  of  the   oil  or  fat  are   dissolved   in   25  cc. 


A.  B. 

I-'lG.    96. 

A.   Gill  and  Hatch's  Calorimeter  for  the  Bromination  Test  with  Oils. 
B.  Wiley's  Pipette  for  Measuring  Bromine  in  Chloroform. 

of  chloroform  or  carbon  tetrachloride,  and  5  cc.  of  this  solution 
(containing  i  gram  of  the  oil)  are  transferred  by  a  pipette  to  the 
inner  tube  of  the  above  calorimeter,  being  careful  not  to  let  it  flow 
down  the  sides  of  the  tube.  The  temperature  of  the  oil  is  then  taken 
by  a  thermometer  graduated  to  0.2°.  The  bromine  reagent,  which 
should  be  freshly  prepared,  is  made  up  by  measuring  from  a  burette 
one  part  by  volume  of  bromine  into  four  parts  of  chloroform  or  carbon 
tetrachloride.  The  reagent  is  transferred  to  a  measuring-flask  de\dsed 
by  Wiley,t  consisting  of  a  side-necked  filter-flask  provided  with  a  per- 


*  Jour.  Am.  Chem.  See,  XXI  (1899),  p.  27.     Gill,  Oil  Analysis,  p.  50. 
t  Jour.  Am.  Chem.  Soc,  XVIII  (1896),  p.  378. 


496 


FOOD  INSPECTION  .-IND  ANALYSIS. 


forated  rubber  stopper  into  which  the  stem  of  a  5-ee.  pipette  is  fittedi 
Fig,  06.  A  bulb  on  the  side-neck  serves  to  i'lll  the  pipette.  This  pipette, 
filled  to  the  mark  with  the  bromine  r agent  (whicli  should  be  at  the  same 
temperature  as  the  oil  st)lution  in  the  calorimeter),  is  Jirst  covered  by  the 
linger  and  removed,  and  its  contents  of  5  cc.  allowed  to  flow  down  the 
sides  of  the  inner  tube  of  the  calorimeter  and  mingle  with  the  oil  without 
stirring.  The  rise  in  temperature  is  very  c^uick,  and  the  highest  point 
is  noted.  The  difTerence  between  the  highest  and  the  initial  temperature 
constitutes  the  heat-of-bromination  number. 

This  number,  in  the  case  of  Gill  and  Hatch's  calorimeter,  is  somewhat 
lower  than  when  a  vacuum  jacketed  tube  is  em[)loyed,  and  differs  some- 
what with  the  diluent  of  the  oil  and  bromine.  In  spite  of  these  variations 
and  that  due  to  the  personal  equation,  concordant  results  may  be  obtained 
with  the  vaiious  oils,  when  the  method  is  carried  out  under  precisely  the 
same  conditions.  The  analyst  should  carefully  work  out  the  test  several 
times  with  a  particular  oil  till  the  results  agree,  and  should  then  with 
e(|ual  care  determine  the  iodine  number  of  the  same  oil.  The  iodine 
number,  divided  by  the  heat-of-bromination  number,  gives  the  factor 
which  is  to  be  employed  under  the  same  conditions  for  calculating  one 
constant  from  the  other.  In  the  case  of  Hehner  and  Mitchell's  work 
with  the  vacuum  tube,  measuring  i  cc.  of  undiluted  bromine  into  i  gram 
of  oil  dissolved  in  10  cc.  of  chloroform,  it  w^as  found  that  the  factor  to 
be  used  in  calculating  the  iodine  number  was  5.5. 

The  following  are  some  of  the  results  on  edible  oils  obtained  by  Hehner 
and  Mitchell: 


Oi 

Lard 

Butter 

Olive  oil 

Corn  oil 

Cottonseed  oil 


Heat  of 
Bruinination. 


Iodine 

Number. 


Calculated 
Iodine  Number. 


10.6 
6.6 

IS 

21-5 

19.4 


57-15 
,17-07 
80.76 

122 

107.13 


58.3 

82.5 
118. 2 
106.7 


As  in  the  case  of  the  Maumene  test  with  sulphuric  acid  (wherein 
the  rise  in  temperature  of  sulphuric  acid  and  water  is  taken  as  a  standard), 
it  is  convenient  to  employ  some  standarrl  for  the  bromination  test,  whereby 
var>-ing  results  due  to  difference  in  ap[)aratus,  etc.,  may  be  compared. 

In  this  case  Gill  and  Hatch  found  that  sublimed  camphor  may  be 
prepared  sufTiciently  jjure  to  be  used  for  such  a  standard.  Applying  the 
bromination  test  with  their  calorimeter,  as  aVjove  described,  to  5  cc.  of  a 


EDIBLE   OILS  AND  FATS. 


497 


solution  of  72  grams  of  camjjhor  in  25  cc.  of  carbon  tetrachloride,  an  average 
rise  in  temperature  of  4.2°  was  obtained,  and  the  specific  temperature 
reaction  is  calculated  for  each  oil  by  dividing  the  heat  of  bromination 
by  this  number.  Furthermore,  by  dividing  the  iodine  number  of  several 
oils  by  this  specific  temperature  reaction,  the  factor  to  be  employed  for 
the  calculation  of  the  iodine  number  was  found  to  be  17.18,  as  in  the  fol- 
lowing cases : * 


OiL 


specific  Tem- 
perature 
Reaction. 


Iodine  Number. 


Calculated. 


Found. 


Prime  lard 
No.  I  lard. 

Olive 

Cottonseed 
Corn 


3-705 
4.096 
4.762 
=^-667 
6.381 


63 


97 
109 


63.8 

73-9 

82.0 

103.0 

107.8 


The  Acetyl  Value.  —  On  heating  fats  with  acetic  anhydride  they 
become  "  acetylated  " ;  i.e.,  the  hydrogen  atom  of  their  alcoholic  hydroxyl 
group  is  exchanged  for  the  acetic  acid  radicle,  in  accordance,  for  example, 
with  the  folio wincr  reaction: 


C„H32(OH)COOH+  (C2H30)20  =  Ci7H32(0,C,H30)COOH+  QH.O^ 


Ricinoleic 
acid 


Acetic  anhy- 
dride 


Acetyl-ricinoleic 
acid 


Acetic 
acid 


By  the  actyl  value  is  meant  the  number  of  milligrams  of  potassium 
hydroxide  necessary  to  neutralize  the  acetic  acid  formed  by  the  saponifi- 
cation of  I  gram  of  the  acetylated  fat. 

Lewkowitsch's  method  of  procedure  is  as  follows:  10  grams  of  the 
oil  are  boiled  with  an  equal  volume  of  acetic  anhydride  for  two  hours 
in  a  flask  with  a  return-flow  condenser,  and  the  mixture  is  then  trans- 
ferred to  a  large  beaker  containing  500  cc.  of  water,  and  boiled  for  half 
an  hour.  To  prevent  bumping,  a  current  of  carbon  dioxide  is  slowly 
passed  through  it  during  the  boiling,  introduced  through  a  finely  drawn, 
bent  glass  tube  reaching  nearly  to  the  bottom  of  the  beaker.  The  mix- 
ture on  standing  separates  into  two  layers,  of  which  the  lower,  or  aqueous 
layer,  is   siphoned  off,  and   the  oily  layer  boiled  with  fresh  portions  of 


*  Gill,  Oil  Analysis,  p.  128. 


49S  FOOD  INSPECTION  ^ND   /iN/t LYSIS. 

water,  which  arc  in  turn  siphoned  olT,  the  operation  being  repeated  till 
the  \va>h  water  tests  free  from  acid  Ijv  litmus  paper. 

The  acetylatcd  fat  is  then  separated  from  the  water  by  dr}'ing  at 
icx)°  in  an  oven. 

From  2  to  4  grams  of  the  acetylated  fat  is  weighed  into  a  flask,  and 
saponified  with  alcoholic  potash  in  })recisely  the  same  manner  as  for 
the  determination  of  the  saponification  number.  Evaporate  the  alcohol 
and  dissolve  the  soap  in  water.  One  of  two  methods  may  be  carried 
out  for  freeing  the  acetic  acid  for  titration,  one  by  distillation  and  the 
other  by  filtration. 

For  the  former  or  distillation  process,  acidify  the  aqueous  solution 
of  the  soap  with  i :  10  sulphuric  acid,  and  distill  in  the  same  way  as  in  the 
Reichert  process,  excepting  that  in  this  case  from  Coo  to  700  cc.  of  dis- 
tillate must  be  obtained,  so  that  water  should  be  added  from  time  to 
time  through  a  stoppered  funnel  fixed  in  the  cork  of  the  distilling-flask. 
The  distillate  should  be  received  in  a  funnel  with  a  loose  cotton  plug,  so 
as  to  filter  it  free  from  insoluble  acids  mechanically  carried  over.  The 
filtrate  is  titrated  with  tenth-normal  sodium  hydroxide,  using  phenol- 
phthalein  as  an  indicator.  The  number  of  cujjic  centimeters  of  alkali 
used  is  multiplied  by  5.61,  and  the  product  divided  by  the  number  of 
grams  of  acetylated  fat  taken.     The  result  is  the  acetyl  value. 

If  the  filtration  process  is  used  (which  is  more  rapid  and  should  give 
concordant  results  with  the  distillation  process),  the  exact  amount  of 
alcoholic  potash  used  in  the  saponification  should  be  accurately  measured 
in  carr}-ing  out  the  former  part  of  the  test,  and  the  exact  number  of  cubic 
centimeters  of  standard  acid  corresponding  to  the  amount  of  alkali 
employed  should  be  added  to  the  aqueous  soap  solution.  The  mixture 
should  be  gently  warmed,  and  the  fatty  acids  will  gather  in  a  layer  at  the 
top.  These  are  filtered  off  and  washed,  till  free  from  acid,  with  boiling 
water.  The  filtrate  is  titrated  with  tenth-normal  sodium  hydroxide,  and 
the  acetyl  value  calculated  as  in  the  distillation  process. 

EDIBLE    OILS    ARRANGED    IN   ORDER   OF    ACETYL   VALUE. 

Average. 

Cottonseed  oil 18.0 

Rape  oil 14. 7 

Poppyseed  oil 1 3 .  i 

Sesame  oil 11. 5 

Olive  oil 10.6 

Peanut  oil 3.4 


F.DIRI.F.     OILS   yIND  FATS.  499 

The  Valenta  Test.— This  depends  upon  the  solubility  of  the  oil  in 
glacial  acetic  acid.  Pour  from  3  to  5  cc.  of  the  oil  into  a  test-tube,  and 
add  an  equal  volume  of  glacial  acetic  acid  (specific  gravity  1.0562). 
Place  a  thermomeLer  in  the  tube  and  warm  gently  till  the  oil  goes  into 
solution.  Then  allow  the  mixture  to  cool,  and  observe  the  temperature 
at  which  the  solution  begins  to  appear  turbid. 

Castor  oil  and  oil  of  the  olive  kernel  are  soluble  in  glacial  acetic  acid 
at  ordinary  temperatures,  while  rape  and  mustard  seed  oils  are  insoluble 
even  in  the  boiling  acid. 

Elaidin  Test. — This  is  based  on  the  conversion  by  nitrous  oxide  of 
liquid  olcin  into  the  solid  elaidin,  a  crystalline  compound  isomeric  with 
olcin,  while  other  common  glyceridcs  remain  liquid  under  treatment 
with  this  reagent.  By  the  consistency  of  the  fmal  product,  when  sub- 
jected under  certain  conditions  to  the  action  of  nitrous  oxide,  some  idea 
as  to  the  character  of  the  oil  may  be  gained. 

Manipulation. — To  carry  out  the  test  according  to  Pontet  (modified), 
weigh  5  grams  of  the  oil  into  a  beaker,  add  7  grams  of  nitric  acid  (specific 
gravity  1.34)  and  about  0.5  gram  of  copper  wire.  Place  the  beaker  in 
water  at  15°  and  stir  thoroughly  with  a  glass  rod  in  such  a  manner  as 
to  make  an  intimate  mixture  of  the  oil  and  the  evolved  nitrous  oxide  gas. 
After  the  wire  has  been  dissolved,  add  another  piece  of  about  the  same 
size  and  again  stir  vigorously.  Set  aside  for  about  two  hours,  at  the  end 
of  which,  in  the  case  of  pure  olive,  almond,  peanut,  or  lard  oil,  it  will 
have  been  changed  into  a  solid  white  mass. 

Nearly  all  the  seed  oils,  especially  cottonseed  and  mustard,  are  turned 
into  a  pasty  or  buttery  mass. 

Another  modification  of  Pontet's  test  consists  in  mixing  10  grams 
of  the  oil,  5  grams  of  nitric  acid  (specific  gravity  1.38),  and  i  gram  of 
mercury  in  a  test-tube,  shaking  for  three  minutes  and  allowing  to  stand 
twenty  minutes,  when  it  is  again  shaken. 

The  behavior  of  various  oils  after  that  time  on  further  standing  is  as 
follows : 

Solidified  after 

Olive  oil 60  minutes 

Peanut  oil 80       ", 

Sesame  oil 185       '' 

Rape  oil 185       " 

Free  Fatty  Acids.* — Weigh  20  grams  of  the  oil  or  fat  into  a  150-cc. 
Erlcnmeyer  flask,  and  add  50  cc.  of  95%  alcohol,  which  has  previously 

*  Allen,  Com.  Org.  Anal.,  4  Ed.,  Vol.  11,  p.  9. 


50O  FOOD  INSPECTION  AND   ANALYSIS. 

been  carefully  neutralized  wilh  a  weak  solution  of  sodium  hydroxide, 
using  phenolphthalein  as  an  indicator.  Warm  the  mixture  to  about  60°, 
and  add  carefully  from  a  burette  tenth-normal  sodium  hydroxide  (using 
the  above  indicator)  till  a  pink  color  is  produced,  shaking  tlioroughly 
during  the  titration. 

The  result  may  be  reported  in  terms  of  percentage  of  oleic  acid  (each 
cubic  centimeter  of  tenth-normal  alkali  is  equivalent  to  0.0282  gram  of 
oleic  acid)  or  as  the  "acid  number,"  by  which  is  meant  the  number  of 
cubic  centimeters  of  tenth-normal  alkali  necessary  to  saturate  the  free 
acid  in   i  gram  of  llie  fat  or  oil. 

Constants  of  the  Free  Fatty  Acids. — Often  much  information  as  to 
the  character  of  an  oil  or  fat  may  be  obtained  by  determining  such  con- 
stants of  its  fatty  acids  as  the  mehing-  and  solidifying-point,  the  iodine 
number,  etc. 

To  prepare  the  fatty  acids  for  examination,  saponify  a  quantity  of  the 
oil  or  fat  with  alcoholic  potash,  evaporate  the  alcohol,  and  dissolve  the 
soap  in  hot  water.  Decompose  the  soap  by  the  addition  of  an  excess 
of  hvdrochloric  or  sulphuric  acid,  continuing  the  heating  till  the  fatty 
acids  rise  in  a  layer  to  the  top  of  the  licjuid,  from  which  they  may  be 
removed.  The  melting-point,  iodine  number,  etc.,  are  determined  as 
wilh  the  nil  or  fat  i.self. 

Solidifying-point  of  the  Fatty  Acids,  or  Titer  Test. — Modified 
Wolfbauer  Method* — Saponify  75  grams  of  fat  in  a  metal  dish  wilh  60  cc. 
of  30'^c  sodium  hydroxide  (36°  Baume)  and  75  cc.  of  95S0  by  volume 
alcohol  or  120  cc.  of  water.  Boil  to  dryness,  wilh  constant  stirring  to 
prevent  scorching,  over  a  very  low  flame,  or  over  an  iron  or  asbestos  plate. 
Dis.solve  the  dry  soap  in  a  liter  of  boiling  water,  and  if  alcohol  has  been 
used,  boil  for  forty  minutes  in  order  to  remove  it,  adding  sufficient  water 
to  replace  that  lost  in  boiling.  Add  100  cc.  of  30%  sulphuric  acid  (25° 
Baum(?)  to  free  the  fatty  acids,  and  boil  uniil  they  form  a  clear,  trans- 
parent layer.  Wash  wilh  boiling  water  until  free  from  sulphuric  acid, 
collect  in  a  small  beaker,  and  place  on  the  steam  bath  until  the  water  has 
settled  and  the  fatty  acids  are  clear;  then  decant  them  into  a  dry  beaker, 
filler,  using  a  hot- water  funnel,  and  dry  twenty  minutes  at  100°  C. 

When  flried,  cool  the  fatty  acids  to  15  or  20°  C.  above  the  expected 
titer,  and  transfer  to  the  titer  tube,  which  is  25  mm.  in  diameter  and  100 
mm.  in  length  (i  by  4  inches),  and  made  of  gla.ss  about  i  mm.  in  thickness. 
Place  in  a  i6-ounce  saltmouth  bottle  of  clear  gla.ss,  about  70  mm.  in 
diameter  and  150  mm.  high  (2.8  by  6  inches),  fitted  with  a  cork,  which  is 
perforated  so  as  to  hold  the  tube  rigidly  when  in  position.     Suspend  the 

*  A.  O.  A.  C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem..  Bui.  107,  p.  135. 


EDIBLE   OILS    ^ND   FATS.  501 

thermometer,  graduated  to  0.10°  C,  so  that  it  can  be  used  as  a  stirrer, 
and  stir  the  mass  slowly  until  the  mercury  remains  stationary  for  tliirty 
seconds.  Then  allow  the  thermometer  to  hang  c[uietly,  with  the  bulb  in 
the  center  of  the  mass,  and  observe  the  rise  of  the  mercury.  The  highest 
point  to  which  it  rises  is  recorded  as  the  titer  of  the  fatty  acids. 

Test  the  fatty  acids  for  complete  saponification  as  follows: 

Place  3  cc.  in  a  test  tube  and  add  15  cc.  of  alcohol  (95%  by  volume). 
Bring  the  mixture  to  a  boil  and  add  an  equal  volume  of  ammonium 
hydroxide  (0.96  sp.  gr.).  A  clear  solution  should  result,  turbirh'ly  inch'cat- 
ing  unsaponified  fat.  The  titer  must  be  made  at  about  20°  C.  for  all 
fats  having  a  titer  above  30°  C.  and  at  10°  C.  below  the  titer  for  all  other 
fats. 

The  thermometer  must  be  graduated  in  tenth  degrees  from  10°  to  60°, 
with  a  zero  mark,  and  have  an  auxiliary  reservoir  at  the  upper  end,  also 
one  between  the  zero  mark  and  the  10°  mark.  The  cavity  in  the  capillary 
tube  between  the  zero  mark  and  the  10°  mark  must  be  at  least  i  cm.  below 
the  10°  mark,  the  10°  mark  to  be  about  3  or  4  cm.  above  the  bulb,  the 
length  of  the  thermometer  being  about  15  inches  over  all.  The  ther- 
mometer is  annealed  for  75  hours  at  450°  C,  and  the  bulb  is  of  Jena 
normal  16"'  glass,  moderately  thin,  so  that  the  thermometer  will  be 
quick  acting.  The  bulb  is  about  3  cm.  long  and  6  mm.  in  diameter. 
The  stem  of  the  thermometer  is  6  mm.  in  diameter  and  made  of  the  best 
thermometer  tubing,  with  scale  etched  on  the  stem,  the  graduation  to  be 
clear  cut  and  distinct,  but  quite  fme.* 

Unsaponifiable  Matter. — As  will  be  seen  by  reference  to  the  table 
on  page  509,  the  unsaponifiable  matter  in  pure  edible  oils  and  fats  is 
comparatively  insignificant  in  amount,  consisting  largely  of  cholesterol  or 
phytosterol.  A  high  content  of  unsaponifiable  matter  is  indicative  of 
adulteration,  pointing  to  the  presence  of  mineral  or  coal-tar  oils,  or  to 
paraffin. 

Determination  of  Unsaponifiable  Matter. f— Weigh  7  to  10  grams  of 
the  fat  or  oil  in  a  250-cc.  llask,  and  saponify  by  boihng  with  25  cc.  of 
alcoholic  potassium  hydroxide  and  25  cc.  of  alcohol  under  a  return- 
flow  condenser.  After  saponification,  add  30  to  40  cc.  of  water,  and 
bring  to  the  boiling-point.  Cool  and  transfer  the  contents  from  the 
flask  to  a  separatory  funnel,  washing  out  the  flask  first  with  a  small  amount 


*  Tolman,  T_I.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  90,  p.  75. 
t  Honig  and  Spitz,  Jour.  Soc.  Chem.  Ind.,  1891,  p.  1039. 


S^2  FOOD   INSPECTION   AND  ANALYSIS. 

of  50^-  alcohol,  and  finally  with  50  cc.  of  petroleum  ether  (B.P.  40^-70"), 
adding  both  washings  to  the  separatory  funnel.  Shake  the  latter 
thoroughly,  but  avoid  if  possible  forming  an  emulsion.  If  the  latter 
persists  in  forming,  add  a  volume  of  water  equal  to  that  of  the  soap  solu- 
tion, which  will  sometimes  break  it  up.  After  separation  of  the  petro- 
leum ether  layer,  draw  off  the  underlying  soap  solution  into  a  beaker, 
and  wash  the  petroleum  ether  two  or  three  times  with  50%  alcohol,  which 
is  drawn  off  and  added  to  the  soap  solution.  The  petroleum  ether  is 
then  run  into  a  tared  Erlenmeyer  llask,  and  the  soap  solution  extracted 
twice  more  with  fresh  portions  of  petroleum  ether,  washing  the  ether 
each  time  with  50%  alcohol  as  before  and  then  transferring  the  ether 
to  the  tared  llask.  The  petroleum  ether  is  then  removed  by  placing 
the  flask  on  the  water-bath,  bumping  being  prevented  by  means  of  a 
spiral  of  platinum  wire  weighed  with  the  llask.  Finally  remove  all  traces 
of  remaining  ether  by  blowing  hot  air  through  the  llask,  or,  in  the  absence 
of  mineral  oils  (some  of  which  are  volatile),  dry  in  the  water-oven  to  con- 
stant weight,  cool  in  a  desiccator,  and  weigh. 

Cholesterol  and  Phytosterol. — These  arc  monatomic  alcohols,  and 
combine  with  the  fatty  acids  forming  esters.  Both  respond  to  the  same 
reactions,  and  are  separated  by  the  same  process  from  the  oils  and  fats 
in  which  they  occur.  Phytosterol  was  long  thought  to  be  the  same  as 
cholesterol,  and  some  confusion  seems  to  have  arisen  from  the  fact  that 
early  writers  purport  to  have  found  cholesterol  in  vegetable  oils,  when 
in  reality  the  substance  was  phytosterol.  The  latter  was  first  distinguished 
from  cholesterol  by  Hesse,  who  named  it. 

Cholesterol  (C26H44O)  crystallizes  in  white,  nacreous,  monoclinic 
lamina-,  having  a  melting-point  of  145°  and  specific  gravity  1.067.  ^^^ 
reaction  is  neutral,  it  is  devoid  of  taste  or  smell,  insoluble  in  water,  sparingly 
soluble  in  cold,  but  readily  soluble  in  boiling  alcoh(i,  and  soluble  in  ether, 
chloroform,  methyl  alcohol,  benzene,  and  oil  of  turpentine.  It  subhmes 
unchanged  at  200°,  but  at  higher  temperatures  decomposes. 

Commercial  cholesterol  is  obtained  from  wool  oil  and  is  known  as 
lanolin,  being  used  largely  in  medicine  as  a  basis  for  ointment. 

Cholesterol  occurs  also  in  the  yolk  of  eggs,  in  many  animal  secretions, 
and  in  most  animal  oils  and  fats. 

It  separates  in  laminated,  transparent  crystals  from  a  mixture  of 
2  volumes  alcohol  and  i  volume  ether,  and  in  the  form  of  anhydrous 
needles  from  chloroform. 

Phytosterol   {(Z^):{^C),Y{.f))   is   rao^X   abundantly  found  in  the  legu- 


EDIBLE    OILS   AND    FATS.  503 

minous  seeds,  and  is  prepared  commercially  from  these,  especially  from 
peas  and  lentils.     It  is  a  constituent  of  most  vegetable  oils. 

It  crystallizes  in  slender,  glittering  plates  from  chloroform,  ether, 
and  petroleum  ether,  and  from  alcohol  in  tufts  of  needles.  In  solubility  it 
much  resembles  cholesterol, but  its  melting-point  from  132°  to  134°  is  lower. 

Determination  of  Cholesterol  and  Phytosterol. — Melhod  of  Forsler  and 
Reich  1)1(1  II II. ^-^-^o  grams  of  the  oil  or  fat  are-  boiled  for  five  minutes  in 
a  flask  connected  with  a  rellux  condenser  with  two  successive  j^ortions 
of  75  cc.  of  95%  alcohol,  and  in  each  case  the  alcoholic  solution  is  sepa- 
rated by  means  of  a  separatory  funnel.  The  combined  alcoholic  solutions 
are  then  boiled  in  a  flask  provided  with  a  funnel  in  the  neck,  till  one- 
fourth  of  the  alcohol  is  evaporated,  and  then  ])oured  into  an  evaporating 
dish  and  brought  to  dryness.  The  residue  is  then  extracted  with  ether, 
and  the  ether  solution  is  evaporated  to  dryness,  taken  up  again  with  ether, 
filtered,  evaporated  once  more,  and  dissolved  in  hot  95^  ^  alcohol,  from 
which  it  is  allowed  to  crystallize.  Cholesterol  or  phytosterol  will  crys- 
tallize out  under  these  conditions,  and  may  be  weighed. 

Distinguishing  between  Cholesterol  and  Phytosterol. — It  is  some- 
times of  importance  to  determine  which  of  these  substances  is  present  in 
an  oil,  or  whether  indeed  both  occur.  Confirmatory  proof  as  to  the 
presence  of  vegetable  in  animal  oils  may,  for  instance,  be  estabUshed  by 
showing  whether  the  unsaponifiable  residue  in  the  sample  contains  choles- 
terol or  phytosterol  or  both.  Hehner  f  has  made  use  of  this  test  in  deter- 
mining the  presence  of  cottonseed  oil  in  lard. 

The  most  ready  means  of  distinguishing  between  cholesterol  and 
phytosterol  is  furnished  by  the  marked  difference  between  the  form  of  the 
crystals,  the  manner  of  crystalhzation  of  the  two  substances,  and  the 
melting  points  of  the  acetates. 

Separation  and  Crystallization  of  Cholesterol  and  Phytosterol. — • 
Bomer^s  Method.X — Saponify  100  grams  of  the  fat  by  heating  in  a  liter 
Erlenmcyer  flask  on  a  boiling  water  bath  with  200  cc.  of  alcoholic  potash 
solution  (200  grams  of  potassium  hydroxide  + 1  liter  of  alcohol).  The 
flask  should  be  provided  with  a  perforated  rubber  stopper,  through  which 
passes  a  glass  tube  700  cm.  long,  which  serves  as  a  reflux  condenser. 
During  the  first  part  of  the  heating  shake  often  and  vigorously  until  the 
solution  is  clear,  after  which  continue  the  heating  one-half  to  one  hour 
longer  with  occasional  shaking. 

*  Analyst,  22,  1897,  p.  131. 

t  Ibid.,  13,  1888,  p.  165. 

X  Zeits.  Unters.  Nahr.  Genuss.,  i,  1898,  p.  31.     . 


504  FOOD   INSPECTION    AND    ANALYSIS. 

While  still  warm,  transfer  to  a  scparatory  funnel  of  about  1.5  liters 
capacity,  rinsing  the  llask  with  400  cc.  of  water.  When  cool,  add  500  cc. 
of  ether,  shake  vigorously  for  one-half  to  one  minute,  oj)ening  the  cock 
repeatedly,  and  allow  to  stand  for  two  to  three  minutes  until  the  liquids 
separate.  Remove  the  ether  solution  to  a  fla.sk,  and  distil  off  the  ether, 
using  a  few  pieces  of  pumice  stone  to  j^rewnt  bum])ing.  Shake  the  .soap 
solution  two  to  three  more  times  in  the  same  manner  with  200  to  250  cc. 
of  ether,  add  the  ether  solution  after  each  shaking  to  the  residue  in  the 
distilling  t^ask,  and  distil  otT  the  ether. 

Usually  a  small  amount  of  alcohol  remains  in  the  fla.sk  after  removal 
of  the  ether,  which  may  be  removed  by  heating  on  a  boiling  water  bath 
in  a  blast  of  air.  To  saponify  any  remaining  fat,  add  20  cc.of  the  alcoholic 
potash  .solution,  and  heat  for  five  to  ten  minutes  as  before.  Transfer 
to  a  small  separatory  funnel,  rin.se  with  40  cc.  of  water,  cool  and  .shake 
with  150-2CX1  cc.  of  ether  from  one-half  to  one  minute,  allow  to  .stand  two 
to  three  minutes,  and  draw  off  the  lower  layer.  Wa.sh  the  ether  .solution 
three  times  with  10-20  cc.  of  water,  filter,  to  remove  drops  of  water,  into 
a  small  beaker,  and  remove  the  ether  by  cautious  evaporation  on  the 
water  bath,  thus  obtaining  the  crude  cholesterol  or  })hyto.sterol. 

The  unsaponifiable  residue,  which  may  be  weighed  after  drying,  in 
the  case  of  animal  fats  shows  beautiful  radiating  crystals,  and  consists 
largely  of  cholesterol,  while  in  the  case  of  vegetable  fats  it  consists  largely 
of  phytosterol.  Dissolve  the  residue  in  4-20  cc.  of  absolute  alcohol  with 
the  aid  of  heat,  and  allow  to  crystallize  .slowly  in  a  .shallow  di.sh. 

The  crystallization  in  the  case  of  cholesterol  alone  begins  from  the 
margin  of  the  li(|uid  and  gradually  extends  inward  toward  the  center, 
forming  a  uniff)rmly  bright,  thin,  colorless  film  over  the  whole  surface. 
This  film  is  best  removed  with  a  knife  or  .s])atula  and  pres.sed  between 
filter-paper.  The  film  will  be  .seen,  even  mega.scopically,  to  be  composed 
of  large,  glossy  plates  with  a  silk-like  lu.ster.  After  the  removal  of  the 
first  film  a  .second  will  form  similar  to  the  first,  Ijut  compo.sed  as  a  rule 
of  smaller  crystals.  These  are  removed  in  like  manner,  dried  between 
filters,  and  added  to  the  first  in  a  glass.  After  the  .second  crop,  the  mother 
liquid  is  thrown  away.  The  cry.stals  are  then  redissolved  in  ab.solute 
alcohol,  anrl  again  allowed  to  .separate  out,  being  repeatedly  recrystallized 
till  the  melting-point  is  con.stant.  In  lard  and  mo.st  fats  the  crystals 
were  found  pure  V)y  Bomer  after  the  .second  crystallization. 

Phytosterol  is  crystallized  with  greater  difficulty,  esj)ecially  when 
derived  from  .seed  oils,  on  account  of  the  jjresence  of  pigments  and  other 


EDIBLE   OILS  AfJD  FATS. 


505 


foreign  matter.  The  first  procedure  is  the  same  as  above  described  for 
cholesterol,  the  crystals  being  allowed  to  separate  slowly  out  of  a  solu- 
tion in  absolute  alcohol.  Unlike  cholesterol,  no  film  is  formed  on  the 
surface,  but  needles  (sometimes  i  cm.  in  length)  are  gradually  elim- 
inated, beginning  at  the  margin  and  extending  inward  mostly  at  the 
bottom.  In  concentrated  solutions,  fine  needles  would  be  uniformly 
deposited  through  the  liquid.  These  are  best  separated  from  the  mother 
liquid  bv  filtration,  as  they  arc  not  easily  taken  out  with  a  knife.  They 
may  be  washed  on  the  filter  with  small  amounts  of  absolute  alcohol  for 
microscopical  examination,  or  repeatedly  recrystallized,  as  in  the  case 
of  cholesterol,  till  the  melting-point  is  constant. 

I.  Cholesterol  Crystals. — -When  crystallized  separately  under  above 
conditions,  cholesterol  crystals  viewed  under  the  microscoj^e  show  generally 
rhomboidal  forms  of  plates,  as  in  Fig.  97,  but  sometimes  with  a  reenter- 


Fig.  97. — Cholesterol  Crystals  under  the  Microscope.     (After  Bomer.) 


ing  angle.  The  plates  are  often  grown  together  in  masses.  The  most 
characteristic  forms  are  found  from  the  first  crystallization  or  from 
the  first  film  removed.  Sometimes  quadrilateral  cr}^stals  predominate 
amcng  the  plates,  often  also  the  other  shapes  shown  are  found  most 
numerous. 

2.  Phytosterol  Crystals. — Pure  phytosterol  crystallizes  in  needles  or 
narrow  plates,  arranged  commonly  in  star  form  or  in  bunches.  The 
most  common  forms  are  shown  in  Fig.  98,  best  conditions  as  to  shape 
of  crystals  being  obtained  from  slow  crystallization,  in  which  case  the 
needles  are  finer  and  more  regular. 

The  cr)'stals  are  commonly  in  the  form  of  long,  narrow  plates,  thin 
and  slender,  often  pointed  at  both  ends.  Sometimes  the  points  are 
lacking,  or  the  ends  are  beveled.  The  more  frequently  they  are  re- 
cr)'stallized,  the  larger  and  more  varied  are  the  crystal  forms.  The 
broad,  hexagonal  and  quadrilateral   plates  shown   are   products   of  re- 


t;o6 


FOOD  INSPECTION  AND  ANALYSIS. 


cr}-stallization;  the  shorter  forms  are  rarely  met  \\\{\\.     Sometimes  various 
forms  are  found  siilc  by  side  in  the  same  cr}'stallization. 

Phytostcrol  cr}-stals,  from  a  second  of  third  recr}^stallization,  some- 
times grow  together  in  bunches  resembling  at  fil-st  glance  to  the  naked 
eye  the  cholesterol  masses.  They  never  do  this  in  the  first  crystallization, 
whereas  in  the  case  of  cholesterol  the  growing  together  in  masses  is  very 
characteristic  of  the  first  crvstalli/ation. 


XX 

Fig.  98. — Phytosterol  Cn-stals.     (After  Bomer.) 

Thus  for  purj)oscs  of  distinguishing  between  the  two  the  product 
of  the  first  crj'stallization  is  best  observed. 

3.  Crystals  of  Mixed  Cholesterol  and  Phytosterol. — In  mixtures  of  the 
two  they  do  not  crystallize  separately,  but  when  in  nearly  equal  propor- 
tion, or  with  phytosterol  jjrcdominating,  the  crj'stals  much  resemble 
phvtosterol.  Even  when  cholesterol  predominates  to  the  extent  of  20 
parts  to  I  of  phytosterol,  the  mode  of  cr}'stallizati()n  leans  most  toward 
that  of  phytosterol,  though  the  needles  are  of  different  shape.  Such  a 
mixture,  for  instance,  does  not  form  in  a  film  like  cholesterol,  but,  like 
phytosterol,  comes  out  in  needle-like  bunches.  The  needles,  however, 
are  more  often  like  those  shown  in  Fig.  99  when  viewed  under  the  micro- 


"N 


hWj\} 


Fig.   99. — Characteristic  Forms  of  Crystallization  of  Mixed  Cholesterol  and  Phytosterol 

(After  Homer.) 

scope,  showing  needles  for  the  most  part  squarely  cut  off  at  the  ends, 
and  sometimes  placed  end  to  end,  and  of  varying  diameter,  giving  the 
apjK-arance  of  a  spy-glass.  When  cholesterol  predominates  over  phy- 
tosterol 50  to  I,  the  plates  resemble  those  of  cholesterol. 


EDIBLE  OILS  AND    FATS.  507 

Bomer's  Phytosterol  Acetate  Test  for  Vegetable  Fats.* — Dissolve 
the  crude  cholesterol  or  phytosterol,  or  the  mixture  of  the  two,  obtained 
by  Bomer's  method,  as  described  on  page  503,  in  the  smallest  possible 
amount  of  absolute  alcohol,  and  allow  to  crystallize.  Examine  under 
the  microscope  the  first  crystals  that  se{)arate,  comparing  with  the  cuts 
and  descriptions  given  in  the  preceding  section.  Remove  the  alcohol 
completely  by  evaporation  on  the  water  bath,  add  2  to  3  cc.  of  acetic 
anhydride,  cover  with  a  watch  glass,  and  boil  for  one-fourth  minute  on  a 
wire  gauze;  then  remove  the  watch  glass,  and  evaporate  the  excess  of 
acetic  anhydride  on  the  water  bath.  Heat  the  residue  with  sufficient 
absolute  alcohol  to  dissolve  the  esters,  and  add  enough  more  to  prevent 
immediate  crystallization  on  cooling.  Cover  until  the  room  temperature 
is  reached  and  allow  to  crystallize. 

After  one-half  to  one-third  of  the  liquid  has  evaporated  and  the  greater 
part  of  the  esters  have  crystallized,  transfer  the  crystals  to  a  small  filter 
by  the  aid  of  a  small  spatula,  rinsing  with  two  portions  of  2  to  3  cc.  of 
95%  alcohol.  Return  the  crystals  to  the  crystallizing  dish,  dissolve  in 
5  to  10  cc.  of  absolute  alcohol,  and  again  allow  to  crystallize.  After  the 
greater  part  of  the  crystals  have  separated,  collect  on  a  filter  as  before. 
Repeat  the  recrystalhzation  several  times  (5  to  6  is  usually  sufficient), 
determining  the  melting  point  of  the  crystals  after  each  recrystalhzation 
beginning  with  the  third. 

If  after  the  last  crystallization  the  corrected  melting  point  of  the 
crystals  is  above  116°,  the  presence  of  a  vegetable  fat  or  oil  is  indicated,  if 
it  is  117°  or  higher  the  proof  may  be  regarded  positive. 

The  standard  thermometer  used  should  be  graduated  to  tenths  of  a 
degree.     Correct  the  reading  by  the  following  formula: 

5  =  r -!- o.oooi  54W  (T  — /) 
in  which  5'=- the  corrected  melting  point,  r  =  the  observed  melting  point, 
w  =  the  length  of  the  mercury  column  above  the  surface  of  the  liquid, 
expressed  in  degrees,  and  ^  =  the  temperature  of  the  air  about  the  mercury 
column  as  determined  by  a  second  thermometer. 

Bomer  states  that  by  this  method  the  analyst  can  detect  in  edible 
animal  fats  i  to  2  per  cent  of  oils  rich  in  phytosterol  (cottonseed,  peanut, 
sesame,  rape,  hemp,  poppy,  and  linseed),  and  3  to  5  per  cent  of  oils  con- 
taining smaller  amounts  of  this  constituent  (ohve,  palm,  palm  kernel, 
and  probably  cocoanut).  He  found  the  corrected  melting  point  of  choles- 
terol acetate  to  be  114.3°  to  114.8°  and  of  phytosterol  acetate,  125.6°  to 
137.0°  according  to  the  source. 

*  Zeits.  Unters.  Nahr.  Genuss.,  4.  1901,  p.  1070. 


!;oS 


FOOD  INSPECTION  AND  ANALYSIS. 


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5IO  FOOD  INSPECTION  AND   ANALYSIS. 

Numerous  experiments,  made  both  in  Europe  and  America,  show  that 
feeding  milch  cows  and  swine  with  oil  cakes  does  not  introduce  })hytos- 
teroi  into  either  the  fat  of  the  milk  or  the  lard,  although  both  fats  may 
respond  to  the  Halphen  test,  or  give  abnormally  high  Polcnske  numbers 
as  a  result  of  feeding  with  cottonseed  or  cocoanut  cake  respectively,  and 
although  the  lard  (not  the  butter  fat)  may  respond  to  the  Baudouin  test, 
owing  to  feeding  with  sesame  cake.     (See  pp.  531,  560), 

Paraffin,  sometimes  present  as  an  adulterant  of  fats,  is  best  deter- 
mined as  follows:*  Boil  2  grams  of  the  fat  witli  10  cc.  of  95^^  alcohol 
and  2  cc.  of  I :  I  sodium  hydroxide  solution,  connect  the  flask  with  a  reflux 
condenser,  and  heat  for  an  hour  on  the  water-bath,  or  until  saponification 
is  complete.  Remove  the  condenser,  and  allow  the  flask  to  remain  on 
the  bath  till  the  alcohol  is  evaporated  off  and  a  dry  residue  is  left.  Treat 
the  residue  with  about  40  cc.  of  water  and  heat  on  the  bath,  with  frequent 
shaking,  till  ever}-thing  soluble  is  in  solution.  Wash  into  a  separatory 
funnel,  cool,  and  extract  with  four  successive  portions  of  petroleum  ether, 
which  are  collected  in  a  tared  flask  or  capsule.  Remove  the  petroleum 
ether  by  evaporation  and  dr}'  in  the  oven  to  constant  weight. 

It  should  be  noted  that  any  phytosterol  or  cholesterol  present  in  the 
fat  would  come  down  with  the  paraffin,  but  the  amount  would  be  so  insig- 
nificant that  with  added  parafiin  actually  present,  it  may  be  disregarded. 
The  character  of  the  final  residue  should,  however,  be  confirmed  by 
determining  its  melting-point  and  specific  gravity,  and  by  subjecting 
it  to  examination  in  the  butyro-refractometer.  The  melting-point  of 
parafiin  is  about  54.5°  C;  its  specific  gravity  at  15.5°  is  from  0.868  to 
0.915,  and  on  the  butyro-refractometer  the  reading  at  65°  C.  is  from 
II  to  14.5. 

MICROSCOPICAL  EXAMINATION   OF   OILS   AND   FATS. 

Excepting  in  the  case  of  solid  fats,  the  use  of  the  microscope  has 
hitherto  been  comparatively  restricted.  In  the  examination  of  lard  and 
butter  for  adulterants,  the  use  of  the  microscope  is  often  of  great  value, 
and  will  be  described  more  fully  under  these  special  fats.  In  general 
the  best  fat  crystals  are  obtained  by  slow  cr)^stallization  at  room  tempera- 
ture from  an  ether  solution,  or  from  a  mixture  of  ether  and  alcohol.  The 
first  crystals  formed  may  often  with  advantage  be  filtered  out,  and  washed 
■with  the  alcohol  and  ether  mixture  on  the  filler,  dissolved  finally  in  ether, 
and  the  latter  allowed  to  evaporate  spontaneously.  The  crystals  are 
then  examined  in  a  medium  of  ether. 

t  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  65,  p.  46. 


EDIBLE   OILS    AND   FATS. 


511 


If  it  be  desired  to  separate  the  lic^uid  olcins  from  an  oil,  so  that  crystals 
of  the  solid  fats  are  left  for  examination,  Gladding*  recommends  dis- 
solving the  fat  in  a  mixture  of  two  volumes  of  absolute  alcohol  and  one 
volume  of  ether  in  a  test-tube,  which  is  stoppered  with  cotton  and  set 
for  half  an  hour  in  ice  water,  during  which  time  the  more  solid  stearin 
and  palmitin  will  have  crystallized  out.  This  portion  is  then  separated 
from  the  mother  liquor  by  filtration  through  an  alcohol-wet  fdter- paper, 
and  the  crystals  fmally  treated  as  in  the  preceding  section,  being  examined 
in  a  medium  of  olive  or  cottonseed  oil. 

OLIVE    OIL. 

Source. — Olive  oil  is  derived  from  the  fruit  of  the  cultivated  thorn- 
less  oUve  tree,  Oka  Europcea  sativa,'\  of  which  there  are  a  great  many 
varieties,  originally  grown  in  Asia  Minor,  Greece,  Palestine,  and  southern 
Europe,  and  now  cultivated  extensively  in  California,  Peru,  and  Mexico, 
as  well  as  in  Australia.  Most  of  the  olive  oil  of  commerce,  especially 
of  the  choicest  varieties,  is  supplied  by  southern  France,  Spain,  and  Italy. 
The  tree  is  an  evergreen  of  slow  growth  and  great  longevity. 

The  ripe  olive  fruit  is  purple  or  purplish  black  in  color;  it  is  round  or 
oval  in  shape,  and  from  2.5  to  4  cm.  in  diameter.  The  oil  is  contained  in 
the  parenchyma  cells  of  the  fruit  suspended  in  a  watery  fluid.  A  thick 
skin  incloses  the  fruit,  and  within  is  a  kernel,  which  itself  contains  oil. 
The  fruit  contains  from  40  to  60  per  cent  of  oil.  According  to  Brannt,|: 
the  average  composition  of  the  olive  is  as  follows: 


Flesh, 
Per  Cent. 


Stone, 
Per  Cent. 


Seed, 
Per  Cent. 


Oil 

Organic  substances 
Nitrogen  therein 

Ash 

Water 


56.4 
16.70 

2.68 
24.22 


5-75 
85.89 

4. 16 
4.20 


2.50 


12.26 
79-38 

2.16 
6.20 


2.16 


Preparation. — The  finest  virgin  oil  is  produced  from  hand-picked, 
peeled  olives,  from  which  the  kernels  or  pits  have  been  removed.  A 
somewhat  inferior  grade  of  oil  is  produced  from  the  whole  olive  including 
the  pit,  while  a  distinctly  low  grade  oil  is  obtained  from  the  stones,  or 
kernels,  which  are  ground  into  a  coarse  meal  and  subjected  to  pressure,  or 
to  the  action  of  such  solvents  as  carbon  bisulphide. 

*  Jour.  Am.  Chem.  Soc.    i8q6,  i8,  p.  189. 

t  ."^s  distinguished  for  the  wild  thorny  species,  Europcm  sylvesiris. 

X  Animal  and  Vegetable  Fats  and  Oils. 


512  FOOD   INSPECTION  AND  ANALYSIS. 

In  the  process  of  manufacture  the  fruit,  after  first  being  dried,  is  re- 
duced to  a  pulp  in  a  stone  or  iron  mill,  and  the  pulpy  mass,  contained  in 
baskets  or  bags,  is  subjected  to  pressure  in  an  iron  press.  The  very  highest 
grade  of  virgin  oil  is  that  which  runs  out  from  the  pulp  with  little  or  no 
pressure.  After  the  first  pressing,  the  pomace  is  ground,  treated  with 
water,  and  again  subjected  to  pressure.  Several  pressings  in  this  manner 
may  be  carried  out,  each  yielding  an  oil  inferior  to  that  preceding,  the 
lowest  grade.:,  being  used  for  lubricants  and  in  the  manufacture  of  soap. 

Nature  and  Composition. — The  better  grades  of  olive  oil,  suitable  for 
table  and  medicinal  purposes,  possess  a  pleasant,  bland  taste,  and  a 
distinctive  and  agreeable  odor,  unmistakable  in  character  for  that  of  any 
other  oil.  The  finest  virgin  oil  is  pale  green  in  color,  due  to  the  presence 
of  chlorophyll,  which  is  closely  associated  with  the  oil  globules  in  the 
cellular  tissue  of  the  fruit.  Some  varieties  of  olive  oil  are  nearly  color- 
less, while  others  are  a  deep  golden  yellow. 

Olive  oil  contains  28%  of  solid  glycerides,  chiefly  palmitin  and  a 
very  small  amount  of  arachin,  and  72'  ^  of  licjuid  glycerides,  mainly  olein 
with  a  little  linolein.  Stearin  is  practically  absent.  Lewkowitch  *  states 
that  olive  oil  differs  from  most  vegetable  oils  in  containing  cholesterol  but 
not  phytosterol.  Gill  and  Tufts  f  show  that  olive  oil  is  not  thus  excep- 
tional, but  that  the  unsaponifiable  alcohol  is  phytosterol  and  not  cholesterol. 

Olive  oil  is  very  soluble  in  chloroform,  benwl,  and  carbon  bisulphide, 
but  is  sparingly  soluble  in  alcohol.  Five  parts  of  ether  will  dissolve  3 
parts  of  the  oil. 

For  customs  purposes  the  United  States  Government  considers  a 
gallon  e(j[uivalent  to   7.56  pounds  which  is  slightly  below  the  truth. 

Adulterants. — As  a  rule  the  low  grade  olive  oils  are  most  subject 
lo  adulteration,  bv  reason  of  the  fact  that  it  hardly  pays  to  destroy  or  even 
modifv  the  fine  fjuality  and  delicacy  possessed  by  a  first-class  oil,  which 
woulrj  inevitably  be  the  result  if  even  a  small  amount  of  foreign  oil  were 
added.  Furthermore,  if  olive  oil  be  slightly  rancid  or  for  any  reason  lacking 
in  flavor,  the  arJmixture  of  a  bland  oil  tends  rather  to  minimize  the  fact. 

The  most  common  adulterant  of  olive  oil  in  this  country  is  naturally 
cottonseed  oil,  which  is  often  substituted  wholly  for  it.  In  Europe 
peanut  oil  is  sometimes  used  both  as  an  admixture  and  even  as  a  substi- 
tute, since  it  possesses  in  itself  a  rather  pleasant  flavor,  rendering  it 
cspeciiiUy  adapted  for  use  as  an  adulterant.  Other  cheap  oils  used  for 
this  purpose   are  com,  mustard,  yxjppyseed,  rape,  sesame,  and  sunflower 

*  Chcm.  Anal,  of  Oils,  Fals,  c^nrl  Waxes,  zd  ed.,  p.  452. 
t  Jour.  Arn.  Chcm.  Soc,  XXV,  1903,  p.  498. 


EDIBLE   OILS   AND   FATS. 


51.T 


oil.     The  writer  has  also  found   in  samples  of  alleged  olive  oil  sold  in 
Alassacliusells  cocoanut  oil*  and  even  fish  oil. 

Pure  Olive  Oil  of  the  U.  S.  Pharmacopoeia.— The  requirements  of 
the  Pharmacopoeia  arc  as  follows: 

Specific  gravity,  0.910  to  0.915  at  25°  C.  (77°  F.) ;  iodine  value  not 
less  than  80  nor  more  than  88;  saponification  value  191  to  195.  Very 
sparingly  soluble  in  alcohol,  but  readily  soluble  in  ether,  chloroform,  or 
carbon  disulphide. 

When  cooled  to  about  10°  C.  (50°  F.),  the  oil  should  become  some- 
what cloudy  from  the  separation  of  crystalline  particles,  and  at  0°  C. 
(32°  F.)  it  should  form  a  whitish,  granular  mass. 

If  2  cc.  of  olive  oil  be  shaken  vigorously  with  an  equal  volume  of 
nitric  acid  (sp.  gr.  1.37),  the  oil  should  retain  a  light  yellow  color,  not 
becoming  orange  or  reddish  brown,  and  after  standing  for  six  hours,  should 
change  into  a  yellowish-white  solid  mass  and  an  almost  colorless  liquid 
(absence  of  appreciable  quantities  of  cottonseed  oil  and  other  seed  oils), 

Olive  oil  should  not  show  the  cottonseed  oil  reaction  with  the  Bechi  and 
Halphen  test,  p.  5 18,  nor  the  sesame  oil  reaction  with  the  Baudouin  test,  p.  519. 

U.  S.  Standards. — Olive  oil  is  the  oil  obtained  from  the  sound,  mature 
fruit  of  the  cultivated  olive  tree  {Oka  europoea  L.)  and  subjected  to  the 
usual  refining  processes;  is  free  from  rancidity;  has  a  refractive  index 
(25°  C.)  not  less  than  1.4660  and  not  exceeding  1.4680;  and  an  iodine 
number  not  less  than  79  and  not  exceeding  90.  Virgin  olive  oil  is  olive 
oil  obtained  from  the  first  pressing  of  carefully  selected,  hand-picked  olives 

Reaction  with  Strong  Acid. — Pure  olive  oil,  when  shaken  or  stirred 
with  an  equal  volume  of  concentrated  nitric  or  sulphuric  acid,  turns  from 
a  pale  to  a  dark-green  color  in  a  few  minutes.  If,  under  this  treatment, 
a  reddish  to  an  orange,  or  brown  coloration  is  produced,  the  presence 
of  a  foreign  vegetable  oil  (usually  a  seed  oil)  is  to  be  suspected. 

Bach  gives  the  following  table  showing  the  action  of  strong  nitric  acid 
on  various  oils: 


Kind  of  Oil. 

After  Agitation 
with  Nitric  Acid. 

After  Heating  for 
Five  Minutes. 

Consistency  after 

Standing  Twelve  to 

Eighteen  Hours. 

Olive 

Pale  green 
' '     rose 

WTiite 
Dirty  white 
Yellowish  brown 
Pale  rose 

Orange-yellow 
Brownish  yellow 
Orange-yellow 
Brownish  yellow 
Reddish  yellow 
Reddish  brown 
Golden  vellow 

Solid 

Peanut 

Rape 

Sesame 

<  1 

Liquid 
Buttery 

11 

Sunflower 

Cottonseed 

Castor 

*  A  sample  of  alleged   olive   oil   purchased  in  a  Massachusetts  drug   store   and  found  to 
be  adulterated  with  cocoanut  oil,  had  the  following  constants: 

Specific  gravity 0.91 1       Iodine  number 74.5 

Reichert-Meissl  number 2.90         Butro-refractometer  at  26° !;6.5 


SM 


FOOD   mSPECTlOyJ  AND    ANALYSIS. 


The  Zeiss  Butyro-refractometer  furnishes  one  of  the  most  useful 
and  easily  a})plicd  preliniinan-  means  of  judging  the  purity  of  the  sample. 
If  the  reading  is  beyond  the  limits  of  pure  olive  oil,  it  at  once  indicates 
adult crai ion  and  often  points  to  the  particular  adulterant.  On  the  other 
hand,  it  is  not  always  safe  to  assume  the  oil  to  ])e  ])urc  if  the  reading  is 
correct,  since  mixtures  of  higher  and  lower  refracting  foreign  oils  may 
be  so  skillfully  prepared  as  to  read  well  within  the  limits  of  the  pure  oil 
on  the  refractometer  scale.  The  refractometer  reading  of  pure  cottonseed 
oil  is  almost  five  degrees  higher  than  that  of  pure  olive. 

READINGS  OX  ZEISS  REFRACT0MT-:TER  OF  OLIVE  AND  COTTONSEED 

OILS.* 


Scale  Reading. 

Scale  Reading. 

Temperature 
(Centigrade). 

(Centigrade). 

Olive  Oil. 

Cottonseed  Oil. 

Olive  Oil. 

Cottonseed  OiL 

35 -o 

57-0 

61.8 

25-5 

62.4 

67-5 

34-5 

57-2 

62.1 

25.0 

63.0 

67.9 

34-0 

57-4 

62,3 

24-5 

63-3 

68.2 

33-5 

57-7 

62.5; 

24.0 

63.6 

68.5 

33-0 

s8.o 

62.8 

23-5 

63-9 

68.8 

32-5 

58-3 

63.0 

23.0 

64.2 

69.1 

32.0 

58.5 

63-2 

22.5 

64-5 

69.4 

31-5 

59.0 

63.6 

22.0 

64.8 

69.7 

31.0 

59-2 

64.0 

21-5 

65.1 

70.0 

30-5 

59-4 

64.2 

21.0 

65-4 

70-3 

30.0 

59-9 

64-5 

20.5 

65-7 

70.6 

29-5 

60.1 

64.9 

20.0 

66.0 

70.9 

29.0 

60.3 

65.1 

19-5 

66.3 

71.2 

28.^ 

60.6 

65-3 

19.0 

66.6 

71-5 

28.0 

60.9 

65-7 

18-5 

66.9 

71.8 

27-S 

61. 1 

66.0 

18.0 

67.2 

72.1 

27.0 

61-5 

66.5 

17-5 

67-5 

72-4 

26.5 

62.0 

67.0 

17.0 

67.8 

72-7 

26.0 

62.2 

67-3 

16.5 

68.1 

73-0 

The  Elaidin  Test,  in  the  case  of  pure  olive  oil,  is  very  distinctive,  since 
it  yields  by  far  the  hardest  elaidin  of  all  the  common  oils,  and  solidifies 
the  most  quickly. 

.■\rchbutt  t  shows  the  effect  on  this  test  of  the  mixture  with  olive  oil 
of  various  proportions  of  rape  and  cottonseed  oil,  as  follows: 


Kind  of  OiL 


Minutes  Required  for  Solid- 
ification at  25°  C. 


Olive  oil      

■*-  10%  rape  oil 

"        +20%       "        

"        -f- 10^  cottonseed  oil 

"        +20% 


230 

320 
From  9  to  i\\  hours 

"      9  "  1 1 J      " 
More  than  11  j      " 


Consistency. 


Hard  but  penetrable 
Buttery 

Very  soft. 


Ann.  Rep.  Maiss.  State  Bd.  of  Health,  1899,  p.  647.     f  Jour.  Soc.  Chem.  Ind.,  1897,  p.  447. 


EDI  BLR    OILS   AND   FATS.  515 

Cottonseed  Oil  as  an  adulterant  is  best  detected  by  means  of  the  Hal- 
phen  or  Bechi  tests.  Its  presence  in  notable  quantities  increases  the 
specific  gravity,  refractometer  reading,  and  iodine  number  ver)'  materially. 
Its  high  ]\Iaumene  figure  is  also  distinctive. 

Peanut  Oil,  when  present  to  a  considerable  extent,  betrays  its  presence 
by  its  peculiar  bean-like  flavor.  Most  of  the  constants  of  peanut  oil 
lie  within  the  limits  of  olive  oil,  with  the  exception  of  the  higher  iodine 
number  and  refractometer  reading.  A  considerable  admixture  of  peanut 
oil  raises  the  refractometer  reading  perceptibly  over  that  of  pure  olive. 
Its  presence  is  best  shown  positively  by  tests  for  arachidic  acid  (p.  523), 
noting  that  traces  of  arachin  have  been  reported  in  pure  olive  oil,  insuf- 
ficient, however,  to  interfere  with  the  detection  of  added  peanut  oil. 

Sesame  Oil  differs  more  particularly  from  olive  in  its  higher  specific 
gravity  and  iodine  and  Maumene  numbers,  and  is  readily  detected  by 
distinctive  color  tests  (p.  519). 

Rape  Oil  is  characterized  by  a  much  lower  saponification  value  and 
higher  iodine  number  than  olive. 

Com  Oil  differs  materially  from  olive  in  its  exceedingly  high  iodine 
number  and  refractometer  reading.  Its  specific  gravity  and  saponifica- 
tion numbers  are  also  higher. 

Lard  Oil,  when  present  in  considerable  quantity,  is  often  rendered 
apparent  by  its  characteristic  odor  on  warming.  Its  low  refractometer 
reading  and  iodine  number  are  also  distinctive. 

Poppyseed  Oil  differs  most  widely  from  olive  oil  in  its  refractometric 
reading,  its  high  dispersion,  and  its  Maumene  number,  which  in  the  case 
of  poppyseed  is  87°  and  of  olive  about  42°. 

Cocoanut  Oil  in  mixture  with  olive  perceptibly  raises  the  solidifying- 
point.  When  more  than  12%  of  cocoanut  oil  is  present,  the  sample  will 
become  solid  when  placed  in  ice  water. 

Fish  Oils,  when  present,  are  rendered  apparent  by  reason  of  their 
strong  taste  and  smell,  and  by  their  very  high  iodine  number.  Boiling 
the  sample  with  sodium  hydroxide  develops  a  peculiar  reddish  colora- 
tion, when  fish  oils  are  present. 

Routine  Examination  of  Olive  Oil  for  Adulterants. — First  note  the 
smell  and  taste  of  the  sample,  and  then  take  the  refractometric  reading. 
An  abnormally  high  refraction  indicates  adulteration.  Then  test  wdth 
strong  nitric  acid  (p.  513).  If  the  refraction  is  normal,  and  the  color 
resulting  from  the  acid  reaction  a  pale  green,  the  presumption  is  that 
the  oil  is  pure.     Test  first  for  cottonseed  oil  by  the  Halphen  reaction, 


5l6  FOJD  INSPECTION   .4N D   ANALYSIS. 

and  then  in  succession  tn'  the  various  color  reactions  for  sesame  and  rape 
oils.  If  all  these  are  absent,  and,  by  abnormal  constants,  or  by  color 
with  nitric  acid,  there  is  reason  to  believe  the  oil  is  adulterated,  determine 
carefully  such  of  the  constants  as  are  most  indicative,  by  their  wide 
variation  from  olive,  of  poppysecd,  mustard,  and  corn  oils. 

If  all  these  oils  are  presumably  absent,  and  either  a  high  refractom- 
etcr  reading  or  a  color  reaction  with  nitric  acid  still  indicates  adultera- 
tion, peanut  oil  is  more  than  likely  to  be  present,  and  should  be  tested  for 
cither  l)y  Renard's  or  Bellier's  method. 

The  edible  oils  and  aduherants  are  arranged  in  order  of  their  relative 
price  about  as  follows:  Olive  oil,  peanut  oil,  lard  oil,  sesame  oil,  poppy- 
seed  oil,  rape  oil,  corn  oil,  cottonseed  oil. 

COTTONSEED    OIL. 

Source  and  Preparation. — This  oil,  largely  used  as  a  table  oil  and  as 
an  adulterant  of  olive  oil,  is  derived  from  seeds  of  the  various  species 
of  the  cotton  plant,  Gossipium,  of  which  the  most  common  are  G.  herha- 
ceum,  native  to  Asia,  but  cultivated  extensively  in  southern  Europe  and 
in  the  United  States,  G.  arboreiim,  in  Asia  and  Africa,  and  G.  barhadense, 
in  the  West  Indies.  G.  religiosum  and  hirsutum  are  varieties  of  G.  herb- 
ace  urn. 

The  seeds  are  in  reality  a  by-product  in  cotton  manufacture.  In 
shape  they  are  irregularly  oval,  measuring  from  5  to  8  mm.  greatest  diam- 
eter.    The  seed  skin  or  pod  is  covered  with  the  fiber  of  the  cotton. 

The  seeds  are  first  cleaned  and  separated  from  dirt  by  sifting  machines 
and  from  the  fiber  by  specially  constructed  gins,  after  which  they  are 
cut  into  small  pieces,  freed  from  their  hulls,  crushed  between  rollers,  and 
afterward  submitted  to  hydraulic  pressure  in  bags  to  express  the  oil. 
which  is  clarified  by  filtration  or  refined.  The  refining  consists  in  wash- 
ing the  crude  oil  with  sodium  hydroxide  solution,  whereby  the  impuri- 
ties are  dissolved  and  thus  removed. 

Nature  and  Composition  of  Seeds  and  Oil. — The  seeds  of  the  cotton 
plant  are  rich  in  oil,  containing  from  10  to  29  per  cent,  according  to  the 
variety.  Four  samples  of  American  cottonseed  were  found  to  be  composed 
as  shown  in  table  on  top  of  page  517,  according  to  Brannt.* 

Refined  cottonseed  oil  is  a  pale  yellow  oil  of  thick  consistency,  possess- 
ing a  bland  though  pleasant  taste  and  odor.     It  consists  of  the  glycerides 
of  oleic,  stearic,  pahnitic,  and   linolcic  acids,  and  evidently  also  a  small 
content  of  hydroxyacids,  though  this  has  not  been  investigated  as  yet. 
*  Vegetable  Fats  and  Oils,  p.  223. 


EDIBLF.    OILS    AND  FATS. 


517 


Constituents. 


South 
Carolina. 


Georgia 
1. 


Georgia 
II. 


Georgia 
III. 


Water 

Cottonseed  oil 

Nitrogenous  compounds 

Ammonia  making  compounds 

Gum,  sugar,  and  soluble  starch 

Cellulose,  starch,  and  resin 

Ligneous  tissue 

Ash    (phosphate    of    lime,    silica,    alumina, 
iron,  magnesia,  potash,  soda,  etc.) 


9-5 
20. 1 
17.8 

2-3 

.8 

26.2 

17.6 

5-7 


10. 1 
16.2 
17-4 

2-9 

•9 
27.4 
19.2 

S-9 


9.8 
17. 1 
17.2 

3-2 

-7 

26. 1 

19.8 

6.1 


8.2 
19.6 
18. I 

3-7 

-9 

20.7 

22.4 

6.4 


On  cooling  the  oil  to  a  temperature  below  12°  C.  particles  of  solid 
fat  will  separate.  At  about  0°  to  —  5°  C.  the  oil  solidifies.  When  the 
oil  is  brought  in  contact  with  concentrated  sulphuric  acid,  a  dark,  red- 
dish-brown color  is  instantly  produced. 

U.  S.  Standards. — Cottonseed  oil  is  the  oil  obtained  from  the  seeds  of 
cotton  plants  and  subjected  to  the  usual  refining  processes;  is  free  from 
rancidity,  has  a  refractive  index  (25°  C.)  not  less  than  1.4700  and  not 
exceeding  1.4725;  and  an  iodine  number  not  less  than  104  and  not 
exceeding  no. 

"  Winter-yellow  "  cottonseed  oil  is  expressed  cottonseed  oil  from  which 
a  portion  of  the  stearin  has  been  separated  by  chilling  and  pressure,  and 
has  an  iodine  number  not  less  than  no  and  not  exceeding  116. 

Cottonseed  Stearin. — This  product,  used  as  an  adulterant  of  lard 
as  well  as  a  substitute  therefor,  is  obtained  as  a  by-product  in  the  manu- 
facture of  winter-yellow  cottonseed  oil.  It  is  a  light  yellow  fat,  resembling 
butter  in  consistency. 

Bechi's  Silver  Nitrate  Test, — Hehner^s  Modijication. — Two  grams  of 
silver  nitrate  are  dissolved  in  200  cc.  of  95%  alcohol  free  from  aldehyde, 
40  cc.  of  ether  are  added,  and  the  reagent  made  ver}^  slightly  acid  with 
nitric  acid. 

In  applying  the  test,  a  small  quantity  of  the  melted  fat  or  oil  is  mixed 
in  a  test-tube  with  half  its  volume  of  the  above  reagent,  and  the  tube  is 
immersed  in  boiling  water  for  fifteen  minutes.  With  proper  precautions 
the  presence  of  cottonseed  oil  is  indicated  by  a  more  or  less  strong  reduc- 
tion of  the  silver,  while  an  oil  or  fat  free  from  cottonseed  oil  causes  no 
appreciable  reduction. 

Certain  oils  free  from  cottonseed  that  have  become  rancid  or  decom- 
posed, as  well  as  fats  that  have   been  subjected  to  a  high  temperature, 


5lS  FOOD   INSPECTION    AND   yINALYSIS.] 

sometimes  show  a  slight  reduction  with  Bcchi's  test.     In  cases  of  doubt 
it  is  well  to  apply  the  test  on  the  fatty  acids  as  follows: 

MiUiaus  Modification  oj  Bcchi's  Test.* — Heat  20  grams  of  the 
sample  Axith  30  cc.  of  alcoholic  potash  solution  (20'  ^  potassium  hydroxide 
in  70^'  alcohol),  shaking  at  intervals  till  saponification  is  complete. 
Continue  the  heating  for  some  minutes  afterward  until  the  alcohol  is 
driven  otT,  and  dissolve  the  soap  in  250  cc.  of  hot  water.  Add  a  slight 
e.xcess  of  10%  sulphuric  acid,  and  wash  the  separated  fatty  acids  three 
times  by  dccantation  with  water.  Then  proceed  with  a  portion  of  the 
fatty  acids  as  in  Bechi's  test. 

Halphen's  Test. — This  is  a  much  more  delicate  test  for  cottonseed 
oil  than  cither  of  the  preceding,  as  httle  as  2%  of  cottonseed  oil  being 
rendered  apparent  in  olive  oil.  A  mixture  is  made  of  equal  volumes 
of  amyl  alcohol  and  carbon  bisulphide  in  which  1%  of  sulphur  has  been 
dissolved.  From  3  to  5  cc.  of  meked  fat  are  mixed  with  an  equal  volume 
of  the  above  reagent  in  a  test-tube,  loosely  stoppered  with  cotton,  and 
heated  in  a  bath  of  boiling  saturated  brine  for  fifteen  minutes.  If 
cottonseed  oil  is  present,  a  deep-red  or  orange  color  is  produced.  In 
its  absence  little  or  no  color  is  developed. 

Previous  heating  of  the  oil  diminishes  the  delicacy  of  the  Halphen 
test,  and  Holde  and  Pelgry  t  state  that  if  cottonseed  oil  has  been  heated 
at  250°  for  ten  minutes,  it  will  fail  to  respond  to  the  test.  Fulmer  finds 
that  it  is  necessary  to  heat  to  265  to  270°  to  render  it  wholly  inactive  to 
the  test. 

GastaldiJ  finds  that  it  is  the  pyridin  bases  in  amyl  alcohol  that  render 
it  useful.  The  test  can  be  made  by  heating  5  cc.  oil,  4  cc.  carbon  bisul- 
phide containing  1%  of  sulphur,  and  i  drop  of  pyridin  for  from  15  minutes 
to  one  hour  in  a  water-bath. 

SESAME  OIL. 
f^  Sesame  or  bcnne  oil  is  pressed  from  the  .seeds  of  Sesamum  indicum 
and  S.  orientate,  both  of  which  are  now  regarded  as  varieties  of  the  same 
species,  and  .S",  radiattim.  The.se  plants  are  native  to  .southern  Asia,  but 
now  cultivated  in  nearly  all  trof)ical  countries.  The  larger  portion  of 
commercial  .sesame  oil  is  manufactured  in  England,  France,  Germany, 
anrl  Au.stria. 

The  seeds  are  yellow  to  dark  brown,  and  in  .some  cases  black,  inclined 
to  the  oval  in  form,  the  average  longest  diameter  being  about  4  mm. 

•  Moniteur  Scientifique,  1888,  p.  366.  t  Jour.  Soc.  Chem.  Ind.,  18,  1899,  p.  711. 

^  X  Chem.  Zlg.,  35,  191 1,  p.  688. 


EDIBLE   OILS  ^ND  FATS. 


519 


The  seeds  are  commonly  subjected  lo  cold  pressure  once,  and  after- 
wards twice  pressed  when  warm,  thus  yielding  three  grades  of  oil.  From 
47  to  60  ])er  cent  of  oil  is  contained  in  the  seeds. 

According  to  Brannt*  the  composition  of  sesame  seeds  is  as  follows: 


Sesamum 
(Jrieiitalc. 

Sesamum 
Indicum. 

Oil 

55-63 
30-95 

21.42 

3-39 
7-52 
3-90 

50.84 

35-25 

22.30 
3-56 
6.85 
7.06 

Organic  substances 

Protein  tlicrein 

Nitrogen  tlierein 

Ash 

Water 

100.00 

100.00 

Sesame  oil  consists  of  the  glycerides  of  oleic,  stearic,  palmitic,  and 
myristic  acids.  It  is  golden  yellow  in  color,  free  from  odor,  and  pos- 
sesses a  delicate  and  characteristic  flavor,  on  account  of  which  the 
highest  grades  are  by  some  considered  equal  to  olive  oil  as  a  condiment. 
It  is  accordingly  sold  to  some  extent  as  an  edible  oil.  It  was  formerly 
used  as  an  adulterant  of  olive  oil,  but  has  of  late  years  been  largely  dis- 
placed by  cheaper  oils  for  purposes  of  adulteration.  When  cooled  to 
—  3°C.,  sesame  oil  congeals  to  a  yellowish- white  mass.  Concentrated 
sulphuric  acid  converts  it  into  a  brownish-red  jelly. 

U.  S.  Standards. — Refractive  index  (25°)  1.4704  to  1.4717;  iodine 
number  103  to  112. 

Adulterants  to  be  looked  for  in  sesame  oil  arc  cottonseed,  poppy- 
seed,  corn,  and  rape  oils. 

Tocher's  Test.f — ^One  gram  of  pyrogallic  acid  is  dissolved  in  15  cc. 
of  concentrated  hydrochloric  acid  and  mixed  with  15  cc.  of  the  sample 
m  a  separatory  funnel.  After  standing  for  a  minute,  the  aqueous  solu- 
tion is  withdrawn  and  boiled.  If  sesame  oil  is  present,  the  solution 
rfhowG  a  red  coloration  by  transmitted,  and  blue  by  reflected,  light. 

Baudouin's  Test.| — Dissolve  o.i  gram  of  cane  sugar  in  10  cc.  of  hydro- 
chloric acid  (specific  gravity  1.20)  in  a  test-tube,  and  shake  thoroughly 
with  :,'0  grams  of  the  oil  to  be  tested  for  one  minute.  Then  allow  the 
mixture  to  stand.  The  aqueous  solution  quickly  separates  from  the  oil, 
ftnd  in  the  presence  of  1%  or  more  of  sesame  oil  will  be  colored  deep  red. 

Certain  pure  Tunisian  and  Algerian  olive  oils  have  been  found  to 
£ause  a  slight  coloration  with  this  test,  but  of  a  different  shade  from  sesame. 
Moreover,  if  the  test  is  applied  to  the  fatty  acids,  no  coloration  in  the  case  of 
olive  oil  is  produced,  while  with  sesame  the  color  is  the  same  as  with  the  oil. 

*  Vegetable  Fats  and  Oils,  p.  251.  f  Chem.  Zeit.  Rep.,  5,  1891,  p.  15. 

X  Zeits.  angevv.  Chem.,  1892,  p.  509. 


5;2o 


FOOD   INSPECTION  AND   ANALYSIS. 


Villavecchia  and  Fabris  Test.* — This  test  was  suggested  on  account 
of  the  fact  that  the  color  reaction  in  the  Baudouin  test  was  attributed  to 
the  agency  of  the  levulose  produced  by  the  inversion  of  the  sugar  by 
hydrochloric  acid.  .\s  furfurol  is  the  chief  product  of  the -reaction  between 
levulose  and  hydrochloric  acid,  it  was  substituted  as  follows:  Dissolve  2 
grams  of  furfurol  in  100  cc.  of  95%  alcohol,  and  shake  o.i  cc.  of  this  solu- 
tion in  a  test-tube  with  10  cc.  of  the  oil  to  be  tested  and  10  cc.  of  hydro- 
chloric acid  (specific  gravity  1.20)  for  half  a  minute.  The  aqueous 
layer,  on  settling  out,  will  be  colored  deep  red,  if  sesame  is  present. 

Or  0.1  cc.  of  the  alcohol  furfurol  solution  is  mixed  with  10  cc.  of 
oil  and  i  cc.  of  hydrochloric  acid  in  a  separatory  funnel,  shaken  well, 
and  the  separation  aided  by  the  addition  of  chloroform,  which  causes 
the  aqueous  layer,  showing  color  with  sesame  oil,  to  float. 

Since  furfurol  produces  with  hydrochloric  acid  alone  a  violet  colora- 
tion, it  is  necessary  to  use  it  in  dilute  solution  as  above. 

RAPE  OIL. 
Rape  or  colza  oil  is  expressed  from  the  seeds  of  the  Brassica  or  rape- 
plant,  of  which  there  are  three  principal  varities,  Brassica  napis,  B.  cam- 
pcstris,  and  B.  rapa,  one  or  another  of  which  are  cultivated  in  nearly 
every  countr}'  of  Europe,  excepting  Greece.  Large  amounts  are  also 
grown  in  India  and  China.  The  seeds  are  small,  round  grains,  from 
2  to  2.5  mm.  in  diameter,  yielding  from  30  to  45  per  cent  of  oil.  The 
seeds,  according  to  Brannt,t  have  the  following  average  composition: 


1 

'        Fresh  Seeds. 

Old  Seeds. 

Oil 

36.80 

49-30 

2.50 
4.80 
9.10 

38-50 
53-25 

3-II 

3-90 

4-35 

Organic  substances 

Nitrogen  therein 

Ash 

^  Vater 

100.00 

100.00 

In  the  process  of  preparation  the  seeds  are  first  crushed,  and  the  oil 
removed  by  pressing  or  extraction.  The  crude  oil  is  of  a  brownish- 
yellow  color,  and  when  fresh  is  almost  free  from  taste  and  smell,  so  that 
it  scr\'es,  when  cold  pressed,  as  an  edible  oil,  or  an  adulterant  of  such 
oils.  It  develops  a  disagreeable  and  peculiar  taste  and  odor  on  long 
standing,  due  to  the  presence  of  certain  albuminous  and  mucilaginous 
::ubstanccs  which  it  contains.  These  may  be  removed  by  refming,  usually 
by  treatment  with  sulphuric  acid,  but  the  refined  oil  has  an  unpleasant 
taste  and  odor. 


*  Jour.  Soc.  Chem.  Ind.,  1894,  pp.  13-69. 


t  Vegetable  I-'al;  and  Oils,  p.  240. 


E  DIB  LP.    OILS   AND   FATS. 


521 


The  principal  components  of  rape  oil  are  the  glycerides  of  stearic, 
oleic,  erucic,  and  rapic  acids.  The  chief  adulterants  are  cottonseed 
and   poppysecd  oils. 

Palas  Test  for  Rapeseed  Oil.* — Mix  in  the  cold  30  cc.  of  a  1%  solu- 
tion of  fuchsin,  20  cc.  of  sodium  bisulphite  (specilic  gravity  1.31),  200  cc. 
of  water,  and  5  cc.  sulphuric  acid.  If  the  sample  of  oil  to  be  tested  be 
shaken  with  the  reagent,  a  rose-red  coloration  is  obtained  in  the  presence 
of  rape  oil,  said  to  be  delicate  to  the  extent  of  detecting  2%  of  the  oil  in 
mixtures. 


CORN    OR  MAIZE   OIL. 

Corn  oil  is  derived  from  the  seed  of  the  American  grain  Zea  mays,  or 
Indian  corn,  the  constitution  of  the  \ellow  and  while  varieties  of  which 
is,  according  to  Andes,t  as  follows: 


Yellow  Corn, 
Per  Cent. 

White  Corn, 
Per  Cent. 

Organic  matter 

Starch  

82.93 

61.95 
10.71 
1.32 

9-5° 
6.25 

80.76 

62.23 
9.62 
1.04 
10.60 
7.60 

100.00 

Albuminoids 

Ash     

Water 

Oil 

100.00 

Nearly  all  the  oil  is  contained  in  the  germ  of  the  seed,  the  oil  con- 
stituting in  fact  over  20%  of  the  germ.  Corn  oil  consists  chiefly  of  the 
glycerides  of  palmitic  and  oleic  acids.  There  is  some  doubt  as  to  the 
presence  of  stearin.  It  is  golden  yellow  in  color,  and  possesses  a  pleasant 
odor  and  taste,  resembling  in  flavor  freshly  ground  grain. 

It  is  prepared  by  subjecting  to  hydraulic  pressure  the  germ  separated 
in  the  manufacture  of  starch  and  of  glucose,  the  germs  yielding  about 
15%  of  pure  oil.  While  most  of  the  oil  of  commerce  is  a  by-product 
from  starch  and  glucose  factories,  a  small  amount  is  recovered  from  the 
residae  of  fermentation  vats  in  the  manufacture  of  alcohol.  Corn  oil  is 
coming  to  be  used  more  and  more  as  an  adulterant  of  olive  oil,  and, 
according  to  Lewkowitsch,  of  lard. 

It  is  claimed  by  Hopkins,J  by  Hoppe-Seylcr,  and  others,  that  com  oil, 

*  Analyst,  XXII,  p.  45- 

f  Vegetable  Fats  and  Oils,  p.  131. 

J  Jcur.  Am.  Chem.  Soc,  1&98,  20,  p.  948. 


5-^ 


FOOD   INSrFCTON  AND  ANALYSIS. 


unlike  most  vegetable  oils,  contains  cholesterol.  Olive  oil  was  long 
supposed  to  be  unique  as  a  vegetable  oil  in  containing  this  substance. 
Hopkins,  on  the  assumption  that  cholesterol  occurs  in  corn  oil,  sug- 
gested that  a  test  for  corn  oil  as  an  adulterant  of  certain  vegetable  oils 
lav  in  the  identification  of  cholesterol. 

Gill  and  Tufts*  claim  that,  while  the  alcohol  of  corn  oil  is  not  phytos- 
terol,  neither  is  it  cholesterol,  but  a  third  substance,  known  as  sitosterol,f 
occurring  in  wheat  and  rye. 

There  are  no  color  reactions  identifying  corn  oil  as  such.  Its  pres- 
ence in  other  oils  is  indicated  only  by  its  influence  on  the  various  con- 
stants, the  iodine  number  and  refractometric  reading  especially  being 
much  higher  than  those  of  other  edible  oils. 


PEANUT  OIL. 

Peanut  or  arachis  oil  is  obtained  from  the  seeds  of  the  Arachis  hypo- 
gcra  (peanut,  ground  nut,  or  earth  nut)  cultivated  in  most  tropical  coun- 
tries, notably  in  South  America,  China,  India,  and  Japan.  The  plant 
is  a  creeping  herb,  developing  its  blossoms  in  the  axes  of  the  leaves.  The 
fruit  buds  grow  down  into  the  earth,  where  the  fruit  is  ripened,  forming 
the  well-known  peanuts  of  commerce,  the  composition  of  which,  accord- 
ing to  Brannt,  is  as  follows: 


Per  Cent. 

Per  Cent. 

Oil 

Organic  substances 

Albumin  therein 

37-48 
52.86 

27.25 

2.43 

7-37 

to    41.63 
"      53-12 

27.85 

"           2.!^0 
"           2.75 

Ash 

Water 

100.00 

100.00 

Peanut  oil  is  composed  chiefly  of  the  glyceridcs  of  oleic,  palmitic, 
hypogtX-ic,  and  arachidic  acids.  The  oil  is  extracted  by  pressure,  the 
first  cold-drawn  oil  being  practically  colorless,  and  possessing  a  pleasant 
ta.ste  suggestive  of  kidney  beans.  It  is  especially  adapted  for  use  as 
a  salad  or  table  oil.  A  second  pressure  of  the  moistened  residue  from 
the  first  yields  an  inferior  oil,  yellowish  in  color,  also  somewhat  used 
for  edible  jHirjtoscs,  anrl  sometimes  commercially  called  "butterine  oil." 

U.  S.  Standards. — Refractive  index  (25°)  1,4690  to  1.4707;  iodine 
number  87  to  100. 

*  Jour.  Am.  Chcm.  Soc,  XXV,  1903.        f  Burian,  Monatsh.  Chem.,  i8,  1897,  p.  551. 


F.niBI.F.    OILS    AND   FATS.  523 

Adulterants  of  ])canr.i  oil  are  cottonseed,  j^oppyseed,  rape,  and 
sesame  oils.  Very  little  pure  peanut  oil  is  found  in  commerce  in  the 
United  States.  It  is  to  be  looked  for  as  an  adulterant  of  French  and 
Italian  olive  oils. 

Characteristic  Tests. — Peanut  oil,  when  ])ure  or  nearly  pure,  may 
as  a  rule  be  readily  identified  from  other  oils.  When  present  in  large 
admixture  in  other  oils  it  is  not  dilTicult  to  detect,  but  when  onlv  a  small 
amount  is  present,  in  olive  oil  for  instance,  its  detection  becomes  a  more 
troublesome  matter. 

This  difficulty  arises  from  the  fact  that  the  constants  of  peanut  oil 
are  nearly  the  same  as  those  of  olive,  with  the  single  exception  of  the 
refractometric  reading.  Furthermore,  there  is  no  readily  applied  color 
test   identifying  peanut  oil. 

All  the  other  common  adulterants  of  olive  oil,  as  cottonseed,  sesame, 
corn,  poppyseed,  and  rape  oils,  are  readily  identified,  when  present  in 
small  amounts,  either  by  special  color  tests,  or  by  reason  of  the  fact  that 
certain  of  their  constants  differ  very  widely  from  those  of  olive  oil.  Much 
more  care  and  precaution  are  necessary  in  dealing  with  small  admixtures 
of  peanut  oil  than  with  almost  any  other  adulterant. 

The  Renard  Test*  has  long  been  in  use  for  detecting  and  estimating 
peanut  oil  in  mixtures.  In  its  original  form  this  test  did  not  give  entirely 
satisfactory  results,  and  earlier  led  to  some  erroneous  conclusions.  In 
recent  years,  however,  it  has  been  so  modified  and  improved  as  to  be 
capable  of  quite  positive  results  when  carefully  carried  out.  While 
arachin  is  said  to  occur  in  minute  traces  in  olive  oil,  its  presence  is  not 
sufficiently  marked  to  interfere  with  the  use  of  the  Renard  method  in 
detecting  any  decided  admixture  of  peanut  oil. 

The  following  modification  of  the  Renard  method,  devised  by  Tolman,t 
has  been  adopted  by  the  A.  O.  A.  C: 

Twenty  grams  of  the  oil  are  saponified  in  a  250-cc.  Erlenmeyer  flask 
with  200  cc.  of  alcoholic  potassium  hydroxide  (40  grams  potassium 
hydroxide  in  i  liter  of  95%  redistilled  alcohol).  Neutralize  with  dilute 
acetic  acid,  using  phenolphthalein  as  an  indicator,  and  wasli  into  a  500-cc. 
flask  containing  a  boiling  mixture  of  100  cc.  water  and  120  cc.  20% 
solution  of  lead  acetate. 

Boil  for  a  minute  and  cool  the  contents  of  the  flask  by  immersing 
in  cold,  or,  preferably,  ice  water,  whirling  the  flask  occasionally  so  that 

*  Comp.  Rend.,  73,  1871,  p.  1330. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65;   also  Bui.  77,  and  Bui.  107  (rev.). 


5-4  FOOD   INSPECTION  AND   ANALYSIS. 

the  soap  when  cold  adheres  to  the  sides  of  the  flask.  The  water  and 
excess  of  lead  acetate  can  then  be  poured  out,  leaving  the  soap  in  the 
flask.  Wash  by  shaking  and  decantation,  flrst  with  cold  water  and 
then  with  90^0  alcohol.  Add  200  cc.  of  ether,  cork  the  flask,  and  allow 
to  stand  \\'ith  occasional  shaking  till  the  soap  is  disintegrated,  after  which 
boil  on  a  water-bath  under  a  reflux  condenser  for  five  minutes.  Cool 
the  soap  solution  down  to  a  temperature  between  15°  and  17°,  and  allow 
it  to  stand  for  about  twelve  hours. 

Filter  and  thoroughly  wash  the  i)recipitate  with  ether,  after  which  the 
soap  in  the  filler  is  washed  back  into  the  original  flask  with  a  stream  of 
hot  water  acidulated  with  hydrochloric  acid. 

Add  an  excess  of  dilute  hydrochloric  acid,  partially  fill  the  flask  with 
hot  water,  and  heal  unlil  fatty  acids  form  a  clear  oily  layer.  Fill  the  flask 
with  hot  water,  allow  the  fatty  acids  to  harden  and  separate  from  the 
precii)iialed  lead  chloride,  wash,  drain,  repeat  washing  with  hot  water, 
and  dissolve  ihe  fatly  acids  in  100  cc.  of  boiling  c)o''/(  by  volume  alcohol. 
Cool  to  15°  C,  shaking  thoroughly  to  aid  crystallization. 

From  5  to  10  per  cent  of  peanut  oil  can  be  detected  by  this  method,  as 
it  efi'ccts  a  complete  separation  of  the  soluble  acids  from  the  insoluble, 
which  interfere  with  llu'  crystalhzation  of  the  arachidic  acid.  Filter, 
wash  the  precipitate  twice  with  10  cc.  of  90'  ^  alcohol,  and  then  with  70% 
alcohol.  Finally  dissolve  off  the  precipitate  with  boiling  absolute  alcohol, 
evaporate  lo  dryness  in  a  tared  dish,  dry  and  weigh.  To  the  weight  add 
0.0025  gram  for  each  10  cc.  of  90%  alcohol  u.sed  in  the  crystallization  and 
washing,  if  done  at  15°  C,  and  0.0045  gram  for  each  10  cc.  if  done  at 
20°.  The  approximate  amount  of  peanut  oil  is  found  by  multiplying  the 
weight  of  arachidic  acid  by  20. 

Arachidic  acid  crystals  thus  obtained  should  be  examined  micro- 
scopicallv.     The  melting-point  should  lie  between  71°  and  72°  C. 

Methods  of  J.  Bellier,* — Qualilative  Test. — Saponify  i  gram  of  the 
oil  with  5  cc.  of  an  alcoholic  ])olash  solution  containing  85  grams  po- 
tassium hydroxide  per  liter  of  strong  alcohol,  conducting  the  saponi- 
fication in  a  small  Erlenmeyer  flask  on  the  water-bath.  After  saponi- 
fication, boil  for  two  minutes,  neutralize  with  dilute  acetic  acid,  using 
phenolphthalein  as  an  indicator,  and  cool  by  setting  the  flask  in  water 
at  a  temjierature  of  from  17°  to  19°.  After  a  short  time,  a  precipitate 
nearly  always  comes  down.  Then  add  to  the  solution  50  cc.  of  70% 
alcohol,  containing  1%  by  volume  of  strong  hydrochloric  acid  (specific 

*  .\nn.  f  him.  Anal.,  1899,  4,  p.  49;  Zcits.  fiir  untersuch.  Nahr.,  1899,  2,  p.  726. 


EDIBLE    OILS   AND  FATS.  525 

gravity  1.20).  Cork  the  flask,  shake  vigorously,  and  again  cool  by  setting 
the  flask  in  the  above  cooling-bath.  In  the  absence  of  a  precipitate,  the 
oil  may  be  pronounced  free  from  peanut.  If  10%  or  more  of  peanut  oil 
is  present,  a  more  or  less  characteristic  precipitate  forms,  and  often  with 
less  than  10%  a  cloudiness  in  the  solution  is  perceptible  after  standing 
betv^een  17°  and  19°  for  half  an  hour.  Pure  olive  oil  remains  perfectly 
clear  as  a  rule- 

A  few  varieties  of  olive  oil  from  Tunis  especially  high  in  solid  fat 
acids,  as  well  as  cottonseed  oil  and  sesame  oil,  give  similar  turbidity  on 
the  addition  of  the  70%  alcohol.  To  distinguish  between  these  oils 
and  peanut  oil,  heat  the  mixture  on  the  water-bath  till  complete  solution 
takes  place,  and  again  cool  to  17°  to  19°.  In  the  case  of  peanut  oil  the 
cloudiness  or  precipitate  again  occurs  to  the  same  extent  as  before,  while 
in  the  other  cases  the  solution  should  remain  clear  or  nearly  so. 

Quantitative  Determination. — Saponify  5  grams  of  the  oil  with  25  cc. 
of  the  above  alcoholic  potash  solution  in  a  250-cc.  Erlenmeyer  flask, 
neutralize  exactly  with  acetic  acid,  and  cool  quickly  in  water.  After 
standing  an  hour,  pour  upon  a  9-cc.  filter  and  wash  the  precipitate  with 
70%  alcohol  containing  18%  by  volume  of  hydrochloric  acid,  the  tem- 
perature of  the  solution  being  not  less  than  16°  nor  more  than  20°.  Con- 
tinue the  washing  till  the  wash  water  no  longer  shows  turbidity  when 
diluted  with  water. 

Dissolve  the  precipitate  in  25  to  30  cc.  of  hot  95%  alcohol,  dilute  with 
water  until  the  alcohol  is  70%,  let  stand  in  water  at  20°,  filter,  wash  with 
70%  alcohol,  dr>'  at  100°,  and  weigh. 

Bellier  states  that  he  has  recognized  with  certainty  as  small  an  admix- 
ture as  2%  of  peanut  oil  by  this  method. 

MUSTARD  OIL. 

The  fixed  oil  of  mustard  is  a  by-product  expressed  from  the  seeds 
of  the  black  and  white  mustard  {Sinapis  nigra  and  5.  alba)  in  the  process 
of  preparation  of  mustard  flour  as  a  spice.  The  seeds  contain  from 
25  to  35  per  cent  of  oil. 

Mustard  oil  somewhat  resembles  rape  in  composition,  containing 
glycerides  of  erucic,  behenic,   and  probably  rapic  acid. 

Black  mustard  oil  is  brownish  yellow  in  color,  having  a  mild  flavor, 
and  .an  odor  but  shghtiy  suggestive  of  mustard.  White  mustard  oil  is 
golden  yellow,  and  has  a  somewhat  sharp  taste. 


5-^6 


FOOD   I\SPECTION  ^ND   ANALYSIS. 


Mustard  oil  is  an  alleged  adulterant  of  edible  oils,  though  by  no  means 
a  common  one. 


POPPYSEED   OIL. 

This  oil  is  obtained  from  the  seeds  of  the  opium  poppy  {Papaver 
somnijcrum),  native  in  the  countries  east  of  the  Mediterranean,  and  cul* 
ti\-ated  extensively  for  opium  and  for  oil  in  all  parts  of  Europe,  Asiatic 
Turkey,  Persia,  Egypt,  India,  and  China.  Most  of  the  oil  of  commerce 
comes  from  France  and  Germany. 

There  are  two  cliief  varieties  of  poppy,  the  black  (P.  nigrum)  and 
the  white  (P.  album),  the  finest  oil  being  produced  from  the  white.  The 
seeds  are  somewhat  flattened  in  form  and  kidney-shaped,  yielding  from 
40  to  60  per  cent  of  oil.  According  to  Brannt  the  seeds  have  the  follow- 
ing composition: 


White  Poppy- 
seed. 

Black  Poppy- 
seed. 

Oil 

55-62 
32.11 

16   89 

3-42 

8.85 

100.00 

51-36 

35-14 

17-50 
4.00 

9-50 

Organic  substances 

Protein  therein 

Ash 

Water 

100.00 

The  oil  is  obtained  by  crushing  the  seeds  and  applying  pressure. 
The  best  grade  of  cold-drawn  oil  is  pale  yellow  in  color,  possessing  a 
pleasant  taste  when  fresh,  and  being  practically  free  from  odor.  Lower 
grades  shade  into  deeper  yellow  and  even  reddish  color,  possessing  a 
strong  taste  and  odor.  Poppysced  oil  is  much  used  in  Europe  as  a  table 
oil,  and  does  not  readily  turn  rancid.  It  is  composed  of  the  glycerides  of 
stearic,  palmitic,  and  linoleic  acids.  Poppyseed  oil  has  been  used  to  some 
extent  as  an  adulterant  of  olive  oil.  It  is  itself  not  infrequently  adulter- 
ated with  sesame  oil. 


SUNFLOWER  OIL. 


Sunflower  oil  is  derived  from  the  seed  kernels  of  the  plant  of  the  same 
name  (Ilclianthus  annuus),  originally  grown  in  Mexico,  but  now  culti- 
vated most  extensively  on  a  commercial  scale  in  southern  Russia. 


EDIBLE   OILS    /IND   FATS. 


527 


According  lo  S.   M.   Babcock  *  ihc   composition  of  sunflower  seeds 
is  as  follows: 


1         Air-dry. 

Dried. 

Water 

12.68 
3.00 
15.88 
29.21 
18.71 
20.52 

3-43 
18.19 

33-45 
21-43 
23-50 

Ash 

Albuminoids  (N  X  6.25) 

Crufic  filler 

Nitrogen-free  extract 

Fat  (ether  extract) 

100.00 

100.00 

The  seeds  are  long,  black,  and  oval  in  shape,  yielding  from  18  to  28 
per  cent  of  oil.  The  liquid  fatty  acids  of  sunflower  oil  consist  for  the 
most  part  of  linoleic,  but  little  oleic  acid  being  found. 

The  seeds  are  first  shelled,  then  crushed,  and  iinally  submitted  to 
pressure  both  cold  and  hot. 

Sunflower  oil  is  pale  yellow  in  color,  has  a  mild,  pleasant  taste,  and 
is  nearly  free  from  odor.  The  cold-drawn  oil  is  the  variety  most  used 
for  edible  and  culinary  purposes  in  Russia,  and  as  an  adulterant  of  olive 
oil.  Its  use  as  an  adulterant  is,  however,  limited,  and  the  writer  has  no 
knowledge  of  its  having  been  found  in  olive  oils  used  in  the  United  States. 


ROSIN  OIL. 

Rosin  oil  is  prepared  by  the  distillation  of  common  rosin,  and  is  an 
alleged  adulterant  of  olive  oil.  It  may  be  detected  when  present  by 
shaking  i  to  2  cc.  of  the  sample  with  acetic  anhydride  while  warming. 
Cool,  remove  the  anhydride  by  a  pipette,  and  add  a  drop  of  sulphuric 
acid  (specific  gravity  1.53).     Rosin  oil  gives  a  fugitive-violet  color. f 

Cholesterol  also  responds  to  this  color  reaction. 

Renard's  Test  for  Rosin  Oil. — Prepare  a  solution  of  stannic  bromide 
by  allowing  dry  bromine  to  fall  drop  by  drop  upon  tin  in  a  dry,  cool  flask, 
and  dissolving  the  product  in  carbon  bisulphide. 

Add  a  drop  of  this  reagent  to  i  cc.  of  the  oil.  In  presence  of  rosin 
oil  a  violet  color  will  be  produced. 

Polarization  Test  for  Rosin  Oil.f — The  oil  is  dissolved  in  definite 
proportion  in  petroleum  ether,  and  polarized  in  a  200-mm.  tube.     Rosin 

*  The  Sunflower  Plant,  its  Cultivation,  Composition,  and  Uses.     U.  S.  Dept.  of  .A.gric., 
Div.  of  Chem.,  Bui.  60,  p.  18. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  32. 


5^8 


FOOD  INSPECTION  .^ND  /IN  A  LYSIS. 


oil  polarizes  from  +30  to  +40  on  the  cane  sugar  scale,  while  other  oils 
have  a  readinsr  between  + 1  and  —  i. 


COCOANUT    OIL. 

Cocoamit  oil  is  the  fat  expressed  from  the  kernels  of  the  cocoanut 
or  fruit  of  the  cocoa  palm  {Cocos  nucijera),  indigenous  to  the  South  Sea 
Islands  and  to  the  East-Indian  archipelago,  but  grown  in  many  tropical 
countries. 

It  is  sometimes  kno^^'n  as  "copra  oil,"  from  the  copra  or  pulp,  which 
contains  from  60  to  70  per  cent,  of  fat.  According  to  Brannt,  the  com- 
position of  the  pulp  is  as  follows: 


Indian  Copra. 

African  Copra. 

Oil 

68.75 
23-65 

9.16 

1-45 
6.15 

66.80 

25-25 

10.20 
1.50 
6.45 

Organic  substances 

Albuminous  substances 

Ash 

Water 

100.00 

100.00 

In  the  preparation  of  the  oil  the  moist  copra  is  separated  from  the 
shell,  crushed  in  mortars  and  subjected  to  pressure,  yielding  a  milky  mass. 
This  is  then  heated  in  boilers  and  the  oil  removed  by  skimming.  In  some 
localities  the  pulp  is  first  dried  and  then  pressed. 

Cocoanut  oil  is  usually  white  and  possesses  a  mild  taste  and  pleasant 
odor.  The  oil  easily  becomes  rancid  bat  is  seldom  adulterated.  The  cold- 
drawn  Malabar  oil  is  of  greenish  color  and  is  used  by  the  natives  as  an  edible 
oil  or  substitute  for  batter.     This  variety  is  seldom  found  in  commerce. 

Tne  oil  contains,  besides  palmitin  and  olein,  large  proportions  of 
myristin  and  laurin.  Unlike  the  other  vegetable  oils,  it  contains  also 
notable  quantities  of  the  glycerides  of  the  volatile  fatty  acids  caproic, 
capric,  and  caprylic,  hence  the  high  saponification  value  and  Rcichert 
number.  The  most  characteristic  constant  is  the  Polenske  number. 
The  iodine  number  (8-9.5)  i^  strikingly  low,  although  oil  from  the  rind, 
according  to  Richardson,*  runs  as  high  as  40. 

According  to  Andes,  crystals  of  cocoanut  oil  appear  under  the  micro- 
scope as  a  thick  network  of  long  needles. 

*    Jour.  Ind.  Hng.  Chcm.,  3,  191 1,  p.  574. 


EDIBLE   OILS  AND   FATS,  529 

COCOA     rCACAO)    BUTTER. 

This  preparation  is  not,  properly  speaking,  in  itself  an  edible  fat.  It 
is  a  by-product  in  the  manufacture  of  cocoa,  being  removed  by  pressure 
from  the  crushed  and  ground  cocoa  nibs.  The  fat  in  cocoa  beans  varies 
from  36  to  50  per  cent.  The  expressed  fat  is  yellowish  white,  of  a  tallow- 
likc  consistency,  has  a  pleasant  taste  and  an  odor  suggestive  of  chocolate. 
It  keeps  a  long  time  without  turning  rancid.  In  composition  it  consists 
of  the  glycerides  of  stearic,  palmitic,  and  lauric  acids,  with  traces  of  the 
glycerides  of  arachidic  and  butyric  acids. 

Its  demand  for  pharmaceutical  purposes  is,  however,  sufficiently  great 
to  render  the  use  of  cocoa-butter  as  an  adulterant  of  food-fats  extremely 
rare.  It  should  be  borne  in  mind  as  a  possible  adulterant  in  examining 
various  oils. 

It  is  subject  to  adulteration  with  paraffin,  tallow,  and  cottonseed 
stearin. 

TALLOW. 

The  rendered  fats  of  various  animals,  especially  the  cow  and  sheep, 
constitute  what  is  generally  knowm  as  tallow.  The  untreated  fatty  tis- 
sues are  more  properly  known  as  suet,  the  tallow  being  the  clear  fat 
separated  entirely  by  heat  from  the  cellular  material. 

Tallow  consists  almost  entirely  of  olcin,  palmitin,  and  stearin.  Mut- 
ton tallow  is  usually,  but  not  always,  harder  than  beef  tallow. 

Excepting  in  the  manufacture  of  material  for  oleomargarinej  wherein 
the  heart  and  caul  fats  of  beef  are  almost  exclusively  used,  the  fats  from 
different  parts  of  the  animal  are  not,  as  a  rule,  separated. 

Fresh  tallow  has  very  little  free  fatty  acid,  but  when  it  becomes  rancid, 
the  fat  contains  sometimes  as  high  as  12%  of  free  acid,  reckoned  as  oleic. 

Tallow  is  of  chief  interest  to  the  food  analyst  in  connection  with  its 
use  as  an  adulterant  of  lard. 

BUTTER. 

Nature  and  Composition.  —  Butter  is  the  product  obtained  by  the 
churning  of  cream  or  milk,  whereby  the  fat  particles  are  caused  to  adhere 
together  into  a  compact  mass,  inclosing  a  certain  portion  of  the  casein,  the 
excess  of  milk  serum  being  subsequently  largely  removed  by  washing  and 
mechanical  w^orking. 


■30 


FOOD   I\SPECT/ON   AND  ANALYSIS. 


Butter  fat  is  of  extremely  complex  composition,  containing  a  larger 
variety  of  glycerides  than  any  other  fat.  Besides  olcin,  palmitin,  and 
stearin,  the  usual  glycerides  of  the  insoluble  or  fixed  fatty  acids  found 
in  most  fats,  butter  contains  notable  quantities  of  the  glycerides  of  a 
number  of  the  volatile  fatty  acids,  chief  among  which  are  butyrin,  caproin, 
caprin,  and  capr}lin,  to  which  are  due  its  distinctive  taste,  and  which 
bv  exposure  to  light  and  air  readily  become  decomposed  into  their  fatty 
acids — butyric,  caproic,  capric,  and  capr)lic,  respectively.  This  decom- 
position in  butter  causes,  or,  more  properly  speaking,  accompanies,  what 
is  commonly  known  as  "rancidity." 

The  process  of  separation  of  butter  fat  into  its  component  glycerides 
is  a  matter  of  extreme  difficulty,  and  results  obtained  by  different  chemists 
van.'  widely.  Separation  has  been  attempted  by  fractional  distillation, 
by  methods  depending  on  the  difference  in  chemical  affinity  of  the  various 
acids,  and  on  the  dilTcrence  in  solubility  of  the  various  lower  homo- 
logues  in  water  at  ditlerent  temperatures.* 

According  to  Browne,  the  composition  of  butter  fat  is  as  follows: 


Acid.                             ^^^ Tid^^  °^ 

Percentage  of 
Triglycerides. 

Dioxvstearic 

I  .CO 

1.04 

33-95 
1. 91 

40.51 
10.44 

2-73 
0-34 
0-53 
2.32 
6.23 

Oleic 

32-50 

1.83 

38.61 

9.89 

2-57 
0.32 
0.49 
2.09 
5-45 

Stearic 

Palmitic 

Mvristic 

Laurie 

Capric 

Caprvlic 

Caproic 

Butyric 

Totals 

94-75 

100.00 

Upwards  of  300  analyses  of  butter  are  summarized  by  Konig  in  the 
foflowing  table: 


I     Water, 
I  Per  Cent. 

Minimum I       4.15 

Maximum 35-^5 

Mean 13.59 


Fat. 
Per  Cent. 


Casein,     ;      Milk, 
Per  Cent.      Per  Cent. 


69.96 
86.15 
84-39 


0.19 
4.78 
0.74 


•50 


Sugar,      Lactic  Acid, 
Percent.        Per  Cent. 


0-45 
1. 16 


Salts, 
Per  Cent. 


0.02 

15.08 

0.66 


*  Browne,  \  Contribution  to  the  Chemistry  of  Butter  Fat,  Jour.  Am.  Chem.  Soc.,  21, 
1899,  p.  807. 


EDIBLE   OILS  AND    FATS.  531 

Effects  of  Feeding  Oil  Cakes  on  the  Composition  of  Butter. — Experi- 
ments have  shown  that  the  substance  which  causes  cottonseed  oil  to  respond 
to  the  Halphen  test  jjasses  into  the  milk  fat  on  feeding  cows  with  cottonseed 
cake,  but  the  substance  that  gives  the  Baudouin  reaction  is  never  carried 
into  the  milk  on  feeding  with  sesame  cake.  A  number  of  investigators 
have  found  that  feeding  with  cocoanut  cake  raises  somewhat  the  Polenske 
number  of  the  milk  fat.  There  is  good  evidence,  however,  that,  while 
the  addition  of  vegetable  oils  to  butter  introduces  phytosterol,  as  detected 
by  Bomer's  phytosterol  acetate  test,  this  substance  can  not  be  introduced 
into  the  milk  fat  by  feeding.  These  facts  should  be  borne  in  mind  in  the 
examination  of  butter  for  foreign  fats. 

ANALYSIS    OF    BUTTER. 

Preparation  of  the  Sample. — A.  O.  A.  C.  Method* — If  large  quan- 
tities of  butter  are  to  be  sampled,  a  butter-trier  or  sampler  may  be  used. 
The  portions  thus  drawn,  about  500  grams,  are  to  be  perfectly  melted 
in  a  closed  vessel  at  as  low  a  temperature  as  possible,  and  when  melted, 
the  whole  is  to  be  shaken  violently  for  some  minutes  till  the  mass  is  homo- 
geneous, and  sufficiently  solidified  to  prevent  the  separation  of  the  water 
and  fat.  A  portion  is  then  poured  into  the  vessel  from  which  it  is  to  be 
weighed  for  analysis,  and  should  nearly  or  quite  fill  it.  This  sample 
should  be  kept  in  a  cold  place  till  analyzed. 

Water.— y4.  O.  A.  C.  Method.— Ahoxit  two  grams  of  the  sample  are 
weighed  in  a  flat-bottomed  platinum  dish,  such  as  is  used  for  determining 
water  in  milk,  and  the  dish  and  its  contents  kept  in  contact  with  the  live 
stream  of  a  water-bath  till  a  constant  weight  is  attained. 

Patrick's  Rapid  Method.-\ — This  method  is  especially  suited  for  the 
use  of  dairymen,  inspectors  and  others  not  provided  with  laboratory 
facilities. 

Ten  grams  of  the  thoroughly  mixed  butter  are  weighed  into  a  250-cc. 
aluminium  beaker,  which,  together  with  a  glass  rod  has  been  previously 
tared,  and  boiled  over  (but  not  in)  the  flame  of  an  alcohol  lamp  provided 
with  a  conical  asbestos  chimney,  hokling  the  beaker  by  means  of  a  wire 
clamp  in  a  nearly  horizontal  position  to  avoid  loss  from  spattering  or 
foaming,  and  whirhng  constantly  to  prevent  overheating.  The  rod 
serves  to  break  up  lumps  of  curd  which  form,  thus  facilitating  the  drying. 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  46,  p.  43;    Bui.  107  (rev.),  p.  123. 
t  Jour.  Am.  Chem.  See,  28,  1906,  p.  i6ii;  29,  1907,  p.  11 26. 


FOOD  INSPECTION  AND   ANALYSIS. 


The  heating  should  be  so  conducted  as  to  avoid  any  considerable  dis- 
coloration of  the  curd.  With  suit- 
able heating  the  water  may  be  re- 
moved in  less  than  15  minutes, 
after  which  the  beaker  is  cooled  in 
water  and  weighed.  A  balance 
sensitive  to  10  milligrams,  such 
as  is  used  in  weighing  cream  for 
testing  by  the  Babcock  method,  is 
sufficiently  accurate  for  weighing 
the  butter. 

Gray^s  Method* — i.  The  Spe- 
cial Apparatus  for  this  method, 
shown  in  Fig.  100,  consists  of  a  flask 
{A)  connected  by  a  close-fitting 
rubber  stopper  {B)  with  a  gradu- 
ated tube  (C),  and  this  in  turn 
with  a  condenser  jacket  (£)  by  a 
rubber  stopper  {D).  The  tube  C 
is  closed  by  a  glass  stopper,  the 
zero  mark  being  the  end  of  the 
stopper.  Each  mark  of  the  grad- 
uation represents  0.02  cc.  or,  when 
10  grams  of  butter  are  used,  0.2%. 
2.  Process. — Weigh  10  grams 
of  the  well  mixed  butter  on  a 
j)iecc  of  parchment  j^aper  13  cm. 
sfjuare,  introduce  into  the  flask, 
and  add  6  cc.  of  a  mixture  of  5 
parts  of  amyl  acetate  and  i  part 
of  amyl  valerianate,  free  from 
water-soluble  impurities.  Connect 
the  ajjjjaratus  as  shown  in  Fig. 
IOC,  nil  the  condenser  jacket  with 
cool  water  to  within  2.5  cm.  of  the 
toj),  and  remove  the  glass  stopper 
/'".     Heat  the  flask  over  a  Bunsen 

burner,  thus  melting  the  butter  and  boiling  the  water.     Watch  the  con- 


FlG.   100. — fjray's   Apparatus   for  the  Kapid 
Determination  of  Water  in  Butter. 


*  U.  S.  Dept.  of  Agric,  Bur.  of  Animal  Ind.,  Circ.  loo. 


EDIBLE   OILS   AND   FATS.  533 

densation  of  the  steam  in  the  graduated  i)art  of  llie  tube  C,  and  do  not 
allow  the  steam  to  get  higher  than  the  15%  mark.  In  case  of  continued 
foaming,  allow  the  mixture  to  cool,  add  2  cc.  of  the  amyl  reagent,  and 
continue  heating.  After  the  water  in  the  sam])le  has  boiled  out,  the 
temperature  rises  and  the  amyl  reagent  boils,  driving  the  last  traces  of 
water  and  water-vapor  from  the  flask  and  bottom  of  the  stopper.  Some 
of  the  amyl  reagent  is  carried  into  the  tube  C  with  the  steam,  and  some 
is  boiled  over  after  the  water  has  been  driven  off.  This  amyl  reagent 
in  the  tube  is  no  disadvantage.  When  the  mixture  in  the  flask  becomes 
a  brown  color  and  all  the  crackling  noises  in  boiling  cease,  which  usually 
requires  5  to  8  minutes,  it  is  safe  to  conclude  that  all  water  has  been 
driven  from  the  flask. 

Disconnect  the  flask  A  from  the  stopper  B,  place  the  glass  stopper  F 
in  the  tube  C,  giving  it  a  turn  to  insure  its  being  held  firmly;  invert  the 
tube  C,  first  being  sure  that  the  mouth  of  the  small  tube  inside  the  bulb 
is  held  upwards,  pour  the  water  from  the  condensing  jacket  E,  and  remove 
the  jacket.  When  the  tube  C  is  inverted,  the  water  and  reagent  flow 
into  the  graduated  part  of  the  tube.  To  separate  these  and  to  get  the 
last  traces  of  water  down  into  the  graduated  part,  the  tube  C  is  held  with 
the  bulb  in  the  palm  of  the  hand,  and  the  stoppered  end  away  from  the 
body,  raised  to  a  horizontal  position,  and  swung  at  arm's  length  sharply 
downward  to  the  side.  This  is  repeated  a  number  of  times  until  the 
dividing  line  between  the  w^ater  and  reagent  is  very  distinct,  and  no  reagent 
can  be  seen  with  the  water  or  vice  versa.  The  tube  should  then  be  held 
a  short  time  wdth  "the  stoppered  end  downward,  and  the  amyl  reagent  in 
the  bulb  agitated  in  order  to  rinse  down  any  adhering  water. 

The  reading  should  not  be  taken  until  the  tube  and  contents  have  cooled 
so  little  warmth  is  felt.  When  10  grams  of  butter  are  used,  the  percentage 
is  read  directly  at  the  lower  meniscus. 

With  butter  very  low  in  moisture  it  may  be  desirable  to  use  15  grams, 
and  with  butter  very  high,  5  grams. 

Fat. — This  may  be  determined  either  directly  or  indirectly.  For 
the  direct  determination,  a  weighed  amount  of  the  sample,  from  2  to  3 
grams,  is  first  dried  at  100°  in  sand  or  asbestos,  contained  in  a  thin  and 
fragile  round-bottomed  evaporating-shell  (Hoffmeister's  Schalchcni.  If 
desired,  the  moisture  may  be  determined  in  this  connection  by  loss  in 
weight  after  drying.  The  shell  is  afterwards  inclosed  in  a  piece  of  fat-free 
filter-paper,  and  crushed  in  pieces  between  the  fingers  in  such  a  manner 
as  to  avoid  loss.     The  pieces  arc  gathered  in  a  mass  and  folded  together 


534  FOOD    INSPECTION   AND   ANALYSIS. 

in  the  filter-paper  to  form  a  packet  of  a  size  readily  transferable  to  a 
Soxhlet  extractor,  in  which  the  fat  is  removed  in  the  usual  manner  and 
weighed,  after  drying,  in  a  tared  ilask. 

Or,  the  fat  may  be  indirectly  determined  by  subtracting  the  sum  of 
the  water,  casein,  and  ash  from  loo. 

Casein. — The  residue  from  the  determinalion  of  water  by  the 
A  .().  A.  C.  method  is  stirred  with  ])etroleum  ether  until  the  fat  is  dissolved, 
and  transferred  tc  a  tared  Gooch  crucible.  After  thorough  washing  with 
petroleum  ether,  the  crucible  is  dried  at  ioo°,  cooled,  and  weighed,  thus 
obtaining  the  casein  and  ash.  The  loss  on  ignition  at  a  dull  red  heat 
represents  the  casein. 

If  desired  nitrogen  may  be  determined  in  the  residue  after  removal  of 
the  fat  with  petroleum  ether,  and  casein  calculated  from  the  nitrogen, 
using  the  factor  6.37. 

Ash. — The  residue  left  on  the  Gooch  crucible  after  ignition,  obtained 
as  described  in  the  preceding  section  is  the  ash.  It  consists  largely  of 
salt,  which  may  be  calculated  from  the  ])ercentage  of  chlorine  determined 
by  titration. 

Milk  Sugar  and  Lactic  Acid  compose  most  of  the  undetermined 
matter  remaining  after  deducting  from  the  total  solids  the  sum  of  the 
fat,  casein,  and  ash.  Determine  milk  sugar,  if  desired,  in  an  aqueous 
extract  of  the  butter  by  Fehling's  solution. 

Determination  of  Salt. — In  a  tared  dish  or  beaker  weigh  out  about 
5  grams  of  butter,  taking  a  gram  or  so  at  a  time  from  different  parts  of 
the  sample.  Add  hot  water  to  the  weighed  pari,  and  after  it  has  melted,  the 
contents  of  the  dish  are  poured  into  a  separatory  funnel,  shaken  and 
allowed  to  stand  till  the  fat  collects  at  the  top,  after  which  the  underlying 
aqueous  solution  is  drawn  off  into  an  Erlenmeyer  flask,  leaving  the  fat 
in  the  funnel  bulb.  Hot  water  is  again  added,  and  from  ten  to  fifteen 
extractions  are  made,  using  about  20  cc.  of  water  each  time,  all  the  water 
being  collected  in  the  Erlenmeyer  flask. 

.\  few  drops  of  a  solution  of  potassium  chromate  are  then  added  for 
an  indicator,  and  the  sodium  chloride  volumetrically  determined  by  a 
standard  silver  nitrate  solution. 

Salted  butter  contains  from  0.5  to  6%  of  salt. 

Examination  of  Butter  Fat. — The  butter  fat  is  best  obtained  free 
from  curd  anrl  salt  Vjy  filtering  when  hot,  the  sample  being  best  melted 
in  a  Ix-aker  on  the  water-bath.  The  water,  with  the  curd  and  salt,  will 
settle  to  the  bottom.     The  clear  fat  is  then  filtered  at  a  temperature  not 


EDIBLE  OILS  AND  FATS.  535 

exceeding  50°  C,  and  subjected  to  such  examination  as  may  be  desired 

to  determine  its  purity. 

U.  S.   Standard  Butter  Fat  has  a  Reichert-Meissl  number  not  less 

40° 
than  24  and  a  specific  gravity  not  less  than  0.905  at  - — 5  C. 

ADULTERATION   OF    BUTTER. 

Ihe  artificial  coloring  of  butter  is  an  art  practiced  for  so  many  years, 
and  is  so  far  in  accord  with  the  popular  demand,  that  it  can  hardly  be 
considered  as  an  adulteration.  The  most  recent  custom  of  adding  pre- 
servatives other  than  salt  to  butter  is,  however,  very  properly  considered 
in  most  locaHties  as  reprehensible,  unless  the  character  and  amount  of 
the  preservative  be  made  clear  to  the  purchaser  by  a  suitable  label. 

The  most  common  and  time-honored  sophistication  is  the  substitu- 
tion in  whole  or  in  part  of  foreign  fat,  as  in  the  case  of  oleomargarine, 
and,  more  recently,  in  the  fraudulent  sale  of  renovated  or  process  butter 
for  the  freshly  made  article. 

U.  S.  Standard  Butter  is  butter  containing  not  less  than  82.5%  of 
butter  fat.  By  acts  of  Congress  approved  August  2,  1886,  and  May  9, 
1902,  butter  may  also  contain  added  coloring  matter. 

Artificial  Coloring  Matter  in  Butter. — Formerly  carrot  juice 
and  annatto  were  used  almost  entirely  as  butter  colors.  The  carrot  furnished 
10  the  farmer  a  ready  means  of  coloring  his  dairy  butter,  and  its  use  was 
long  in  vogue  for  this  purpose,  before  the  commercial  butter  colors  were 
available.  Other  vegetable  colors,  such  as  turmeric,  marigold,  saffron, 
and  safflower,  are  r^aid  to  have  been  used  for  this  purpose,  but,  with  the 
possible  exception  of  turmeric,  the  writer  is  not  aware  of  authentic  cases 
in  which  they  have  been  found  in  recent  years.  While  annatto  as  a  butter 
cclor  is  still  in  use,  it  is  rapidly  giving  place  to  various  oil-soluble,  azo  coal- 
tar  colors,  which  are  admirably  adapted  to  the  purpose.  All  butter 
colcrs  are  now  put  on  the  market  in  solution  in  oil,  usually  cottonseed 
in  this  country  and  sesame  in  Europe. 

Detection. — Martin'^  devised  a  general  scheme,  applicable  for  the 
detection  of  various  colors  in  butter.  His  reagent  consists  of  a  mixture  of  2 
parts  of  carbon  bisulphide  with  1 5  parts  of  ethyl  or  methyl  alcohol.  25  cc.  of 
this  solution  are  shaken  with  about  5  grams  of  the  butter  to  be  tested,  and, 
after  standing  for  some  minutes,  the  mixture  separates  into  two  layers,  of 

*  Analyst,  12,  p.  70. 


5.-6  FOOD  INSPECTION  /1ND   ANALYSIS. 

which  the  lower  consists  of  the  fat  in  solution  in  the  carbon  bisulphide, 
while  the  upper  is  the  alcohol,  which  dissolves  out  and  is  colored  by  the 
arlincial  dye  employed.  If  saffron  is  present,  the  alcoholic  extract  will  be 
colored  green  by  ni:ric  acid  and  red  by  hydrochloric  acid  and  su^^ar. 

Coal-tar  dyes,  if  present,  may  be  fixed  on  silk  or  wool  by  boiling  bits 
of  the  liber  in  the  alcoholic  extract,  diluted  with  water  and  acidulated 
with  hydrochloric  acid. 

Turmeric  is  to  be  suspected,  if  ammonia  turns  the  alcoholic  extract 
bro\Mi;  marigold,  if  silver  nitrate  turns  it  black,  and  annatto,  if  on  evapo- 
rating the  alcohoUc  solution  to  dryness  anrl  applying  to  the  residue  a  drop 
of  concentrated  sulphuric  acid,  a  greenish-blue  coloration  is  produced. 

Turmeric  is  further  tested  for  in  the  residue  from  the  alcohohc  extract 
as  above  obtained,  by  boiling  the  residue  in  a  few  cubic  centimeters  of 
a  dilute  solution  of  boric  acid  (or  a  solution  of  borax  acidulated  with 
hydrochloric  acid),  and  soaking  a  strip  of  filter-paper  therein.  On  drying 
the  paper,  if  it  assumes  a  cherry-red  color,  turning  dark  olive  by  dilute 
alkali,  the  presence  of  turmeric  is  assured. 

Carrotin  (the  coloring  matter  of  the  carrot  root)  does  not  impart  its 
color  to  the  alcohol  layer  in  Martin's  test.  Aloore  *  has  pointed  out 
this  exception,  and  shown  that  while  with  carrotin  present  the  alcohol 
layer  in  Martin's  test  remains  colorless,  as  in  the  case  of  uncolored  butter, 
that  when,  however,  a  drop  of  very  dilute  ferric  chloride  is  added,  and  the 
test-tube  shaken,  if  carrotin  be  present,  the  alcohol  will  gradually  absorb 
the  yellow  color  from  the  butter.  Care  must  be  taken  to  avoid  an  excess 
of  ferric  chloride,  as  very  little  of  this  reagent  will  suffice. 

Allen  states  that  a  butter  color  commercially  known  as  "carrotin" 
consists  in  reality  of  i  part  of  annatto  in  4  parts  of  oil. 

Detection  of  Annatto  in  Butter. — Treat  2  or  3  grams  of  the  melted 
and  filtered  fat  (freed  from  salt  and  water)  with  warm,  dilute  sodium 
hydroxide.  After  stirring,  pour  the  mixture  while  warm  upon  a  wet 
filter,  using  to  advantage  a  hot  funnel.  If  annatto  is  present,  the  filter 
will  absorb  the  color,  so  that,  when  the  fat  is  washed  off  by  a  gentle  stream 
of  water,  the  paper  will  be  dyed  straw  color.  It  is  well  to  j)ass  the  warm 
alkaline  filtrate  two  or  three  times  through  the  fat  on  the  filter  to  insure 
removal  of  the  color. 

If,  after  dr}dng  the  filter,  the  color  turns  pink  on  application  of  a 
drop  of  stannous  chloride  solution,  annatto  is  assured. 

*  Analyst,  ii,  p    165. 


EDIBLE   OILS  AND  FylTS.  537 

Detection  of  Coal-tar  Colors  in  Butter. — Geisler's  Method* — A  few 
drops  of  the  clarified  fat  are  spread  out  on  a  porcelain  surface  and  a  pinch 
of  fullers'  earth  added.  In  the  presence  of  various  azo-colors,  a  pink 
to  violet-red  coloration  will  be  produced  in  a  few  minutes.  Some  varieties 
of  fullers'  earth  react  much  more  readily  with  the  azo-dyes  than  do  others. 
In  fact  some  do  not  respond  at  all.  When  once  a  satisfactory  sample  of 
this  reagent  is  obtained,  a  large  stock  should  be  secured  of  the  same  variety. 

Low's  Method.^ — ^A  small  amount  of  material  to  be  tested  is  melted 
in  a  test-tube,  an  equal  volume  of  a  mixture  of  i  part  of  concentrated 
sulphuric  acid  and  4  parts  of  glacial  acetic  acid  are  added,  and  the  tube 
is  heated  nearly  to  the  boiling-point,  the  contents  being  thoroughly  mixed 
by  shaking;  the  tubes  are  set  aside,  and  after  the  acid  solution  has  settled 
out  it  will  have  been  colored  wine-red  in  the  presence  of  azo-color,  while 
with  pure  butter  fat,  comparatively  no  color  will  be  produced. 

Doolittle's  Method  for  Azo-colors  and  Annatto.J — The  melted  sample 
is  first  filtered.  Two  test-tubes  are  taken  and  into  each  are  poured  about 
2  grams  of  the  filtered  fat,  which  is  dissolved  in  ether.  Into  one  test- 
tube  are  poured  i  or  2  cc.  of  dilute  hydrochloric  acid,  and  into  the  other 
about  the  same  volume  of  dilute  potassium  hydroxide  solution.  Both 
tubes  are  well  shaken  and  allowed  to  stand.  In  the  presence  of  azo- 
dye,  the  test-tube  to  which  the  acid  has  been  added  will  show  a  pink 
to  wine-red  coloration,  while  the  potash  solution  in  the  other  tube  will 
show  no  color.  If  annatto  has  been  used,  on  the  other  hand,  the  potash 
solution  will  be  colored  yellow,  while  no  color  will  be  apparent  in  the 
acid  solution. 

Cornelison's  Test  for  Artificial  Colors.§ — Melt  10  grams  of  the  clear, 
dry  fat,  and  shake  well  in  a  separatory  funnel  with  10  to  20  grams  of  99.5% 
acetic  acid.  If  the  materials  are  too  hot,  the  fat  will  dissolve,  but  at 
about  35°  it  separates  quickly  and  almost  completely.  Draw  off  the  clear 
acid,  and  after  noting  its  color,  test  by  adding  to  one  portion  of  5  cc.  a  few 
drops  of  concentrated  nitric  acid,  and  to  another  portion  a  few  drops  of 
concentrated  sulphuric  acid. 

Natural  yellow  butter  gives  by  this  test  a  colorless  extract,  which 
remains  colorless  on  adding  nitric  or  sulphuric  acid.  The  acid  extracts  of 
annatto,  curcumin,  and  carrot  are  various  shades  of  yeUow,  both  before 

*  Jour.  Am.  Chem.  Soc,  20,  1898,  p.  110. 

t  Ibid.,  20,  p.  889. 

I  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  152. 

§  Jour.  Am.  Chem.  Soc,  30,  1908,  p.  1478. 


53S  FOOD  INSPECTION  /iND  AN /I  LYSIS. 

and  after  addition  of  nitric  acid,  ^vhilc  with  sulphuric  acid  they  take  on 
a  pink  coloration  on  standing,  which  in  the  case  of  curcumin  is  very  decided. 
Soudan  I  and  butter  yellow  give  pink  extracts,  which  remain  pink  on 
adding  the  stronger  acids,  while  cerasine  orange  G,  yellow  O.B.,  yellow 
A.B.  and  certain  other  coal-tar  dyes  give  extracts  of  various  shades  of 
vcllow,  which  on  treatment  wiili  the  heavy  acids  in  some  cases  remain 
colorless,  but  in  others  become  pink,  while  the  oil  globule  which  separates 
Remains  colorless  or  takes  on  a  |)inkish  color  according  to  the  dye. 

Preservatives  and  their  Detection. — Fresh  or  unsalted  butter 
and  renovated  butter  are  often  found  with  an  added  j^reservative,  the 
one  most  commonly  used  for  this  jnirj^ose  being  the  so-called  "  boric 
mixture  "  (borax  and  boric  acid)  already  discussed  under  milk  adultera- 
tion. Salted  butter  is  occasionally,  though  not  so  often,  found  preserved. 
Other  preservatives  used  in  butter  are  formaldehyde,  and  salicylic  and 
sulphurous  acids.     These  latter  are,  however,  rarely  found. 

Boric  Acid. — This,  if  present,  is  best  detected  in  the  aqueous  solution 
that  settles  to  the  bottom  when  butter  is  melted  at  the  temperature 
of  the  boiling  water  bath,  the  supernatant  fat  being  decanted  off. 
Richmond*  claims  to  be  able  to  distinguish  free  boric  acid  from  borax 
as  follows:  If  on  applying  turmeric-paper  directly  to  the  aqueous  liquid 
the  paper  turns  red,  the  color  being  especially  evident  on  drying,  free 
boric  acid  is  indicated.  As  a  confirmatory'  test  the  reddened  turmeric- 
paper  is  treated  with  dilute  caustic  alkali,  whereupon  it  turns  a  dark  olive- 
green  if  boric  acid  is  present. 

In  the  absence  of  a  red  color  by  the  above  test,  or  when  this  color  is 
faint,  the  aqueous  solution  is  acidified  slightly  with  hydrochloric  acid 
and  the  turmeric-paper  applied  as  before.  If  borax  be  present  to  an 
appreciable  extent,  the  red  color  will  now  be  quite  marked,  even  though 
not  appearing  before.  In  other  words,  testing  with  turmcric-pai)cr  with- 
out acidifying  \\ith  hydrochloric  acid  shows,  according  to  Richmond, 
a  slight  coloration  due  to  the  free  acid  alone,  while  the  more  intense  color 
formed  by  first  acidifying  is  due  to  the  combined  acid  or  borax. 

Dclerminalion  oj  Boric  Acid. — Ten  grams  of  the  butter  fat  are 
weighed  in  a  beaker  and  transferred  with  hot  water  to  a  separator^-  funnel 
in  which  the  fat  is  extracted  with  lo  to  15  portions  of  hot  water  as 
described  on  page  534'  The  combined  aqueous  extract  is  evaporated 
to  dryness  in  a  platinum  dish,  the  residue  made  alkaline,  and  ignited  at 

*  Dairy  Chemistry,  p.  254. 


EDIBLE   OILS   /fND   FATS.  539 

a  dull  red  heat.  Boil  the  ash  with  water,  filter,  and  wash  with  hot  water, 
keeping  the  volume  of  the  filtrate  under  60  cc.  Make  sure  that  the  solu- 
tion is  perfectly  neutral  to  methyl  orange  by  treatment,  if  necessary, 
with  sulphuric  acid  and  tenth-normal  alkali,  add  30  cc.  of  glycerin,  a 
few  drops  of  the  phenolphthalein  indicator,  make  up  to  100  cc,  and 
titrate  with  tenth-normal  sodium  hydroxide  according  to  Thompson's 
method  (p.  829). 

Butter  being  practically  free  from  phosphates,  the  preliminary  treat- 
ment for  removing  phosphoric  acid  in  Thompson's  method  may  be 
omitted. 

Formaldehyde. — The  aqueous  solution  from  which  the  fat  of  the 
butter  meUed  at  low  temperature  has  been  poured  off,  is  added  to  some 
milk  previously  found  free  from  formaldehyde,  and  the  test  for  the  latter 
with  hydrochloric  acid  and  ferric  chloride  is  tried  directly  in  the  milk. 

Salicylic  Acid. — Detection. — See  method  No.  2  for  detection  in  milk, 
page  183. 

Determination  oj  Salicylic  Acid. — Method  oj  the  Paris  Municipal 
Laboratory. — Repeatedly  exhaust  20  grams  of  butter  in  a  separatory 
funnel  with  a  solution  of  sodium  bicarbonate,  thus  obtaining  soluble 
sodium  salicylate,  if  salicylic  acid  be  present.  Acidulate  the  aqueous 
extract  with  dilute  sulphuric  acid,  and  extract  with  ether.  Evaporate 
the  ether,  and  to  the  residue  add  a  little  mercuric  nitrate,  forming  a  pre- 
cipitate nearly  insoluble  in  water.  Filter  this  off,  wash  the  precipitate 
with  water,  and  decompose  into  free  salicylic  acid  with  dilute  sulphuric 
acid.  Redissolve  in  ether,  evaporate  the  solvent  as  before,  and  dr}-  the 
residue  at  a  temperature  of  80°  to  100°.  Extract  the  residue  with  petroleum 
ether,  dilute  the  ethereal  liquid  with  an  equal  volume  of  95^^  alcohol, 
and  titrate  with  tenth-normal  alkali,  using  phenolphthalein  as  an  indicator. 

I  cc.  of  tenth-normal  alkali  =0.0138  gram  salicylic  acid. 

Sulphurous  Acid. — The  aqueous  liquid,  separated  from  the  butter  fat, 
is  distilled,  and  the  distillate  treated  with  bromine  water  and  barium 
chloride.  A  precipitate  on  the  addition  of  the  latter  reagent  indicates  the 
presence  of  sulphurous  acid  or  a  sulphite  in  the  butter. 

Glucose  in  Butter.* — Cramplon  states  that  glucose  has  been  found  by 
him  in  butter  intended  for  export  to  tropical  countries,  added  to  pre- 
' I 

*  Jour.  Am.  Chem.  Soc,  20,  1898,  p.  201. 


5 JO  FOOD  INSPECTION  AND   ANALYSIS. 

vent  decomposition.  In  one  sample  m^de  for  export  to  Guadeloupe 
he  found  over  io*"7  of  glucose. 

For  its  detection  or  estimation  lo  grams  of  the  sample  are  weighed 
out  and  transferred  to  a  separatory  funnel  with  hot  water,  and  shaken 
out  with  successive  portions  of  hot  water.  These  are  combined,  and 
the  aqueous  extract  made  up  to  250  cc.  The  reducing  sugar  may  be 
determined  by  Fehling's  solution  or  by  polarization,  using  in  the  latter 
case  alumina  cream  as  a  clarificr.  While  a  slight  reduction  should  be 
disregarded,  any  considerable  reduction  may  be  undoubtedly  ascribed 
to  glucose. 

BUTTER  "FILLED"  WITH  WATER.— Various  preparations  have  been 
placed  on  the  market  to  aid  in  incorporating  water  with  butter.  So  called 
"  black  pepsin  "  has  been  used  for  this  purpose.  By  churning  the  butter 
with  water  and  a  certain  amount  of  the  preparation  in  such  a  manner 
as  to  destroy  the  grain,  it  is  possible  to  introduce  two  or  three  times  the 
normal  amount  of  water. 

RENOVATED  OR  PROCESS  BUTTER. 

This  product  is  also  variously  termed  "  boiled,"  "  aerated,"  and 
"  sterilized  "  butter.  There  are  various  modifications  of  the  process  of 
manufacture,  but  the  object  is  to  melt  up  and  treat  rancid  butter  in  such 
a  manner  that  for  a  time  at  least  it  is  sweet.  The  following  manner  of 
treatment  is  typical,  and  shows  in  the  main  the  necessary  steps  in  carrying 
out  the  process,  though  details  of  manipulation  vary  in  different  locahties. 

The  butter  is  melted  in  large  tanks  surrounded  with  hot  water  jackets 
at  a  temperature  varying  from  40°  to  45°  C.  By  this  means  the  curd 
and  brine  settle  to  the  bottom,  whence  they  are  drawn  off,  while  the  lighter 
particles  rise  to  the  tojj  in  the  form  of  a  froth  or  .scum  and  are  removed 
by  skimming. 

The  clear  butter  fat  is  then,  as  a  rule,  removed  to  other  jacketed 
tanks,  and,  while  still  in  a  molten  condition,  air  is  blown  through  it,  which 
removes  the  di.sagreeable  odors.  The  melted  fat  is  then  churned  with 
an  admixture  of  milk  (more  often  .skimmed)  till  a  perfect  emulsion  is 
formed,  after  which  it  is  rapidly  chilled  by  running  into  ice  cold  water, 
with  the  result  that  it  becomes  granular  in  form.  It  is  then  drained 
and  "  rij>ened  "  for  .some  hours,  after  which  it  is  worked  free  from  excess 
of  milk  and  water,  salted,  and  packed. 

Under  .some  .state  laws  this  product,  to  be  legally  .sold,  mu.st  conform 
to  rules  of  labeling  as  strict  as  tho.se  prescribed  for  oleomargarine.     In 


EDIBLE  OILS  AND    FATS.  541 

Other  localities  it   may  be   sold   with   imjninity.     Not   infrequently  it   is 
sold  as  choice  creamery  butter,  and  sometimes  at  the  same  price. 

U.  S.  Standard  Renovated  or  Process  Butter  should  contain  not 
more  than  i6',c  oi  water,  and  at  least  82.5^0  of  butter  fat. 

OLEOMARGARINE. 

According  to  the  U.  S.  revenue  laws,  artificial  butter  composed  wholly 
or  in  part  of  fat  other  than  butter  fat  must  be  branded  oleomargarine. 
The  name  butterinc,  although  used  in  advertising  matter,  does  not  have 
the  sanction  of  the  government.  The  i)roduct  is  commonly  known  in 
England  as  margarine.  As  a  rule  the  oleomargarine  of  commerce  is 
comixxscd  of  refined  oleo  oil,  usually  churned  up  with  neutral  lard,  milk, 
and  a  small  amount  of  pure  butter,  the  whole  being  salted  and  sometimes 
colored  to  resemble  butter.  Cottonseed  oil  and  other  vegetable  oils  arc 
also  used  to  some  extent. 

Oleo  oil  is  prepared  from  the  fat  of  beef  cattle  somewhat  as  follow^s:* 
Immediately  after  the  animals  are  killed  the  fresh  intestinal  and  caul 
fat  are  removed  and  placed  in  tanks  of  water  at  a  temperature  of  about 
80°  F.  From  this  water  they  are  transferred  to  other  tanks  of  cold  w^ater 
and  chilled  until  all  animal  heat  is  removed.  The  fat  is  then  cut  or 
hashed  into  small  pieces  and  melted  at  about  130°  F.  in  jacketed  steam 
kettles,  until  the  clear  oil  is  separated  from  the  connective  tissue. 

This  oil  is  then  drawn  off  into  vats,  which,  on  account  of  the  appear- 
ance of  the  oil  on  cooling,  are  called  graining  or  seeding  vats,  where  it 
is  allowed  to  stand  for  twenty-four  hours  or  more  at  a  temperature  of 
about  85°  F.  From  these  vats  the  semi-solid  emulsion  of  oil  and  stearin 
is  dipped  into  cloths,  which  are  folded  and  placed  in  a  press  between  sheets 
of  metal  and  subjected  to  powerful  pressure.  By  this  means  the  oil 
is  separated  from  the  stearin,  and  is  drawn  into  casks  for  export  or  for 
manufacture  into  oleomargarine.  Large  quantities  are  annually  exported 
to  Holland,  where  oleomargarine  is  manufactured,  and  either  sold  for 
consumption  in  that  country,  or  re-exported  to  other  countries  in  Europe. 

The  oleo  oil  thus  expressed  is  a  mixture  of  olein  and  palmitin.  When' 
first  prepared,  it  is  a  clear  amber-colored  fluid,  free  from  odor  or  fatty 
taste.  It  is  packed  in  tierces,  and,  when  opened  at  ordinary  temperature, 
is  a  light-yellow  solid. 

The    further   process   of   manufacture    of   oleomargarine    consists    in 

*  Report  on  Oleomargarine,  Its  Manufacture  and  Sale,  19th  An.  Report,  Mass.  St.  Bd. 
of  Health,  1887. 


542  FOOD  INSPECTION   AND   ANALYSIS. 

\\\c  main  of  mixing  ihe  olco  oil  as  above  obtained  with  varying  propor- 
tions of  neutral  lard,  milk,  and  genuine  butter,  with  or  without  added 
colorintT  matter,  and  churning  the  mixture  at  a  temperature  above  the 
melting-point  of  the  fats,  the  neutral  lard  having  previously  been  cured 
for  at  least  forty-eight  hours  in  salt  brine.  Occasionally  small  quanti:ies 
of  other  vegetable  oils,  as  cottonseed,  peanut,  or  sesame,  are  included  in 
the  above  mixture.  After  the  churning,  the  whole  mass  is  cooled  by 
contact  with  ice  water.  The  chilled  mass  is  drained,  and  afterwards 
salted,  worked,  and  given  much  the  same  treatment  as  butter. 

The  composition  of  commercial  oleomargarine  varies  between  the 
following  limits: 

Olco  oil 20  to  25% 

Neutral  lard 40  "   45% 

Butler 10  "   25% 

Milk,  cream,  salt,  etc 5   "  30% 

Coloring  of  Oleomargarine. — The  artificial  coloring  matters  employed 
are  the  samiC  as  in  the  case  of  butter,  and  are  similarly  tested  for. 

In  many  states  oleomargarine  cannot  be  legally  sold  when  colored 
to  resemble  butter.  Under  other  state  laws  coloring  matter  is  allowable. 
The  federal  law  and  most  state  laws  prescribe  the  most  rigid  rules  for 
marking  packages  containing  oleomargarine,  \\ith  a  view  to  affording 
the  utmost  ])rotection  to  the  ])roducer  of  butter  against  the  fraudulent 
substitution  tlierefor. 

Crampton  and  Simon's  Tests  for  Palm  Oil.* — So  called  "  butter 
oils,"  consisting  of  cottonseed  oil  to  which  has  been  added  2  to  5  per 
cent  of  palm  oil  are  u.sed  to  color  oleomargarine.  The  following  tests 
serve  for  the  detection  of  palm  oil. 

Preparation  of  Sample. — The  sample  should  l)c  kej)!  in  a  cool,  dark 
j)lace  until  tested,  as  exjjosure  to  air  and  light,  or  the  presence  of  water, 
alcohol,  ether  or  similar  reagents  interfere  with  the  tests.  Immediately 
before  testing,  the  sample  is  filtered  as  quickly  as  possible  at  a  temperature 
not  exceeding  70°  C. 

First  Method. — Di.ssolvc  100  cc.  of  the  fat  in  300  cc.  of  petroleum  ether, 
and  shake  out  with  50  cc.  of  0.5%  7>ota.ssium  hydroxide.  Draw  off  the 
watery  layer,  make  distinctly  acid  with  hydrochloric  acid,  and  shake  out 

*  Jour.  Am.  Chem.  Soc,  27,  1905,  p.  270. 


EDIBLE   OILS   /1ND  FATS.  543 

wilh  10  cc.  of  colorless  C.  P;  carbon  Iclrachloridc.  Se]jarate  the  carbon 
tclrachloride  solution,  transfer  a  j)ortion  to  a  [)orcelaln  crucible,  add 
2  cc.  of  a  mixture  of  one  part  of  colorless,  crystallized  C.  P.  phenol  and 
2  parts  01  carbon  tetrachloride,  then  5  droy)s  of  hydrobromic  acid  (sp.  gr. 
1. 19),  and  mix  by  gentle  agitation.* 

The  almost  immediate  development  of  a  bluish-green  color  is  indicative 
of  })alm  oil. 

Second  Mclhod.  -Shake  10  cc.  of  the  melted  and  liltered  fat  with  an 
cciual  volume  of  colorless  C.  P.  acetic  anhydride,  add  one  drop  of  sulphuric 
acid  (sp.  gr.  i.^^))^  ^"d  shake  a  few  seconds  longer.f 

If  ])alm  oil  be  present,  the  lower  layers  on  settling  out  will  be  found 
to  be  colored  blue  with  a  tint  of  green.  The  color  in  this  as  in  the  preceed- 
ing  test  is  transient. 

Of  the  edible  oils  only  sesame  and  mustard  oils  give  a  similar  color 
reaction.  Se.same  oil,  after  repeated  extractions  with  alcohol,  will  not 
give  the  blue  color,  but  cottonseed  oil  containing  as  little  as  1%  of  palm 
oil  still  responds  to  the  test. 

Adulterants  of  Oleomargarine. — This  product  is  liable  to  adultera- 
tion not  only  by  the  use  of  inferior  and  unwholesome  fat,  but  bv  the  admix- 
ture in  some  cases  of  paraffin. |  This  so])histication  is  m.ade  manifest, 
if  an  appreciable  amount  of  the  adulterant  has  been  used,  by  the  high 
melting-point  and  thq  low  saponification  number,  as  well  as  by  the  low 
specific  gravity.  If  a  clear  saponification  is  Impossible  under  ordinary 
conditions,  paraffm  is  to  be  suspected.  It  may  be  separated  and  cjuanti- 
tati\'ely  determined  as  described  on  p.  510. 

Healthfulness  of  Oleomargarine. — Under  the  directions  of  the  Mas- 
sachusetts Board  of  Health, §  a  large  number  of  artificial  digestion  experi- 
ments were  made  to  show  the  relative  nutritive  value  of  butter  and  oleo- 
margarine, and  at  the  same  time  the  wholesomeness  of  oleomargarine 
as  a  food  was  carefully  investigated.  The  general  conclusions  reached 
were  that,  when  comparing  the  best  grades  of  both  products,  there  is 
little  if  any  difference  between  butter  and  oleomargarine  on  grounds  of 
digestibility,  while  a  good  oleomargarine  is  much  to  be  preferred  to  i. 


*  Halphen  uses  a  similar  reagent  to  detect  rosin  oil  in  mineral  oil.     Jour.  Soc.  Chem. 
Ind.,  21,  1902,  p.  1474. 

t  The  reagents  are  the  same  as  used  in  the  Liebermann-Stnrrh  test  for  rosin  oil. 

X  Geissier,  Jour.  Am.  Chem.  Soc,  21,  1899,  p.  605. 

§  19th  An.  Report,  Mass.  State  Board  of  Health,  1887,  p.  248. 


44 


FOOD  INSPECTION  /iND  y4NALYSIS. 


poor  butter  from  a  nutritive  standpoint.  As  to  its  wholesomeness,  a 
large  number  of  experts  consulted  were  unanimous  in  expressing  their 
favorable  opinions  of  oleomargarine  as  a  healthful  article  of  food. 

\\'hen  sold  on  its  own  basis  in  accordance  with  the  law,  it  forms  an 
excellent  cheap  substitute  for  butter.  It  is  only  when  fraudulently  sold 
as  butter  or  in  violation  of  the  various  state  and  federal  laws,  that  it 
comes  within  the  province  of  the  health  authorities  to  condemn  it,  and, 
unfortunately,  by  reason  of  its  close  resemblance  to  the  dairy  product 
the  temptation  to  sell  it  for  what  it  is  not  is  always  great. 

Distinguishing  Oleomargarine  from  Butter. —  The  two  products, 
made  up  as  they  are  of  mixtures  of  the  same  fats,  and  differing  for  the 
most  part  only  in  the  percentage  composition  of  these  fats,  show  many 
properties  in  common.  For  instance,  the  melting-point  is  so  nearly  the 
game  for  both  products  as  to  be  of  no  use  as  a  distinguishing  indication. 
Other  physical  characteristics,  as  of  taste  and  smell,  are  very  similar  in 
both  products,  except  in  the  hands  of  the  expert.  The  microscope  is 
of  limited  value,  except  in  so  far  as  it  indicates  that  the  fat  has  first  been 
melted  and  afterwards  solidified. 

From  the  fact  that  oleo  oil  and  neutral  lard  form  by  far  the  larger 
portion  of  the  mixture  known  as  oleomargarine,  the  glycerides  that  make 
up  the  fat  of  the  latter  are  chiefly  those  of  the  insoluble  fatty  acids,  stearic, 
oleic,  and  palmitic.  The  percentage  of  volatile  fatty  acids  present  in 
oleomargarine  is  very  small,  and  the  presence  of  these  volatile  acids  is 
due  entirely  to  the  admixture  of  butter  which  it  contains.  This  furnishes 
the  most  ready  means  of  distinguishing  chemically  between  the  two 
products,  and,  as  indicated  by  the  Reichert  number,  is  the  chief  reliance 
of  the  analyst  for  court  evidence. 

Incidentally,  as  will  be  seen  by  the  accompanying  table,  the  refrac- 

CONSTANTS  OF  BUTTER  FAT  AND  OLEOMARGARINE. 


c< 


t:_^ 


V  5  c 


Butter  fat; 

Maximum o.87o||3i  .55! 

Minimum .&<l^\    4-AAX 

Oleomargarine.  |  | 

Maximum |.8625{iii  .69I 

Minimum .8s8s§]  9.34! 


89.6ot 
8s.63t 


S.94t 

3.oot 


S.62t 
o.ool 


.875| 

•  i-st 


3.l0tl 
o.49ti 


233| 
222S 


is.st 

I2.4t 


9S.45t     I.i6t     3-64|  .35ot       o.74ti    2035 
Q2.46t    0.12}     2.391 -3063^    0.63^     1928 


47 -yt 

44  .St 


S-St    S4.81 
o.stl    S3   0I 


35' 
35'' 

K 

35' 


♦  Number  of  rn^ix'  r-entimeters  N/io  alkali  neutralizing  volatile  acids  in  2.5  g^rams  fat. 

t  From  a:,  .  •in  Mass.  State  Board  of  Health  laboratory. 

I  Prom  a  in  laVy^ratory  of  U.  S.  Dept.  of  Agric,  Bur.  of  Chem. 

I  Prom  -a.:.  :  .\.  H.  Allen. 


EDIBLE   OILS  /fND    F^TS. 


545 


tometer  reading,  the  iodine  number,  the  saponification  equivalent,  and 
the  specific  gravity  are  all  useful  constants  in  indicating  points  of  differ- 
ence between  the  two  fats,  it  being  understood  that  in  oleomargarine, 
as  in  butter,  the  fat  for  examination  is  melted  and  separated  by  filtra- 
tion or  otherwise  from  the  curd,  salt,  and  other  constituents. 

The  constants  for  varying  mixtures  of  butter  with  foreign  fat  as  found 
by  Villiers  and  Collin  *  are  tabulated  below. 

Odor  and  Taste.  —  It  is  easy  with  a  little  practice  to  become  so 
accustomed  to  the  odor  and  taste  of  oleomargarine,  as  to  be  able  to  pass 
judgment  with  considerable  confidence  by  these  senses  alone,  whether 
a  sample  in  question  is  oleomargarine  or  butter.  The  distinction  is 
rendered  more  apparent  by  melting  a  portion  of  the  sample  on  the  water- 
bath.  If  the  product  is  butter,  either  fresh  or  renovated,  the  butyric 
odor  of  the  melted  fat  is  very  characteristic,  while  the  melted  oleomargarine 
not  only  is  lacking  in  the  butyric  odor  (a  negative  property),  but  possesses 
a  distinctive  "meaty"  smell  peculiar  to  itself,  which,  while  not  unpleasant,, 
is  unmistakable.  The  flavor  of  oleomargarine  to  one  experienced  in  dis- 
tinguishing between  the  two  products  is  very  apparent.  This  flavor, 
slight  though  it  is,  might  be  compared  to  that  of  cooked  meat. 


Hehner's 

Soluble 

Koettstorfer's 

Volatile 

Number. 

Acids. 

Equivalent. 

Acids. 

Pure  butter 

88 

s 

224 

26 

Butter,  95%; 

foreign  fat,    5% 

88.35 

4-8 

222.6 

24.7 

"        90% 

"        "     10%.... 

88 

70 

4.5 

221.2 

23-4- 

"        85% 

"        "     15%---- 

89 

05 

4-3 

»           219.8 

22.2- 

"        80% 

"        "     20%.... 

89 

40 

4-1 

218.4 

20. 9' 

"        75% 

"        "    25%.... 

89 

75 

3-9 

217 

ig.6 

"        70% 

"        "    30%.-.. 

90 

10 

3-6 

215.6 

18.3 

"        65% 

"        "    35%---- 

90 

45 

3-4 

214.8 

17. 1 

"        60% 

"        "    40%.... 

90 

80 

3-2 

212.8 

15. S 

"        55% 

"        "    45%---- 

91 

15 

3 

211.4 

14-5 

"        50% 

"        "    50%-..- 

91 

50 

2-7 

210 

13-2 

"•'        45% 

"        "    55%---- 

91 

85 

2-5 

208.6 

12 

"        40% 

"        ">  60%.... 

92 

20 

2-3 

207.2 

10.7 

"        35% 

"        "    65%.... 

92 

55 

2.1 

205.8 

9-4 

•"       30% 

"        "    70%.--- 

92 

90 

1.8 

204.4 

8.1 

"        25% 

"        "    75%---- 

93 

25 

1.6 

203 

6.^ 

'-        20% 

"        "    80%.... 

93 

60 

1-4 

201.6 

5-^ 

"        15% 

"        "    85%-... 

93 

95 

1.2 

200.2 

4-3 

"        10% 

"        "    90%---. 

94 

30 

0-9 

198.8 

3 

".       5% 

"        "    95%---- 

94 

65 

0.7 

197.4 

i.S 

Foreign  fat.  . 

95 

0-5 

196 

0.5 

yo 

*  Les  Substances  Alimentaires,  p.  731. 


54<5  FOOD   INSPECTION  ^ND  ANALYSIS. 

DISTINGUISHING    BETWEEN    BUTTER,    PROCESS    BUTTER,    AND 
OLEOMARGARINE. 

With  the  increased  occurrence  in  the  market  of  the  commercial  product 
known  as  "  process ''  butter,  especially  in  localities  where  its  sale  is 
restricted  or  regulated  by  law,  it  becomes  incumbent  on  the  analyst  to 
distinguish  it  from  the  other  products  which  it  resembles. 

.\s  a  rule,  the  tests,  chiefly  physical,  that  are  applied  on  the  edible  prod- 
uct as  a  whole  (i.e.,  without  separation  of  the  curd,  salt,  etc.),  such  as  the 
foam  test,  the  milk  test,  the  microscopical  examination,  and  the  appear- 
ance of  the  mehcd  sample,  distinguish  broadly  between  pure  fresh  butter 
on  the  one  hand,  and  oleomargarine  on  the  other.  In  other  words,  al- 
though there  are  those  skilled  in  making  the  above  tests  who  claim  to 
be  and  doubtless  are  able  to  note  distinguishing  features  between  oleo- 
margarine and  process  butter,  yet  these  two  products  respond  alike, 
though  perhaps  in  var}-ing  degrees,  to  these  tests,  and  are  classed  together 
as  distinguished  from  pure  butter. 

On  the  other  hand,  such  tests  as  depend  upon  the  refractometer, 
the  Reichert  number,  and,  indeed,  all  the  so-called  chemical  constants, 
which  are  applied  to  the  separated  fat,  freed  from  other  substances,  will 
ser\'e  to  distinguish  between  oleomargarine  and  butter,  whether  "pro- 
cess" butter  or  otherwise,  since  the  "processing"  or  "renovating"  of 
butter  does  not  change  the  character  of  its  fat  sufficiently  to  materially 
alter  these  constants. 

It  is  best,  therefore,  for  purposes  of  routine  preliminary  separation 
to  submit  all  samples  to  the  "foam"  test  and  to  examine  them  by  the 
butyro-refractometer.*  These  tests  alone,  which  arc  very  quickly  and 
readily  applied,  will  rarely  fail  to  separate  into  the  three  classes,  butter,  pro- 
cess butter,  and  oleomargarine,  the  products  under  examination,  after  which 
such  confirmatory  tests  as  are  desired  are  made  on  adulterated  samples. 

The  Butyro-refractometer. — ^This  instrument,  as  its  name  implies 
was  i^rimarily  intended  by  Zeiss  for  the  examination  of  butter,  and,  while 
its  use  has  been  extended  for  work  with  other  fats  and  oils,  its  construc- 
tion is  such  as  to  show  particularly  a  distinction  between  butter  and 
oleomargarine  by  the  appearance  of  the  critical  line  of  the  fat.  This 
mode  of  diflcrentiation  is  due  to  the  peculiar  construction  of  the  double 

*  Out  of  the  large  numhier  of  samples  of  butter  and  oleomargarine  examined  on  the 
but)To-refractomcter  in  the  author's  laboratory  during  eight  years,  he  has  never  found  a 
single  instance  where  the  instrument  failed  to  show  the  difference  between  the  two  products 


EDIBLE  OILS  AND    FATS.  547 

prism,  which  shows  differences  of  dispersive  power  by  different  appear- 
ances of  the  critical  Hnc.  The  prisms  are  so  constructed  that  the 
critical  line  of  pure  butter  is  colorless,  while  margarine  and  artificial 
butter,  which  have  greater  dispersive  powers  than  natural  butter,  show 
a  blue-colored  critical  line.  But  anomalies  in  the  color,  both  with  pure 
butter  and  mixtures,  are  more  or  less  observable,  which  render  it  im- 
possible to  draw  a  sharp  line  between  adulterated  and  genuine  butter. 
The  appearance  of  a  blue  fringe  may,  however,  be  a  useful  factor  in 
cases  of  suspected  adulteration. 

The  following  particulars  respecting  the  application  of  the  refractom- 
eter  for  analysis  of  butter  are  contained  in  a  paper  of  Dr.  R.  WoUny  of 
Kiel,*  who  assisted  in  the  construction  of  the  instrument.  The  readings 
of  the  refractive  indices  of  a  large  number  of  butter  samples  taken  at 
25°  C.  by  Dr.  Wollny  ha^•e  been  directly  reduced  to  scale  divisions  and 
yield  the  following  equivalents: 

Natural  butter. .  .(1.4590  — 1.4620): 49. 5  — 54.0  scale  divisions 
Oleomargarine- .  .(1.4650  — 1. 4700): 58. 6  — 66.4     "  ** 

Mixtures  (artificial 

butter)   (1.4620  — i.469o):54.o  — 64.8      **  '* 

Limit  0}  Scale  Reading  for  Pure  Butter. — Whenever  in  the  refracto- 
metric  examination  of  butter  at  a  temperature  of  25°  C.  higher  values 
than  54.0  are  found  for  the  critical  line,  these  samples  will,  according 
to  Wollny,  by  chemical  analysis  always  be  found  to  be  adulterated;  but 
with  all  samples  in  which  the  value  for  the  position  of  the  critical  line 
does  not  reach  54.0  chemical  analysis  may  be  dispensed  with,  and  the 
samples  may  be  pronounced  to  be  pure  butter.  Wollny  suggests,  as  a 
means  of  removing  all  chances  of  adulterated  butter  escaping  detection, 
that  the  above  limit  be  placed  still  lower,  and  that  all  samples  exhibiting 
values  exceeding  52.5  (at  a  temperature  of  25°  C.)  be  set  aside  for  chemi- 
cal analysis. 

In  calculating  the  position  of  the  critical  line  for  other  temperatures 
than  25°  C.  allow  per  1°  C.  variation  of  temperature  a  mean  value  ot 

*  Dr.  R.  Wollny,  Schlussbericht  iiber  die  Butteruntersuchungsfrage,  Milchwirthschaft- 
licher  Verein,  Korrespondenzblatt,  No.  39,  1891,  p.  15. 

Older  papers  on  butter  tests  by  refraction  of  light  will  be  found  in:  Mueller,  Rep.  d. 
anal.  Chemie,  1886,  pp.  346,  366.  Skalweit,  Milchzeitung,  1886,  15,  p.  462.  Wollny,  Ueber 
die  Kunstbutterfrage,  Leipzig,  1887,  p.  50. 


54S 


FOOD  INSPECTION  AND  ANALYSIS. 


0.55  scale  division.*  The  following  tabic,  which  has  been  compiled 
in  this  manner,  shows  the  ^•alues  corresponding  to  various  temperatures, 
each  value  being  the  u})per  limit  of  scale  divisions  admissible  in  ])ure 
butter: 


Temper- 

Scale 

Temper- 

Scale 

Temper- 

Scale 

Temper- 

Scale 

ature. 

Division. 

ature. 

Division. 

ature. 

Division. 

ature. 

Division. 

45= 

41-5 

40<= 

44-2 

35= 

47.0 

30= 

49-8 

44= 

42.0 

39= 

44-8 

34° 

47-5 

29° 

50-3 

43° 

42.6 

38° 

45-3 

3,f 

48.1 

28° 

50.8 

42= 

43-1 

37= 

45-9 

32° 

48.6 

27C 

51-4 

41° 

43-7 

36= 

46.4 

31° 

49-2 

26° 

51-9 

40° 

44.2 

35° 

47.0 

30°      . 

49-8 

25° 

52.5 

If,  therefore,  at  any  temperature  between  45°  and  25°  values  be 
found  for  the  critical  line  which  are  less  than  the  values  corresponding 
to  the  same  tem])erature  according  to  the  table,  the  sample  of  butter  may 
safely  be  j^ronounced  to  be  natural,  i.e.,  unadulterated  butter.  If  the 
reading  shows  higher  numbers  for  the  critical  line,  the  sample  should  be 
reser\-ed  for  chemical  analysis. 

Note. — Dr.  Eichel  of  Metz  has  suggested  that  instead  of  comparing 
the  scale  divisions  at  the  same  temperature,  the  position  of  the  critical 
line  may  be  determined  at  the  moment  when  the  butter  begins  to  set. 
In  this  case  he  gives  fifty-four  as  the  highest  admissible  number  for  the 
critical  line  of  pure  butter. 

Xo  sharjj  distinction  is  apparent  between  pure  and  renovated  butter 
on  the  refractometer. 

Special  Thermometer  for  the  Butyro-refractometer. — Instead  of  em- 
yjloying  the  ordinary  thermometer,  as  shown  in  Fig.  36,  a  special  ther- 
mometer (Fig.  loi)  has  been  devisal  for  work  both  with  butter  and 
with  lard.  This  instrument  has  two  scales,  arranged  sirle  by  side,  one 
for  butter  and  one  for  lard,  each  of  which  indicates  at  once  the  highest 
allowable  reading  for  the  pure  fat,  corresponding  to  the  temperature 
at  which  the  observation  is  made,  which,  however,  need  not  be  noted. 

If  the  scale  reading  of  the  instrument,  as  observed  through  the  tele- 
scope, differs  materiall}-  from  the  reading  of  the  special  thermometer, 
the  fat  under  examination  is  undoubted  In-  adulterated,  or,  in  the  case 
of  butter,  a  higher  reading  indicates  oleomargarine.  The  special  ther- 
mometer thus  indicates  the  highest  permissible  number  for   pure  butter. 


*  With  natural  butter  this  number  is',  as  a  rule,  somewhat  less  (0.53),  with  oleomargarine 
a  little  greater  (0.56). 


EDIBLE   OILS   ^ND   F/1TS. 


549 


iT: 


The  Reichert  or  Reichert-Meissl  Number  *  is  by  far  the  most  impor- 
tant single  determination  in  establishing  j^roof  of  the  character  of  the 
sample,  whether  butter  or  oleomargarine,  for  evidence  in  Q 

court,  and  in  such  cases  this  determination  is  indispensable. 
The  result  is  conclusi\-e,  exce])ting  in  those  rare  instances 
where  the  admixture  of  foreign  fat  is  so  small  as  to  cause 
the  Reichert  number  to  ap])roximate  that  of  pure  butter. 
In  common  instances  of  creamery  butter  anrl  commercial 
oleomargarine  the  Reichert  number  shows  a  very  marked 
distinction  (see  table,  p.  544). 

It  is  dltTicult  to  fix  a  .minimum  figure  below  which,  in 
doubtful  cases,  a  sample  may  be  ])ronounced  imj)ure  by 
reason  of  admixture  with  foreign  fat.  In  general,  how- 
ever, a  Reichert  number  under  10  would  be  almost  sure 
to  show  adulteration,  though  instances  are  on  record  where 
butter  of  known  purity  has  shown  a  Reichert  number  even 
lower  than  this.  It  is  in  fact  rare  that  pure  butter  has 
a  Reichert  number  under  12. 

Stebbins  t  gives  the  maximum,  minimum,  and  average 

of  the  Reichert  number  obtained  by  him  on  317  samples 

of  unadulterated  butter,  some  of  which  were  of  low  grade,  ^        '"'^     .  , 
'  '^  '  Fig.  10 1.— Special 

as  follows:  Maximum,  18.2;  Minimum,  11. 2;  Average,  14.7.     Butyro-refrac- 
As   a   rule   little   difference   is   apparent   between    pure     to"^eter  Ther- 

.  mometer      for 

and  "renovated"  samples  as  regards  their  Reichert  Butter  and 
number.  ^^''^• 

Yieth  has  shown  that  the  Reichert  number  of  butter  is  generally  a- 
trifle  lower  after  it  becomes  rancid. 

Specific  Gravity. — Skalweit  has  shown  that  the  specific  gravity  of 
butter  and  oleomargarine  relative  to  each  other  varies  with  the  temper- 
ature at  which  it  is  taken,  the  difference  between  the  two  growing  less 
and  less  as  the  temperature  increases  above  35°,  The  greatest  variation 
being  at  35°,  he  recommends  this  temperature  as  the  best  at  which  to 
make  the  determination. 

The  Foam  Test,  also  known  as  the  "  boiling  "  or  "  spoon  "  test.J 
This,  though  originally  intended  as  a  household  test,  is  in  reality  one  of 

*  The  writer  prefers  to  carry  out  this  process  on  2.5  grams  of  the  butter  fat,  expressing 
thus  the  Reichert  number,  this  being  practically  the  half  Reichert-Meissl  number,  which  is 
based  on  the  use  of  5  grams.  • 

t  Jour.  .\m.  Chem.  Soc,  21,  1899,  p.  939. 

J  Farmer's  Bulletin,  No.  131. 


55 ^  FOOD   INSPECTION  AND   ANALYSIS. 

the  ven-  best  laboraton-  methods  of  separating  ymwq.  Ijutter  samples  from 
renovated  butter  and  oleomargarine.  A  small  lump  of  the  sample  (from 
3  to  5  grams)  is  heated  in  a  large  spoon  over  a  Bunscn  flame,  turned 
ver}-  low,  stirring  constantly  during  the  heating.  Genuine  butter,  under 
these  conditions,  will  boil  quietly,  but  with  the  production  of  consider- 
able froth  or  foam,  which  will  often  swell  up  over  the  sides  of  the  spoon, 
when,  just  after  boiling,  the  latter  is  raised  from  the  llamc.  Renovated 
butter  or  oleomargarine,  under  this  treatment,  will  bump  and  sputter 
noisily  like  hot  grease  containing  water,  but  will  not  foam.*  Another 
point  of  dilTerence  is  that  on  removing  the  spoon  from  the  flame  and 
observing  the  character  of  the  curdy  particles,  in  the  case  of  genuine 
butter  these  particles  of  curd  will  be  very  small  and  finely  divided  in 
the  melted  fat,  being  indeed  hardly  perceptible,  while  with  oleomargarine 
and  renovated  butter,  the  curd  will  gather  in  somewhat  large  masses  or 
lumps. 

The  test  may  be  carried  out  in  a  test-tube  if  desired. 

The  Waterhouse  or  Milk  Test.f — This  test  is  based  on  the  assump- 
tion that  butter  fat,  which  is  in  itself  exclusively  the  product  of  milk, 
will  mingle  intimately  with  the  milk  when  added  thereto  in  a  melted 
condition  and  cooled  therein,  whereas  oleomargarine,  being  foreign  to 
milk  fat,  will,  under  like  conditions,  refuse  to  diffuse  itself  naturally 
in  milk  as  a  medium. 

About  50  cc.  of  well-mixed  sweet  milk  are  heated  nearly  to  boiling 
in  a  beaker,  and  from  5  to  10  grams  of  the  fat  sample  are  added.  The 
mixture  is  then  stirred,  preferably  with  a  small  wooden  stick,  until  the 
fat  is  melted.  The  beaker  is  then  placed  in  a  dish  of  ice  cold  water,  and 
the  stirring  continued  till  the  fat  reaches  the  solidify ing-point,  at  which 
period,  if  the  sample  is  oleomargarine,  the  fat  can  readily  be  collected 
by  the  stirrer  into  one  lump  or  clot,  but,  if  butter,  it  cannot  be  so  collected, 
but  remains  in  a  granulated  condition,  distributed  through  the  milk 
in  small  particles.  It  is  not  necessary  to  keep  up  the  stirring  through 
the  entire  term  of  cooling,  but  to  begin  stirring  before  the  fat  starts  to 
solidify,  which  should  require  from  ten  to  fifteen  minutes  after  the  mixture 
is  placed  in  cold  water. 

This  test,  if  carefully  carried  out,  shows  a  marked  distinction  between 
butter,  whether  pure  or  renovated,  and  oleomargarine.  Under  certain 
conditions,  as  when  the  cooling  is  too  rapid,  samples  of  renovated  butter 

*  A  very  slight  foam  is  sometimes  observable  with  occasional  renovated  samples,  but 
nothing  like  the  abundant  amount  produced  by  the  genuine  product.  < 

t  Parsons,  Jour.  Am.  Chem.  Soc.,  23,  1901,  p.  200. 


F.DIRLE   OILS   ^ND   F^TS.  55  r 

fat  will  sometimes  show  a  slight  tendency  to  clot  together  as  in  the  case 
of  oleomargarine,  but  to  no  such  extent  as  the  latter. 

The  author's  experience  with  this  test  has  shown  it  to  be  very  reliable 
not  only  in  identifying  oleomargarine  from  butter,  but  in  nearly  every 
case  renovated  butter  can  be  distinguished  from  genuine.  As  a  rule, 
genuine  butter  fat,  even  after  cooling  to  the  solidifying-point,  shows  the 
greatest  tendency  to  emulsionize  with  the  milk  when  stirred,  without 
adhering  to  the  wooden  rod,  and  is  slow  to  come  to  the  surface  when 
the  stirring  is  stopped.  Renovated  butter  fat,  when  stirred  in  the  cold 
milk,  almost  instantly  gathers  in  a  film  on  the  surface  of  the  milk  when 
the  stirring  is  stopped,  without  emulsioni/.ing.  It  does  not  clot  together 
like  oleomargarine,  but  it  tends  to  adhere  to  the  wooden  rod. 

Patrick  *  recommends  the  use  of  skimmed  or  partially  skimmed 
milk,  and  heats  to  the  boiling-point  after  the  fat  has  been  introduced 
into  the  hot  milk. 

Examination  of  the  Curd. — The  curd  of  genuine  butter  is  made  up 
largely  of  such  of  the  milk  proteins  as  are  insoluble  in  water  and  hence 
pass  into  the  cream  when  separated.  These  proteins  form  a  gelatinous 
mass  in  the  butter,  readily  clotting  together  when  the  fat  is  melted.  On 
the  other  hand,  the  curd  of  process  butter,  which  is,  as  it  were,  artificially 
derived  from  the  entire  or  skim  milk  used  in  its  manufacture  (in  order 
to  replace  the  natural  curd  which  has  been  reniDvei  in  the  "purifying" 
process),  differs  from  the  proteins  of  cream  in  that  it  is  granular  and 
flaky,  consisting  chiefly  of  coagulated  casein.  Hence  the  distinction 
noted  as  to  the  appearance  of  the  curd  in  the  foam  test. 

For  the  same  reason,  if  beakers  containing  pure  and  renovated  butter 
are  melted  on  the  water-bath,  the  curd  of  the  pure  sample  will  settle  at 
once,  or  in  a  very  few  minutes,  to  the  bottom  after  melting,  leaving  a 
comparatively  clear  supernatant  fat.  The  renovated  sample  will  nearly 
always  fail  to  settle  out  clear,  even  after  standing  on  the  water-bath  for 
half  an  hour  or  more,  but  will  still  be  cloudy  throughout  the  mass,  due 
to  particles  of  non-cohesive,  floating  curd. 

In  the  case  of  oleomargarine,  the  curd  of  which  is  composed  partly 
of  pure  butter  curd  (from  cream  proteins)  and  partly  of  the  ])roteins 
of  the  milk  with  which  it  is  churned,  the  cloudiness  of  the  fat  on  melting 
depends  on  the  relative  proportion  of  milk  proteins,  and  in  general  is  not 
especially  characteristic. 

*  Farmer's  Bulletin,  No.  131. 


55-^  FOOD  INSPECTION  AND   ANALYSIS. 

Identification  of  the  Source  of  the  Curd.*  Half  fill  a  small  beaker 
^vilh  the  sample  and  melt  on  the  water-bath.  Decant  as  much  as  possible 
of  the  fat  and  pour  the  rest,  consisting  largely  of  the  water,  salt,  and 
curd,  ui)on  a  wet  filter.  Acidify  the  filtrate,  which  contains  the  salt 
and  soluble  proteins,  with  acetic  acid  and  boil.  If  the  sam])le  is  pure 
butter,  only  a  slight  milkiness  is  found,  indicating  absence  of  albumins, 
whereas,  in  the  case  of  process  butter,  a  white,  llocculent  albuminous 
precipitate  is  produced. 

Apply  to  the  filtrate  also  Liebermann's  test  for  all)umin;  i.e.,  add 
strong  hydrochloric  acid.  If  a  violet  coloration  is  produced,  the  sample 
is  j)resumably  "  ])rocess  "  butter. 

Microscopical  Examination  of  Butter.  Considerable  information  may 
in  general  be  gained  b\-  an  examination  of  the  samjile  under  ordinary 
light  and  with  a  rather  low  power,  say  from  120  to  150  diameters.  For 
examination  in  this  way  a  bit  of  the  sample  on  the  edge  of  a  knife  blade 
is  placed  on  the  glass  slide,  and  simply  pressed  lightly  into  a  tliin  film 
by  the  cover-glass.  A  very  characteristic  difference  between  genuine 
and  renovated  butter  is  at  once  seen  in  the  relative  opacity  of  the  fields. 
The  fat  film,  in  the  case  of  the  fresh,  ])ure  butter,  is  much  more  transparent 
than  that  of  the  renovated.  Again,  the  curd  is  so  finely  divided  through- 
out the  mass  of  genuine  butter  fat  that  the  field  is  much  more  even  than 
that  of  the  reno\ated,  wherein  often  large  and  opac^ue  patches  of  curd 
are  frequently  distributed  throughout  the  field. 

When  a  renovated  butter  sample,  mounted  as  above,  is  viewed  by 
rejlected  light,  for  which  purpose  the  microscope  mirror  is  turned  so  as 
not  to  transmit  light  through  the  instrument,  one  sees  a  very  dark  and 
scarcely  perceptible  field;  but  the  ojjafjue  ])atches  of  curd  above  referred 
to  are  strikingly  apparent  as  white  masses  against  a  dark  backgrounfl. 

With  Polarized  Light. — It  has  already  been  stated  that  the  micro- 
scope is  useful  in  showing  whether  or  not  a  fat  has  been  melted,  the 
cr}'stalline  structure  of  the  fat  once  melted  and  afterward  cooled  being 
rendered  ay)parent,  especially  when  viewed  by  polarized  light.  This 
fact  has  long  been  known  and  put  to  practical  use  in  the  identification 
microscopicall}'  of  butter  and  oleomargarine. f 

When  viewed  by  jjolari/.ed  light  between  crossed  Nicols  under  a 
low   magnification,   pure  butter  not  previously  melted   should   show  no 

*  Hess  and  DooliUle,  Jour.  Am.  Chem.  Soc,  22,  1900,  p.  151. 
t  Hummel,  ibid.,  22,  p.  327;  Crampton,  loc.  cit.,  supra,  p.  703. 


EDIBLE  OILS   AND   FATS.  553 

crystalline  structure,  l)einji;  uniformly  bright  throughout,  and,  if  the 
selenite  ])late  be  used,  should  present  an  e\en  colored  held,  entirely 
devoid  of  fat  crystals.  On  the  other  hand,  with  process  butter  or  oleo- 
margarine, both  of  which  ha\e  been  melted  and  subsequently  cooled 
the  crystalline  structure  should  be  marked,  showing  with  polarized  light 
a  more  or  less  mottled  appearance,  and  a  play  of  colors  with  the  selenite. 

Various  conditions  enter  in  to  affect  the  reliability  of  the  polarized  light 
test.  It  is  nearly  always  possible  in  cold  weather  to  observe  these  dis- 
tinctions in  i)ractice,  as  above  described,  in  a  sliarp  and  striking  manner. 
Figs,  269,  270,  and  271,  PI.  XXXVIII,  show  typical  helds  of  the  three 
products  with  crossed  Nicols  and  selenite  plate.  The  appearance  of  pure 
butter  is  perfectly  blank,  while  oleomargarine  presents  a  much  more 
mottled  appearance  than  renovated  butter.  Such  well-defined  points 
of  variation  as  are  shown  in  Plate  XXX\TII  are  not  always  to  be  seen 
in  practice,  even  in  the  hands  of  an  expert.  Pure  butter  sometimes 
exhibits  a  somewhat  mottled  field,  due  to  a  slight  crystallization  at  some 
period  of  its  history.  In  the  summer-time,  for  instance,  when  butter 
melts  so  easily  at  ordinary  temperature,  these  distinctions  between  pure 
and  adulterated  samples  as  shown  by  polarized  light  are  by  no  means 
as  satisfactory  as  in  the  winter. 

Great  care  should  be  taken  on  this  account,  on  the  part  of  the  col- 
lector of  sam])les  as  well  as  the  analyst,  to  keep  the  sample  from  melting 
under  ordinary  conditions  before  it  is  examined. 

Hess  and  Doolittle's  Method  of  Examining  the  Curd.* — A  convenient 
portion  of  the  sample  of  suspected  butter  is  melted  in  a  beaker,  as  much 
of  the  fat  as  possible  is  decanted  off,  and  the  remaining  curd,  washed 
free  from  fat  with  ether,  is  poured  out  on  a  glass  plate  and  dried.  A 
sample  of  pure  butter  is  treated  in  like  manner  b\-  wa}-  of  comparison. 
When  examined  under  a  very  low  magnihcation  of  from  3  to  6  diameters, 
the  curd  from  the  pure  sample  will  be  seen  to  be  non-granular  and 
amorphous  in  appearance,  while,  in  the  case  of  reno\-ated  butter,  the 
curd  will  ap])ear  ver}-  coarse  grained  and  mottled, 

Zega's  Test  for  Oleomargarine.^ — A  ])ortion  of  the  filtered  fat  is 
])Oured  into  a  test-tube  and  kej)t  for  two  minutes  in  a  boiling  water-bath. 
I  cc.  of  this  fat  is  then  measured  with  a  hot  pipette  into  a  50-cc.  tube  con- 
taining 20  cc.  of  a  mixture  of  6  parts  ether,  4  parts  alcohol,  and  i  part 
glacial  acetic  acid.     The  tube  is  stoppered,  shaken  well,  and  cooled  in 

■*  Jour.  Am.  Chem.  Soc,  22,  1900,  p.  151. 
f  Chem.  Zeit.,  1899,  23,  312;   .-Kbs.  Analyst,  24,  p.  206. 


55*  FOOD    I\'SPECTION  AND  ANALYSIS. 

water  at  15°  to  iS°  C.  In  the  case  of  pure  butter  fat,  the  soluLion  remains 
clear  for  some  time,  a  slight  deposit  being  apparent  only  after  standing 
an  hour  or  more.  With  oleomargarine,  a  deposit  is  evident  in  a  very 
short  time,  and  in  ten  minutes  a  heavy  precipitate  comes  down.  With 
10%  of  oleomargarine  in  butter,  a  separation  occurs  in  about  fifteen 
minutes.  WHien  a  few  solid  particles  have  separated  out,  they  are  with- 
drawn and  examined  under  the  microscope.  With  genuine  butter,  long 
narrow  rods  appear,  sometimes  pointed  at  the  ends,  often  bent,  and  grouped 
as  a  rule  centrally  in  star-shaped  bundles.  Oleomargarine  presents  an 
appearance  of  bundles  of  fine  needles,  closely  packed  to  form  masses 
frequently  resembling  sheaves  and  dumb  bells  in  shape. 

Identification  of  Various  Oils  and  Fats.  —  Cottonseed  oil  may  be 
recognized,  if  present  in  butter  or  its  substitutes,  by  the  Halphen  test, 
and  sesame  oil  by  the  Baudouin  test.  Peanut  oil  is  tested  for  by  the 
Bellier  or  Renard  test. 

Cocoanut  oil  "is  sometimes  said  to  be  present  in  butter  substitutes. 
It  has  a  higher  Reichcrt  number  than  most  adulterants,  and  hence  a 
larger  admixture  of  this  than  of  other  foreign  fats  could  be  used,  without 
lowering  the  Rcichert  number  of  the  whole  below  the  allowable  limits 
of  pure  butter.  Its  presence  would,  however,  be  rendered  apparent  by  the 
low  iodine  and  rcfractometer  numbers  and  the   high  Polenske  number. 

LARD. 

Nature  and  Composition. — Lard  is  the  fat  of  hogs,  separated  by  heat 
from  the  scraps  or  containing  tissues.  The  choicest  or  highest  grade  of 
lard  is  known  as  leaf  lard,  and  is  derived  from  the  fat  which  surrounds 
the  kidneys.  A  comparatively  small  part  of  the  lard  of  commerce  is, 
however,  strictly  speaking,  pure  leaf  lard.  Most  of  it  is  derived  from 
the  whole  fat  of  the  animal  by  rendering,  by  the  aid  of  steam  under 
pressure,  either  in  open  kettle  or  in  closed  tanks,  the  former  being  used 
more  often  for  rendering  lard  on  a  small  scale,  and  the  latter  being  the 
most  common  commercial  method. 

Next  to  the  leaf,  the  fat  from  the  hog's  back  is  considered  the  best 
in  quality,  after  which  is  graded,  in  the  order  named,  the  fat  from  the 
head,  the  region  of  the  heart,  and  the  small  intestines,  the  last  two  grades 
constituting  what  is  commonly  known  as  "trimmings." 

Good  lard  is  white  and  granular,  having  the  consistency  of  salve.  It 
has  an  agreeable,  characteristic  odor  and  taste. 

The  leaf  or  kidney  fat  furnishes  also  the  source  of  the  so-called  neutral 
lard,  already  mentioned  as   an  ingredient  of  oleomargarine.     The   leaf, 


EDIBLE  OILS  .4ND   E/tTS. 


555 


being  first  chilled  and  finely  groi'.nd,  is  placed  in  the  kettle  and  ren- 
dered at  a  temperature  of  from  40°  10  50°  C,  at  which  heat  only  a  portion 
of  the  lard  separates.  This  portion  is,  while  melted,  washed  with  water 
containing  salt  or  dilute  acid,  and  forms  the  neutral  lard,  a  product 
almost  entirely  free  from  odor.  The  remainder  of  the  leaf  is  then  trans- 
ferred to  the  closed  tank  and  subjected  for  some  hours  to  steam  under 
pressure  at  a  temperature  of  230°  to  290°  F.,  the  resulting  lard  being 
graded  as  pure  leaf  lard. 

The  composition  of  the  mixed  fatty  acids  of  lard  is  thus   calculated 
by  Twitchell: 

Linoleic  acid 10.06% 

Oleic  acid 49-39% 

Solid  acids  (by  difference),  stearic  and  palmitic  ..  48.55% 

Lewkowitsch  *  gives  the  following  constants  for  American  lards  made 
from  fat  from  different  parts  of  the  animal: 


Fat  from 


Specific 

Gravity 

at  1 00°  C. 

(Water  at 

iS°C.  =  i.) 


Iodine 
Value. 


Maumene 

Number  at 

40°  C. 


Melting-point,  Bense- 
mann'st  Method. 


Temp.  C. 
of  Incipient 

Fusion. 


Melted  to 
a  Clear 
Drop. 


Refractive 
Index. 


Butyro- 

refractom- 

eter  at 

40°  C. 


Head 

Back 

Leaf. 

Foot. 
Ham 


0.8637 
0.8629 
0.8631 
0.8611 
0.8621 
0.8616 
0.8637 
0.8615 
0.8700 
0.8589 
0.8641 
0.8615 


Ham  (German) 


0.8597 


66.2 
66.6 
65.0 
61.5 
65.0 
65.1 
62.2 
59-0 
63.0 
68.8 
68.4 
66.6 
68.3 


33 
32 
34 
37 
35 
38 


30 
38 


55-0 


30 


24 

24 

24 

28.5 

28.5 

31-5 
26 
29 
28.5 

24 
26 
26 
26 


44-8 
44.8 
45-0 


46 

45 

44 

44- 

40 

45 
44 
44. 


52.6 

52. 5 
52.0 

52-4 
51-8 
51-9 
51-4 
50.2 
52-0 
44.8 

51-9 
51.9 

53-0 


32 


46 


49-2 


Lard  Oil. — This  oil  is  obtained  by  subjecting  lard  contained  in  woolen 
bags  to  hydraulic  pressure  in  the  cold.  The  lard  oil  (chiefly  olein) 
thus  expressed  constitutes  nearly  60%  of  the  whole,  and  the  residue 
is  known  as  lard  stearin. 

Lard  oil  is  a  thin  fluid,  pale  yellow  in  color,  and  with  var)'ing  specific 

♦Oils,  Fats,  and  Waxes,  1904,  p.  781. 

t  Bensemann  distinguishes  between  the  temperature  at  which  the  fat  begins  to  liquefy 
and  that  at  which  it  becomes  completely  transparent. 


556  FOOD   INSPECTION  AND  ANALYSIS. 

gravity,  due  to  var}-mg  conditions  of  pressure  and  temperature.  It  has 
a  pleasant,  though  somewhat  bland  taste,  and  is  used  to  some  extent  as 
an  edible  oil.  It  is  used  in  France  as  an  adulterant  of  olive  oil,  and 
^^^th  the  Maumene,  claidin,  and  nitric  acid  tests,  it  behaves  much  like 
olive  oil. 

According  to  the  U.  S.  Pharmacopoeia,  the  specific  gravity  of  lard  oil 
should  be  from  0.910  to  0.920  at   15°  C. 

At  a  temperature  a  little  below  10°  C.  it  should  form  a  semi-solid 
white  mass. 

When  it  is  brought  in  contact  with  concentrated  sulphuric  acid,  a 
dark  reddish-brown  color  should  instantly  be  produced. 

Lard  oil  should  not  respond  to  the  Bechi  test  for  cottonseed  oil. 

If  5  cc.  of  the  oil,  contained  in  a  small  flask,  be  mixed  with  a  solution 
of  2  grams  of  potassium  hydroxide  in  2  cc.  of  water,  then  5  cc.  of  alcohol 
added,  and  the  mixture  heated  for  about  five  minutes  on  a  water-bath 
^^•ith  occasional  agitation,  a  perfectly  clear  and  complete  solution  should 
be  formed,  which,  on  dilution  with  water  to  the  volume  of  50  cc,  should 
form  a  transparent,  light-yellow  liquid,  without  the  separation  of  an 
oily  layer  (absence  of  a])prcciable  cjuantities  of  paraffin  oils). 

Adulterants  of  lard  oil  are  cottonseed  and  corn  oils. 

Compound  Lard. — The  article  so  extensively  made  and  sold  under 
this  name  is  a  mixture  consisting  usually  of  lard  stearin,  beef  stearin, 
and  cottonseed  oil.  Sometimes  no  lard  whatever  is  present,  but  only 
a  mixture  of  beef  and  cottonseed  stearins. 

Lard  stearin  is  the  residue  left  in  the  cloths  after  the  lard  oil  has  been 
removed  by  pressure  (p.  555). 

Beef  stearin  is,  similarly,  the  residue  from  wliich  oleo  oil  has  been 
expressed  (p.  541).  The  cottonseed  oil  used  is  highly  refined,  and  finally 
decolorized  by  mixing  with  fullers'  earth  and  filtering. 

U.  S.  Standards. — Standard  Lard  and  Standard  Lea}  Lard  are  lard  and 
leaf  lard  respectively,  free  from  ranc  idily,  containing  not  more  than  1% 
of  substances  other  than  fatty  acids,  not  fat,  necessarily  incorporated 
therewith  in  the  process  of  rendering,  and  standard  leaf  lard  has  an  iodine 
number  not  greater  than  60. 

Adulteration  of  Lard. — The  mixture  known  as  "compound  lard" 
is  quite  commonly  fraudulently  sold  for  pure  lard.  Indeed,  the  adul- 
terants of  lard  usually  met  with  are  cottonseed  oil  or  stearin  and  beef 
stearin.  Other  oils  said  to  have  been  used  as  adulterants  are  j^eanut, 
sesame,    com,    and    cocoanut.     Formerly    water    was    incorjjorated   into 


EDIBLE   OILS  AND  FATS.  557 

the  fat  to  such  an  extent  as  to  materially  cheapen  it,  but  this  sophistica- 
tion is  now  rare.     Moisture  is  determined  as  in  the  case  of  butter. 

The  Butyro-refractometer  Reading. — The  refracting  degree  of  cotton- 
seed oil  on  the  butyro-refractometer  is  about  8.9  in  excess  of  the  standard 
refraction  of  lard,  while  that  of  beef  tallow  is  about  3.8  less  than  the 
standard.  If,  therefore,  the  refractometer  reading  is  unusually  low,  the 
presence  of  beef  stearin  is  to  be  suspected;  if  unusually  high,  cottonseed 
oil  should  be  looked  for.  A  mixture  of  the  two  adulterants  with  pure 
lard  such  as  is  found  in  "compound  lard,"  may  sometimes,  though  not 
often,  be  found  to  give  refractomctric  readings  within  the  limits  of  pure 
lard. 

Detection  of  Foreign  Oils. — Cottonseed  oil  is  best  detected  by  the 
Halphen  test.  A  very  slight  color  reaction  should  not  be  taken  as  proof 
positive  of  the  admixture  of  cottonseed  oil,  since  it  has  been  found  that 
the  fat  of  hogs  fed  on  cottonseed  meal  gives  a  slight  reaction  with  both 
the  Bechi  and  the  Halphen  tests.  Sesame  and  peanut  oils  are  detected 
by  their  special  tests.  Corn  oil  is  indicated  by  the  abnormally  high 
refractomctric  reading  and  iodine  number,  cocoanut  oil  by  the  high 
Reichcrt  number,  the  high  saponification  equivalent,  and  especially  the 
high  Polenske  number. 

Beef  stearin  is  difficult  to  identify  chemically,  but  is  usually  distin- 
guished by  a  microscopical  examination  of  the  fat  after  cr}^stallization 
as  follows: 

The  Microscopical  Examination  of  Lard. — From  2  to  5  grams  of 
the  fat  are  dissolved  in  10  to  20  cc.  of  ether*  in  a  test-tube,  and  the  solu- 
tion allowed  to  stand  12  hours  or  over  night  at  about  20°  C,  the  test- 
tube  being  loosely  stoppered  with  cotton.  The  crystals  obtained  vary 
considerably  with  the  condition  of  heat,  amount  of  solvent,  rate  of  crys- 
tallization, etc.,  so  that  the  operator  had  best  vary  these  conditions  till 
he  is  satisfied  that  the  best  possible  resuks  have  been  obtained.  It  is 
often  advantageous  to  separate  the  crystals  first  obtained  by  filtration 
from  the  mother  liquor,  and  to  redissolve  in  ether  and  recr}'stallize  in 
a  second  test-tube.  The  crystals  formed  at  the  bottom  of  the  test-tube 
are,  for  the  purpose  of  thus  purifying,  separated  from  the  mother  liquor 
by  filtration  through  a  small  filter,  and  the  precipitate  washed  several 
times  with  ether.  The  washing  with  ether  should  not  be  continued 
so  long  that  the  cr^'stals  are  perfectly  freed  from  mother  liquor  and  olein, 
for  in  this  case  they  are  so  dry^  and  pulverulent  as  to  require  a  mountant 
when  on  the  slide  for  microscopical  examination.     The  wTiter  prefers 

» . ■ ■ ■ — ■ • « 

*  Some  analysts  get  better  results  with  a  mixture  of  ether  and  alcohol. 


55 S  FOOD  INSPECTION  AND  ANALYSIS. 

to  ha\-e  ihem  slightly  oleaginous,  so  that  when  api^lied  to  the  slide  no 
mount  ant  need  be  used.  In  this  case  the  cn^stals  seem  to  stand  out  in 
wider  contrast  to  the  background  than  when  cottonseed  oil,  the  usual 
medium,  is  used. 

If  the  cr}'stals  are,  however,  in  a  pulverulent  condition,  a  drop  of 
alcohol  can  be  used  as  a  mountant,  or  oil,  as  preferred.  Mounted  under 
a  cover-glass  they  are  examined  under  various  powers  of  the  microscope. 

Figs.  272  and  273,  PI.  XXXIX,  show  the  typical  appearance  of 
pure  lard  stearin  from  a  leaf  lard  of  knowTi  purity,  and  Figs.  276,  277^ 
and  27S  illustrate  beef  stearin.  These  figures  show  distinctive  crystal- 
lization of  each  form  under  the  best  conditions.  The  lard  stearin 
cr}'stals  when  thus  obtained  are  flat  rhomboidal  plates  cut  ofiE  obliquely 
at  one  end,  and  are  grouped  irregularly,  as  if  thrown  carelessly  together. 
The  beef  stearin  crystals,  on  the  other  hand,  are  cylindrical  rods  or 
needles,  often  curved,  with  sharp  ends,  and  are  arranged  as  shown  in  fan- 
shaped  clusters.  Conditions  of  crystallization  are  frequently  such  as  not  to 
show  the  sharp  distinctions  noted  above.  Both  forms  of  crystals  are  at 
times  apt  to  gather  in  clusters  that  at  first  sight  appear  somewhat 
similar,  and  are  often  misleading  as  to  their  true  character.  It  is  found 
almost  invariably  that  the  beef  stearin  cr}'stals  gather  in  clusters,  radiat- 
ing from  a  common  center  or  point,  often  with  a  peculiar  twisted  appear- 
ance, breaking  up  into  little  fans.  Lard  crystals,  it  is  true,  do  not  always 
lie  flat  in  irregular  groups  as  shown  in  Fig.  272,  but,  as  in  Fig.  274,  form 
clusters  that,  unless  studied  carefully,  might  at  first  sight  be  considered 
as  identical  with  the  fan  shapes  of  the  beef  stearin  already  described. 
It  will  be  seen,  however,  that  if  the  best  possible  conditions  are  attained, 
the  crystals  of  lard,  instead  of  radiating  from  a  point,  are  arranged  more 
like  feathers  or  alternate  leaves  on  a  branch,  each  crystal  being  given  forth 
from  another  close  at  hand.  Moreover,  the  lard  crystals  are  themselves 
straight  and  not  cun^ed,  the  apparent  curve  in  the  appearance  of  the 
clusters  being,  on  careful  examination,  especially  under  high  power, 
seen  to  be  chiefly  due  to  several  of  these  straight  crystals  arranged  at 
angles  to  each  other. 

Even  when  the  highest  powers  of  the  microscope  are  applied  to  the 
beef  stearin  crystals,  they  will  always  appear  as  cylindrical,  sharp- 
pointed  rods,  some  straight,  others  curved;  while  with  the  lard  crystals 
ihcy  should  be  cajjable  of  showing  the  thin,  flat,  oblique-ended  structure 
when  examined  with  higher  j;owers,  even  when  they  are  arranged  in  the 
feathery  clusters,  the  apparently  i)ointed  ends  of  some  of  the  crystals 


EDIBLE   OILS  AND  EATS. 


5S9 


being  due  to  the  fact  that  the  plates  arc  viewed  edgewise.  This  is  apparent 
in  Fig.  275,  in  which  the  crystals  are  magnified  to  480  diameters. 

According  to  Belfield,  who  was  one  of  the  earliest  to  employ  the  micro- 
scope for  identification  of  foreign  fat  in  lard,  it  is  possible  to  detect  well- 
defined  crystals  of  both  lard  and  beef  stearin  in  mixtures  crj^stallized 
out  in  the  above  manner  from  ether.  Later  investigators,  however,  find 
difTiculty  in  getting  both  kinds  of  crj^stals  in  the  final  deposit,  it  being 
the  more  common  experience  that  the  character  of  the  final  cr}'stals  from 
a  mixture  of  the  two  fats  more  often  tends  to  one  or  the  other  forms  of 
crystallization.  Repeated  crystallizations  may  change  the  character  of 
the  crystals  and  a  number  of  such  cr)'talhzations  should  therefore  be 
made  before  final  judgment  is  passed. 

The  Iodine  Number  (p.  487). — This  test  is  generally  prefigured  by 
the  refractometer.  Cottonseed  oil  will  absorb  about  108%  of  its  weight 
of  iodine,  while  beef  fat  will  absorb  about  37%. 

ANALYSES  OF  SAMPLES   ILLUSTRATING   TYPES   OF  LARD,  LARD   SUBSTI- 
TUTES, AND  MIXTURES. 


Nitric  Acid  Test. 


Crystallization. 


Bechi  Reac- 
tion. 


Butyro-refrac- 
tometer. 


SQ 


f^ 


.555: 


Conclusion- 


A 
B 
C 
D 
E 
F 
G 
H 
I 

J 
K 
L 

M 

N 


Slight  color. . . 
Red 

Slight  color  . . 


Very  slight  color 
Deep-brown  red 

Red 

Very  slight  color 
Deep  brown . . . . 
Red 


Lard  stearin 


None 


Beef  stearin 
Few     small 

bunches 
Lard  stearin 

Lard  and 

beef  stearin 
Lard  stearin 


Lard  and 
beef  stearin 


Deep  color 
<(       (i 

None 
Deep  color 


42.5 

42 

41-S 

43 

41-3 

42 

42 

50 
42 

43 

43 

43-5 

43-7 
43-5 


49-7 

50 

50.1 

50 

51 

50-5 

49-7 

41.2 

58.7 

50-5 

48.5 

51 

50-1 
49-1 


-l-o.i 

-FO.2 

-1-0.0 
-1-0.6 
-1-0.8 
-1-0.7 

—  O.I 

-3-8 
-F8.9 

+  1-3 

-0.7 

■f  I.I 

+  1-3 
+  0-3 


58.1 
59-9 
58.7 
63-7 
64.6 
64.8 
56-4 
37-3 
108 

69-5 

55-2 
71.4 

66.7 

54-7 


Lard 


Leaf  lard 
Beef  tallow 
Cottonseed  oil 

Lard  and  cotton- 
seed oil 

Lard  and  beef 
tallow 

Lard  and  cotton- 
seed oil 
Ditto 

Lard,  beef  tallow, 
and  cottonseed 
oil 


Notes  on  the  Above  Table. — It  will  in  general  be  noted  that  adultera- 
tion of  lard  with  cottonseed  oil  alone  is  indicated  by  an  abnormally  high 


5^0  FO':n   IS'SPECTION   .4ND   AN ^1  LYSIS. 

rcfraclomctcr  number,  while  ihc  presence  of  tallow  will  result  in  an 
abnormally  low  refraction.  But  both  adulterants  may  be  present  and 
a  normal  refraction  result.  In  such  a  case  the  positive  detection  of  one 
oi  them,  such  as  the  cottonseed  oil  by  the  Bechi  or  Halphcn  test,  will 
indirectly  show  the  presence  of  the  other  (tallow),  and  this  indirect  proof 
will  l)e  confirmed  by  cr\stallization. 

Samples  A,  B,  and  C  give  reactions  corresponding  to  normal,  pure 
lard.  D,  E,  and  F  show  somewhat  high  refractometer  and  iodine 
numbers,  but  give  no  direct  reaction  for  cottonseed  oil  by  the  Bechi  test. 
G,  although  showing  low  iodine  and  refractometer  numbers,  gives  no 
evidence  of  the  presence  of  tallow  by  cr)'stallization.  In  fact,  the  cr}'s- 
tals  from  lliis  sample  proved  under  all  circumstances  to  be  most  clearly 
typical  of  pure  lard,  broad  and  fiat  plates  with  obliquely  cut  ends. 

This  sample  was,  in  fact,  i)ure  leaf  lard.  It  is  generally  true  that  a 
stifi",  strictly  pure  leaf  lard,  which  both  by  its  consistency  and  by  its  low 
iodine  and  refractometer  numbers  might  suggest  the  presence  of  beef  fat, 
shows  on  cr}'Stallization  much  more  definitely  characteristic  lard  stearin 
than  does  a  whole-hog  lard,  whose  iodine  and  refractometer  numbers 
are  more  nearly  the  normal  standard. 

In  distinction  from  such  leaf  lard,  a  sample  which  may  have  a  similar 
consistency  and  iodine  and  refractometer  numljers,  but  which  is  composed 
of  a  whole-hog  lard  of  a  comparatively  high  iodine  number,  together 
with  beef  fat,  gives  unmistakable  proof  of  its  adulteration  by  its  crystal- 
lization. 

Effects  of  Feeding  Hogs  on  Oil  Cakes. — Fulmer,*  Emmett  and 
Grindlcyt  and  other  investigators  have  found  that  feeding  cottonseed 
meal  to  hogs  causes  the  lard  from  these  hogs  to  give  a  color  with  the 
Halphen  test,  but  Tolman,;]:  Farnsteiner§  and  Polenske||  have  shown 
that  the  lard  does  not  contain  ])hyloslerol  when  examined  by  Bomer's 
phytosterol  acetate  method. 

Lard  from  hogs  fed  on  sesame  cake  has  been  shown  to  respond  to  the 
Baudouin  test,  but  not  to  the  phytosterol  acetate  test. 

*  Jour.  Am.  Chem.  Soc,  26,  1904,  p.  837. 

t  Ibid.,  27,  1905,  p.  263. 

X  Ibid.,  p.  589. 

§  Zeits.  Unters.  Nahr.  Gcnuss.,  11,  1906,  p.  i. 

II  Arb.  K?iiscrl.  Gesundheilsamt.,  22,  1905,  p.  568. 


EDIBLE  OILS   /IND   FATS.  561 


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564  FOOD   INSPECTION   AND  ANALYSIS. 

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Am.  Chcm.  Soc..  24,  1902,  p.  1149. 
On  Reactions  of  Lard  from  Cottonseed  Meal  fed  Hogs  with  Halphen's  Reagent. 

Ibid.  26,  1904,  p.  837. 
Gl.\dding,  T.  S.     Examination  of  Lard  for  Adulteration.     Analyst,  14,  1889,  p.  32. 

Microscopic  Detection  of  Beef  Fat  in  Lard.     Jour.  Am.  Chem.  Soc,  18,  p.  189. 

Hehner,  O.     On  Beltield's  Test  for  Beef  Stearin  in  Lard.    Analyst,  27,  1902,  p.  247. 
KoNiG,  J.,  und  SCHLUEKEBiER,  J.     Ucbcr  den  Einfluss  des  Futterfettes  auf  das  Korper- 

fett  bei  Schweinen  mit  besonderer  Beriicksichtigung  des  Verbleibs  des  Phytos- 

terins.     Zeits.  Unters.  Nahr.  Genuss.,  15,  1908,  p.  641. 
Macf.'VRL.\ne,  T.     Lard.     Canadian  Inl.  Rev.  Dept.,  Bui.  7. 
Stock,  W.  F.  K.     On  the  Estimation  of  Beef  Fat  in  Lard.     Analyst,  19,  1894,  p.  2. 
Tennile,  G.  F.     Determination  of  Solid  P'ats  in  Compound  Lard.     Jour.  Am.  Chem. 

Soc,  19,  1897,  p.  51. 
ToLM.\N,  L.  M.     E.xamination  of  Lard  from  Cottonseed  Meal-fed  Hogs,  by  Phytos- 

terol  Acetate  Method  of  Bomer.     Jour.  Am.  Chem.  Soc,  27,  1905,  p.  589. 
Wesson,  D.     Examination  of  Lard  for  Impurities.     Jour.  Am.  Chcm.  Soc,  17,  1895, 

P-  7^3- 
Wile\,  H.  W.     Quantitative  Estimation  of  Adulterants  in  Lard.     Analyst,  14,  1889, 

P-  73- 
Lard  and  Lard  Adulterations.     U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13, 

part  4 
WiRTHLE,  F.     Detection  of  Cottonseed  Stearin  in  Lard.     Analyst,  27,  1902,  p.  247. 
Conn.  Exp.  Sta.  An.  Rep.,  1896,  p.  128. 
Mass.  State  Board  of  Health  An.  Rep.,  1895,  p.  668. 


CHAPTER  XIV. 
SUGAR  AND  SACCHARINE  PRODUCTS. 

Nature  and  Classification  of  Sugars. — Of  all  classes  of  food  mate- 
rials the  sugars  from  their  great  solubility  are  the  most  readily  available, 
and  on  this  account  are  very  valuable  as  nutrients.  As  in  the  natural 
processes  of  digestion  the  starches  and  more  difficultly  digestible  of  the 
carbohydrates  are  converted  into  sugar  and  thus  rendered  assimilable, 
so  by  processes  quite  analogous  to  those  that  take  place  in  the  alimentary 
tract,  the  chemist  converts  these  same  carbohydrates  into  sugar  as  an 
end-point  for  purposes  of  definite  determination. 

The  sugars  are  characterized  by  their  sweet  taste,  their  ready  solu- 
bility in  water,  their  power  to  rotate  the  plane  of  polarized  light,  and 
their  insolubility  in  ether  and  absolute  alcohol. 

The  sugars  occurring  commonly  in  food  naturally  divide  themselves 
into  two  groups:  First,  the  Saccharoses,  or  cane  sugar  group,  having 
the  composition  CjjHooOn,  of  which  the  most  prominent  members  are 
sucrose,  maltose,  and  lactose;  and,  second,  the  Glucoses,  or  grape  sugar 
group,  expressed  by  the  formula  CgHisOg,  which  includes  dextrose,  levulose 
and  galactose,  besides  other  less  common  sugars. 

The  members  of  both  groups  are  intimately  related.  Thus  by  the 
ordinary  process  of  so-called  inversion  sucrose,  or  cane  sugar,  belonging  to 
group  I,  is  converted  by  the  action  of  heat  and  dilute  acid  into  two  sugars, 
dextrose  and  levulose,  which  are  members  of  group  2,  in  accordance 
"with  the  following  reaction: 

C„H,,0,i+ H,0  =  C„H,,0«+  C«Hi30e. 

Cane  sugar  Dextrose  Levulose 

The  same  formula  expresses  also  the  result  that  takes  place  w^hen 
lactose,  or  milk  sugar,  is  heated  with  dilute  acids,  breaking  up  into  dextrose 
and  galactose. 

565 


566 


FOOD  INSPECTION  AND  ANALYSIS. 


Occurrence. — Sugars  occur  in  root^,  grasses,  stems  of  plants,  trunks 
of  trees,  leaves,  and  fruits,  usually  in  the  form  of  cane  sugar,  or  sucrose, 
and  of  invert  sugar  (dextrose  and  levulosc)  mixed  in  var}'ing  propor- 
tions. 

The  follo^^'ing  table  from  BuigncL  *  shows  the  kind  and  amount  of 
suE^ars  occurring  in  some  of  the  common  fruits: 


Apricots 

Pineajiplcs 

English  cherries. . 

I>emons 

Figs 

Strawberries 

Raspberries 

GcM3seberries 

Oranges 

Peaches  (green). . 
Pears  (Madeleine) 
Apples 

Prunes 

Grapes  (hothouse) 
' '        green 


Cane  SuKar. 


.04 

•33 
.00 

-41 
.00 


4.22 

.92 

-36 

5.28 

2  .19 

5-24 
.00 
.00 


Reducing 
Sugar. 


2.74 

1. 98 

10.00 

1.06 

11.=;=; 

4-9'^ 

6.40 
4-36 
1.07 
8.42 
8.72 
5-45 
2-43 
17.26 
1.60 


Acid. 


1.864 

•547 
.661 

4.706 
•057 
•550 

1.380 

^•574 

.448 

3.900 

•IIS 
1. 148 

1.288 

•345 
2.485 


CANE    SUGAR,    OR    SUCROSE. 

Nature  and  Occurrence. — This,  the  most  common  of  all  the  sugars, 
is  nearly  always  understood  by  the  unqualified  term  of  sugar.  It  crys- 
tallizes in  monoclinic  prisms.  Its  specific  gravity  is  1.595.  Its  melting- 
point  is  about  160°  C.  Its  specific  rotary  power  [a]^,  in  solutions  having 
a  concentration  of  from  10  to  20  grams  in  100  cc.  is,  according  to  Tollens, 
66.48°.  Sucrose  is  extremely  soluble  in  water,  which,  when  cold,  will 
hold  in  solution  twice  its  weight  of  the  sugar. 

Cane  sugar  is  ordinarily  derived  from  four  sources — the  sugar  beet, 
the  .sugar  cane,  the  maple  tree,  and  the  sorghum  plant.  The  first  two 
sources  .supply  the  principal  output  of  commercial  cane  sugar,  about 
half  the  sugar  on  the  world's  market  being  furnished,  by  the  sugar  beet 
and  the  other  hah'  by  the  sugar  cane.  It  shoukl  be  understood  that  the 
product  sucrose,  or  cane  sugar,  is  chemically  the  same  whether  derived 
from  cither  of  the  above  sources  and  thoroughly  refined. 

U.  S.  Standard  Sugar  is  white  sugar  containing  at  least  99.5%  of 
sucrose. 


*  Ann.  Chim.  Phys.,  59,  233. 


SUG/1R  /1ND  SACCHARINE  PRODUCTS. 


567 


The  Sugar  Cane  {Sacchariim  officinarum)  is  cuhi\ale(l  i)rincipally  in 
Louisiana  and  other  southern  states,  in  Cuba  and  the  West  Indies,  and 
in  the  Hawaiian  Islands.  Its  growth  and  cultivation  form  an  industry 
in  nearly  all  tropical  countries. 

Allen  *  has  compiled  the  following  table  showing  the  composition 
of  the  juice  of  the  sugar  cane  from  different  localities: 


Locality  and  Kind 
of  Cane. 

Water. 

Sugar. 

Woodv 
Fiber. 

Salts.                     Authority. 

Martinituie 

72.1 
72.0 
77.0 

65-9 
69.0 

76.73 
76.08 

18.0 
17-8 
12.0 
17.7 
20.0 

13-39 
14.28 

9.9 

9.8 

II. 0 

16.4 

10. 0 

9.07 

8.87 

PfliVnt- 

Guadaloupc 

0.4 

I.O 

.39 

•35 

Dupuy 

Cuba 

Mauritius 

Ribbon  cane 

Tahiti 

Avequin 
Avequin 

The  composition  of   raw  cane  sugar  ash  according  to  Monier  is  as 
follows : 

RAW   CANE    SUGAR   ASH. 

Carbonate  of  calcium 49 .00 

"           "   potassium 16.50 

Sodium  and  potassium  sulphate 16 .00 

Sodium  chloride 9 .00 

Silica  and  alumina 9  •  50 


100.00 


Manufacture  of  Cane  Sugar. — The  process  of  manufacturing  raw 
sugar  from  sugar  cane  is  briefly  as  follows:  The  juice  is  first  extracted 
from  the  canes  by  crushing  in  roll  mills  and  is  freed  from  nitrogenous 
bodies,  organic  acids,  etc.,  by  the  process  of  defecation,  which  consists 
in  heating  to  coagulate  the  albumin,  and  nearly  neutralizing  with  milk 
of  lime,  the  impurities  being  removed  as  a  scum.  The  juice  is  then 
subjected  to  evaporation  and  cr}^stallization,  the  raw,  or  muscovado  sugar, 
which  contains  from  87  to  91  per  cent  of  sucrose,  being  separated  from 
the  molasses,  which  is  the  mother  liquor,  by  draining  or  by  centrifugal. 

Some  of  the  best  grade  of  muscovado,  or  raw  sugar,  is  used  as  '  *  brown 
sugar"  without  further  refining,  and  much  of  the  molasses  is  used  as  a 
table  syrup  and  for  cooking,  while  the  lower  grades  of  molasses  are  used 
in  the  manufacture  of  rum. 


Com.  Org.  Anal.,  4  Ed.,  Vol.  I,  p.  359. 


5*^ 


FOOD  INSPECTION  AND  ANALYSIS. 


The  following  table  from  Thoq)c  *  shows  the  average  composition 
of  raw  and  rotmed  sugar: 


Cane 
Sugar. 


Glucose'. 


Water. 


Organic 
Matter. 


Ash. 


R.\\V    SL'GAR. 

CiooA  centrifugal 

Poor  centrifugal 

Good  muscovado. 

Poor  muscovado  . . . . 

Molasses  sugar 

JaggarA'  sugar 

Manilla  sugar 

Beet  sugar,  i  st 

Beet  sugar,  2d 


REFINED   SUGAR. 

Granulated  sugar 

White  cotTee  sugar 

"S'ellow  X  C  sugar 

Yellow  sugar 

Barrel  sugar 


06.5 
92.0 
01 .0 
82.  o 
S5.0 

75-0 
87.0 

95 -o 
91 .0 

99-8 
91.0 
87.0 
82.0 
40.0 


0-75 
2.50 
2.25 
7.00 
3-00 
11.00 

5-5° 
0.00 
0.25 

0.20 
2.40 
4-50 
7-50 
25.00 


1.50 
3.00 
5.00 
6.00 
S-oo 
8.00 
4.00 
2.00 
3.00 


0.00 

5-5° 

6.00 

6.00 

20.00 


•75 
.  10 

-50 
.00 
.00 
■25 
■75 
■25 


coo 

0.80 
1.50 
2.50 

10.00 


0.40 

0-75 
0-65 
1.50 

2.00 
2.00 

1.25 

1-25 

2.50 

0.00 

0.30 

1. 00 

2.00 

s.OO 




'  The  term  "glucose"  includes  sugars  which  reduce  Fehling's  solution,  but  are  not  necessarily 
optically  active. 

"The  following  minimum  and  ma.ximum  figures  are  taken  from  analyses 
made  by  Babington  f  of  twenty-two  samples  of  brown  sugar  and  thirty- 
one  samples  of  molasses. 

BROWN    SUGAR. 

Direct  polarization 84      to  87 

Invert           "           -27       "  -29 

Sucrose  by  Clerget 83 . 5   ''  91.5 

Reducing  sugar 3       "  6 

Moisture 3.5  "  6 

Ash 0.8  "  3.0 

MOLASSES. 

Direct  polarization 30  to  50 

Invert            "           -10  "  -21 

Sucrose  by  Clerget. 32  "  52 

Reducing  sugar 13  "  24 

Moisture 29  "  32 

Ash 0.5  ''  4 

*  Outlines  of  Industrial  Chem.,  p.  383. 
t  Can.  Inl.  Rev.  Dcpt.  Bui.  25. 


SUGAR   AND  SACCHARINE   PRODUCTS.] 


569 


The  Sugar  Beet  {Beta  vulgaris)  is  grown  chiefly  in  France  and  Ger- 
many, and  to  a  h'sser  extent  in  Holland  and  England.  The  successful 
growth  o[  the  sugar  beet  in  the  United  States  is  conlined  mainly  to  Cali- 
fornia, Colorado,  Utah,  and  Nebraska,  and  the  entire  output  of  beet  sugar 
in  this  country  is  comparatively  small. 

According  to  R.  Hoffmann,  sugar  beets  have  about  the  following 
composition,  three  types  being  selected — first,  those  poor  in  sugar;  second, 
those  having  a  medium  sugar  content,  and  third,  those  rich  in  sugar: 


COMPOSITION  OF  THE  SUGAR  BEET. 


First  Type. 

Second  Type. 

Third  Type 

89.20 

83.20 

75.20 

4.00 

9.42 

15.00 

1. 00 

1.64 

2.20 

4-13 

3-34 

4-23 

1. 01 

1.50 

2.07 

0.66 

0.90 

1.30 

100.00 

100.00 

100.00 

Water 

Sugar 

Nitrogenous  compounds 

Non-nitrogenous  compounds 

Soluble 

Insoluble  (cellulose) 

Ash 


The  following  is  the  mean  composition  of  ten  samples  of  California 
sugar  beet :  * 

Per  cent  juice  extracted 61 .38 

Specific  gravity i  .062  to  i  .075 

Per  cent  of  reducing  sugar 0.91 

Per  cent  of  sucrose 14-38 

Total  solids  calculated 16.58 

Total  solids  weighed 1 7 .  20 

Per  cent  of  ash o .  994 

The  composition  of  beet  sugar  ash  according  to  Monier  is  as  follows: 

RAW    BEET   SUGAR    ASH. 

Carbonates  of  potassium  and  sodium 82 .  20 

Carbonate  of  calcium 6 .  7c 

Potassium  and  sodium  sulphate  and  sodium  chloride.  ...   11 .10 

100.00 

Manufacture  of  Beet  Sugar. — In  making  raw  sugar  from  sugar  beets 
the  latter  are  first  washed  and  sliced  by  machinery  and  the  juice  extracted 
*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  27,  p.  ao2. 


573  FOOD  INSPECTION  AND  ANALYSIS. 

by  di /fusion  oi  digestion  with  warm  water.  The  juice  is  then  clarified 
or  defecated  in  much  the  same  manner  as  that  from  the  sugar  cane,  after 
which  it  is  usually  bleached* with  sulphur  dioxide. 

The  subsequent  evaporation  and  crystallization  are  carried  out  usu- 
ally in  vacuum  pans,  and  the  sugar  separated  out  by  centrifugals. 

Beet  sugar  molasses  is  unfit  for  food,  due  to  the  presence  of  nitroge- 
nous bodies,  which  give  it  a  ver}'  unpleasant  taste  and  smell. 

Process  of  Refining. — In  refining  raw  sugar,  a  syrup  is  made,  which 
is  subjected  to  centrifuging  and  further  defecation,  using  lime,  clay, 
liquid  blood,  calcium  acid  phosphate,  and  other  substances  as  clarifiers. 
The  juices  are  then  filtered,  first  through  cloth  bags  and  then  through 
bone  char,  after  which  they  are  evaporated  and  allowed  to  cr>'stallize,  the 
resulting  granulated  sugar  being  separated,  as  in  the  case  of  raw  sugar, 
by  centrifugal  machines. 

Granulated  Sugar  of  commerce  is  without  doubt  the  purest  food  product 
on  the  market,  being  generally  99.8%  sucrose.  It  is  usually  treated  with 
an  extremely  weak  solution  of  ultramarine  to  counteract  the  natural 
yellow  color. 

The  syrup  from  which  the  granulated  sugar  is  separated  forms  the 
"golden,"  or  "drip,"  syrup  used  on  the  table.  Its  typical  composition 
is  as  follows:  Sucrose,  40%;  reducing  sugars,  25%;  water,  20%;  organic 
matter,  10%;   ash,    5%. 

The  dry  sugars,  whether  white  or  brown,  are  rarely  subjected  to 
adulteration. 

Maple  Sap. — The  sap  of  the  maple  tree,  Acer  saccharimim,  or  Acer 
barbatum,  furnishes  a  sugar  considerably  prized  for  its  peculiar  flavor. 
The  majjle  sugar  industrj'  is  largely  confined  to  the  northeastern  states 
and  to  Canada,  and  the  maple  sugar  season  is  generally  limited  to  six 
weeks  or  two  months  in  the  spring. 

The  following  are  minimum  and  maximum  figures  from  the  analyses 
of  five  samples  of  maple  sap  made  in  Massachusetts: 

Specific  gravity i  -007  to  i  .015 

Sucrose 0.769  "   2.777 

Reducing  sugar "  0.012 

The  ash  of  maple  sap  varies  from  0.04  too. i  per  cent.  Albuminoids 
arc  present  in  amount  varying  from  0.008  to  0.03  per  cent. 

Maple  Sugar  and  Syrup  arc  made  by  simply  boiling  down  the  sap 
to  the  proj;er  consistency,  usually  in  open  j^ans,  and  removing  the  scum 


SUG^R  AND  SACCHARINE  PRODUCTS. 


571 


with  great  care,  since  this  contains  nitrogenous  matters  that  would  cause 
fermentation  in  the  finished  jjroduct.  Pure  cane  sugar  is  never  com- 
mercially produced  from  the  maple  sap,  since  the  rcfming  process  would 
deprive  it  of  the  flavor  which  gives  to  maple  sugar  the  chief  value. 

McGill  gives  the  following  as  the  average  analyses  of  six  samples 
of  maple  syrup  of   known  j)urity: 


Saccharim-     Cane  Sugar 
eter  Invert,     by  Clerget. 

By  Copper. 

Ash. 

Water. 

Saccharim- 
eter  Direct. 

Reducing 

Sugar. 

Cane  Sugar. 

Solids. 

+  62.2 

—  21.2              62.4 

.42 

63-36 

-53 

35-70 

64.30 

The  variation  in  the  composition  of  pure  maple  products  is  shown 
by  the  following  table  compiled  by  A.  H.  Bryan  *  from  analyses  published 
by  Hortvetjt  Jones,J  and  Winton§,  and  some  sixty  analyses  made  at 
the  sugar  laboratory  of  the  Bureau  of  Chemistry,  U.  S.  Department  of 
Agriculture. 


Maple  Sugar. 


Mini- 
mum. 


Maxi- 
mum. 


Average. 


Maple  Syrup. 


Mini- 
mum. 


Maxi- 
mum. 


Average. 


Water per  cent 

Direct  polarization " 

Invert  sugar " 

Lead  number 

Total  ash per  cent 

Soluble  ash " 

Insoluble  ash ■ " 

Alkalinity  of  soluble  ash 

Alkalinity  of  insoluble  ash 

Ratio  of  insoluble  to  soluble  ash 

Iodine  reaction 

Polarization  at  87°  after  inversion. . . .  °V. 
Malic  acid  value 


3-05 
72.6 
1. 16 
1.83 
0.64 

0-33 
0.20 
0.40 

0-55 
0.50 


II  .0 
87.4 

8-37 
2.48 
1.32 
0.67 
0.87 

0-95 
1.72 


-2.0 
o.6^ 


-1-2. 0 

1.67 


2.23 

0.91 
0.46 
0.46 

0.63 
0.94 

1. 00 
none 


Not  m 

51-0 
0-34 
1. 19 
0.46 
0.21 
o.  14 
0.26 

0-31 
0.60 


ore  tha 
62.2 
9.17 
2.03 
1. 01 
0.63 
0.56 
0.68 
0.94 
3.20 


-  2.0 
C.41 


+  2.0 


n  32.00 


1-49 
0.60 
0.38 
0.23 
0.50 

0-54 
1.70 
none 


.76;    0.78 


Partial  ash  analyses  of  maple  products  and  brown  sugar  have  been 
made  by  Jones II  with  the  following  maxima  and  minima  results: 


*  U.  S.  Dept.  Agric,  Bur.  of  Chem.,  Circular  No.  40,  p.  10. 

t  Jour.  Am.  Chem.  Soc,  26,  1904,  p.  1523. 

X  Vt.  Agric.  Exp.  Sta.  Rep.,  1904,  p.  446;    1905,  p.  315. 

§  Jour.  Am.  Chem.  Soc,  28,  1906,  p.  1204. 

II  Loc.  cit.,  1905,  p.  331. 


J/  - 


FOOD  INSPECTION  AND  ANALYSIS. 


loo  Parts  of  Ash  Contain 

Ratio  of 

Number 

of 
Analysis. 

1 

CaO. 

K20. 

SO3. 

CaO  to  K2O 
Xioo. 

CaO  to  SOalK-O  to  SOa 
Xioo.       ^      X  100. 

Maple  syrup: 

Min.  .  .. 

6 

18.03 

30.00 

0.68 

150 

3-4 

1.9 

Max.    .. 

23.98 

38.  q8 

2.30 

181 

12.7 

7-2 

Maple  sugar: 

Min.  .  .  . 

4 

21.03 

18.26 

I-51 

57 

5-2 

5-1 

Max 

31-74 

32.95 

2.42 

153 

10.4 

9-4 

Brown  fugar: 

Min.  .  .  . 

4* 

4-17 

30.72 

4-58 

257 

27 

II 

Max.... 

21.62 

55-40 

17.78 

949 

157 

58 

*  Including  one  analysis  by  Hortvet. 


U.  S.  Standards  for  Maple  Products. — Maple  Sugar  is  the  solid 
product  resulting  from  the  eva])oraiion  of  maple  sap,  and  contains  in  the 
water-free  substance  not  less  than  0.65%  of  maple  sugar  ash. 

Maple  syrup  is  syrup  made  by  the  evaporation  of  maple  sap  or  by  the 
solution  of  maple  concrete,  and  contains  not  more  than  32%  of  water 
and  not  less  than  0.45'^^'^'  of  maple  .syrup  ash. 

Adulteration  of  Maple  Sugar  and  Syrup. — The  chief  adulterants  of 
maple  sugar  are  brown,  or  molasses  sugar,  and  white,  or  refined  sugar, 
the  latter  being  often  used  in  mixture  with  burnt  or  inferior  maple  stock, 
which  itself  would  be  abnormally  dark  in  color  and  of  a  rank  taste. 
Maple  syrup  is  commonly  adulterated  with  a  syrup  made  from  refined 
cane  sugar,  le.ss  often  with  golden  or  drip  syrujj,  or  molas.ses.  Gluco.se, 
which  formerly  was  a  common  adulterant,  is  now  seldom  employed. 

Refined  Sugar  or  refined  sugar  syrup  added  to  maple  products,  while 
not  greatly  affecting  the  polarization,  diminishes  the  percentage  of  total 
ash  and  the  lead  number,  as  well  as  the  malic  acid  value  and  ash  con,stants. 
The  ash  of  maple  sugar  should  not  be  less  than  0.64%  and  of  mai)lc 
syrup  not  le.ss  than  0.4590  while  the  lead  number  of  maple  sugar  should 
not  be  le.ss  than  1.83  and  of  maple  syrup  not  le.ss  than  1.19. 

According  to  analy.ses  by  Jones  and  Hortvet,  brown  sugar  of  various 
grades  contains  from  0.59  to  4.33%  of  total  a.sh,  some  of  the  grades  with 
low  a.sh  content,  or  .syrups  made  from  them,  not  being  distinguishable 
from  maple  sugar  or  maple  .syrup  respectively  by  this  determination  alone; 
the  ratio  of  in.soluble  to  .soluble  a.sh,  however,  is  commonly  higher  in 
brown  .sugar  than  in  maple  products.  It  is  frecjuently  po.ssible  to  identify 
brown,  or  molas.ses  sugar,  especially  when  it  forms  the  larger  portion 
of  the  alleged  majjle  sugar  or  syrup,  by  the  physical  sense  of  taste.  When 
the  perfectly  characteristic  taste  of  brown,  or  molas.ses  sugar,  or  of  "  drip 
syrup,"  .so  far  predominates  over  the  majjle  flavor  as  to  be  unmistakable. 


SUG^R   yIND   SACCHARINE  PRODUCTS.  573 

especially  in  cases  where  the  maple  llavor  is  entirely  lacking,  one  need 
have  little  hesitation  in  condemning  the  product.* 

Glucose  in  maple  products  is  detected  by  polarization  both  before  and 
after  inversion.  A  reading  of  the  inverted  solution  much  in  excess  of 
3  degrees  Ventzke  at  87°  C.  furnishes  evidence  of  the  presence  of  this 
adulterant. 

Sorghum  {Andropogon  sorghum,  variety  saccharatus)  has  for  many 
years  been  grown  cpn'te  extensively  in  the  southern  and  western  states, 
and  used  as  a  source  of  syrup,  but  onl)-  in  recent  years  has  it  been  found 
practicable  to  produce  crystallized  cane  sugar  from  it  on  account  of  the 
presence  of  starch,  uncrystallizablc  sugar,  etc. 

Much  experimental  work  has  been  done  of  late  along  this  line  by  the 
U.  S.  Department  of  Agriculture.  The  sorghum  plant  is  as  yet,  however, 
a  very  small  factor  in  the  production  of  cane  sugar,  though  much  progress 
is  being  made. 

The  composition  of  the  juice  of  the  sorghum  plant  is  shown  by  the 
following  results  of  analyses  of  eleven  varieties  made  by  Hardin  if 

Total  solids.  .. : 15 -97      1018.71 

Specific  gravity i  .0656  "     i  .0775 

Solids  not  sugar 5.02       "   10.63 

Cane  sugar 2.81       "     8.01 

Reducing  sugars 3.87       "     7.55 

Some  varieties  of  sorghum  juice  have  been  known  to  contain  15  or 
even  17  per  cent  of  sucrose. 

In  making  syrup  from  sorghum,  the  ripe  canes  are  crushed,  the  juice 
is  heated  with  milk  of  lime,  and  the  scum  removed.  The  juice  is  then 
concentrated  usually  in  open  pans  to  the  required  consistency. 

GRAPE  SUGAR,  OR  DEXTROSE. 

Dextrose  (C6H12O6  +  H2O),  designated  (/-glucose  by  Fischer  and 
known  in  its  commercial  form  as  starch  sugar,  occurs  in  honey  wdth 
levulose,  and  in  fruits  with  both  levulose  and  cane  sugar.  It  is  produced 
by  the  action  of  dilute  acids  or  of  certain  ferments  on  starch,  dextrin, 
or   cane   sugar.     Grapes   contain    about    15%   of  dextrose.     Anhydrous 

*  The  sense  of  taste,  if  properly  cultivated,  and  with  its  limitations  recognized,  should 
be  entitled  to  as  much  consideration  as  the  other  senses  in  forming  an  opinion.     Taste  and 
smell  are  often  very  useful  factors  in  detecting  adulterants,  but  should  of  course  be  used 
with  discretion. 
J        t  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  37,  p.  75. 


574  FOOD  INSPECTION   /1ND   ANALYSIS. 

dextrose  is  soluble  in  1.2  jxirls  of  cold  water.     It  is  soluble  in  alcohol,  but 
less  so  than  cane  sugar.     It  is  much  less  sweet  than  cane  sugar. 
The  specific  rotan,-  power  of  dextrose  is 

[a]D  =  52.3,     [a],  =  58. 

A  normal  solution  of  dextrose  on  the  Solcil-Ventzke  scale  polarizes  at 
78.6°.       For  the  commercial  preparation  of  dextrose  see  p.  576. 

U.  S.  Standards  for  Various  Sugars. — Stajidard  70  sugar,  or  brewers^ 
sugar,  is  hydrous  starch  sugar  containing  not  less  than  70%  of  dextrose, 
and  not  more  than  o.89o  of  ash. 

Standard  80  sugar,  climax,  or  acme  sugar,  is  hydrous  starch  sugar 
containing  not  less  than  80%  of  dextrose,  and  not  more  than  1.5%  of  ash. 

St-andard  anhydrous  starch  sugar  is  anhydrous  starch  sugar  contain- 
ing not  less  than  95'^^,  of  dextrose  without  water  of  crj-staUization,  and 
not  more  than  0.8%  of  ash. 

The  ash  of  these  standard  products  consists  almost  entirely  of  chlorides 
and  sulphates  of  lime  and  soda. 

LEVULOSE. 

Levulose,  also  known  as  (/-fructose  and  /-J-fructose,  occurs  in  foods 
as  the  product  of  inversion  of  cane  sugar.  It  is  prepared  by  the  action 
of  dilute  acids  on  inulin.  Normally  it  is  in  the  form  of  a  syrup,  but 
with  extreme  care  pure  anhydrous  levulose  can  be  obtained.  Diabetene 
is  a  commercial  form  of  dry  levulose.  Levulose  is  formed  with  dextrose 
in  the  inversion  of  cane  sugar  (p.  565),  and  with  dextrose  occurs  in  honey 
and  in  many  fruits.  The  specific  rotary  power  of  levulose  varies  with 
the  temperature.  At  15°  C.  [•'Ijd=  ~  98.8°,  decreasing  by  0.6385°  for 
each  degree  increase  in  temperature.  Its  left-handed  reading  on  the 
Vcntzke  sugar  scale  at  15°  C.  is  equivalent  to  148.6°.  Levulose  is  sweeter 
than  dextrose.  Its  reducing  power  on  Fehling's  sohuion  is  assumed 
to  be  the  same  as  that  of  dextrose. 

MALT    Si:OAR,    OR    MALTOSE. 

Maltose  (CijHjzOji+HjO)  is  of  little  importance  from  the  standpoint 
of  the  food  analyst,  excepting  as  an  ingredient  of  commercial  glucose, 
and  as  Vjcing  the  sugar  produced  by  the  action  of  ptyaline,  the  ferment 
of  the  saliva  on  the  starch  of  food  in  the  ordinary  process  of  digestion. 
When  gelatinized  starch  is  subjected  to  treatment  with  malt  extract  at 
55°  to  60°  C,  it  Ls  converted  into  dextrin  and  maltose  as  follows: 

10C12H20O10  +  8H2O  =  2C12H20O10  +  8C12H22O11. 

Starch  Dextrin  Maltose 


SUGAR.  AND  SACCHARINE  PRODUCTS.  SIS 

In  its  commercial  preparation  mallosc  is  separated  from  dextrin  by 
crystallization  in  alcohol.  By  the  action  of  weak  acids  and  heat  both 
dextrin  and  maltose  are  further  converted  into  dextrose. 

Maltose  usually  crystaUizes  in  minute  needles,  and  its  molecule  of 
water  is  expelled  at  iio°C.  It  is  somewhat  less  soluble  in  water  than 
dextrose.  It  is  slightly  soluble  in  alcohol,  though  less  than  sucrose.  So- 
lutions of  maltose  possess  the  property  of  birotation;  i.e.,  when  freshly 
prepared  they  do  not  at  once  assume  their  true  optical  activity.  The 
rotation  of  a  freshly  j)repared  solution  of  maltose  increases  on  standing, 
requiring  several  hours  to  reach  its  maximum.  The  specific  rotary 
power,  according  to  O'Sullivan,  of  anhydrous  maltose  is  [a]/j=  139.2, 
[a]y=  154.5.     For  hydrated  maltose  [a]/,  would  thus  be  132.2. 

A  normal  solution  of  maltose  hydrate  on  the  SoleilA'entzke  scale  should 
polarize  at  198.8°. 

DEXTRIN.      COMMERCIAL  GLUCOSE. 

Dextrin,  (C6Hio05)„,  possesses  more  the  nature  of  a  gum  than  of  a 
sugar,  and  is  sometimes  called  British  gum.  It  is  said  to  occur  naturally 
in  the  sap  of  various  plants,  but  this  is  not  definitely  assured. 

It  undoubtedly  occurs  in  beer  and  in  bread  crust,  and  is  one  of  the 
constituents  of  commercial  glucose.  Like  starch,  it  is  convertible  by 
hydrolysis  \^'ith  acid  into  dextrose.  By  treatment  of  starch  with  malt 
extract  or  diastase,  starch  is  converted  into  dextrin  and  maltose,  these 
two  bodies  being  separated,  in  the  commercial  preparations  of  dextrin, 
by  repeated  treatment  with  alcohol. 

Dextrin  is  an  uncrystallized,  colorless,  tasteless  body,  capable  of 
being  pulverized.  It  is  readily  soluble  in  water,  slightly  soluble  in  dilute 
alcohol,  but  insoluble  in  alcohol  of  60%  or  stronger.  It  is  not  colored 
by  iodine,  and  exercises  no  reducing  action  on  alkaline  copper  solution. 
Its  specific  rotary  power  is  [«]£,  =  200,  [a];=22  2. 

Amylodextrin,  erythrodextrin  and  achroodcxtrin  are  intermediate 
products  formed  in  the  transformation  of  starch  into  dextrose.  Amylo- 
dextrin is  colored  purple  and  erythrodextrin  red  by  iodine  solution,  while 
achroodcxtrin  produces  no  coloration.  It  is  probable  that  some  of  these 
dextrins  arc  not  simple  substances. 

Commercial  Glucose,  otherwise  known  as  mixing  syrup,  crystal  syrup, 
and  starch,  or  corn  syrup,  is  a  heavy,  miklly  sweet,  colorless,  semi-fluid 
substance,  having  a  gravity  of  40°  to  45°  Baume.  It  is  largely  used  as 
an  adulterant  of  maple  syrup,  molasses,  honey,  drip  syrup,  and  jellies 
and  jams,  and  as  an  ingredient  of  confectionery. 

In  France  and  Germany  it  is  made  from  potato  starch,  but  in  the  United 


57^  FOOD  INSPECTION  AND  ANALYSIS. 

States  mainly  from  corn  starch.  The  conversion  is  etTcctcd  by  boihng 
with  dikite  sulphuric  or  hydrochloric  acid,  after  which  the  acid  is  neutral- 
ized with  marble  dust,  or  sodium  carbonate  respectively,  the  juice  is 
filtered  through  bone  black,  and  finally  concentrated  by  evaporation, 
the  degree  of  conversion  and  of  concentration  depending  on  whether 
the  liquid  glucose  or  the  solid  dextrose  is  wanted  for  the  final  product. 
The  end  product  obtained  by  complete  conversion  is  the  dry  commercial 
grape  sugar,  or  dextrose,  which  is  purified  by  repeated  crystallization. 

Commercial  glucose  is  a  mixture  of  dextrin,  maltose,  and  dextrose 
cf  the  following  varying  composition: 

Dextrin 29.8%     1045.3% 

Maltose 4.6%     "19-3% 

Dextrose 34.3%     "  36.5% 

Ash 0.32%"    0.52% 

Water 14.2%     "17.2% 

Calcium  sulphate  is  usually  found  in  the  ash  if  sulphuric  acid  was  used 
for  conversion. 

Solid  commercial  grape  sugar,  or  dextrose,  has  the  following  com. 
position: 

Dextrin 0%  9 . 1% 

Maltose 0%  1.8% 

Dextrose 72%  99-4% 

Ash 0.3%  0.75% 

Water 0.6%  i7-5% 

U.  S.  Slandard  glucose,  mixing  glucose,  or  conjeclioners'  glucose,  is  color- 
less glucose,  var)ang  in  density  between  41°  and  45°  Baum^,  at  a  tempera- 
ture of  100°  F.  (37.7°  C).  It  conforms  in  density,  within  these  limits,  to 
the  degree  Baume  it  is  claimed  to  show,  and  for  a  density  of  41°  Baume 
contains  not  more  than  2190  <^>f  water,  and  for  a  density  of  45°  not  more 
than  14%.  It  contains  on  a  basis  of  41°  Baume  not  more  than  1%  of 
ash,  ron'^i'^ting  chiefly  of  chlorides  and  sulphates  of  lime  and  soda. 

Healthfulness  of  Glucose. — The  analyst  alleging  commercial  glucose 
as  an  adulterant  is  frequently  asked  in  court  as  to  its  healthfulness,  so 
that  the  following  conclusions  of  a  committee  a[)])ointed  some  years  ago 
by  the  National  Academy  of  Sciences  to  ascertain  among  other  things 
whether  there  is  any  danger  attending  the  use  of  this  product  in  food  are 
in  point:  "First,  that  the  manufacture  of  sugar  from  starch  is  a  long- 
established  industr)',  scientifically  valuable  and  commercially  important; 


SUG/IR   AND   S/1CCHARINE  PRODUCTS.  577 

second,  that  the  processes  which  it  employs  at  the  ])rescnt  time  are  unob- 
jectionable in  their  character  and  leave  the  product  uncontaminated; 
third,  that  the  starch  sugar  thus  made  and  sent  into  commerce  is  of  excep- 
tional purity  and  uniformity  of  com[)osition  and  contains  no  injurious 
substances;  and  fourth,  that  though  having  at  best  only  about  two- 
thirds  the  sweetening  power  of  cane  sugar,  yet  starch  sugar  is  in  no  way 
inferior  in  healthfulncss,  there  being  no  evidence  before  the  committee 
that  maize  starch  sugar,  either  in  its  normal  condition  or  fermented,  has 
any  deleterious  effect  upon  the  system,  even  when  taken  in  large  quan- 
tities." 

MILK    SUGAR,    OR   LACTOSE. 

Lactose  (CiaHooOn+HsO)  is  prepared  commercially  from  skim- 
milk  by  coagulating  with  rennet  and  digesting  the  whey  with  chalk  and 
aluminum  hydroxide.  The  insoluble  matter  is  filtered  out,  and  the 
filtrate  is  concentrated  in  vacuo  to  a  syrup,  which,  on  standing,  yields 
crystals  of  lactose.     The  product  is  purified  by  repeated  crystallization. 

Lactose  ordinarily  crystallizes  in  rhombic,  hemihedral  crystals.  Its 
specific  gravity  is  1.525.  Its  water  of  crystallization  is  lost  by  drying  at 
130°  C.  It  is  soluble  in  6  parts  of  cold  water,  and  in  2  i  or  less  of  boiling 
water.  It  is  insoluble  in  absolute  alcohol  and  ether.  It  has  a  ver\'  slightly 
sweet  taste. 

The  specific  rotary  power  of  milk  sugar,  after  remaining  in  solution 
long  enough  to  overcome  its  birotation,  is 

[a]^  =  52.5. 

In  the  ordinary  souring  of  milk  the  lactose  becomes  converted  into 
lactic  acid. 

On  heating  lactose  with  dilute  acids  it  undergoes  inversion,  forming 
dextrose  and  galactose  in  accordance  with  the  formula  given  on  p.  565, 
illustrating  the  inversion  of  cane  sugar. 

Milk  sugar  is  of  considerable  importance  by  reason  of  the  large  amount 
used  of  late  in  the  preparation  of  modified  milk  for  infant  feeding. 

Grape  sugar  and  cane  sugar  are  to  be  looked  for  as  adulterants  of 
milk  sugar. 

The  purity  of  milk  sugar  is  best  established  l)y  titrating  against  Feh- 
ling's  solution,  10  cc.  of  which  are  equivalent  to  0.067  gram  of  lactose. 

'  RAFFINOSE. 

Raffinose,  CisHgjOieSHjO,  is  a  sugar  belonging  neither  to  the  saccha- 
rose nor  the  glucose  group,  but  to  the  so-called  saccharoid  group,  the  other 
members  of  which  do  not  occur  in  foods. 


;s 


FOCD    I\SPnCTION   AND   ANALYSIS. 


RalTinose  occurs  in  beet  root  molasses  to  the  extent  of  from  3  to  4 
per  cent.  It  is  a  crystalline,  slightly  sweet  substance,  soluble  ^n  water 
and  slightly  soluble  in  alcohol.  It  does  not  reduce  Fehling's  solution, 
but  readily  undergoes  fermentation  with  bottom  yeast.  On  inversion  it 
splits  up  into  levulose  and  melibiose  (Ci.Hj.On). 

The  melting-point  of  raffinose  is  iiS°  to  119"  C.  Its  specific  rotary 
power  [a]£)==  + 104.5  ^^^  ^^  te.iiperature  of  20°  C. 

THE    POL.VRISCOPE    AND    S.VCCHARIMETRY. 

A  full  discussion  of  the  i)rinciples  of  polarized  light  and  even  a  detailed 
description  of  their  application  to  the  polariscope  will  not  be  given  here, 
but  the  reader  who  wishes  full  information  along  this  line  h  referred  to 
the  various  text-books,  and  especially  to  those  of  Tucker,  Spencer,  and 
Landolt,*  in  which  various  forms  of  polariscopes  are  described  and  their 
underlying  principles  discussed. 

The  Soleil-Ventzke  Saccharimeter  is  the  one  most  commonly  used 
in  this  country,  being  adopted  as  the  standard  for  all  United  States  govern- 
ment work.     Fig.  102  shows  this  instrument,  known  as  the  half -shadow 


I  B0|  D 


'S^ 


D     <\ 


KiG.  102. — Single-wedge   Saccharimeter. 

apparatus,  in  its  simplest  form  with  a  single  movable  wedge  in  its  com- 
pensating system. 

An  excellent  light  for  work  with  this  instrument  is  that  furnished  by 
the  WelsVjach  burner,  a  convenient  form  of  lamp  being  shown  in  Fig.  iii, 
in  which  the  burner  is  inclosed  in  a  sheet-metal  chimney  of  suitable  con- 
struction.    An  argand,  gas,  or  kerosene  burner  may  however  be  used, 

\  *  See  references,  p.  651. 


SUG^R   /tND   SACCHARINE  PRODUCTS.  579 

and    in  a  late  form  of  Schmidt   and  Hacnsch   instrument,    Fig.    103,  a 
specially  constructed  incandescent  electric  lamp  is  supplied. 

The  Single-wedge  Saccharimeler. — The  following  description  of  the 
saccharimeter  and  directions  for  its  use  are  from  the  revised  regulations 
of  the  U.  S.  Internal  Revenue  Department.  The  tub*^  N,  Fig.  102,  con- 
tains the  illuminating  system  of  lenses  and  is  placed  next  to  the  lamp; 
the  polarizing  prism  is  at  O  and  the  analyzing  prism  at  H.  The  quartz 
wedge  compensating  system  is  contained  in  the  portions  of  the  tube  marked 
FEG  and  is  controlled  by  the  milled  head  M.  The  tube  /  carries  a  small 
telescope,  through  which  the  field  of  the  instrument  is  viewed,  and  just 
above  is  the  reading-tube  K,  which  is  provided  with  a  mirror  and  magnify- 
ing lens  for  reading  the  scale. 

The  tube  containing  the  sugar  solution  is  shovm  in  position  in  the 
trough  between  the  two  ends  of  the  instrument.  In  using  the  instrument 
the  lamp  is  placed  at  a  distance  of  at  least  200  mm.  from  the  polarizing 
end;  the  observer  seats  himself  at  the  opposite  end  in  such  a  manner 
as  to  bring  his  eye  in  line  with  the  tube  /.  The  telescope  is  moved  in  or 
out  until  the  proper  focus  is  secured  to  give  a  clearly  defined  image, 
when  the  field  of  the  instrument  will  appear  as  a  round,  luminous 
disk,  divided  into  halves  by  a  vertical  line  passing  through  its  center, 
and  darker  on  one  half  of  the  disk  than  on  the  other,  when  the  com- 
pensating quartz  wedge  is  displaced  from  the  neutral  position.  If  the 
observer,  still  looking  through  the  telescope,  will  now  grasp  the  milled 
head  M  and  rotate  it  first  one  way  and  then  the  other,  he  will  find 
that  the  appearance  of  the  field  changes,  and  at  a  certain  point  the 
dark  half  becomes  light  and  the  light  half  dark.  By  rotating  the  inilled 
head  delicately  backward  and  forward  over  this  point  he  will  be  able  to 
find  the  exact  position  of  the  quartz  wedge  operated  by  it,  in  which  the 
field  is  neutral,  or  of  the  same  intensity  of  light  on  both  halves.  The 
three  difi'erent  appearances  presented  by  the  field  are  sho^\^l  in  Fig.  ic6, 
opposite  page  582, 

One  of  the  compensating  quartz  wedges  is  fixed  and  the  other  is 
movable,  sliding  one  way  or  the  other  according  as  the  milled  head  is 
turned,  so  that  for  different  relative  positions  of  the  two  wedges  a  difi'erent 
thickness  of  quartz  is  interposed  in  the  path  of  the  polarized  ray.  By 
this  means  the  amount  of  the  rotation  which  the  sugar  solution  or  other 
optically  active  substance  examined  exerts  upon  the  light  polarized  by 
the  prism  at  O  may  be,  as  it  were,  counteracted  by  var^'ing  the  relative 
position  of  the  wedges. 


S8o 


FOOD  INSPECTION  ANb  ANALYSIS. 


With  the  milled  head  set  at  the  point  which  gives  the  api^earancc  of 
the  middle  disk  shown  in  Fig.  io6,  the  eye  of  the  observer  is  raised  to  the 
reading  tube  A',  wliich  is  adjusted  to  secure  a  plain  reading  of  the  divisions, 
antl  the  position  of  the  scale  is  noted.  It  will  be  seen  that  the  scale  proper 
is  attached  to  the  quartz  wedge,  which  is  moverl  by  the  milled  head; 
and  attachetl  to  llie  other  (piart/  wedge  is  a  small  scale  called  a  vernier^ 
which  is  fixed,  and  which  serves  for  the  exact  determination  of  the  i)osi- 
tion  of  the  movable  scale  with  reference  to  it.  On  each  side  of  the  zero 
line  of  the  vernier  a  space  corresponding  to  nine  divisions  of  the  movable 
scale  is  divided  into  ten  equal  parts.  By  this  device  the  fractional  part 
of  a  degree  indicated  by  the  position  of  the  zero  line  is  ascertained  in 


fiG.  103. — Double-wedge  SoleilA'cntzke    Saccharimctcr,    mounted    on    Bock    Stand    and 
provided  with  Incandescent  Electric  Lamp. 

tenths;  it  is  only  necessar}'  to  count  from  zero  until  a  line  is  found  which 
makes  a  continuous  line  with  one  on  the  movable  scale. 

With  the  neutral  field,  as  indicated  above,  the  zero  of  the  movable 
scale  .should  correspond  closely  with  the  zero  of  the  vernier,  unless  the 
zero  point  is  out  of  adjustment. 

Adjusting  tJie  Instrument. — If  the  observer  desires  to  secure  an  exact 
adjustment  of  the  zero  of  the  scale,  or  in  any  case  if  the  latter  deviates 
more  than  two-tenths  of  a  degree,  the  zero  lines  are  made  to  coincide  by 
moving  the  milled  head  and  securing  a  neutral  iield  at  this  point  by 


SUG^R   AND   SACCHARINE  PRODUCTS.  581 

means  of  the  small  key  which  comes  with  the  inslrument,  and  which 
fits  a  small  nipple  on  the  /e//-hand  side  of  F,  the  hxed  quartz  wedge  of 
the  compensating  system.  This  nij^ple  must  not  be  confounded  with 
a  similar  nipple  on  the  rlghl-hand  side  of  the  analyzing  prism.  H,  which 
it  fits  as  well,  but  which  musl  never  be  touched,  as  the  adjustment  of 
the  instrument  would  be  seriously  distur]:»cd  ])y  moving  it.  With  the 
key  on  the  proper  nipple  it  is  turned  one  way  or  the  other  until  the 
field  is  neutral.  Unless  the  deviation  of  the  zero  be  greater  than  0.2°  it 
will  not  be  necessarj*  to  use  the  key,  but  only  to  note  the  amount  of  the 
deviation,  and  for  this  purpose  the  observer  must  not  be  content  with 
a  single  setting,  but  must  perform  the  operation  five  or  six  times  and  take 
the  mean  of  these  different  readings.  If  one  or  more  of  the  readings 
show  a  deviation  of  more  than  0.2°  from  the  general  average  they  should 
be  rejected  as  incorrect.  Between  each  observation  the  eye  should  be 
allowed  a  moment  of  rest. 

The  Scale  usually  has  no  equal  divisions  on  one  side  of  the  zero  foi 
reading  right-handed  polarization,  and  20  equal  divisions  on  the  othe;. 
side  for  left-handed  polarization.  The  scale  is  an  arbitrary  one,  based 
on  the  plan  that  a  normal  aqueous  solution  of  pure  cane  sugar  (26.048 
grams  made  up  to  100  cc.)  will  read  exactly  100°  or  divisions  to  the  right 
of  the  zero. 

The  accuracy  of  various  portions  of  the  scale  may  be  verified  by 
quartz  control  plates  of  varying  thickness,  usually  mounted  in  tubes, 
the  correct  polariscopic  reading  of  each  of  which  plates  has  been  accurately 
cetermined,  this  reading  being  as  a  rule  marked  on  the  tube.  As  the 
sugar  value  of  such  a  quartz  plate  varies  with  the  temperature,  the 
temperature  at  which  the  particular  reading  marked  thereon  applies  is 
usually  specified,  and  in  many  cases  a  table  giving  its  exact  value  at 
different  temperatures  from  10°  to  35°  accompanies  the  plate. 

The  Double-wedge  Saccharimeter  is  shown  in  Fig.  104,  the  arrangement 
of  the  optical  parts  being  also  shown. 

In  this  instrument  the  two  sets  of  wedges  employed  are  of  oppo- 
site optical  properties,  so  that  extreme  accuracy  may  be  arrived  at  by 
making  the  readings  with  both,  the  inaccuracies  of  one  being  compen- 
sated for  by  the  other.  Ordinarily  in  using  this  form,  one  movable  wedge, 
say  the  one  controlled  by  the  right-hand  milled  screw  head,  is  set  at  zero, 
while  the  reading  of  the  sugar  solution  or  other  substance  to  be  polar- 
ized is  made  with  the  other  movable  wedge. 

The  Triple-field   Saccharimeter. — The    latest    form  of    saccharimeter 


i52 


FOOD  INSPECTION  AND  ANALYSIS. 


Fig.  104. — Triple-wedge,  Triple-field  Soleil-Ventzke  Saccharimeter. 

is  the  triple-lield    instrument,   the   construction    of    the  polarizer    being 
shown  in  Fig.  105. 

In  this  form  the  analyzer  is  the  same  as  in  the  fore- 
going instruments,  but  the  polarizer  consists  of  one  large 
and  two  small  Nicol  j)risms  I,  II,  and  III,  the  construction 
and  arrangement  being  such  that  when  the  compensating 
wedges  are  at  the   neutral  point,  sections  i,  2,  and  3  of 
the  circular  field  (corresponding  respectively  to  the  prisms 
I,  II,   and   III)  are   evenly   lighted,  forming  a  circular 
uniformly  colored  field,  while  in  any  other  position  of  l_ 
the  wedges  section  i  is  dark  while  2  and  3  are  light  or  j 
vice  versa.    The  accompanying  diagram,  Fig.  106,  shows  | 
the  appearance  of  the  field  of  this  instrument  in  the  three 
positions  of  the  quartz  wedge,  viz.,  at  the  neutral  point 
and  at  both  sides  thereof. 

The  lamp  used  for  illumination  shoukl  be  separated 
from  the  polariscope  on  account  of  the  influence  of  its  ^^^-  ^°S' 

heat   on  the   readings.      This    is    best   accomplished  by 
ha\ing   the  lamp   in  a  separate  compartment   from  the  polariscope,  so 


i 

*v 

1 

Fig.  io6. — Appearance  of  the    Field  in  ihe    Half-shade  (above)   and   Triple-shade  (below) 

Saccharimeter. 


SUGAR   ^\0  SACCHARINE    PRODUCTS.  ^^^ 

that  both  arc  on  opposite  sides  of  a  parlilion,  an  opening  in  which  trans- 
mits the  Hght.  In  any  event  some  kind  of  screen  should  be  interposed 
between  the  two.  Best  resuhs  are  obtained  if  the  room  in  which  the 
observations  arc  made  is  dark. 

Comparisons  of  Scales  of  Various  Polariscopes. — Besides  the  Sokil 
Ventzkc  instrument,  there  are  various  other  forms  of  polariscopc.  Among 
the  best  known  of  these  are  Laurent's,  Wild's,  and  Duboscq's,  all  of 
which  are  made  with  scales  reading  in  circular  degrees,  while  in  some 
cases  modified  forms  ha\e  scales  in  which,  like  the  Soleil- Ventzkc,  per- 
centages of  sugar  are  directly  read  off.  Some  instruments  are  provided 
with  double  scales  reading  both  circular  degrees  and  percentages  of  sugar, 
and  in  certain  of  the  Duboscq  instruments  additional  scales  for  percent- 
ages of  milk  sugar  and  diabetic  sugar  are  provided. 

In  the  Wild,  Duboscq,  and  Laurent  instruments  the  source  of  light 
is  the  sodium  llamc,  yielding  what  is  termed  a  monochromatic  light. 
This  is  produced  by  fused  sodium  chloride  passing  through  a  Bunsen 
flame,  various  mechanical  devices  being  employed  for  making  the  light 
continuous.  In  the  Ventzke  instrument,  as  was  stated  above,  the  ordinary 
light  from  a  bright  gas  or  oil  flame  is  used. 

For  convenience  in  conversion  of  readings  on  one  instrument  to  their 
equivalents  on  other  scales,  the  following  factors  can  be  used: 

1°  Ventzke  =0.3468°  angular  rotation  Z). 


1°  angular  rotation  U 

=  2.««35" 

ventzke. 

1°  Ventzke 

=  2.6048° 

Wild  (sugar  scale). 

1°  Wild  (sugar  scale) 

=0.3840° 

Ventzke. 

1°     " 

=0-1331° 

angular  rotation  D. 

1°  angular  rotation  D 

=  7.5110 

Wild  (sugar  scale) 

1°  Laurent  (sugar  scale) 

=  0.2167° 

angular  rotation  D. 

1°  angular  rotation  D 

=  4-6154° 

Laurent  (sugar  scale). 

1°  Soleil-Duboscq 

=  0.2167° 

angular  rotation  D. 

1°      " 

=0.2450° 

j. 

1°      " 

=0.620° 

Soleil-Ventzke. 

1°      " 

=  1.619° 

Wild. 

1°  Soleil-Ventzke 

=  1.608" 

Soleil-Duboscq  (old  scale). 

jO      .. 

=  1-593° 

"            "        (new  scale). 

1°  Wild 

=  0.611° 

"            "        (Wild  normal  weight  10). 

jO        It 

=  1.223° 

"        (    "          "           "       20). 

Normal  Weights  of  Sugar  for  Different  Instruments. — The  follow- 
ing normal  weights  (number  of  grams  in  100  cc.  at  17.5°  C.)  are  those  on 
which  the  scales  of  the  various  instruments  are  based:  Soleil-Ventzke, 
26.048;  Soleil-Dubosc(i  16.29  (formerly  16.19);  Wild,  usually,  10  or  20; 
Laurent,  16.29. 

The  International  Commission  for  Uniform  Methods  in  Sugar  Analysis 
has  decided  to  use  for  the  Ventzke  scale  26  grams  and  make  up  at  20°  C. 
to  100  metric  cc,  which  figures  are  approximately  equivalent  to  26.048 
grams  made  up  to  100  Mohr  cc. 


5M  FOOD  INSPECTION  AND  ANALYSIS. 

Specific  Rotary  Power. — This  is  a  theoretical  term  to  express  a  stand- 
ard by  which  the  various  optically  active  substances  may  be  compared, 
and  is  understood  to  mean  the  amount  in  angular  degrees  through  which 
the  plane  of  polarization  of  a  ray  of  light  of  stated  wave  length  is  rotated 
by  I  gram  of  a  given  substance  in  aqueous  sokition  of  i  cc.  and  forming 
a  column  i  decimeter  in  length.  The  actual  rotary  power  of  a  solution, 
varies  directly  with  the  length  of  the  column  traversed  by  the  light,  with 
the  concentration  of  the  solution,  and  with  the  wave  length  of  light, 
hence  the  need  of  a  purely  theoretical  basis  for  puri)oses  of  comparison. 

The  specific  rotar}-  power  is  usually  expressed  as  [a]/?  or  \_a\j,  the 
letters  D  or  y  indicating  the  character  of  the  light.  Thus,  D  indicates 
the  monochromatic  light  obtained  from  the  sodium  flame,  named  from  the 
D  line  of  Fraunhofer  in  the  yellow  portion  of  the  spectrum,  while  /  (from 
the  French  jaunc)  indicates  what  is  known  as  the  transition  tint,  the 
rcse-purple  color  produced  when  ordinary  white  light  passes  through 
the  polarizer  and  analyzer,  placed  with  their  principal  sections  parallel 
to  each  other  and  with  a  plate  of  quartz  3.75  mm.  thick  interposed  between 
them.* 

The  specific  rotar}'  j)ower  is  determined  as  follows: 

r  1  r   1      ^Q°^ 

Ya\n    or    L«Jy  =  -^> 

where  a  =  observed  angular  rotation, 

c= grams  of  the  substance  in  100  cc.  of  the  solution,  and 
/= length  of  the  observation-tube  in  decimeters;  or,  in  cases  where, 
instead  of  the  grams  per  100  cc,  the  percentage  composition  is  known 
(expressed  by  />  =  grams  of  the  suljstancc  in  100  grams  of  the  solvent), 

and  the  specific  gravity  (expressed  hy  d),  then  [a]/;  or  [<^]/  =  ~y,  jr* 

Birotation. — In  j^olarizing  solutions  of  all  the  common  sugars  other 
than  sucrose  the  phenomenon  of  Ijirotation  should  be  taken  into  account, 
whereby  a  change  in  optical  activity  is  shown  by  standing.  Thus,  solu- 
tions of  dextrose,  levulosc,  and  lactose  polarize  much  higher  when  freshly 
prepared  than  after  long  standing,  requiring  in  some  instances  several 
hours  before  the  lowest  or  normal  figure  is  reached.  Maltose,  on  the 
other   hand,    increases    in   polarization   after   standing   in   solution.     By 

*  Some  confusion  is  caused  by  the  adoption  of  the  characters  D  and  /,  since  both  would 
naturally  seem  to  indicate  yellow  light.  The  so-called  transition  tint  aVjovc  defined  is,  how- 
ever, complementary  to  the  mean  yellow,  or  jaune  moyen,  and  it  is  the  complementary  color 
and  not  the  yellow  itself  that  is  indicated  by  the  character  / 


SUGAR  AND  SACCHA.'INn   PRODUCTS,  S^S 

boiling  the  solution  it  may  be  at  once  brought  to  its  correct  reading.  The 
desired  result  may  also  be  accomplished  by  adding  a  few  drops  of  ammo- 
nia, cither  treatment  being  resorted  to  before  the  soUition  is  made  up  to 
the  required  volume. 

ANALYSIS   OF   CANE    SUGAR    AND    ITS    PRODUCTS. 

Qualitative  Tests  for  Sucrose. — (a)  Polariscope  Test. — The  substance 
to  be  tested,  if  not  already  in  solution,  is  dissolved  in  water,  and  if  the 
solution  is  not  perfectly  clear,  is  clarified  by  the  addition  of  alumina 
cream  or  by  subacetate  of  lead  (p.  586)  and  filtered.  An  observation 
tube  is  filled  with  the  clear  solution  and  the  polariscope  reading  note.l. 
A  measured  portion  of  the  same  solution  is  then  treated  with  one-tenth  its 
volume  of  concentrated  hydrochloric  acid  and  is  subjected  to  inversion 
(p.  588),  after  which  the  same  tube  as  before  is  filled  with  the  inverted 
solution  and  a  second  reading  obtained,  one-tenth  of  the  observed  reading 
being  added  for  the  true  invert  polariscopic  reading.  If  the  two  readings 
are  virtually  the  same,  sucrose  is  absent,  but,  in  the  presence  of  sucrose, 
the  second  reading  will  be  considerably  lower  than  the  first  or  may  even 
be  to  the  left  of  the  zero. 

(b)  Test  with  Nitrate  oj  Cobalt.'^ — Prepare  a  5%  solution  of  cobaltous 
nitrate,  and  a  50%  solution  of  potassium  hydroxide.  If  the  sugar  solution 
to  be  tested  contains  dextrin  or  gums,  these  should  first  be  removed 
by  treatment  with  alcohol.  15  cc.  of  the  sugar  solution  to  be  tested  arc 
mixed  with  5  cc.  of  the  col^altous  nitrate  reagent,  and  2  cc.  of  the  potas- 
sium hydroxide  solution  are  added.  Sucrose  produces  under  these  con- 
ditions a  permanent  amethyst-blue  color,  while  dextrose  gives  at  first  a 
turquoise-blue  passing  over  into  light  green.  In  a  mixture  of  the  two 
sugars  the  color  due  to  sucrose  will  predominate. 

According  to  Wiley,  i  part  of  sucrose  in  9  parts  of  dextrose  may  be 
detected  by  this  test. 

Analysis  of  Cane  Sugar. — In  the  case  of  commercial  granulated  or 
loaf  sugar  the  sucrose  determination  is  usually  all  that  is  necessary 
to  determine  its  purity,  and  the  same  is  true,  as  a  rule,  of  the  powdered 
white  sugars.  A  fairly  complete  analysis  of  raw  or  brown  sugar  con- 
sists in  the  determinations  of  moisture,  sucrose,  invert  sugar,  ash,  organic 
'  non-sugars,  and  c^uoticnt  of  purity.  Care  should  be  taken  that  the 
portion  subjected  to  analysis  is  a  fair  representation  of  the  whole,  and  is 
perfectly  homogeneous. 

*  Wiley,  Ag.  Anal.,  p.  1S9. 


5S6  FOOD  IWSPHCTION  AND   /iN  A  LYSIS. 

Determination  of  Moisture. — 2  to  5  grams  of  the  sample  are  dried 
in  a  tlat,  tared  metal  dish,  to  constant  weight  iti  vacuo,  or  in  a  McGill 
oven*  in  a  current  of  air,  at  about  7o°C.,at  which  temperature  levulosc 
is  not  decomposed.  For  ordinary  jnirposes  sufficiently  accurate  results 
may  be  obtained  by  the  A.  O.  A.  C.  method  of  drying  to  constant  weight 
at  100°  C.  in  a  water  oven. 

Determination  of  the  Ash. — The  residue  from  the  moisture  deter- 
mination is  burned  slowly  and  cautiously  over  a  low  flame  until  frothing 
has  ceased.  Afterwards  increase  the  flame  and  ignite  to  a  white  ash 
at   a  low,  red  heat. 

In  igniting  saccharine  substances  which  contain  an  appreciable  amount 
of  cane  sugar,  the  contents  of  the  dish  will  swell  up  and  frolh,  unless 
great  care  be  taken,  to  such  an  extent  as  to  flow  over  the  sides  of  the 
dish,  occasioning  loss  and  inconvenience.  Such  frothing  may  be  largely 
held  in  check  by  directing  the  flame  at  first  down  from  above  upon  the 
pastv  mass,  instead  of  from  under  the  dish  as  ordinarily,  till  all  is  reduced 
to  a  dr}'  char,  afterwards  continuing  the  ignition  from  below  in  the  usual 
manner. 

Organic  Non-sugars. — These  consist  mainly  of  compounds  of  organic 
acids,  together  with  gum,  coloring  matter,  albuminous  bodies,  etc.  They 
are  determined  by  difference  between  100%  and  the  sum  of  the  sucrose, 
invert  sugar,  moisture,  and  ash. 

Quotient  of  Purity. — By  this  term  is  meant  the  percentage  of  pure 
sugar  in  the  dr)-  substance.  It  is  calculated  by  dividing  the  per  cent 
of  sucrose  by  the  percentage  of  total  solids  and  multij)lying  the  result  by  100. 

Determination  of  Sucrose  by  the  Polariscope. — Reagents. — Lead  Sub- 
acetate  Soliition.'\ — Boil  for  half  an  hour  430  grams  of  normal  lead 
acetate,  130  grams  of  litharge,  and  1000  cc.  of  water,  allow  to  cool  and 
settle.  Dilute  the  supernatant  liquid  to  1.25  specific  gravity  with  recently 
boiled  water. 

*  A.  McGill,  Laboratory  of  Inland  Revenue,  Ottawa,  Canada,  has  devised  a  forced- 
draft  water-oven  for  drjing  at  temperatures  between  60°  and  90°  C.  The  oven  is  heated 
by  means  of  ordinary  gas-burners,  and  the  temperature  is  controlled  by  introducing  at  the 
bottom  of  the  oven  a  blast  of  air  from  a  blower  run  Ijy  a  small  water-motor.  Before  dis-  ""; 
charging  into  the  oven,  the  air-tube  enters  the  water-chamber  and  is  coiled  a  number  of 
times  in  order  to  sufficiently  warm  the  air  before  it  enters  the  oven.  The  exit  end  of  iho 
air-tube  Ls  covered  with  a  concavo-convex  dislc  in  order  to  distribute  the  blast  and  to  pre- 
vent harmful  currents.  By  regulating  the  burners  and  the  flow  of  air,  a  fairly  constant  tem- 
perature can  be  obtained.  The  bottom  of  the  oven  is  curved  instead  of  flat,  to  j)revent 
bumping  when  the  water  is  boiling;   a  perforated  plate  serves  as  a  false  bottom. 

t  U.  S.  P.  lead  subacetate,  sometimes  sold  as  Goulard's  extract,  may  also  Ix;  used. 


SUGAR  AND  SACCHARINE  PRODUCTS. 


587 


Anhydrous  lead  subacctale,  first  proposed  Ijy  Home,*  may  be  sub- 
stituted for  the  sokition. 

Alumina  Cream. — Divide  a  cold,  saturated  solution  of  alum  into 
two  unequal  portions,  add  to  the  larger  a  slight  excess  of  ammonia,  then 
by  degrees  the  remaining  portion  to  faint  acid  reaction. 

Process. — If  the  Soleil-Ventzke  polariscope  is  to  be  used,  weigh  out 
26  grams  of  the  sugar,  which  may  conveniently  be  done  in  the  German- 


FiG.  107. — Gern^an-silver  Sugar-tray  with  Tare. 

silver,  tared  tray  especially  designed  for  this  purpose  (Fig.  107).  If  any 
other  instrument  is  employed,  weigh  out  the  standard  or  normal  weight 
for  that  instrument  (see  p.  583).     Transfer  the  sugar  by  washing  to  a 


Fig.   108. — A  Convenient  Sugar-scale. 

icxD-cc.  graduated  sugar-flask,  and  if  the  solution  is  perfectly  clear,  as 
would  be  the  case  with  a  refined  sugar,  make  up  to  the  mark  and  shake 
to  insure  a  uniform  solution.  If  the  solution  is  slightly  turbid,  or  more 
or  less  opaque  or  dark-colored,  a  clarifier  must  be  added  before  making 
up  to  the  mark  to  obtain  a  clear  solution  for  polarization.  The  kind 
and  amount  of  clarifier  to  be  used  depends  on  the  nature  of  the  sugar 
solution  and  must  be  learned  by  experience.  If  the  turbidity  is  only  slight, 
from  5  to  10  cc.  of  alumina  cream  alone  will  often  prove  sufficient;  if 
more  opaque,  10  cc.  of  lead  subacetate  solution  or  a  small  amount  of 
the  dry  salt  may  be  used. 

*  Jour.  Am.  Chem.  See,  26,  1904,  p.  1S6. 


SSS  FOOD  INSPECTION  ANn  ANALYSIS. 

For  addhional  details  as  to  clarification  see  page  614.  under  Molasses. 

After  adding  the  clarifier,  the  flask  is  lilleJ  to  the  mark  with  water 
and  shaken,  the  solution  being  poured  upon  a  dr}-  filter  and  the  first 
few  cubic  centimeters  of  the  filtrate  rejected.  A  200-mm.  observation- 
tube  is  filled  with  the  clear  sugar  solution  and  the  polarization  noted. 
If  sucrose  is  the  only  optically  active  substance  present,  the  direct  read- 
ing on  the  polariscope  will  indicate  its  percentage. 

Process  0}  Inversion. — In  the  presence  of  invert  or  other  sugars  the 
normal  solution  as  above  prepared  is  subjected  to  inversion  as  follows: 
Free  a  portion  of  the  solution  from  lead  by  treating  with  anhydrous 
sodium  carbonate,  sodium  sulphate  or  potassium  oxalate,  filter,  place 
50  cc.  in  a  loo-cc.  flask,  add  25  cc,  of  water  and  little  by  little,  while 
rotating  the  flask,  5  cc.  of  38.8%  hydrochloric  acid.  Heat  in  a  water 
bath  at  70°  C,  so  that  the  solution  in  the  flask  reaches  67°  to  69°  C.  in 
two  and  one-half  to  three  minutes.  ^Maintain  at  69°  C.  during  seven  to 
seven  and  one-half  minutes,  making  a  total  time  of  heating  of  ten  minutes. 
Remove  the  flask,  cool  the  contents  rapidly  to  20°  C,  and  dilute  to 
100  cc.  Polarize  this  solution  in  a  200-mm.  tube  provided  with  a  lateral 
branch  and  a  water  jacket,  passing  a  current  of  water  around  the  tube 
to  maintain  a  temperature  of  20°  C. 

The  inversion  may  also  be  accomj^lishcfl  by  allowing  a  mixture  of 
50  cc.  of  the  clarifled  solution,  freed  from  lead,  and  5  cc.  of  the  acid  to 
stand  for  24  hours  at  not  less  than  20°  C.  or  for  10  hours  at  not  less  than  25°. 

The  sucrose  is  obtained  by  the  following  formula  of  Clerget,  based  on 
the  rotation  of  cane  sugar  before  and  after  inversion, 

„_  looia  —  b) 
o , 

142,66— //2 

where  .9  =  per  cent  of  sucrose,  a  =  direct  polarization,  6  =  invert  polari' 
zation,  and  /  =  temperature.  Note  that  if  the  direct  polarization  is  to 
the  right  or  positive,  and  the  invert  to  the  left  or  negative,  then  a  —  b  would 
be  the  sum  of  the  two  polarizations. 

In  many  cases  where  it  is  almost  impossible  to  obtain  a  colorless 
solution  for  polarizatir)n  in  the  200-mm.  tuh>e,  a  loo-mm.  tube  may  be 
employed,  and  the  readings  multiplied  by  2,  or  half  the  normal  weight,* 
viz.,  13  grams,  of  the  sample  may  be  taken  and  made  up  to  100  cc,  the 
200-mm.  tube  employed,  and  the  readings  multiplied  by  2, 

*  Wherever  the  term  "normal  weight"  occurs  hereafter  will  be  meant,  unless  otherwise 
noted,  the  normal  weight  of  sugar  for  the  Soleil-\''entzke  polariscope,  viz.,  26  grams,  and 
by  a  "normal  solution"  will  be  meant  26  grams  in  ico  cc.  of  water  at  20°  C.  Clerget's 
formula,  as  originally  worked  out  Vjy  him,  was  not  based  on  this  normal  weight,  but  oa 
16,35  grams.     It  is,  however,  applicable  to  26  grams. 


SUGAR  AKD   SACCHARINE    PRODUCTS.  589 

The  determination  of  sucrose  by  the  Clerget  formula  is  appUcable 
to  all  mixtures  of  the  common  sugars  excepting  those  in  which  lactose,  or 
milk  sugar,  is  present. 

Theory  0}  Inversion. — On  p.  565  a  reaction  is  given  showing  that 
when  sucrose  is  subjected  to  inversion  by  the  action  of  dilute  acids  or 
of  invertase  or  yeast  it  splits  up  into  the  two  sugars  dextrose  and  levulose, 
forming  equal  quantities  of  each.  The  dextrose  is,  however,  dextro- 
TOtary  and  the  levulose  laevorotary.  Invert  sugar  is  the  term  applied 
to  the  mixture  of  dextrose  and  levulose  formed  by  the  inversion  of  sucrose. 
The  specific  rotary  power  of  sucrose  varies  so  little  with  the  temperature 
as  to  be  regarded  for  practical  purposes  as  constant.  At  87°  a  solution 
of  invert  sugar  polarizes  at  zero.  This  is  due  to  the  fact  that  the  rotary 
power  of  levulose,  unlike  that  of  sucrose  and  dextrose,  varies  with  the 
temperature.  At  from  87°  to  88°  the  left-handed  rotation  of  the  levulose 
balances  the  right-handed  rotation  of  the  dextrose  in  the  invert  sugar, 
hence  the  zero  reading.  As  the  temperature  decreases  from  87°,  the 
rotar}'  power  of  the  levulose  proportionally  increases,  till  at  0°  the  normal 
invert  sugar  solution  would  polarize  44°  to  the  left  of  the  zero.  On  these 
facts  Clerget's  formula  (p.  583)  is  based,  assuming  that  a  normal  solution 
of  pure  cane  sugar  polarizes  at  -j- 100°,  while  after  inversion  the  reading 
for  0°  temperature  would  be  —44°  and  would  decrease  half  a  degree 
for  each  degree  in  temperature  above  0°.  Thus  at  20°  the  invert  reading 
would  be  —34. 

Detection  of  Invert  Sugar. — Methyl-blue  Test. — This  test  depends  on 
the  decolorization  of  methyl  blue  by  invert  sugar.  20  grams  of  sugar  are 
dissolved  in  water  and  made  up  to  100  cc.  If  the  solution  is  not  clear, 
sufficient  subacetate  of  lead  solution  is  added  to  clarify  before  making 
up  to  the  mark,  and  the  solution  is  filtered.  Add  to  the  filtrate  enough 
10%  sodium  carbonate  solution  to  make  alkaline,  and  filter  a  second 
time.  Take  about  50  cc.  of  the  filtrate  in  a  casserole,  add  2  drops  of  a 
1%  solution  of  methyl  blue,  and  boil  over  a  free  flame,  noticing  particu- 
larly the  time  the  solution  begins  to  boil. 

If  the  color  disappears  in  one  minute  after  boiling,  there  is  present 
at  least  0.01%  of  invert  sugar.  If  it  is  not  completely  decolorized  by 
three  minutes'  boiling,  no  invert  sugar  is  present. 

Determination  of  Invert  Sugar  in  Cane  Sugar  Products  by  the  Polar- 
iscope. — ^While  invert  sugar  is  best  determined  by  Fehling's  solution  as 
described  elsewhere,  it   may  be  approximately  estimated  by  the  polari- 


5:o  FOOD  INSPECTION  AND  /fN  A  LYSIS. 

scope,  though  less  satisfactorily.  On  p.  626  a  method  is  given  for  the- 
determination  of  levulose  by  polarlscopic  readings  at  two  different  tem- 
peratures. Since  'nvert  sugar  is  composed  of  equal  j^arts  by  weight  of 
de.xtrosc  and  levulose,  the  percentage  of  levelose  multi])lied  by  2  would 
give  that  of  invert  sugar. 

Test  for  Ultramarine  in  Sugar.* — A  large  amount  of  the  sugar  is 
dissolved  in  water  and  the  coloring  matter  is  allowed  to  settle  out, 
washing  the  residue  several  times  by  decantation.  On  treatment 
Aviih  hydrochloric  acid,  the  blue  color  is  discharged  if  due  to  ultra- 
marine. 

SUGAR   DETERMIX.\TIO>r   BY    COPPER   REDUCTION. 

\'arious  convenient  methods  of  determining  sugars  depend  on  the 
readiness  ^^•ith  ^vhich  certain  of  them,  known  as  reducing  sugars,  act  on 
copper  salts,  especially  on  the  tartrate  of  copper,  reducing  it  to  cuprous 
oxide. 

This  reducing  power  is  exercised  in  a  definite  degree  under  fixed 
conditions,  so  that  the  amount  of  reducing  sugar  present  may  be  accurately 
determined.  Of  the  common  sugars,  sucrose  is  the  only  one  that  has 
no  direct  reducing  action,  but  on  undergoing  inversion  it  is  converted 
into  reducing  sugars,  which  are  readily  determined. 

Use  of  Fehling's  Solution. — There  are  various  well-known  mixtures 
of  copper  sulphate,  tartaric  acid  salts  (usually  Rochelle  salts  or  cream 
of  tartar),  and  alkalies,  called  after  chemists  who  have  employed  them 
in  the  determination  of  the  reducing  sugars,  each  one  possessing  certain 
arlvantages,  but  none  have  become  so  widely  adopted  as  Fehling's  solu- 
tion, the  use  of  which  in  one  form  or  another  is  now  well-nigh 
universal. 

There  are  a  number  of  methods  by  which  Fehling's  solution  is  employed 
for  this  purpose,  both  volumetric  and  gravimetric.  The  former  are 
simpler  and  quicker  of  manipulation,  and  thus  are  preferable  for  com- 
mercial work  where  extreme  accuracy  is  not  required.  The  gravimetric 
methods  are  usually  considered  more  delicate  and  accurate,  calling  for 
less  skill,  but  more  time  in  arriving  at  results,  and  with  leas  of  the  "  per- 
sonal element"  than  the  volumetric. 

Some  modifications  of  the  Fehling  method,  especially  as  carried  out 
gravimctrically,  differ  for  the  various  reducing  sugars  to  be  determined^ 

*  Leffmann  and  Beam,  Select  Methods  of  Food  Analysis,  p.  126. 


SUGAR  AND  SACCHARINE   PRODUCTS.  591 

and  others  are  carried  out  alike,  so  far  as  manipulation  is  concerned,  whethei 
the  particular  sugar  to  be  determined  be  dextrose,  maltose,  or  lactose. 

While,  strictly  speaking,  the  reducing  power  of  dextrose,  Icvulose,  and 
invert  sugar  are  not  identical,  it  is  customary  in  commercial  work  to 
regard  them  as  such,  and  no  appreciable  error  arises  in  consequence 
except  in  extreme  cases.  Thus  the  term  "reducing  sugars"  is  com- 
monly applied  indiscriminately  to  dextrose,  levulosc,  and  invert  sugar, 
the  same  factor  being  used  in  calculating  either,  in  mixtures  wherein 
other  reducing  sugars,  as  lactose,  maltose,  etc.,  having  widely  different 
reducing  powers  are  absent. 

Feliling's  solution  is  made  up  in  two  separate  parts  as  follows: 

A.  Fehllng's  Copper  Solution. — 34.639  grams  of  carefully  selected 
cr}''stals  of  pure  copper  sulphate  dissolved  in  water  and  diluted  to  exactly 
500  cc. 

B.  Fehlhig's  Alkaline  Tartrate  Solution. — 173  grams  Rochelle  salts 
and  50  grams  sodium  hydroxide  arc  dissolved  in  water  and  diluted  to 
exactly  500  cc. 

The  Fehling  solution  should  be  standardized  by  dissolving  0.5  gram 
of  pure  anhydrous  dextrose  in  water,  and  diluting  to  exactly  100  cc.  10  cc. 
of  this  dextrose  solution  should  exactly  reduce  the  copper  in  10  cc.  of 
the  Fehling  (5  cc.  each  of  solutions  A  and  B)  when  conducted  according 
to  the  volumetric  process  described  below. 

VOLUMETRIC  FEHLING  PROCESS.— For  determining  dextrose,  Icvulose, 
or  invert  sugar  in  a  raw  or  brown  sugir,  make  a  solution  of  the  sugar  of  such 
a  strength  that  an  accurately  weighed  amount  dissolved  in  water  and 
made  up  to  100  cc.  shall  contain  not  more  than  1%  of  the  reducing  sugar, 
as  nearly  as  can  be  guessed  at  with  reference  to  the  class  of  sugar  under 
examination,  or  from  a  rough  preliminary  titration. 

Measure  accurately  into  a  flask  of  about  250  cc.  capacity  5  cc.  Feh- 
ling's  copper  sulphate  solution,  A,  and  5  cc.  of  the  alkali  solution,  B. 
Add  about  40  cc.  of  water,  mix  and  boil  over  a  free  flame,  ^^'ith  copper 
gauze  beneath  the  flask.  While  still  boiling,  add  from  a  pipette  or  burette 
a  measured  quantity  of  the  sugar  solution,  prepared  as  above,  until  the 
copper  after  three  minutes'  boiling  is  all  reduced  to  cuprous  oxide.  The 
end-point  is  determined  in  a  variety  of  ways.  Practice  will  soon  enable 
the  eye  to  judge  the  near  approach  of  the  end-point  by  the  changes  in  color 
that  take  place  in  the  solution,  which  turns  from  a  deep  blue,  first  to  green, 
then  to  a  dull-red  tint,  and  fmally  to  a  bright  brick-red.  The  sugar- 
containing  solution  may  be  added  from  the  burette  quite  rapidly  until 


592 


FOOD  INSPECTION   AND   ANALYSIS. 


ihe  solution  reaches  the  dull-red  tint,  after  which  care  is  taken  to  add  a 
little  at  a  time,  keeping  account  of  the  total  amount  added.  If  the  flask 
be  removed  from  the  flame,  and  the  bright,  diffused  light  from  a  window 
viewed  through  the  solution  with  the  eye  on  a  level  with  the  surface,  a  thin 
film  scarcely  wider  than  a  line  will  be  observed  just  below  the  surface 
(see  Fig.  109),  which  is  blue  so  long  as  some  of  the  copper  in  the  solu- 
tion remains  unreduced.  When,  however,  all  the 
copper  has  been  reduced,  this  film  ceases  to  be 
blue  and  becomes  colorless  or  yellow. 

If  the  film  is  not  at  once  apparent,  it  may  often 
be  made  quite  noticeable  by  sim]:)ly  diluting  the 
solution  in  the  tlask  with  water.  At  the  approach 
of  the  end-point  the  sugar-containing  solution 
should  be  added  a  \erf  little  at  a  time.  The 
exact  end-point  is  best  arrived  at  by  decanting  a 
few  drops  of  the  mi.xture  in  the  flask  through  a 
filter,  acidifying  the  fdtrate  with  acetic  acid,  and 
adding  a  drop  of  a  solution  of  ferrocyanidc  of 
potassium.  As  long  as  there  is  unreduced  copper 
present,  a  precipitate  or  brown-red  coloration  will 
appear  when  the  ferrocyanidc  is  added.  The 
sugar  solution  toward  the  end  should  be  added 
to  the  contents  in  the  flask  in  smaU  installments 
(say  half  a  cubic  centimeter  each  time),  boiling 
the  liquor  for  at  least  three  minutes  after  each 
addition,  until  no  brown-red  coloration  is  pro- 
duced by  adding  the  ferrocyanidc  to  a  little  of  the  filtered  acidified  liquid. 
When  the  number  of  cubic  centimeters  of  sugar  solution  necessary  to 
reduce  the  copper  has  thus  been  determined,  a  second  titration  should  be 
made  to  verify  the  first,  running  the  entire  amount  of  sugar-containing 
liquid  found  necessary  in  the  first  case  into  the  second  flask. 

The  equivalents  of  10  cc.  of  Fehling's  solution  in  the  above  volumetric 
method  are,  in  terms  of  the  common  reducing  sugars,  as  follows: 

i  invert  sugar,  i 

0.05  gram  of  -;   dextrose,  or   r  will  reduce  10  cc.  Fehling's  solution. 

(       levulose      ) 

I  cane  sugar  '\ 

0.0475  gram  of  -     after  in-    .-will  reduce  10  cc.  Fehling's  solution. 

(     version     j 


Fig.  109. — Flask  and  Con- 
tents used  in  Volumetric 
Fehling  Determinations. 
Showing  layer  just  be- 
neath the  surface,  the 
color  of  which  indicates 
the  end-point  in  adding 
the  sugar-containing  li- 
<iuid. 


SUGAR    AND  SACCHARINE   PRODUCTS,  Sg.:? 

0.0807  gram  of  maltose  will  reduce  10  cc.  Fehling's  solution. 

0.067    gram  of  lactose      "       "         10  cc.        "  " 

Suppose,  for  example,  a  sample  of  brown  sugar  is  to  be  examined 
for  invert  sugar.  This  class  of  sugar  has  usually  from  2  to  6  per  cent 
of  invert  sugar.  Hence,  if  10  grams  of  the  sample  are  dissolved  in  100 
cc,  the  resulting  solution  will  contain  not  more  than  1%  of  invert  sugar. 

Suppose  12.9  cc.  of  this  10%  sugar  solution  were  found  by  the  above 
process  to  reduce  10  cc.  of  Fehling's  solution. 

10  cc.  Fehling's  solution  are  equivalent  to  0.05  gram  invert  sugar. 

Therefore  12.9  cc.  of  the  sugar  solution  contain  0.05  gram  invert- 
sugar. 

100  cc.  sugar  solution  contain  10  grams  samjjlc,  and  12.9  cc.  contain 

1.29  grams  sample,  the  equivalent  of  0.05  gram  invert  sugar. 

^^                          .                         0.0s  X 100 
Hence  per  cent  mvert  sugar  =  — ^ =3-9- 

Gravimetric  Fehling  Processes. — In  determining  reducing  sugars 
by  gravimetric  processes,  a  measured  volume  of  the  sugar  solution  is 
allowed  to  act  upon  a  measured  volume  of  hot  Fehling's  solution  for  a 
fixed  time,  thus  forming  cuprous  oxide.  This  may  be  dried  and  weighed 
direct,  but  is  more  commonly  converted  cither  into  cupric  oxide  by  ignition, 
or  into  metallic  copper  by  reduction  with  hydrogen  or  by  electrolvsis. 
In  any  case  the  sugar  is  calculated  from  the  weight  of  the  cuprous  oxide, 
the  cupric  oxide,  or  the  metallic  copper  (whichever  method  be  used)  by 
the  employment  of  the  proper  factor,  or  by  the  use  of  tables  compiled 
for  the  purpose. 

Note. — Much  difference  of  opinion  exists  as  to  the  best  and  most 
accurate  Fehling  gravimetric  method  to  em])loy.  For  the  determination 
of  dextrose,  the  Association  of  Official  Agricultural  Chemists  has  given 
its  approval  to  the  Allihn  metl*d,  wherein  the  cuprous  oxide  deposited 
is  further  reduced  to  metallic  copper  and  the  dextrose  calculated  from 
the  copper  by  Allihn's  table. 

The  author  for  two  reasons  prefers  the  method  of  O'Sullivan  as 
employed  by  Defren,  with  the  use  of  the  Defren  tables,  in  accordance 
with  which  the  reducing  sugar  is  expressed  in  terms  of  its  equivalence 
to  cupric  oxide,  first  because  of  its  comparative  simplicity,  involving  as  it 
does  less  processes  than  the  Allihn  method  (each  addhional  process 
introducing  a  possible  source  of  error),  and,  second,  because  the  same 
method  as  carried  out  is  applicable  for  the  determination  not  only  of 
dextrose,  but  also  of  maltose  and  lactose,   Defren  having   worked  out 


5H  FOOD   I\SPECTION   AND   ANALYSIS. 

tables  adapted  for  them  all.  Munsen  and  Walker*  have  also  devised  a 
simple  method  with  accompanying  tables,  adapted,  with  a  uniform  system 
of  procedure,  to  the  determination  of  the  various  reducing  sugars.  In 
using  the  tables  for  dextrose,  maltose,  and  lactose  compiled  by  Allihn, 
Wein,  and  Soxhlet,  the  method  employed  must  in  each  case  be  carried 
out  in  strict  accordance  to  the  minutest  details  adopted  by  each  of  the 
above  authorities,  and  they  are  by  no  means  uniform. 

The  Defren-O'SuUivan  Method. f— Mix  15  cc.  of  Fehhng's  copper 
solution,  A  (p.  591),  wiili  15  cc.  of  the  tartrate  solution,  B,  in  a  quarter- 
liter  Erlenmeyer  flask,  and  add  50  cc.  of  distilled  water.  Place  the  flask 
and  its  contents  in  a  boiling  water  bath  and  allow  them  to  remain  five 
minutes.  Then  run  rapidly  from  a  burette  into  the  hot  liquor  in  the 
flask  25  cc.  of  the  sugar  solution  to  be  tested  (which  should  contain  not 
more  than  one-half  per  cent  of  reducing  sugar).  Allow  the  flask  to  remain 
in  the  boiling  water  bath  just  fifteen  minutes  after  the  addition  of  the 
sugar  solution,  remove,  and  with  the  aid  of  a  vacuum  filter  the  contents 
rapidly  in  a  platinum  or  porcelain  Gooch  crucible  containing  a  layer 
of  prepared  asbestos  fiber  about  i  cm.  thick,  the  Gooch  with  the  asbestos 
having  been  previously  ignited,  cooled,  and  weighed.  The  cuprous 
oxide  precipitate  is  thoroughly  washed  with  boiUng  distilled  water  till 
the  w'ater  ceases  to  be  alkaline. 

The  asbestos  used  should  be  of  the  long-fibered  variety,  and  should 
be  specially  prepared  as  follows:  Boil  first  with  nitric  acid  (specific 
gravity  1.05  to  i.io),  washing  out  the  acid  with  hot  water,  then  boil  with 
a  25%  solution  of  sodium  hydroxide,  and  finally  wash  out  the  alkali  with 
hot  water.  Keep  the  asbestos  in  a  wide-mouthed  flask  or  bottle,  and 
transfer  it  to  the  Gooch  by  shaking  it  up  in  the  water  and  pouring  it 
quickly  into  the  crucible  while  under  suction. 

Dry  the  Gooch  with  its  contents  in  the  oven,  and  finally  heat  to  dull 
redness  for  fifteen  minutes,  during  which  the  red  cuprous  oxide  is  con- 
verted into  the  black  cupric  oxide.  If  a  platinum  Gooch  is  used  (and 
this  variety  is  preferred  by  the  writer),  it  may  be  heated  directly  over 
the  low  flame  of  a  burner.  If  the  Gooch  is  of  porcelain,  considerable 
care  must  be  taken  to  avoid  cracking  the  crucible,  the  heat  being  increased 
cautiously  and  the  operation  preferably  conducted  in  a  radiator  or  mufile. 
After  oxidation  as  above,  the  crucible  is  transferred  to  a  desiccator,  cooled, 
and  quickly  weighed.  From  the  milligrams  of  cupric  oxide,  calculate 
the  milligrams  of  dextrose  from  the  following  table: 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  241. 

t  Jour.  ,\m.  Chcm.  Soc,   18,   1896,  p.  749,  and  Tech.  Quart.,   10,   1897,  p.   167. 


SUGAR  AND  SACCHARINE  PRODUCTS. 


595 


IDEFREN'S  TABLE  FOR  THE  DETERMINATION  OF  DEXTROSE,  MALTOSE, 

AND  LACTOSE. 


Milligrams 

of  Cupric 

Oxide. 

Milligrams 

Milligrams 

Milligrams 

Milligrams 

of  Cupric 

O.xide. 

Milligrams 

Milligrams 

Milligrams 

of  Dextrose. 

of  Maltose. 

of  Lactose. 

of  Dextrose. 

of  Maltose. 

of  Lactose. 

3° 

13-2 

21.7 

18.8 

80 

35-4 

58-1 

50-5 

31 

13-7 

22.4 

19-5 

81 

35-9 

58-9 

51-I 

32 

14. 1 

23.1 

20.1 

82 

36.3 

59-6 

51-7 

3,2, 

14.6 

23-9 

20.7 

83 

36.8 

60.3 

52-4 

34 

15.0 

24.6 

21.4 

84 

37-2 

61. 1 

53-0 

35 

15-4 

25-3 

22.0 

85 

37-7 

61.8 

53-6 

36 

15-9 

26.1 

22.6 

86 

38-1 

62.5 

54-3 

37 

16.3 

■  26.8 

23-3 

87 

38-5 

63-3 

54-9 

38 

16.8 

27-5 

23-9 

88 

39 -o 

64.0 

55-5 

39 

17.2 

28.3 

24-5 

89 

39-4 

64.7 

56.2 

40 

17-6 

29.0 

25.2 

90 

39-9 

65-5 

56.8 

41 

18. 1 

29-7 

25.8 

91 

40.3 

66.2 

57-4 

42 

18.5 

30-5 

26.4 

92 

40.8 

66.9 

58-1 

43 

19.0 

31-2 

27.1 

93 

41.2 

67.7 

58-7 

44 

19.4 

31-9 

27.7 

94 

41.7 

68.4 

59-3 

45 

19.9 

32-7 

28.3 

95 

42.1 

69.1 

60.0 

46 

20.3 

33-4 

29.0 

96 

42.5 

69.9 

60.6 

47 

20.7 

34-1 

29.6 

97 

43-0 

70.6 

61.2 

48 

21 .2 

34-8 

30.2 

98 

43-4 

71-3 

61.9 

49 

21.6 

35-5 

30.8 

99 

43-9 

72.1 

62.5 

50 

22.1 

36.2 

31-5 

100 

44-4 

72.8 

63-2 

51 

22.5 

37-0 

32.1 

lOI 

44-8 

73-5 

63.8 

52 

23.0 

37-7 

32-7 

102 

45-3 

74-3 

64-4 

53 

23  4 

38-4 

?,?,■?, 

103 

45-7 

75-0 

65.1 

54 

23.8 

39-2 

34-0 

104 

46.2 

75-7 

65-7 

55 

24.2 

39-9 

34-6 

105 

46.6 

76.5 

66.3 

56 

24-7 

40-5 

35-2 

106 

47.0 

77-2 

67.0 

57 

25-1 

41-3 

35-9 

107 

47-5 

77-9 

67.6 

58 

25-5 

42.1 

36-5 

108 

48.0 

78-7 

68.2 

59 

26.0 

42.8 

37-1 

109 

48-4 

79-4 

68.9 

60 

26.4 

43-5 

37-8 

no 

48.9 

80.1 

69-5 

61 

26.9 

44-3 

38-4 

III 

49-3 

80. 9 

70.1 

62 

27-3 

45-0 

39-0 

112 

49-8 

81.6 

70.8 

63 

27.8 

45-7 

39-7 

"3 

50.2 

82.3 

71-4 

64 

28.2 

46-5 

40-3 

114 

50-7 

83-1 

72.0 

65 

28.7 

47-2 

40.9 

115 

51-1 

83-8 

72-7 

66 

29.1 

47-9 

41.6 

116 

51.6 

84-5 

73-3 

67 

29-5 

48.6 

42.2 

117 

52.0 

85-2 

74.0 

68 

30.0 

49-4 

42.8 

118 

52-4 

85-9 

74-6 

69 

30-4 

50.1 

43-5 

119 

52-9 

86.6 

75-2 

70 

30-9 

SO.  8 

44.1 

120 

53-3 

87-4 

75-9 

71 

31-3 

51.6 

44-7 

121 

53-8 

88.1 

76.6 

72 

31.8 

52-3 

45-4 

122 

54-2 

88.9 

77-2 

73 

32-2 

53-0 

46.0 

123 

54-7 

89.6 

77-9 

74 

32-6 

53-8 

46.6 

124 

55-1 

90-3 

78-5 

75 

Zi-"^ 

54-5 

47-3 

I2> 

55-6 

91.1 

79- r 

76 

33-5 

55-2 

47-9 

126 

^6.0 

91 .8 

79-8 

77 

34-0 

56.0 

48-5 

127 

56.5 

92-5 

80.4 

78 

34-4 

56-7 

49-2 

128 

56.9 

93-3 

81.  r 

79 

34-9 

57-4 

49-8 

129 

57-3 

94.0 

8r.7 

596 


FOOD  INSPECTION  yIND  ANALYSIS. 


DEFRENS  TABLE  FOR  THE  DETERMINATION  OF   DEXTROSE,  MALTOSE, 
AND   'LhCTOS^— {Continued). 


Milligrams 

of  Cupnc 

Oxide. 

Milligrams 

Milligrams 

Milligrams 

Milligrams 
of  Cvipric 

Milligrams 

1 
Milligrams 

Milligrams 

of  Dextrose. 

of  Maltose. 

of  Lactose. 

Oxide. 

of  Dextrose. 

of  Maltose. 

of  Lactose. 

130 

57-8 

94-8 

82.4 

180 

80.4 

131. 8 

114.6 

I.;i 

^8.2 

95-5 

83-0 

181 

80.8 

132-5 

"5-2 

13^ 

58.7 

96.2 

83-6 

182 

81-3 

133-2 

115.8 

133 

59-1 

97.0 

84.2 

183 

81.8 

134-0 

116.5 

134 

59-6 

97-7 

84.9 

184 

82.2 

134-7 

117. 1 

135 

60.0 

98. 4 

85-5 

185 

82.7 

13^-5 

117. 8 

136 

60.5 

99-2 

86.1 

186 

83.1 

136.2 

118.4 

137 

60.9 

90-0 

86.8 

187 

83-5 

136.9 

119. 1 

138 

61.3 

100.7 

87-4 

188 

84.0 

137-7 

119.7 

130 

61.8 

101.4 

88.1 

189 

84.4 

138.4 

120.4 

140 

62.2 

102. 1 

88.7 

190 

84.9 

139- 1 

121.0 

141 

62.7 

102.8 

89-3 

191 

85-4 

139-9 

121.7 

142 

63.1 

103.5 

90.0 

192 

85-9 

140.6 

122.3 

143 

63.6 

104-3 

90.6 

193 

86.3 

141-4 

123-0 

144 

64.0 

105.0 

91-3 

194 

86.8 

142. 1 

123.6 

145         1 

64-5 

105.8 

91.0 

105 

87.2 

142.8 

124.3 

146 

64.9 

106.5 

92.6 

196 

87.7 

143.6 

124.9 

147 

65-4 

107.2 

93-2 

197 

88.1 

144.3 

125.6 

148 

65.8 

108.0 

93-9 

198 

88.6 

145-1 

126.2 

149 

66.3 

108.7 

94.5     j 

199 

89.0 

145-8 

126.9 

150 

66.8 

109-5 

95-2 

200 

89.5 

146.6 

127-5 

151 

67-3 

no. 2 

05-8 

201 

89.9 

147-3 

128.2 

152 

67.7 

III.O 

96.5 

202 

90.4 

148. 1 

128.8 

153 

68.3 

III. 7 

97-1 

203 

90.8 

148.8 

129-5 

154 

68.7 

112. 4 

97-8 

204 

91-3 

149.6 

130-1 

155 

69.2 

"3-2 

98-4 

205 

91.7 

150.3 

130.8 

156 

69.6 

"3-9 

99-1 

206 

92.2 

151. 1 

131-5 

157 

70.0 

"4-7 

99-7 

207 

92.6 

151. 8 

132-1 

158 

70-5 

"5-4 

100.4 

208 

93-1 

152-5 

132-8 

159 

70.9 

116. 1 

lOI.O 

209 

93-5 

153-3 

133-4 

160 

71-3 

116. 9 

101.7 

210 

94-0 

154-1 

134-1 

161 

71.8 

117. 6 

102.3 

211 

94-4 

154.8 

134-7 

162 

72-3 

118. 4 

103.0 

212 

94-9 

155-6 

135-4 

1^3 

72.7 

119. 1 

103.6 

213 

95-3 

156-3 

136.0 

164 

73-2 

"9-9 

104.3 

214 

95-8 

157-1 

136-7 

'65 

73-6 

120.6 

104.9 

215 

96-3 

157-8 

137-3 

166 

74-1 

121. 4 

105.6 

216 

96.7 

158.6 

138.0 

167 

74-5 

122. 1 

106.2 

217 

97-2 

159-3 

138.6 

168 

1        74.9 

122.9 

106.9 

218 

97-6 

160.  ^ 

139-3 

169 

75-4 

123.6 

107-5 

219 

98.1 

160.8 

139-9 

170 

75-8 

124.4 

108.2 

220 

98.6 

161.5 

140.6 

171 

76-3 

125-1 

108.8 

21  I 

99.0 

162.3 

141.2- 

172 

76.8 

12s. 8 

109.5 

222 

99-5 

163-0 

141. 9 

173 

77-3 

126.6 

no. I 

223 

99-9 

163-7 

142.5 

174 

77-7 

127-3 

110.8 

224 

100.4 

164-5 

143-^ 

»75 

78.2 

128. 1 

III. 4 

225 

100.9 

165-3 

143-8 

176 

78.6 

128.8 

112. 0 

226 

101.3 

166.0 

144-5 

177 

79.1 

"9-5 

112. 6 

227 

101.8 

166.8 

145-I 

178 

79-5 

130-3 

^n-i 

228 

102.2 

167.5 

145-8 

179 

80.0 

131. 0 

"3-9 

229 

102.7 

168.3 

146.4 

.^m 

SUG/IR   AND    SACCHARINE  PRODUCTS. 


597 


DEFREN'S  TABLE  FOR  THE  DETERMINATION   OF   DEXTROSE,  MALTOSE, 
AND   I.ACTOSE— (Concluded). 


Milligrams 

of  Cupric 

Oxide. 

Milligrams 

Milligrams 

Milligrams  . 

Milligrams 

of  Cupric 

Oxide. 

Milligrams 

Milligrams 

Milligrams 

of  Dextrose. 

of  Maltose. 

of  Lactose. 

of  Dextrose. 

of  Maltose. 

of  Lactose. 

230 

103.1 

169.1 

147.0 

280 

126.1 

206.8 

179-6 

231 

103.6 

169.8 

147-7 

281 

126.5 

207.5 

180.2 

232 

104.0 

170.6 

148.3 

282 

127.0 

208.3 

180.9 

233 

104.5 

171-3 

149 -o 

283 

127.4 

209.0 

181. 5 

234 

105.0 

172. I 

149.6 

284 

127.9 

209.8 

182.2 

235 

105.4 

172.8 

150-3 

285 

128.^ 

210.5 

182.9 

236 

105.9 

173-6 

150-9 

286 

128.8 

211. 3 

183.6 

237 

106.  T, 

174-3 

151.6 

287 

129.3 

212.1 

184.2 

238 

106.8 

I75-I 

152.2 

288 

129.7 

212.8 

184.9 

239 

107.2 

175-8 

152-9 

289 

130.2 

213.6 

185.6 

240 

107.7 

176.6 

1 53 -5 

290 

130.6 

214-3 

186.2 

241 

108.  I 

177-3 

154-2 

291 

131. 1 

215.1 

186.9 

242 

108.6 

178.1 

154-8 

292 

131 -5 

215-9 

187.6 

243 

109.0 

178.8 

155-5 

293 

132.0 

216.6 

188.2 

244 

109.5 

179.6 

156.1 

294 

132.5 

217-4 

188.9 

245 

109.9 

180.3 

156.8 

295 

133-0 

218.2 

189-5 

246 

IIO.4 

181. 1 

157-4 

296 

133-4 

218.9 

190.2 

247 

110.9 

181.8 

158.1 

297 

133-9 

219.7 

190.8 

248 

III. 3 

182.6 

158-7 

298 

134-3 

220.4 

191-5 

249 

111.8 

183-3 

159-4 

299 

134.8 

221.2 

192. 1 

250 

112. 3 

184. 1 

160.0 

300 

135-3 

221.9 

192.8 

251 

112.7 

184.8 

160.7 

301 

135-7 

222.7 

193-4 

252 

113.2 

185.5 

161.3 

302 

136.2 

223-5 

194.1 

253 

"3-7 

186.3 

162.0 

303 

136.6 

224.2 

194-7 

254 

114. 1 

187.1 

162.6 

304 

137-1 

225.0 

195-3 

255 

114. 6 

187.8 

^(>3-3 

305 

137-6 

225.8 

196.0 

256 

115.0 

188.6 

163.9 

306 

138-0 

226.5 

196.6 

257 

"5-5 

189.3 

164.6 

307 

1.38.5 

227.3 

197-3 

258 

116.0 

190.1 

165.2 

308 

138.9 

228.1 

197.9 

259 

116. 4 

190.8 

165.9 

309 

139-4 

228.8 

198.6 

260 

116.9 

191. 6 

166.5 

310 

139-9 

229.6 

199-3 

261 

"7-3 

192.4 

167.2 

311 

140.3 

230.4 

199-9 

262 

117.8 

193- 1 

167.8 

312 

140.8 

231.1 

200.6 

263 

118.3 

193-9 

168.1 

3^3 

141. 2 

231.9 

201.3 

264 

118.7 

194.6 

169.5 

314 

141.7 

232.7 

202.0 

265 

119.2 

195-4 

169.8 

315 

142.2 

233.4 

202.6 

266 

119. 6 

196. 1 

170.4 

316 

142.6 

234.2 

203-3 

267 

120.1 

196.9 

171. 1 

317 

143-1 

234.9 

203.9 

268 

120.6 

197-7 

171. 7 

318 

143.6 

235-7 

204.6 

269 

121. 0 

198.4 

172.4 

319 

144.0 

236-5 

205-3 

270 

121.4 

199.2 

173-0 

320 

144-5 

237.2 

205.9 

271 

121.9 

199.9 

173-7 

272 

122.4 

200.7 

174-4 

273 

122.8 

201.5 

175.0 

274 

123-3 

202.2 

175-7 

275 

123.7 

203.0 

176.3 

276 

124.2 

203.7 

177.0 

277 

124.6 

204.5 

177.6 

278 

125.1 

20;. 2 

178-3 

279 

125.6 

206.0 

T78.0 

,  .^ 

598  FOOD  INSPECTION   /1ND  /IN  A  LYSIS 

Munson  and  Walker  Method.* — i.  Preparation  of  Solutions  and 
Asbestos. — Use  the  copper  sulphate  solution  and  alkaline  tartate  solution 
as  given  on  page  591.  Prepare  the  asbestos,  which  should  be  the 
amphibolc  variety,  by  first  digesting  with  1 13  hydrochloric  acid  for  two  or 
three  days.  Wash  free  from  acid,  and  digest  for  a  similar  period  with 
soda  solution,  after  which  treat  for  a  few  hours  with  hot  alkaline  copper 
tartrate  solution  of  the  strength  cmj^loyed  in  sugar  determinations.  Then 
wash  the  asbestos  free  from  alkali,  tmally  digest  with  nitric  acid  for  several 
hours,  and  after  washing  free  from  acid,  shake  with  water  for  use.  In 
preparing  the  Gooch  crucible,  load  it  with  a  film  of  asbestos  one-fourth  inch 
thick,  wash  this  thoroughly  with  water  to  remove  fme  particles  of  asbestos; 
fmally  wash  with  alcohol  and  ether,  dry  for  thirty  minutes  at  100°  C, 
cool  in  a  desiccator  and  weigh.  It  is  best  to  dissolve  the  cuprous  oxide 
with  nitric  acid  each  time  after  weighing,  and  use  the  same  felts  over  and 
over  again,  as  they  improve  with  use. 

2.  Process. — Transfer  25  cc.  each  of  the  copper  and  alkaline  tartrate 
solutions  to  a  400-cc.  Jena  or  Non-sol  beaker,  and  add  50  cc.  of  reducing 
sugar  solution,  or,  if  a  smaller  volume  of  sugar  solution  be  used,  add 
water  to  make  the  final  volume  100  cc.  Heat  the  beaker  upon  an  asbestos 
gauze  over  a  Bunsen  burner,  so  regulate  the  flame  that  boiling  begins  in 
four  minutes,  and  continue  the  boiling  for  exactly  two  minutes.  Keep 
the  beaker  covered  with  a  watch-glass  throughout  the  entire  time  of 
heating.  Without  diluting,  filter  the  cuprous  oxide  at  once  on  an  asbestos 
felt  in  a  porcelain  Gooch  crucible,  using  suction.  Wash  the  cuprous 
oxide  thoroughly  with  water  at  a  temperature  of  about  60°  C,  then  with 
10  cc.  of  alcohol,  and  finally  with  10  cc.  of  ether.  Dry  for  thirty  minutes 
in  a  water  oven  at  100°  C,  cool  in  a  desiccator  and  weigh  as  cuprous 
oxide. 

The  number  of  milligrams  of  copper  reduced  by  a  given  amount  of 
reducing  sugar  differs  when  sucrose  is  present  and  when  it  is  absent. 
In  the  tables  on  pp.  599  to  607  the  absence  of  sucrose  is  assumed,  except 
in  the  two  columns  under  invert  sugar,  where  one  for  mixtures  of  invert 
sugar  and  sucrose  (0.4  gram  of  total  sugar  in  50  cc.  of  solution),  and  one 
for  invert  sugar  and  sucrose  when  the  50  cc.  of  solution  contains  2  grams 
of  total  sugar  are  given,  in  addition  to  the  column  for  invert  sugar 
alone. 


♦Jour.  Am.  Chem.  .Vk.,  28,  1906,  p.  163;    29,   1907,  p.   541*,     U.  S.  Dept.  Agric,  Bur. 
of  Chem.,  Bui.  107  (rev.),  p.  241;   Circ.  82. 


SUGAR   AND    SACCHARINE   PRODUCTS. 


599 


MUNSON  AND  WALKER'S  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 
SUGAR,    LACTOSE,    AND   MALTOSE. 

[Weights  in  milligrams.] 


o 

Invert  Sugar 
and  Sucrose. 

Lactose. 

Maltose. 

0 

3 

3 

u 

0 

Q> 

"3 

^^ 

d 

d 

d 

V 

-3 

o 

1- 

0 

u 
ca 

M 

3 

:/3 

0 

CO 

0 

0 

X 

+ 

6 

+ 

6 

6 

X 

+ 

6 

•5? 
0 

3 

0 

% 

u 

u 

0  3 

0!  sp 

P, 

gi 

» 

& 

S) 

p 

3 

0.        1 

a 
0 

lU 

lU 

> 

c 

u  3 

ffi 

ffi 

EC 

w 

X 

u 

a 

3 

O 

0 

Q 

d 

N 

c5 

6 

c 

6 

(J 

0 

lO 

8.9 

4.0 

45 

1.6 

3.8 

3.9 

4.0 

59 

6.2 

10 

II 

9.8 

4.5 

5° 

2  . 1 

45 

4.6 

4.7 

6.7 

7.0 

II 

13 

10.7 

4.9 

S-4 

2.5 

S.I 

5.3 

5.4 

7.5 

7-9 

12 

13 

IIS 

5-3 

5-8 

30 

5.8 

5-9 

6.1 

8.3 

8.7 

13 

14 

12.4  , 

5-7 

6.3 

3-4 

6.4 

6.6 

6.8 

9.1 

9.5 

14 

IS 

13-3 

6.2 

6.7 

3-9 

7.1 

7.3 

7.5 

9.9 

10.4 

IS 

l6 

14-2 

6.6 

7.2 

4-3 

7.8 

8.0 

8.2 

10.6 

II  .2 

16 

17 

IS-I 

7.0 

7.6 

4.8 

8.4 

8.6 

8.9 

II. 4 

12  .0 

17 

i8 

16.0 

7-5 

8.1 

5-2 

9.1 

9.3 

9-5 

12  .2 

12.9 

18 

19 

16.9 

7.9 

8.5 

5-7 

9.7 

lO.O 

10.2 

13.0 

13.7 

19 

30 

17.8 

8.3 

8.9 

6.1 

10.4 

10.7 

10.9 

13.8 

14.6 

20 

31 

18.7 

8.7 

9-4 

6.6 

II. 0 

II. 3 

II. 6 

14.6 

15.4 

21 

33 

195 

9.2 

9.8 

7.0 



II. 7 

12.0 

12.3 

15.4 

16.2 

22 

33 

20.4 

9.6 

10.3 

7-5 

12.3 

12.7 

13.0 

16.2 

17.1 

23 

24 

21-3 

10. 0 

10.7 

7-9 

13-0 

13.4 

13.7 

17.0 

17.9 

24 

as 

22  .  2 

10. s 

II  .  2 

8.4 

13.7 

14.0 

14.4 

17.8 

18.7 

25 

26 

231 

10 . 9 

II. 6 

8.8 

14.3 

14.7 

15. 1 

18.6 

19.6 

36 

27 

24.0 

II-3 

12.0 

9-3 

15.0 

15-4 

IS. 8 

19.4 

20.  4 

27 

28 

24.9 

II. 8 

12. S 

9-7 

15.6 

16. 1 

16.5 

20.2 

21.2 

28 

39 

2S.8 

12  . 2 

12.9 

10.2 

16.3 

16.7 

17. 1 

21.0 

22  .  I 

29 

3° 

26.6 

12.6 

13-4 

10.7 

4-3 

16.9 

17.4 

17.8 

21.8 

22  . 9 

30 

31 

27-5 

I3-I 

13.8 

II  .  I 

4-7 

17.6 

18. 1 

18.5 

22.6 

23.7 

31 

32 

28.4 

13-5 

14.3 

II. 6 

s? 

18.3 

18.7 

19.2 

23.3 

24.6 

32 

33 

29.3 

13-9 

14-7 

12  .0 

5-6 

18.9 

19.4 

19.9 

24.1 

25.4 

33 

34 

30.2 

14-3 

15.2 

12.5 

6.1 

19.6 

20.1 

20.6 

24.9 

26.2 

34 

35 

311 

14.8 

15.6 

12.9 

6.5 

20.2 

20.8 

21.3 

25.7 

27.1 

35 

36 

32.0 

152 

16. 1 

13-4 

7.0 

20.9 

21.4 

22.0 

26. s 

27.9 

36 

37 

32.9 

IS. 6 

16. s 

13.8 

7.4 

21. S 

22.1 

22.7 

27.3 

28.7 

37 

38 

33.8 

16. I 

16.9 

14-3 

7.9 

22.2 

22.8 

23.4 

28.1 

29.6 

38 

39 

34.6 

16. s 

17.4 

14.7 

8.4 

22.8 

23.5 

24.1 

28.9 

30.4 

39 

40 

355 

16.9 

17.8 

lS-2 

8.8 

23-5 

24.1 

24.8 

29.7 

313 

40 

41 

36.4 

17-4 

18.3 

15-6 

9-3 

24.2 

24.8 

25.4 

30. s 

32.1 

41 

42 

37-3 

17.8 

18.7 

16. 1 

9.7 

24.8 

25. 5 

26.  I 

31.3 

32.9 

42 

43 

38.2 

18.2 

19.2 

16.6 

10.  2 

25-5 

26.2 

26.8 

32.1 

33.8 

43 

44 

39-1 

18.7 

ig.6 

17.0 

10.7 

26.1 

26.8 

27-S 

32.9 

34.6 

44 

45 

40.0 

19. I 

20. 1 

17-5 

1 1  .  I 

26.8 

27.  5 

28.2 

33-7 

35. 4 

45 

46 

40.9 

19.6 

20. s 

17.9 

II. 6 

27.4 

28.2 

28.9 

34.4 

36.3 

46 

47 

41.7 

20.0 

21.0 

18.4 

12.0 

28.1 

28.9 

29.6 

35-2 

37-1 

47 

48 

42  .6 

20.  4 

21.4 

18.8 

12. s 

28.7 

29. 5 

30.3 

36.0 

37.9 

48 

49 

43    5 

20.9 

21.9 

193 

12.9 

29.4 

30.2 

31.0 

36.8 

38.8 

49 

50 

44-4 

21.3 

22.3 

197 

13. 4 

30.1 

30.9 

31.7 

37-6 

39-6 

SO 

SI 

45-3 

21.7 

22.8 

20.2 

13-9 

30.7 

31.5 

32.4 

38.4 

40.4 

SI 

52 

46.2 

22 . 2 

23.2 

20.7 

14-3 

31.4 

32.2 

33.0 

39.2 

41-3 

52 

S3 

47-1 

22  .6 

23 -7 

21 .  I 

14.8 

32.1 

32.9 

33.7 

40.0 

42.1 

S3 

54 

48.0 

23.0 

24.1 

21.6 

IS-2 

32.7 

33.6 

34-4 

40.8 

42.9 

54 

5  5 

48.9 

23.  S 

24.6 

22  .0 

15.7 

33-4 

34.3 

35.1 

41.6 

43-8 

55 

56 

49-7 

239 

25.0 

22. s 

16.2 

34-0 

34-9 

35.8 

42.4 

44.6 

56 

57 

SO.  6 

24.3 

255 

22.9 

16.6 

34-7 

35.6 

36.5 

43-2 

45. 4 

57 

58 

515 

24.8 

259 

23-4 

17. I 

35-4 

36.3 

37.2 

44.0 

46.3 

58 

59 

52-4 

25.2 

26.  4 

239 

17-5 

36.0 

37.0 

37-9 

44.8 

47.1 

59 

60 

53-3 

25.6 

26.8 

243 

18.0 

36.7 

37.6 

38.6 

45-6 

48.0 

60 

61 

54-2 

26.1 

27-3 

24.8 

18. s 

37-3 

38.3 

39.3 

46.3 

48.8 

61 

63 

SS-I 

26. s 

27-7 

25.2 

18.9 

38.0 

39.0 

40.0 

47.1 

49-6 

62 

63 

56.0 

27.0 

28.2 

25-7 

19.4 

38.6 

39.7 

40.7 

47.9 

SO.S 

63 

64 

568 

27.4 

28.6 

26.2 

19.8 

39.3 

40.3 

41.4 

48.7 

Si-3 

64 

DOO 


FOOD   INSPECTION   AND    ANALYSIS. 


MUNSON  AND  WALKERS  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 

SUGAR,    LACTOSE,    AND    MMJYOSY.— {Continued). 

(Weights  in  milligrams.] 


c 

Invert  Sugar 
and  Sucrose. 

Lactose. 

Maltose. 

d 

s 

y 

s 

0 

V 

"is 

__ 

C 

c 

d 

0) 

•a 
o 

"a 
0 

3 

I 
^u 

a 

1 

X 

+ 

X 

+ 

X 

+ 

"2 
0 

m 

i 

t/2 

W    l" 

s 

;; 

~ 

~ 

^ 

I 

a 

3 

o 

I 
a 

c 

K 

ti 

a 

u 

> 
c 

6 

E  <3 

0 

X 

0 

CJ 

0 
X 

CJ 

0 

CJ 

3 
0 

u 

a 

3 
U 

65 

57-7 

27.8 

29.1 

26.6 

20.3 

40.0 

41 .0 

42.1 

49. 5 

52. 1 

6S 

66 

58.6 

28.3 

295 

27.1 

20.8 

40.6 

41.7 

42.8 

50.3 

53.0 

66 

67 

59-5 

28.7 

30.0 

27-5 

21.2 

41.3 

42.4 

43-5 

5 1.  I 

53.8 

67 

68 

60.4 

29.2 

30    4 

28.0 

21.7 

41.9 

43. 1 

44.2 

5 1.  9 

S4.6 

68 

69 

61.3 

29.  6 

30-9 

28.5 

22  .  2 

42.6 

43.7 

44.8 

52.7 

55.5 

69 

70 

62.2 

300 

31-3 

28.9 

22.6 

43.3 

44.4 

45.5 

53.5 

56.3 

70 

71 

63.1 

30. S 

3J.8 

29.4 

23.1 

43.9 

45.  1 

46.  2 

54-3 

57.1 

71 

72 

64   0 

30    9 

32.3 

29.8 

23.5 

44.6 

45.8 

46.9 

55.  I 

58.0 

72 

73 

64.  S 

31-4 

32.7 

30 -3 

24.0 

45-2 

46.4 

47.6 

55.9 

S8.8 

73 

74 

6S-7 

3>.8 

33-2 

30.8 

24.5 

45.9 

47-  1 

48.3 

S6.7 

59-6 

74 

75 

66.6 

32.2 

33.6 

31-2 

24.9 

46.6 

47.8 

49.0 

57.  S 

60.  s 

75 

76 

67-5 

32.7 

34-1 

31-7 

254 

47.2 

48.5 

49.7 

58.2 

61.3 

76 

77 

68.4 

33.1 

34-5 

32.1 

25. 9 

47-9 

49.1 

50.4 

.S9.0 

62.1 

77 

78 

69 -3 

33.6 

35-0 

32.6 

26.3 

48.  5 

49.8 

51.  I 

59-8 

63.0 

78 

79 

70.2 

340 

35.4 

33    I 

26.8 

49.2 

SO. 5 

51.8 

60.6 

63.8 

79 

80 

71. 1 

34-4 

35-9 

33    S 

27.3 

49-9 

SI. 2 

52. S 

61  .  4 

64.6 

80 

81 

719 

34    9 

36.3 

340 

27-7 

505 

SI. 9 

53.2 

62.2 

65. 5 

81 

82 

72.8 

35-3 

36.8 

34-5 

28.2 

51  -2 

52.5 

53.9 

63.0 

66.3 

82 

83 

73-7 

35.8 

37-3 

34    9 

28.6 

51.8 

53.2 

54.6 

63.8 

67.1 

83 

84 

74.6 

36.2 

37-7 

35-4 

29.1 

52.5 

S3.  9 

55.3 

64.6 

68.0 

84 

8S 

75-5 

36.7 

38.2 

35.8 

29.6 

53-  I 

54-6 

s6.o 

65.4 

68.8 

8S 

86 

76.4 

371 

38.6 

36.3 

30.0 

53.8 

55.2 

56.6 

66.2 

69.7 

86 

87 

77-3 

37-5 

39-1 

36.8 

30. S 

54. 5 

55.9 

57.3 

67  .0 

70.  5 

87 

88 

78.2 

38.0 

39-5 

37-2 

31.0 

55    I 

56.6 

58.0 

67.8 

71.3 

88 

89 

79   I 

38.4 

40.0 

37-7 

31-4 

55.8 

57.3 

58.7 

68.  s 

72.2 

89 

90 

79-9 

38.9 

40.4 

38.2 

31.9 

56.4 

58.0 

59.4 

69.3 

73.0 

90 

91 

80.8 

39-3 

40.9 

38.6 

32.4 

57. I 

58.6 

60. 1 

70.  I 

73.8 

91 

92 

81.7 

39-8 

41  .4 

39-1 

32.8 

57.8 

59.3 

60.8 

70.9 

74.7 

92 

93 

82.6 

40.2 

41.8 

39-6 

33-3 

S8.4 

60.0 

61. 5 

71.7 

75.5 

93 

94 

83.  S 

40.6 

42.3 

40.0 

33.8 

S9.I 

60.7 

62.2 

72. S 

76.3 

94 

95 

84.4 

41  .  I 

42.7 

40.5 

34.2 

S9.7 

61.3 

62.9 

73-3 

77.2 

95 

96 

853 

41    5 

43-2 

41  .0 

34.7 

60.4 

62.0 

63.6 

74.  I 

78.0 

96 

97 

86.2 

42.0 

43-7 

41  .4 

35.2 

61. I 

62.7 

64.3 

74.9 

78.8 

97 

98 

87.1 

42.4 

44.1 

41.9 

35.6 

61.7 

63.4 

65.0 

75.7 

79.7 

98 

99 

87 -9 

42.9 

44-6 

42.3 

36.1 

62.4 

64.0 

65." 

76.  S 

80.5 

99 

100 

88.8 

43-3 

450 

42.8 

36.6 

63.0 

64.7 

66.4 

77.3 

81.3 

100 

101 

89-7 

43-8 

455 

43-3 

37.0 

63.7 

65.4 

67.1 

78.1 

82.2 

101 

102 

90.6 

44  .2 

46.0 

43-8 

37. 5 

64.4 

66.  I 

67.8 

78.8 

83.0 

1  02 

lOJ 

91S 

44-7 

46.4 

44-2 

38.0 

65.0 

66.7 

68.5 

79.6 

83.8 

103 

104 

92.4 

45-1 

46.9 

44-7 

38.5 

65.7 

67.4 

69.  I 

80.4 

84.7 

104 

105 

93-3 

455 

47-3 

45-2 

38.9 

66.4 

68.1 

69.8 

81.2 

85.5 

lOS 

106 

94-2 

46.0 

47.8 

45.6 

39.4 

67.0 

68.8 

70. S 

82.0 

86.3 

106 

107 

9S.O 

46.4 

48.3 

46.  I 

39.9 

67.7 

69.5 

71.2 

82  .8 

87.2 

107 

108 

95-9 

46.9 

48.7 

46.6 

40.3 

68.3 

70.1 

71.9 

83  . 6 

88.0 

108 

109 

96.8 

47.3 

49-2 

47-0 

40.8 

69.0 

70.8 

72.6 

84.4 

88.8 

109 

110 

97-7 

47    8 

49-6 

47.5 

41.3 

69.7 

71. 5 

73.3 

8.5.2 

89.7' 

1 10 

III 

98.6 

48.2 

SO.  I 

48.0 

41.7 

70.3 

72.2 

74.0 

86.0 

90.  5 

I  I  I 

113 

99    S 

48.7 

50.6 

48.4 

43.2 

71.0 

72.8 

74.7 

86.8 

91  .3 

I  1  2 

««3 

100  . 4 

49    I 

S'O 

48.9 

42.7 

71.6 

73.5 

75.4 

87.6 

92.2 

113 

114 

lOI  .3 

49    6 

Si-5 

49-4 

43.2 

72.3 

74.2 

76.1 

88.  4 

93.0 

1  14 

»15 

102 . 2 

50.0 

51-9 

49.8 

43-6 

73-0 

74.9 

76.8 

89.2 

93.9 

IIS 

J16 

J 03  .0 

50.5 

52.4 

50.3 

44.1 

73.6 

75.6 

77.  s 

90.0 

94.7 

116 

H7 

»03-9 

50.9 

52.9 

50.8 

44.6 

74.3 

76.2 

78.2 

90.7 

95.  S 

liV 

irS 

t04.8 

51-4 

53    3 

51.3 

45.0 

75-0 

76.9 

78.9 

9«.5 

96.4 

Ji3 

119 

J05-7 

SI. 8 

S3. 8 

Si-7 

45. S 

7S.6 

77.6 

79.6 

92.3 

97.2 

119 

SUGAR  AND  SACCHARINE  PRODUCTS 


6oi 


MUNSON  AND  WALKKR'S  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 

SUGAR,    LACTOSE,    AND    M.\UTO^E— {Continued). 

[Weights  in  milligrams.] 


o 

Invert  Sugar 
and  Sucrose. 

Lactose. 

Maltose. 

q 

3 

3 

o 

0 

^^ 

b 

(U 

rS 

»- 

0 

d 

QJ 

!2 

^ 

u 

CO 

1 

0 

X 

£ 

X 

t3 

O 

3 

0 

« 

3 
t/3 

H 

^ 

+ 

+ 

s. 

+ 

0 

3 

2 

a 

3 

u 

a 
a 
0 
u 

0 

y. 

Q 

C 

6 

1  ^ 
0<w 

6 
u 

6 

6 
c3 

6 
s 
X 

C 

X 

3 

2 

a 
3 
0 

I20 

106.6 

S2-3 

54-3 

52.2 

46.0 

76.3 

78.3 

80.3 

93-1 

98.0 

120 

121 

107.5 

52-7 

54.7 

52.7 

46.5 

76.9 

79-0 

81.0 

93-9 

98.9 

121 

122 

108.4 

53-2 

55-2 

S3 -I 

46.9 

77.6 

79-6 

81.7 

94-7 

99-7 

123 

"3 

109.3 

53-6 

55-7 

53-6 

47-4 

78.3 

80.3 

82.4 

95-5 

too.  5 

123 

124 

1 10. 1 

54-1 

56.  I 

54-1 

47-9 

78.9 

8i  .0 

83.1 

96-3 

101  . 4 

124 

12  5 

1 1 1 .0 

54-5 

56.6 

54-5 

48.3 

79.6 

81.7 

83.8 

97-  I 

102  .  2 

125 

126 

1 1 1 .9 

550 

5  7.0 

5S-0 

48.8 

80.3 

82.4 

84.5 

97-9 

103  .0 

126 

127 

112. 8 

55-4 

57. 5 

SS-5 

49-3 

80.9 

83.0 

85.2 

98.7 

103.9 

127 

128 

113-7 

55-9 

58.0 

55-9 

49-8 

81.6 

83.7 

85.9 

99-4 

104.7 

128 

*9 

114.6 

56.3 

58.4 

56-4 

50.2 

82.2 

84.4 

86.6 

100  .  2 

105.  5 

129 

130 

i'S.5 

56.8 

58.9 

56.9 

50.7 

82.9 

85.1 

87.3 

lOI  .0 

106.  4 

130 

I3t 

116.4 

57.2 

59-4 

57-4 

SI. 2 

83.6 

85 -7 

88.0 

loi  .8 

107  .  2 

131 

132 

"73 

57-7 

59-8 

57-8 

Si-7 

84.2 

86.4 

88.7 

102  .6 

108.0 

132 

ii3 

ri8.i 

58.1 

60.3 

58.3 

52.1 

84.9 

87.1 

89.4 

103.4 

108.9 

133 

134 

1190 

58.6 

60.8 

58.8 

52  .6 

85.  5 

87.8 

90.  I 

104.  2 

109.7 

134 

135 

"9  9 

59.0 

61.2 

59-3 

53-  I 

86.2 

88.5 

90.8 

105.0 

1 10.  5 

13s 

136 

120.8 

59-5 

61.7 

59-7 

53-6 

86.9 

89.  I 

91-S 

105.8 

1 1 1  .4 

136 

137 

121  .  7 

60.0 

62.2 

60.  2 

S4-0 

87.  S 

89.8 

92.1 

106.6 

1 12  . 2 

137 

138 

122  .6 

60 .  4 

62.6 

60.  7 

54-5 

88.2 

90. 5 

92.8 

107.4 

113-0 

138 

139 

1235 

60.9 

03.1 

61.2 

55-0 

88.9 

91.2 

93.5 

108.2 

"3-9 

139 

140 

124.4 

^'1 

63  . 6 

61.6 

55-5 

89. S 

91.9 

94-2 

109 . 0 

114.7 

140 

141 

125.2 

61  .8 

64  .0 

62.1 

55-9 

90.  2 

92.5 

94  9 

109.  8 

"S-S 

141 

142 

126.  I 

62.2 

64.  5 

62.6 

56-4 

90.8 

93.2 

95-6 

1 10.  s 

116.4 

142 

143 

127-0 

62.7 

65  -0 

63.1 

56.9 

91. s 

93.9 

96.3 

111. 3 

117. 2 

143 

144 

127.9 

63.1 

65-4 

63-5 

57.4 

92.2 

94-6 

97  0 

112.1 

"8.0 

144 

I4S 

128.8 

63-6 

659 

64  .0 

57-8 

92.8 

95.  3 

97.7 

1 12  . 9 

118. 9 

I4S 

146 

129.7 

64  .0 

66.4 

64.5 

58.3 

93  5 

95.9 

98.4 

"3-7 

119-7 

146 

147 

130-6 

64.  5 

66.9 

65.0 

S8.8 

94-2 

96.6 

99.  I 

114.5 

120.5 

147 

148 

131. S 

65.0 

67-3 

65-4 

59-3 

94-8 

97.3 

99.8 

"5-3 

121.4 

148 

149 

132-4 

65-4 

67-8 

65-9 

59-7 

95  5 

98.0 

100. 5 

116.1 

122  .2 

149 

150 

133.2 

65 -9 

68.3 

66.4 

60.  2 

96.  I 

98.7 

lOI  .  2 

1 16.  9 

123,0 

150 

151 

134. 1 

66.3 

68.7 

66.9 

60.  7 

96.8 

99.3 

101.9 

"7.7 

123-9 

151 

152 

1350 

66.8 

69 .  2 

67-3 

61  .2 

97.5 

100.  0 

102.6 

118.5 

124.7 

152 

153 

135-9 

67.2 

69.7 

67-8 

61.7 

98.  I 

100.  7 

103.3 

"9-3 

125-S 

153 

IS4 

136.8 

67-7 

70.1 

68.3 

62.1 

98.8 

lOI  .  4 

104.0 

120  .0 

126  .  4 

154 

I5S 

137.7 

68.2 

70.  6 

68.8 

62.6 

99.  S 

102.  I 

104.7 

120.8 

127.2 

155 

156 

138.6 

68-6 

71.  I 

69 . 2 

63.1 

IOC.  I 

102.8 

105. 4 

121  .6 

128.0 

156 

157 

139-5 

69. 1 

71.6 

69.7 

63-6 

100.8 

103.4 

106.  I 

122.4 

128.9 

157 

158 

140.3 

69 -5 

72.0 

70.2 

64.  1 

loi  .5 

104.  I 

106.8 

123.2 

129.7 

158 

159 

141  .  2 

70.0 

72.5 

70.7 

64-5 

102 . 1 

104.8 

107.  5 

124.0 

130.5 

159 

160 

142.  I 

70.4 

730 

71.2 

65  .0 

102.8 

105.3 

108.2 

124.8 

131  4 

160 

161 

1430 

70.9 

73-4 

71.6 

65 -5 

103.4 

106.2 

108.9 

125.6 

132.2 

i6[ 

162 

143-9 

71.4 

73-9 

72.  I 

66.0 

104.  I 

106.8 

109.6 

126.4 

133  0 

162 

163 

144.8 

71.8 

74-4 

72.6 

66. s 

104.8 

107.5 

IIO. 3 

127.2 

133-9 

163 

164 

I4S-7 

72.3 

74-9 

73-  I 

66.9 

105.4 

108.2 

III.O 

128.0 

134-7 

164 

i6s 

146.6 

72.8 

75.3 

73-6 

67.4 

106.  I 

ro8.9 

III. 7 

128.8 

135  5 

i6s 

i66 

147-5 

73.2 

75-8 

74.0 

67.9 

E06.8 

109.6 

1 12.4 

129 .6 

136.4 

166 

167 

148-3 

73-7 

76-3 

74. S 

68.4 

107-4 

IIO. 3 

113. 1 

130.3 

137-2 

167 

168 

149-2 

74-1 

76.8 

7S-0 

68.9 

108.  . 

IIO. 9 

113  8 

131-t 

132.0 

168 

169 

150-1 

74-6 

77.2 

75-5 

69.3 

108.8 

1 1 1 .6 

114  5 

131-9 

138.9 

169 

170 

151-0 

7S-I 

77.7 

76  .0 

69.8 

109.4 

112. 3 

IIS. 2 

132-7 

139.7 

170 

171 

lSI-9 

75-5 

78.2 

76.4 

70.3 

IIO.  I 

113. 0 

IIS  9 

133-S 

140.5 

171 

172 

152.8 

76.0 

78.7 

76.9 

70.8 

110.8 

113. 7 

116. 6 

134  3 

141.4 

I7> 

173 

153-7 

76.4 

79  I 

77.4 

71  3 

III. 4 

114  3 

117. 3 

135  I 

142  .  2 

173 

174 

154-6 

76.9 

79.6 

77-9 

71.7 

112. 1 

IIS.O 

118. 0 

■35-9 

143-0 

174 

602 


FOOD   INSPECTION   AND  ANALYSIS. 


MUXSON  AND  WALKER'S  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 

SUGAR,    LACTOSE,   AND   MALTOSE— (Con/f«M«f). 

[Weights  in  milligrams.] 


o 

Invert  Sugar 
and  Sucrose. 

Lactose. 

Maltose. 

0 

3 

1 

3 

u 
4j 

"S 

_ 

C 

d 

d  ' 

0 

c 

a 

3 
0 

u 

si 

0 

t-i 

0 

15 
1/1  l" 

6 

6 

+ 
d 

d 

X 

+ 

d 

•0 

0 
«) 

3 

0 

u 

u 

u 

c3  00 

a 

a 

a 

a 

p 

u 

C. 

a 

0. 

a 
0 

0 

> 

E  3 
0^ 

ffi 

X 

ffi 

X 

X 

& 

3 

U 

0 

Q 

6 

« 

6 

0 

d 

0 

tj 

0 

175 

155-5 

77-4 

80.1 

78.4 

73.2 

112. 8 

IIS. 7 

118. 7 

136.7 

143-9 

175 

176 

156.3 

77-8 

80.6 

78.8 

72.7 

113. 4 

116. 4 

119-4 

137-5 

144-7 

176 

177 

157-2 

78.3 

8i.o 

79-3 

73-2 

114.  I 

117 .  I 

120. 1 

138-3 

145-5 

177 

178 

158.1 

78.8 

81. 5 

79-8 

73-7 

114. 8 

117.8 

120.8 

139-1 

146.4 

178 

179 

159-0 

79-2 

82.0 

80.3 

74-2 

iiS-4 

118. 4 

121. 5 

139-8 

147-2 

179 

180 

159-9 

79-7 

83.5 

80.8 

74.6 

116. 1 

119.  1 

122. 2 

140.6 

148.0 

i8o- 

181 

160.8 

80.  I 

82.9 

81.3 

75-1 

116. 7 

119. 8 

122 .9 

141-4 

148.9 

181 

182 

161  . 7 

80.6 

83-4 

81.7 

75-6 

117. 4 

120. s 

123.6 

142 . 2 

149-7 

182 

183 

162.6 

81.1 

83-9 

82.2 

76.1 

118. I 

121. 2 

124.3 

143-0 

150.5 

183 

184 

163.4 

81. 5 

84.4 

82. > 

76.6 

118. 7 

121. 8 

125.0 

143-8 

151  -4 

184 

18s 

164.3 

82  .0 

849 

83.2 

77-1 

119. 4 

122.5 

I2S.7 

144.6 

152-2 

185- 

J  86 

165.2 

82.5 

8S-3 

83-7 

77-6 

120.  I 

123.2 

126.4 

I4S-4 

IS3-0 

186 

187 

166.1 

82.9 

85.8 

84.2 

78.0 

120.  7 

123.9 

127. 1 

146.  2 

153-9 

187 

188 

167  .0 

83-4 

86.3 

84.6 

78. 5 

121. 4 

124.  6 

127.8 

147-0 

154-7 

188 

189 

167.9 

83 -9 

86.8 

85.1 

79.0 

122. 1 

1253 

128. 5 

147-8 

155-5 

189- 

190 

168.8 

84 -3 

87.2 

85.6 

79-5 

122.7 

125-9 

129.2 

148.6 

156.4 

190 

191 

169.7 

84-8 

87.7 

86.1 

80.0 

123.4 

126.6 

129.9 

149-3 

157-2 

191 

19J 

170.5 

8S-3 

88.2 

86.6 

80.  S 

124. I 

127.3 

130.6 

ISO.  I 

158.0 

192 

193 

171-4 

85-7 

88.7 

87.1 

81.0 

124.7 

128.0 

131-3 

150.9 

158.9 

193 

194 

172-3 

86.2 

89.2 

87-6 

81.4 

125.4 

128.7 

132.0 

I5I-7 

159-7 

194 

195 

173-2 

86.7 

89.6 

88.0 

81.9 

126. 1 

129.4 

132.7 

152.5 

160.  5 

195 

196 

174.  I 

87.1 

90. 1 

88.5 

82.4 

126.7 

130.0 

133.4 

IS3-3 

161  . 4 

196 

197 

175-0 

87.6 

90.6 

89.0 

82.9 

127.4 

130.7 

134-1 

IS4-I 

162  .  2 

197 

198 

175-9 

88.1 

91.1 

89  5 

83-4 

128.  I 

131-4 

134-8 

154-9 

163.0 

198 

199 

176.8 

88.5 

91 .6 

90.0 

83-9 

128.7 

132. I 

135.  5 

155-7 

163-9 

199 

200 

177-7 

89.0 

92  .0 

90.  5 

84-4 

129.4 

132.8 

136.2 

156.5 

164.7 

200- 

201 

178. 5 

89-5 

92.5 

91.0 

84-8 

130.0 

133  5 

136.9 

IS7-3 

165-5 

201 

202 

179-4 

89-9 

93-0 

91.4 

85-3 

130.7 

134-1 

137.6 

158.1 

166.4 

202 

203 

180.3 

90.4 

93-5 

91.9 

85.8 

131.4 

134-8 

138.3 

158.8 

167.2 

203 

204 

181.2 

90.9 

94  0 

93.4 

86.3 

132.0 

135-5 

139.0 

159-6 

168.0 

204 

205 

182.1 

91-4 

94-5 

92.9 

86.8 

132.7 

136.2 

139.7 

160.4 

168.9 

205 

306 

183.0 

91.8 

94-9 

93-4 

87-3 

133-4 

136.9 

140.4 

161 . 2 

169.7 

206 

207 

183  9 

92.3 

95-4 

93-9 

87-8 

1340 

137.6 

141 .  1 

162  .0 

170.5 

207 

208 

184-8 

92.8 

95-9 

94-4 

88.3 

134-7 

138.3 

141. 8 

162.8 

171.4 

208 

309 

185.6 

93-2 

96.4 

94-9 

88.8 

135-4 

138.9 

142.5 

163.6 

172  .2 

209 

210 

186. 5 

93-7 

96.9 

95-4 

89.2 

136.0 

139-6 

143.2 

164.4 

173-0 

210 

211 

187.4 

94-2 

97-4 

95-8 

89-7 

136.7 

140.3 

143  9 

165.2 

173-8 

211 

313 

188.3 

94  6 

97-8 

96 -3 

90.  2 

137.4 

141 .0 

144.6 

166.0 

174-7 

212 

2>3 

189.2 

95-1 

98.3 

96.8 

90.7 

138.0 

141-7 

14s. 3 

166.8 

175-5 

213 

214 

190.  I 

95-6 

98.8 

97-3 

91.2 

138.7 

142.4 

146.0 

167.5 

176.4 

214 

315 

191  .0 

96.  1 

99-3 

97-8 

91.7 

139-4 

143  0 

146.7 

168.3 

177-2 

215 

3l6 

191  .9 

96.5 

99-8 

98.3 

92.2 

140.0 

143.7 

147.4 

169. 1 

178.0 

216 

217 

192.8 

97-0 

1 00 . 3 

98.8 

92.7 

140.7 

144.4 

148.  I 

169.9 

178.9 

217 

3l8 

193-6 

97-5 

100.8 

99  ? 

93-2 

141. 4 

145-1 

148.8 

170.7 

179-7 

218 

319 

194  5 

98.0 

101  .2 

99  8 

93-7 

142.0 

145-8 

149.  5 

171.5 

180.5 

219 

220 

'95  4 

98.4 

101.7 

100.3 

94.2 

142.7 

146.  5 

150.2 

172-3 

181. 4 

220 

221 

^96.3 

98.9 

102  .  2 

100.8 

94-7 

143.4 

147.2 

150.9 

I73-I 

182.2 

221 

333 

'97-2 

99-4 

102  .  7 

101  .  2 

95-3 

144  0 

147-8 

151-6 

173-9 

183.0 

222 

323 

198.  I 

99-9 

103  .  2 

101  .7 

95-6 

144-7 

148. S 

152.3 

174-7 

183.9 

223 

324 

199  0 

100.3 

103 -7 

102.3 

96. 1 

145-4 

149-2 

1530 

175-5 

184-7 

224 

235 

199  9 

100.8 

104-2 

I03.  7 

96.6 

J46.0 

149-9 

153-7 

176.2 

185.5 

225 

336 

200.  7 

1 0 1  ,3 

104.6 

103.3 

97-1 

146.7 

150.6 

154.4 

177.0 

186.4 

226 

227 

201  .6 

loi  .8 

105  <  I 

103-7 

97.6 

147-4 

151-3 

155.1 

177.8 

1872 

227 

238 

203.5 

102 . 2 

105  .6 

104-3 

98.1 

148.0 

IS2-0 

155.8 

178.6 

188.0 

228 

239 

203  4 

102  .  7 

106. 1 

104.7 

98.6 

148.7 

152.6 

156.5 

179-4 

188.8 

229 

SUGAl.    AND   SACCHARINE   PRODUCTS. 


6=3 


MUNSON  AND  WALKER'S  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 

SUGAR,    LACTOSE,   AND   MALTOSE— (Co«/i«z^e(/). 

[Weights  in  milligrams.] 


B 

Invert  Sugar 
and  Sucrose 

Lactose. 

Maltose. 

0 

3 

3 

O 

0 

, 

d 

a 

S 

*^ 

d 

d 

9i 

O 

0 

3 

0 

a 

0 

+ 

CM 

X 

+ 

•a 
0 

lA 

<D 

CO 

t/3  i_* 

z^ 

^ 

^ 

2 

— 

3 

u 

0 

2  S, 

E  ?, 

0 

0 

0 

0 

0 

3 

£ 

a 

3 

c 
c. 
0 

Q 

u 

c 

0^ 

2^ 

a 
K 

a 

X 

X 

3 

u 

0 

6 

" 

0 

C 

(5 

0 

6 

0 

230 

204.3 

103.2 

106.6 

105.2 

99-1 

149-4 

153-3 

157. 2 

180.2 

189.7 

230 

231 

205.2 

103.7 

107 . 1 

105-7 

99-6 

150.0 

1S4-0 

157.9 

181.0 

190.  5 

231 

232 

206. 1 

104. 1 

107.6 

106. 2 

100. 1 

150.7 

154-7 

158.6 

181.8 

191-3 

232 

233 

207  .0 

104 . 6 

108.1 

106.  7 

100.6 

151-4 

I5S-4 

159.3 

182.6 

192 . 2 

233 

234 

207. '9 

105. 1 

108.6 

107 . 2 

101  . 1 

152.0 

156.  I 

160.0 

183.4 

1930 

234 

235 

208.7 

105.6 

109 . 1 

107.7 

loi  .6 

152.7 

IS6.7 

160.7 

184.2 

193-8 

235 

236 

209 . 6 

106.0 

I09-5 

108.2 

102  . 1 

153. 4 

157.4 

161. 4 

184.9 

194-7 

236 

237 

210. 5 

106.  5 

I  lO.O 

108.7 

102  . 6 

1540 

158.1 

162 . 1 

185.7 

195-5 

237 

238 

2  1 1  .  4 

107  .0 

no.  5 

109 . 2 

103  .  I 

154-7 

158.8 

162.8 

186.5 

196.3 

238 

239 

212.3 

107 -S 

1 1 1 .0 

109.  6 

103.5 

155-4 

159. 5 

163.  S 

187.3 

197-2 

239 

240 

213.2 

108.0 

in. 5 

1 10 .  I 

104 . 0 

156.  I 

160.2 

164.3 

188. 1 

198.0 

240 

241 

214.  I 

108.4 

112.0 

110.6 

104-5 

156.7 

160.9 

165.0 

188.9 

198.8 

241 

242 

21  ■;  .0 

108.  9 

112.5 

in  .  1 

105.0 

157.4 

161. 5 

165.7 

189.7 

199-7 

242 

243 

215.8 

109.4 

113.0 

111.6 

loS-S 

158.1 

162.2 

166.4 

190.5 

200.5 

243 

244 

216.7 

109.9 

II3-5 

112.1 

106.0 

158.7 

162.9 

167.  I 

191. 3 

201 .3 

244. 

245 

217.6 

no.  4 

114  .0 

112.6 

106.  5 

159.4 

163.6 

167.8 

192.1 

202  .2 

24s 

246 

218.5 

no. 8 

114-5 

113.1 

107  .0 

160.  I 

164.3 

168.  5 

192.9 

203.0 

246 

247 

219.4 

III. 3 

115.0 

113-6 

107-5 

160.7 

165.0 

169.2 

193.6 

203.8 

247 

248 

220.3 

in. 8 

iiS-4 

114. 1 

108.0 

161 .4 

165.7 

169.9 

194.4 

204.7 

248 

249 

221.2 

112. 3 

IIS-9 

114.6 

108.5 

162.  I 

166.3 

170.6 

195.2 

205.5 

249 

250 

222  . 1 

112. 8 

116.4 

ns-i 

109.0 

162.7 

167.0 

171-3 

196.0 

206.3 

250 

251 

223.0 

113-2 

116. 9 

115.6 

109s 

163.4 

167.7 

172.0 

196.8 

207  .  2 

251 

252 

223.8 

113-7 

117. 4 

116.1 

no.o 

164.  I 

168.4 

172.7 

197.6 

208.0 

252 

253 

224.7 

114.2 

117. 9 

116.6 

no. 5 

164.7 

169.  I 

173.4 

198.4 

208.8 

253 

254 

225.6 

114.7 

118. 4 

117.1 

n  1 .0 

165.4 

169.8 

174- I 

199.2 

209.7 

254 

255 

226.5 

115. 2 

118.9 

117.6 

111.5 

166.  I 

170.5 

174-8 

200.0 

210.5 

255 

256 

227.4 

iiS-7 

119.4 

118.1 

112.0 

166.8 

17I-I 

175-5 

200.8 

211.3 

256 

257 

228.3 

116. 1 

119.9 

118.6 

112.5 

167.4 

171. 8 

176.2 

201 .6 

212.2 

257 

258 

229.  2 

116. 6 

120.4 

119. 1 

113-0 

168.  I 

172. S 

176.9 

202.3 

213.0 

258 

259 

230. 1 

117. 1 

120.9 

119. 6 

113.5 

168.8 

173-2 

177.6 

203.1 

213-8 

259 

260 

231 .0 

117.6 

12  I  .  4 

120.  1 

114.0 

169-4 

173-9 

178.3 

203.9 

214-7 

260- 

261 

231.8 

118.1 

121.9 

120.6 

114. S 

170.  I 

174-6 

179.0 

204.7 

2  15-5 

261 

262 

232.7 

118.6 

122  .4 

121  .  I 

nS-o 

170.8 

I7S-3 

179.8 

20S-5 

216.3 

262 

263 

233.6 

119. 0 

122  .9 

121.6 

115-5 

171.4 

176.0 

180. 5 

206.3 

217.2 

263 

264 

234-5 

119-S 

123-4 

122.1 

116.0 

172. X 

176.6 

181. 2 

207 . 1 

218.0 

264. 

26s 

235-4 

120.0 

123.9 

122.6 

116.5 

172.8 

177.3 

181. 9 

207.9 

218.8 

26s 

266 

236.3 

120.5 

124.4 

123.1 

117  .0 

I73-S 

178.0 

182.6 

208.7 

219-7 

266. 

267 

237-2 

121.0 

124.9 

123-6 

1 1 7  -  5 

174-  I 

178.7 

183.3 

209.5 

220.5 

267 

268 

238.1 

121.5 

I2S-4 

124.  1 

118.0 

174-8 

179-4 

184.0 

210.3 

221.3 

268 

269 

238.9 

122.0 

125-9 

124.6 

118.5 

1755 

180. 1 

184.7 

211 .0 

222  .  I 

269- 

270 

239-8 

122.5 

126.  4 

125.1 

119.0 

176.  I 

180.8 

185-4 

211. 8 

223.0 

270 

271 

240.7 

122.9 

126.9 

125.6 

II9S 

176.8 

181. S 

186. I 

212.6 

223.8 

271 

272 

241  .6 

123.4 

127-4 

126.  2 

120.0 

177-5 

182. 1 

186.8 

213.4 

224.6 

272 

273 

242.  5 

123.9 

127.9 

126.  7 

120.6 

178. I 

182.8 

187. 5 

214.2 

225.5 

273 

274 

243-4 

124.4 

128.4 

127  .2 

121 . 1 

178.8 

183-S 

188.2 

215.0 

226.3 

274 

27s 

244-3 

124.9 

128.9 

127.7 

121  .6 

179.5 

184-2 

188.9 

215.8 

227.1 

275 

276 

245-2 

125.4 

129.4 

128.2 

122.1 

180.2 

184-9 

189.6 

2v6.6 

228.0 

276 

277 

246. 1 

125-9 

129.9 

128.7 

122  .6 

180.8 

18S.6 

190.3 

217.4 

228.8 

277 

278 

246.9 

126.4 

130.4 

129.  2 

123. 1 

181. 5 

186.3 

191. 0 

218.2 

229.6 

278 

279 

247.8 

126.9 

130.9 

129-7 

123.6 

182.2 

187.0 

191.7 

218.9 

230. 5 

279 

280 

248.7 

127-3 

131-4 

130-2 

124.1 

182.8 

187.7 

192.4 

219.7 

231.3 

280 

281 

249.6 

127.8 

1 3 1  -  9 

130-7 

124.6 

183.  S 

188.3 

193.1 

220.  5 

232.1 

281 

282 

250-S 

128.3 

132.4 

1312 

12S-I 

184.2 

189.0 

193.9 

221.3 

233.0 

282 

283 

251.4 

128.8 

132.9 

131-7 

125.6 

184.8 

189.7 

194-6 

222 . 1 

233.8 

283 

284 

252.3 

129-3 

133-4 

132.2 

126. 1 

185.5 

1 

190.4 

195-3 

222  .9 

234.6 

2S4 

b04 


FOOD  INSPECTION  ^ND   ANALYSIS. 


ML  NSON  AND  WALKER'S  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 
SUGAR,    LACTOSE,    AND   MALTOSE— (CoM/i«ued). 
(Weights  in  milligrams.] 


f 

Invert  Sugar 
and  Sucrose. 

Lactose. 

Maltose. 

0 

B 

o 

0 

0 

o 

"3 

^^ 

d 

d 

4) 

o 

3 

"a 
0 

u 

5 

a 
00 

3 

1 

6 

+ 
0 

X 

+ 
6 

6 

+ 
d 

73 

3 

1 

3 
O 

C. 
0 

u 

X 

(5 

> 

0  a 
6 

2^ 
0^ 

0 

8 

0 

& 

X 
6 

a 

2 

a 

3 
0 

j85 

353.3 

139.8 

133-9 

133.7 

126.6 

186.2 

191 . 1 

196.0 

223-7 

235-5 

28s 

a86 

a540 

130.3 

134-4 

133.2 

127. 1 

186.9 

191  .8 

196.  7 

224-s 

236.3 

286 

j87 

254.9 

130.8 

134-9 

133.7 

127.6 

187.5 

192.5 

197-4 

225.3 

2371 

287 

3  88 

155-8 

I3I-3 

135-4 

134-3 

128. 1 

188.2 

193.2 

108.  I 

226 . 1 

238.0 

288 

389 

356.7 

131  .8 

1359 

134-8 

128.6 

188.9 

193.8 

198.8 

226.9 

238.8 

289  . 

390 

357-6 

133.3 

136.4 

1353 

129.2 

189.5 

194 -5 

199-5 

227  . 6 

239.6 

290 

391 

358-5 

133.7 

136.9 

I3S-8 

129,7 

190.2 

193-2 

200.  2 

228.4 

240.5 

291 

393 

359-4 

133-2 

137.4 

136.3 

130. 2 

190.9 

195-9 

200.9 

229.  2 

241 .3 

292 

393 

360.3 

133-7 

137.9 

136.8 

130.7 

191  5 

196.6 

201  .6 

230  .0 

242. 1 

293 

394 

361  .3 

134-2 

138.4 

137.3 

131-2 

192.2 

197-3 

202.3 

230.8 

242.9 

294 

395 

363  .0 

134-7 

138.9 

137.8 

131-7 

192.9 

198.0 

203 .  0 

231.6 

243-8 

295 

396 

363  .9 

I3S-3 

139.4 

138.3 

132-2 

193.6 

198.7 

203.7 

232.4 

244-6 

296 

397 

363.8 

135-7 

140.0 

138.8 

132-7 

194  2 

199.3 

204.4 

233-2 

245-4 

297 

398 

264.7 

136-2 

140.5 

139-4 

133-2 

194-9 

200.0 

205.  I 

234.0 

246.3 

298 

399 

365.6 

136.7 

141 .0 

139-9 

133.7 

IPS. 6 

200.7 

205.8 

234-8 

247-  I 

299 

300 

366.5 

137-2 

141.5 

140.4 

134.2 

196.2 

201.4 

206.6 

235-S 

2479 

300 

301 

367.4 

137-7 

143  .0 

140.9 

134-8 

196.9 

202.  I 

207.3 

236.3 

248.8 

301 

302 

368.3 

138-2 

143.5 

141. 4 

135-3 

197.6 

202.8 

208.0 

237-1 

2496 

302 

303 

369.  I 

138-7 

143.0 

141. 9 

135  8 

198.3 

203.5 

208.7 

237-9 

250.4 

303 

304 

370.0 

139-2 

143.5 

142.4 

136.3 

198.9 

204.2 

209.4 

238.7 

251.3 

304 

30s 

370.9 

139-7 

144.0 

142.9 

136.8 

199.6 

204.9 

210.  I 

239- 5 

252.  r 

305 

306 

271.8 

140.  2 

144. 5 

143.4 

137-3 

200.3 

205.5 

210.8 

240.3 

252.9 

306 

307 

372.7 

140.7 

145-0 

144-0 

137-8 

201  .0 

206.  2 

211. S 

241  .  I 

253-8 

307 

308 

273-6 

141.2 

145-S 

144-5 

138.3 

201 .6 

206.9 

212.2 

241  .9 

254.6 

308 

309 

274-5 

141. 7 

146. 1 

145.0 

138.8 

202.3 

207.6 

212.9 

242.7 

255-4 

309 

310 

275.4 

142 . 3 

146.6 

145-S 

139-4 

203.0 

208.3 

213-7 

243  •  5 

256.3 

310 

3«i 

376.3 

142.7 

147.  I 

146.0 

139-9 

203.6 

209.0 

214.4 

244.2 

257.1 

3" 

312 

377-1 

143.2 

147.6 

146.5 

140.4 

204.3 

209 .  7 

215.  I 

245  0 

257-9 

312 

3«3 

378.0 

143.7 

148. I 

147.0 

140.9 

205.0 

210.4 

215.8 

245-8 

258.8 

313 

3«4 

378.9 

144.2 

148.6 

147-6 

14I-4 

205.7 

211  .  I 

216. 5 

246.6 

259-6 

314 

31S 

379-8 

144-7 

149-1 

148.1 

141-9 

206.3 

211. 8 

217.2 

247-4 

260.  4 

31S 

316 

380.7 

145-2 

149.6 

148.6 

142-4 

207  0 

212. S 

217-9 

248.2 

261  .  2 

316 

3<7 

381.6 

145-7 

150.  I 

149.1 

143-0 

207.7 

213.  I 

218.6 

249.0 

262  .  I 

317 

318 

383.5 

146.  3 

150.7 

149.6 

143-5 

308.4 

213.8 

219.3 

249.8 

262  .9 

318 

3«9 

383.4 

146.7 

151.2 

150.  I 

144-0 

209.0 

214.5 

220.0 

250.6 

263.7 

319 

320 

384.3 

147.2 

151. 7 

150.7 

144-S 

209.7 

215.  2 

220.7 

251-3 

264  .6 

320 

3»i 

385.1 

147-7 

153.3 

151. 2 

145-0 

210.4 

2IS-9 

221.4 

252.1 

265.4 

321 

3»» 

386. 0 

148.2 

153-7 

151.7 

145-5 

211. 0 

216.6 

222.2 

252.9 

266 . 2 

322 

333 

286.9 

148.7 

153-2 

152.3 

146.0 

211  .7 

217.3 

222.9 

253-7 

267 .  I 

323 

3»4 

387.8 

149-2 

153-7 

152.7 

146.6 

312.4 

218.0 

223.6 

254-S 

267.9 

324 

3»S 

388.7 

149-7 

154-3 

153.2 

147-1 

ai3.i 

218.7 

224.3 

255-3 

268.7 

32s 

3»6 

389.6 

150.2 

154-8 

153-8 

147-6 

213.7 

219.4 

225.0 

256.  I 

269.6 

326 

327 

290.5 

150.7 

155-3 

154-3 

148. 1 

214.4 

.120.  I 

225.7 

356.9 

270.4 

327 

3»8 

391  -4 

151. 2 

iSS-8 

154-8 

148.6 

215. I 

220.  7 

226.4 

357-7 

271  .2 

328 

3*9 

393  .  3 

151.7 

156.3 

iSS-3 

149-1 

315-8 

221  .4 

227.1 

358.5 

272.  I 

329 

330 

393  -  I 

153.2 

156.8 

155-8 

149-7 

216.4 

333.  I 

227.8 

259-3 

272.9 

330 

J?l 

394-0 

152.7 

157.3 

156.4 

150.2 

317.  I 

322.8 

228. s 

260.0 

273-7 

331 

33  » 

394-9 

153-3 

157. 9 

156.9 

150.7 

217.8 

223.  S 

229.  2 

260.8 

2746 

332 

333 

395-8 

IS3-7 

158.4 

157.4 

151  -2 

218.4 

224.  2 

230.0 

261.6 

275-4 

5i3 

334 

396.7 

154-3 

158.9 

157.9 

151-7 

319-  1 

224.9 

230.7 

363  . 4 

276.2 

334 

335 

397-6 

154-7 

159. 4 

158.4 

152.3 

319.8 

335.6 

231-4 

263.3 

277-0 

335 

336 

398.  5 

155  3 

159. 9 

1590 

153.8 

320.5 

226.3 

22.1 

264.0 

277-9 

336 

337 

299  3 

155  8 

160.5 

159.  5 

153- 3 

221.  r 

237.  0 

232.8 

264.8 

278.7 

337 

338 

300.3 

156.3 

161  .0 

160.0 

153-8 

321.8 

227.  7 

233  s 

265.6 

279-  5 

338 

339 

301 .  I 

156.8 

161. s 

160.5 

IS4-3 

322.  5 

228.3 

234-2 

366  .4 

280.4 

339 

SUGAR   AND  SACCHARINE    PRODUCTS. 


605 


MUNSON  AND  WALKER'S  TABLE  FOR  CALCULATING  DEXTROSE,  LNVERT 

SUGAR,    LACTOSE,    AND   MALTOSE— {Continued). 

[Weights  in  milligrams.] 


Invert  Sugar 

0 

and  Sucrose. 

Lactose. 

Maltose. 

0 

3 

3 

0 

0 

_ 

d 

0 

nj 

^^ 

d 

d 

0 

■?, 

0 

3 
0 

6 

3 

1 

0 
H 

X 

+ 

X 

+ 

X 

+ 

0 

0 

u 

a 
3 

<u 

a 

§■ 
0 

I 
Q 

> 

a 

s5  <« 
d 

E  =5 

6 

K 
u 

i 

X 
0 

6 

d 

?! 

K 
'J 

d 
?) 

X 

'J 

3 

2 

a 
3 
0 

340 

302  .0 

157.3 

162 .0 

161  .0 

154-8 

223.2 

229.0 

234  9 

267 . 1 

281 .2 

340 

341 

302.9 

157-8 

162.  5 

161 .6 

155.4 

223.8 

229.7 

235.6 

267.9 

282.0 

341 

342 

303 -8 

158.3 

163  . 1 

162  . 1 

155-9 

224. 5 

230.4 

236.3 

268.7 

282.9 

342 

343 

304-7 

158.8 

163.6 

162.6 

156.4 

225.2 

231. 1 

1  237.0 

369.5 

283.7 

343 

344 

3056 

159-3 

164 . 1 

163.  I 

156.9 

225.9 

231.8 

237.8 

270.3 

284.5 

344 

345 

306.  S 

159-8 

164 , 6 

163-7 

157-S 

226. s 

232.  5 

238.  S 

271  .1 

285.4 

345 

346 

3073 

160.3 

165.1 

164 . 2 

158-0 

227.2 

233.2 

239.2 

271  .9 

286.2 

346 

347 

308.2 

160.8 

165-7 

164.7 

158-5 

227.9 

233.9 

239.9 

272.7 

287.0 

347 

348 

309.1 

161 . 4 

166.2 

165.2 

1590 

228. s 

234-6 

240.6 

273-5 

287.9 

348 

349 

310.0 

161 .9 

166.7 

165-7 

159.5 

229.  2 

235-3 

241.3 

274-3 

288.7 

349 

35° 

310.9 

162  . 4 

167 .  2 

166.3 

160.  I 

229.9 

235-9 

242.0 

275-0 

289.5 

350 

351 

3  1 1  •  8 

162  . 9 

167.7 

166.8 

160.  6 

230.6 

236.6 

242.7 

275-8 

290.4 

351 

352 

312.7 

163.4 

168.3 

167.3 

161. I 

231.2 

237.3 

243.4 

276.6 

291 . 2 

352 

353 

3136 

163-9 

168.8 

167.8 

161.6 

231.9 

238.0 

244.1 

277-4 

292.0 

353 

354 

314-4 

164.4 

169-3 

168.4 

162.2 

232.6 

238.7 

244.8 

278.2 

292.8 

354 

355 

315-3 

164.9 

169.8 

168.9 

162.7 

233.3 

239.4 

245.6 

279.0 

293-7 

355 

356 

316.2 

165.4 

170.4 

169-4 

i  163.2 

233.9 

240.  I 

246.3 

279-8 

294-5 

3S6 

357 

317-1 

166.0 

170.9 

170.0 

163-7 

234.6 

240.8 

247.0 

280.6 

295-3 

357 

3S8 

318.0 

166.5 

171-4 

170. S 

164.3 

235. 3 

241 -S 

247.7 

281.4 

296. 2 

358 

359 

318.9 

167.0 

171-9 

171.0 

164.8 

236.0 

242.  2 

248.4 

282.2 

297.0 

359 

360 

319-8 

167.5 

172-5 

171-S 

1  165.3 

236.7 

242.9 

249.1 

282.9 

297.8 

360 

361 

320.7 

168.0 

173-0 

172. 1 

165.8 

237.3 

243-6 

249.8 

283.7 

298.7 

361 

362 

321 .6 

168. 5 

173-S 

172.6 

166 . 4 

238.0 

244.3 

250. 5 

284.  5 

299-5 

362 

363 

322.4 

169  .0 

174.0 

173.1 

1  ;6.  9 

238.7 

245.0 

251.2 

285.3 

300.3 

363 

364 

3233 

169.6 

174-6 

173-7 

167.4 

239.4 

24s.  7 

252.0 

286.1 

301.2 

364 

365 

324-2 

170.  I 

175-1 

174-2 

167-9 

240.0 

246.4 

252.7 

286.9 

302.0 

36s 

366 

325-  I 

I  70.  6 

175-6 

174-7 

168.5 

240.7 

247.0 

2534 

287.7 

302.8 

366 

367 

326.0 

171. I 

176. 1 

175.2 

169.0 

241.4 

247.7 

254-1 

288.  5 

3036 

367 

.368 

326.9 

171 .6 

176.7 

175-8 

169-5 

242 .  I 

248.4 

254-8 

289.3 

3045 

368 

369 

327.8 

172.  I 

177.2 

176-3 

170.0 

242.7 

249.  I 

2SS-5 

290.0 

305 -3 

369 

370 

328.7 

172.  7 

177-7 

176.8 

170.6 

243.4 

249.8 

256.2 

290.8 

306.1 

370 

371 

329  5 

173.2 

178.3 

177-4 

171. 1 

244.1 

250. S 

256.9 

291 .6 

307.0 

37t 

372 

3.'0.4 

173-7 

178.8 

177-9 

171.6 

244.8 

2SI.2 

257.7 

292.4 

307.8 

372 

373 

33  X.  3 

174.2 

179-3 

178-4 

172.2 

245-4 

251.9 

258.4 

293-2 

308.6 

373 

374 

332.2 

174-7 

179-8 

179-0 

172.7 

246.  1 

252.  6 

259.1 

294-0 

309-5 

374 

375 

333-1 

175-3 

180.  4 

179-5 

173-2 

246.8 

253.3 

259.8 

294-8 

310-3 

375 

376 

3340 

I7S-8 

180.  9 

180.0 

173-7 

247.5 

254-0 

260.  5 

295.6 

311.  I 

376 

377 

334.9 

176-3 

181.4 

180.6 

174.3 

248.1 

254-7 

261 .2 

296.4 

312.0 

377 

378 

335-8 

176-8 

182.0 

181. 1 

174.8 

248.8 

255 -4 

261 .9 

297.2 

312.8 

378 

379 

336-7 

177.3 

182.5 

181.6 

175-3 

249.  S 

256.  I 

262.6 

297-9 

313-6 

379 

380 

337-5 

177-9 

183-0 

182.  I 

175-9 

250.2 

236.8 

263.4 

298.7 

314-5 

380 

381 

338-4 

178-4 

183.6 

182.7 

176.  4 

250.8 

257-5 

264. 1 

299-5 

315-3 

381 

382 

339-3 

178.9 

184.1 

183.2 

176-9 

2515 

258.  I 

264.8 

300 . 3 

316-  1 

382 

383 

340.2 

179-4 

184.6 

183.8 

177-5 

252.2 

258.8 

265.5 

301  . 1 

316.9 

383 

384 

341-I 

180.0 

185.2 

184.3 

178.0 

252.9 

259- 5 

266.2 

301.9 

317-8 

384 

38^ 

342.0 

180.  s 

185.7 

184.8 

178. 5 

253.6 

260.2 

266.9 

302.7 

318-6 

38s 

386 

342-9 

181  ,0 

186.2 

185.4 

179. I 

254-2 

260.9 

267.6 

303  .  5 

319-4 

386 

387 

343-8 

181.5 

186.8 

185.9 

179.6 

254  9 

261.6 

268.3 

304-2 

320-3 

387 

388 

344-6 

182.0 

187-3 

186.4 

180.  r 

255  6 

262.3 

269.0 

3050 

321.  I 

388 

389 

345-5 

182.6 

187-8 

:87.o 

180.6 

256.3 

263.0 

269.8 

305-8 

321-9 

389 

.190 

346.4 

183.1 

188.4 

187.5 

181.2 

256.9 

263.7 

270. S 

306.6 

322.8 

390 

391 

347.3 

183.6 

188.9 

188.0 

181.7 

257-6 

264.4 

271.2 

307.4 

323.6 

391 

392 

348.2 

184.1 

189.4 

188.6 

182.3 

258-3 

265.  I 

271.9 

308.2 

324.4 

392 

393 

349.  I 

184-7 

190.0 

189.1 

182.8 

250.0  1 

265.8 

272.6 

309.0 

325  .2 

393 

394 

3SO.O 

185.2 

190. 5 

189.7 

183.3 

2S9-6 

1 

266.  s 

273  3 

309-8 

326.  I 

394 

6o6 


FOOD   INSPECTION   AND  ANALYSIS. 


MUNSON  AND  WALKER'S  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 

^rr.AR,    LACTOSE,    AND   MALTOSE— (Cow/jHued). 

(Weights  in  milligrams] 


c 

Invert  Sugar 
and  Sucrose. 

Lactose. 

Maltose. 

0 

3 

3 

o 

0 

0 

V 

H 

^^ 

d 

d 

0 

'k 
C 

0 

3 

0 
6u 

+ 

X 

+ 

X 

+ 

•a 

•a 

0 

0 

C/3 

tf)  iJ 

s 

3 

2 

3 

2 

3 

u 

d 

2  rt 

E  fl, 

0 

0 

0 

0 

0 

3 

£ 

c. 

c 

0 

0 
> 
q 

2^ 

X 

X 

2 

a 

3 

O 

U 

Q 

d 

" 

6 

6 

(J 

0 

0 

u 

395 

3SO-9 

185.7 

191  .0 

190.  2 

183-9 

260.3 

267.2 

274-0 

310.6 

326.9 

395 

396 

351-8 

186.2 

191.6 

190.7 

184-4 

261.0 

267.9 

274-7 

311-4 

327-7 

396 

397 

351-6 

186.8 

192  .  1 

191-3 

184.9 

a6i.7 

268.6 

275-5 

312. 1 

328.6 

397 

398 

353-5 

187.3 

192.7 

191.8 

185. 5 

262.3 

269.3 

276.2 

312.9 

329-4 

398 

399 

354.4 

187.8 

193-2 

192.3 

186.0 

263.0 

269.9 

276.9 

313-7 

330.2 

399 

400 

335-3 

188.4 

193.7 

192.9 

186. 5 

263.7 

270.6 

277.6 

314-5 

331-1 

400- 

401 

356-2 

188.9 

194-3 

193-4 

187.1 

264.4 

271-3 

278.3 

31S-3 

331-9 

401 

40a 

357-1 

:89.4 

194-8 

194.0 

187.6 

365.0 

272.0 

279.0 

316- 1 

332.7 

402 

403 

358.0 

189.9 

195-4 

194-5 

188.1 

265.7 

272.7 

279.7 

316.9 

333-6 

403 

404 

358-9 

190.5 

195-9 

19S-0 

188.7 

266.4 

273-4 

280.4 

317-7 

334-4 

404 

40s 

359-7 

191 .0 

196.4 

195-6 

189.2 

267 . 1 

274- 1 

281.1 

318.5 

335.2 

40s 

406 

360.6 

191.5 

197.0 

196. 1 

189.8 

267.8 

274-8 

281.9 

319-2 

336.0 

406 

407 

361.5 

192  . 1 

197.5 

196.7 

190.3 

268.4 

275-5 

282.6 

320.0 

336.9 

407 

408 

362.4 

192.6 

198.1 

197.2 

190.8 

269. 1 

276.  2 

283.3 

320.8 

337.7 

408 

409 

3633 

193. 1 

198.6 

197-7 

191  -4 

269.8 

276.9 

284.0 

321 .6 

338. 5 

409 

410 

364.  s 

193.7 

199.1 

198.3 

191.9 

270. 5 

277.6 

284.7 

322.4 

339.4 

410 

411 

365.1 

194.2 

199-7 

198.8 

192.5 

271.2 

278.3 

285.4 

323-2 

340.2 

411  - 

412 

366.0 

194.7 

200.  2 

IQ9-4 

193-0 

271.8 

279.0 

286.2 

324.0 

341.0 

412 

413 

366.9 

195-2 

200.  8 

199-9 

193-5 

272. S 

279.7 

286.9 

324.8 

341.9 

413 

414 

367.7 

195-8 

201 .3 

200 .  5 

194-1 

273.2 

280.4 

287.6 

325.6 

342.7 

414 

41S 

368.6 

196-3 

201  .8 

201  .0 

194.6 

273.9 

281. 1 

288.3 

326.3 

343.5 

415 

416 

369.5 

196-8 

2C2  .4 

201.6 

195-2 

274.6 

281.8 

289.0 

327.1 

344-4 

416 

417 

370.4 

197-4 

202  .9 

202  . 1 

I9S-7 

275.2 

282.5 

289.7 

327.9 

345.2 

417 

418 

371-3 

197-9 

203-5 

202  .6 

196.  2 

275-9 

283.  2 

290.4 

328.7 

346.0 

418 

419 

372.2 

198.4 

204.0 

203.3 

196.8 

276.6 

283.9 

291.2 

329.5 

346.8 

419 

4ao 

373.1 

1990 

204.6 

203.7 

197.3 

277.3 

284.6 

291.9 

330.3 

347.7 

420 

421 

3740 

1995 

205.  I 

204.3 

197.9 

277.9 

28s.  3 

292.6 

331. 1 

348.5 

421 

422 

374.8 

200.  1 

205.7 

204.8 

198.4 

278.6 

286.0 

293.3 

331.9 

349-3 

422 

4»3 

375. 7 

200.6 

206.  2 

205.4 

198.9 

279.3 

286.7 

294 -0 

332.7 

3  5° -2 

423 

434 

376.6 

201  .  I 

206.  7 

205.9 

199-S 

280.0 

287.4 

294-7 

333-4 

351  .0 

424 

42s 

377.5 

201  .  7 

207.3 

206.  5 

200.0 

280.7 

288.  I 

295.4 

334-2 

351-8 

425 

426 

378.4 

202  .  2 

207.8 

207  .0 

200.  6 

281.3 

288.8 

296.2 

335-0 

352.7 

426 

427 

379  3 

202.8 

208.  4 

207  .6 

201  . 1 

282.0 

289.4 

296 .  9 

335-8 

353-5 

427 

428 

380.2 

203.3 

208.9 

208.  1 

201  .  7 

282.7 

290.  I 

297.6 

336.6 

354-3 

428 

429 

381.  I 

203.8 

209.5 

208.7 

202  .  2 

283.4 

290 .  8 

298.3 

337.4 

355-1 

429 

430 

382.0 

204.4 

210.0 

209 .  2 

202  .  7 

284.  I 

291.  5 

299.0 

338.2 

356.0 

430 

431 

382.8 

204.9 

210.6 

209.8 

203.3 

284.7 

292 .  2 

299 . 7 

339-0 

356.8 

431 

43a 

383.7 

205.5 

21 1  . 1 

210.3 

203.8 

285.4 

292.9 

300.5 

339-7 

357-6 

432 

433 

384.6 

206.0 

211.7 

210.9 

204.4 

286.1 

293  .  6 

301.2 

340.5 

358.5 

433 

434 

385.5 

206.5 

212.2 

21 1 .4 

204.9 

286.8 

294  3 

301.9 

341.3 

359-3 

434 

435 

386.4 

207  . 1 

212.8 

212.0 

205.5 

287.  5 

295-0 

302.6 

342.1 

360.1 

435 

436 

387.3 

207  .6 

213-3 

212.5 

206.0 

288.  I 

295  .  7 

303.3 

342.9 

361  .0 

436 

*H 

388.2 

208.2 

213  9 

213-1 

206.6 

288,8 

296 .  4 

304.0 

343-7 

361.8 

437 

438 

J89  I 

208.7 

214-4 

213  6 

207.1 

289.5 

297  -  1 

304.7 

344-5 

362.6 

438 

439 

390.0 

209.  2 

215.0 

214.3 

207.7 

290.2 

297-8 

305.  S 

345-3 

363-4 

439 

440 

390.8 

209.8 

2 1  5  -  5 

214-7 

208. 3 

290.9 

298.  S 

306.3 

346.1 

364-3 

440 

441 

391.7 

210.3 

216.  I 

215-3 

208.8 

29T.S 

299.  2 

306.9 

346.8 

365-1 

441 

44a 

39»  6 

210.9 

216.6 

215-8 

209.3 

392.2 

299.9 

.^07-6 

347-6 

365-9 

443 

443 

393.5 

211. 4 

217.2 

216.4 

209.9 

292.9 

300.6 

308.3 

348.4 

366.8 

443 

444 

394.4 

212.0 

217.8 

216.9 

210.4 

293.6 

301.3 

309.0 

349-2 

567-6 

444 

445 

395.  3 

212.5 

218.3 

217-5 

2  I  I  .  0 

294-2 

302.0 

309.7 

350.0 

368.4 

445 

446 

396.2 

2 1 3  . 1 

218.9 

218.0 

211  .5 

294  -  0 

302.7 

310. 5 

350.8 

369-3 

446 

**l 

397  « 

213.6 

219.4 

218.6 

212  .  I 

295  •  6 

303.4 

311. 2 

351  -6 

370.1 

447 

448 

397.9 

214  I 

220.0 

219.1 

2  12.6 

296.3 

304.  I 

,511.9 

312. c 

352-4 

370.9 

448 

449 

398.8 

314.7 

220.  5 

219.7 

313.3 

297.0 

304.8 

353-2 

371-7 

449 

SUGAR   AND   SACCHARINE  PRODUCTS. 


607 


MUNSON  AND  WALKER'S  TABLE  FOR  CALCULATING  DEXTROSE,  INVERT 

SUGAR,    LACTOSE,    AND   MALTOSE— (CoK/i;jHe(f). 

[Weights  in  milligrams.] 


Invert 

Suear 

0 

and  Sucrose. 

Lactose. 

Maltose. 

0 

B 

3 

0 

0 

d 

u 

<A 

^M 

C 

c 

V 

73, 
'!< 
0 

3 

u 

M 
3 

iS 

X 

+ 

X 

+ 

X 

+ 

•0 
0 

i 

C/D 

52  v- 

M 

3 

s 

n 

n 

0 

3 

u 

0 

2  S, 

E  S, 

0 

0 

0 

0 

c 

3 

0 

a 
3 

a 
c 
0 

Ui 

u 

> 

C  3 

— 

X 

n 

X 

V. 

X 

1 

3 

u 

<J 

Q 

6 

« 

0 

0 

0 

6 

c 

0 

4SO 

399-7 

215-2 

221  .  I 

220. 2 

213.7 

297.6 

305.5 

313-3 

353.9 

372.6 

4SO 

4SI 

400.6 

215.8 

221.6 

220.8 

214-3 

298.3 

306.2 

3I4-0 

354.7 

373-4 

451 

452 

401. s 

216.3 

222  .2 

221.4 

214.8 

299 -0_ 

306.9 

314-7 

355-5 

374-2 

452 

453 

402.4 

216.9 

222.8 

221 .9 

2154 

299-7 

307.6 

315.5 

356-3 

375-1 

453 

454 

403-3 

217.4 

223.3 

222.5 

215-9 

300.4 

308.3 

316.2 

357-1 

375-9 

454 

455 

404.2 

218.0 

223.9 

223.0 

216.5 

301 . 1 

309.0 

316.9 

357-9 

376-7 

455 

456 

405.  I 

218.5 

224.4 

223.6 

217.0 

301.7 

309.7 

317.6 

358.7 

377-6 

456 

457 

405-9 

219.  I 

225.0 

224.  I 

217.6 

302.4 

310.4 

318.3 

359.5 

378-4 

457 

4S8 

406.8 

219.6 

225.5 

224.7 

218. 1 

303 -I 

311  .  I 

3190 

360.3 

379.2 

458 

459 

407.7 

220.  2 

226.  I 

225.3 

218.7 

303-8 

311. 8 

319.8 

361  .0 

380.0 

459 

460 

408.6 

220.  7 

226.  7 

225.8 

219.2 

304 -5 

312. 5 

320.S 

361.8 

380.9 

460 

461 

409 -5 

221.3 

227.2 

226.4 

219.8 

305-1 

313.2 

321.2 

362.6 

381.7 

461 

462 

410.4 

221.8 

227.8 

226.9 

"20.3 

305-8 

313-9 

321.9 

363.4 

382.5 

462 

463 

411 -3 

222  .4 

228.3 

227.5 

220  9 

Zo'o.S 

314-6 

322  6 

364.2 

383-4 

463 

464 

412 . 2 

222  .  9 

228.9 

228.1 

221 .4 

307  -  2 

315-3 

323-4 

365-0 

384-2 

464 

46  s 

413-0 

223. 5 

229. s 

228.6 

222  .0 

307.9 

316.0 

324-1 

365.8 

385.0 

465 

.466 

413-9 

224.0 

230.0 

229.2 

222  .  5 

308.6 

316.7 

324.8 

366.6 

385.9 

466 

467 

414.8 

224.6 

230.6 

229.7 

223.  r 

309.2 

317.4 

325.5 

367.3 

386.7 

467 

468 

415-7 

225.  I 

231-2 

230.3 

223.7 

309.9 

318.  I 

326.2 

368.1 

387-5 

468 

469 

416.6 

225.7 

231.7 

230.9 

224 . 2 

310.6 

318.8 

326.9 

368.9 

388.3 

469 

470 

417-5 

226.  2 

232.3 

231  -4 

224-8 

311. 3 

319. 5 

327.7 

369.7 

389-2 

470 

471 

418.4 

226.8 

232.8 

232  .0 

225-3 

312.0 

320.2 

328.4 

370.5 

390.0 

471 

472 

419-3 

227.4 

233-4 

232. 5 

225.9 

312.6 

320.9 

?29.l 

371.3 

390.8 

472 

473 

420.  2 

227.9 

234-0 

233.1 

226.4 

313.3 

321.6 

329.8 

372.1 

391  .7 

473 

474 

421.0 

228.5 

234.5 

233.7 

227.0 

314-0 

322.3 

330-5 

372.9 

392.5 

474 

475 

421  .9 

229.0 

235-1 

234-2 

227.6 

314-7 

323 -0 

331-3 

373.7 

393.3 

475 

476 

422.8 

229.6 

235-7 

234-8 

228.1 

315-4 

323.7 

332-0 

374-4 

394.2 

476 

477 

423.7 

230.1 

236.2 

235-4 

228.7 

316.  I 

324-4 

332.7 

3  7  5-2 

39S-0 

477 

478 

424.6 

230.7 

236.8 

235.9 

229.2 

316.7 

32s -I 

333  4 

376.0 

395-8 

47? 

479 

425-5 

231-3 

237.4 

236-5 

229.8 

31T.4 

325-8 

334-1 

376.8 

396.6 

470 

480 

426.4 

231.8 

237-9 

237-1 

230.3 

318. 1 

326.  S 

334-8 

377.6 

397  -  5 

480 

481 

427-3 

232-4 

238. 5 

237-6 

230.9 

318.8 

327.2 

335-6 

378.4 

398-3 

481 

482 

428.1 

232.9 

239-  I 

238.2 

2315 

319-5 

327-9 

336.3 

379-2 

399-  I 

482 

483 

429.0 

233-5 

239.6 

238.8 

232.0 

320. 1 

328.6 

337-0 

380.0 

400.0 

483 

484 

429.9 

234-1 

240.  2 

239-3 

232.6 

320.8 

329-3 

337-7 

380.7 

400.  8 

-^84 

485 

430.8 

234.6 

240.  8 

239  9 

233.2 

321. S 

330.0 

338-4 

381. 5 

401 . 6 

48s 

486 

431-7 

235.2 

241.4 

240.5 

233-7 

322.2 

30.7 

339    I 

382.3 

402.4 

486 

487 

432-6 

235-7 

241.9 

241  .0 

234-3 

322.9 

331  4 

339.9 

383-1 

403-3 

487 

488 

433-5 

266.3 

242. 5 

241.6 

234-8 

323-6 

332.  I 

340.6 

383-9 

404.  I 

488 

489 

434-4 

236.9 

243-  I 

242  .  2 

235-4 

324  2 

33.^.8 

341-3 

384-7 

404.9 

489 

490 

435-3 

237-4 

243.6 

242.7 

236.0 

324  9 

333-5 

342-0 

385-5 

405.8 

490 

6b8  FOOD   INSPECTION  AND  ANALYSIS. 

AUihn's  Method  for  the  Determination  of  Dextrose.*— The  solutions 
used  arc  those  described  on  page  i^gi,  exce])l  that  125  grams  of  potassium 
hydroxide  are  used  in  place  of  50  grams  of  sodium  hydroxide  in  preparing 
the  alkaline  tartrate  solution.  IHace  30  cc.  of  Fehling's  copper  solution, 
30  cc.  of  the  alkaline  tartrate  solution,  and  ()o  cc.  of  water  in  a  beaker 
and  heat  to  boiling.  Add  2^  cc.  of  the  sugar  solution,  which  must  be 
so  prcjiared  as  not  to  contain  more  than  \'  [  dextrose,  and  boil  over  the 
llame  for  two  minutes.  Filter  immediately  without  diluting  through  a 
Gooch  :rucible  containing  a  layer  of  asbestos  fiber,  prej^ared  as  described 
on  page  594,  and  wash  thoroughly  with  hot  water,  using  reduced  pressure. 
Transfer  the  asbestos  fiber  and  the  adhering  cuprous  oxide  by  means  of 
a  glass  rod  to  a  beaker  and  rinse  the  crucible  with  about  30  cc.  of  a  boiling 
mixture  of  dilute  sulphuric  and  nitric  acids  containing  ()5  cc.  of  sulphuric 
acid  (specific  gravity  1.84)  and  50  cc.  of  nitrx  acid  (specific  gravity 
1.42)  per  liter.  Heat  and  agitate  till  the  solution  is  complete,  then  lilter 
into  a  scrupulously  clean,  tared  platinum  dish  of  loo-cc.  capacity,  taking 
care  to  wash  out  all  the  copper  solution  from  the  filter  into  the  dish. 
Deposit  the  copper  electrolytically  in  the  ])latinum  dish  and  weigh.  Detcr- 
iiiine  the  dextrose  from  AUihn's  table,  p.  609. 

Or,  the  metallic  copper  may  be  calculated  by  means  of  the  factor 
0.7989  from  the  cupric  oxide  oljtained  as  in  Defren's  method  (p.  594) 
and  AUihn's  table  used. 

Or,  the  cuprous  oxide  as  directly  obtained  by  either  AUihn's  or  Defren's 
method  may  be  washed  with  alcohol  and  ether,  dried  for  twenty  minutes 
at  100°  C,  and  weigherl,  its  equivalent  in  dextrose  being  ascertained  from 
.\llihn's  table. 

Electrolytic  Apparatus. — The  author  has  devised  the  apparatus  shown 
in  Fig.  1 10  for  the  electrolytic  deposition  of  copper  in  sugar  analysis  and  for 
other  work  of  like  nature.  A,  Fig.  no,  is  a  hard-rubber  plate  50  cm. 
long  and  25  cm.  wide  provi  led  with  four  insulated  metal  binrling  posts,  B, 
each  carr)-ing  at  the  toj)  a  thumb  screw  by  which  a  coiled  platinum  wire 
electrode,  C,  may  be  attached.  In  front  of  each  post  is  a  copper  plate 
about  4  cm.  square  covered  with  thin  platinum  foil,  P,  which  is  bent 
around  the  edges  of  the  copper  ])late  and  so  held  in  place,  the  copper  plate 
being  screwed  to  the  rubber  from  beneath.  On  the  square  platinum- 
covered  plate  is  set  the  platinum  evaporating-dish  which  holds  the  solu- 
tion from  which  the  coj)y)er  is  to  be  deposited,  the  inside  of  the  dish  form- 
ing the  cathode,  while  the  electrode  C,  dipping  below  the  surface  of  the 
solution,  forms  the  anode.      In  front  of    each  platinum-covered  plate 

*  Tour,  fur  praktische  Chemie.  22  (1880),  p.  46. 


SUJAR   JND  SACCHARINE    PRODUCTS. 


609 


ALLIHN'S  TABLE  FOR  THE  DETERMINATION  OF  DEXTROSE 

* 

Milli- 

Milli- 

MilU- 

Milli- 

Milli- 

Milli- 

Milli- 

Milli- 

Milli- 

MilU- 

Milli- 

MilU- 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

of 

of  Cu- 

of 

of 

of  Cu- 

of 

of 

of  Cu- 

of 

of 

of  Cu- 

of 

Cop- 

prous 

Dex- 

Cop- 

prous 
Oxide. 

Dex- 

Cop- 

prous 
Oxide. 

Dex- 

Cop- 

prous 
Oxide. 

Dex- 

per. 

Oxide. 

trose. 

per. 

trose. 

per. 

trose. 

per. 

trose. 

IX 

12.4 

6.6 

76 

85.6 

38.8 

141 

158.7 

71.8 

206 

231-9 

105-8 

12 

13s 

7-  I 

77 

86.7 

39-3 

142 

159-9 

72.3 

207 

233-0 

106.3 

13 

14.6 

7.6 

78 

87.8 

39-8 

143 

161.0 

72.9 

208 

234-  2 

106.8 

14 

15.8 

8.  I 

70 

88.9 

40-3 

144 

162. 1 

73-4 

209 

235-3 

107.4 

IS 

16.9 

8.6 

80 

90 . 1 

40.8 

145 

163.2 

73-9 

210 

236.4 

107.9 

16 

18.0 

9.0 

81 

91.2 

41  -3 

146 

1 64 . 4 

74-4 

211 

237.6 

108.4 

17 

19.  I 

95 

82 

92.3 

41  .8 

147 

165.5 

74-9 

21 2 

238.7 

109.0 

18 

20.3 

10. 0 

83 

93-4 

42.3 

148 

1 66.  6 

75-5 

213 

239-8 

109-5 

19 

21.4 

10. 5 

84 

94.6 

42.8 

149 

167.7 

76.0 

214 

240.9 

no.o 

20 

22. s 

n  .0 

8S 

95-7 

43-4 

150 

168.9 

76. 5 

215 

242. 1 

1 10.6 

21 

23-6 

ii-S 

86 

96.8 

43.9 

151 

1 70.0 

77-0 

216 

243-2 

1 1 1 . 1 

22 

24.8 

12.0 

87 

970 

44.4 

152 

171  -I 

77-5 

217 

244-3 

1 1 1  .  6 

23 

25-9 

12.5 

88 

99.  I 

44-0 

153 

172-3 

78.1 

218 

245-4 

112.1 

24 

27.0 

13.0 

89 

100.  2 

45-4 

154 

173-4 

78.6 

219 

246.  6 

112.7 

25 

28.1 

13-5 

90 

101.3 

45-9 

155 

174-5 

79.1 

220 

247-7 

113-2 

26 

29.3 

14.0 

91 

102.4 

46.4 

156 

175-6 

79-6 

221 

248.7 

113.7 

27 

30.4 

14-5 

92 

103.6 

46.  9 

157 

176.8 

80.1 

222 

249.9 

114-3 

28 

31-5 

15.0 

93 

104.  7 

47-4 

158 

177-9 

80.7 

223 

251  .0 

1.4.8 

29 

32-7 

15-5 

94 

105.8 

47-9 

159 

1790 

81.2 

224 

252-4 

115. 3 

30 

33-8 

16.0 

95 

107  .0 

48-4 

160 

180. 1 

81.7 

225 

253-3 

115-9 

31 

34-9 

16. 5 

96 

108.  I 

48.9 

161 

181.3 

82.2 

226 

254-4 

116.4 

32 

36.0 

17.0 

97 

109 .  2 

49-4 

162 

182.4 

82.7 

227 

255-6 

116.9 

3i 

37-2 

I7-S 

98 

110.3 

49-9 

163 

183-5 

83.3 

228 

256.7 

117-4 

34 

38.3 

18.0 

99 

1 1 1 .  5 

50-4 

164 

184.6 

83.8 

229 

257-8 

118-0 

35 

39-4 

18. S 

100 

112. 6 

50.9 

165 

185.8 

84-3 

230 

258.9 

118. 5 

36 

40.  S 

18.9 

lOI 

1 1 3  •  7 

51-4 

166 

1 86. 9 

84.8 

231 

260. 1 

119.0 

37 

41.7 

19.4 

102 

114. 8 

51-9 

167 

188.0 

85-3 

232 

261  .  2 

119.6 

38 

42.8 

19.9 

103 

1 16.0 

52-4 

16S 

189.1 

85-9 

233 

262.3 

I  20 .  1 

39 

43-9 

20 . 4 

104 

117. 1 

52-9 

169 

190.3 

86.4 

234 

263.4 

120.  7 

40 

45 -0 

20 . 9 

los 

118. 2 

53-S 

170 

191.4 

86.9 

235 

264  6 

121.2 

41 

46.  2 

21.4 

106 

I  1 9  ■  3 

54-0 

I  7  I 

192.5 

87-4 

236 

265.7 

121.7 

42 

47-3 

21.9 

107 

120.  5 

54-5 

172 

193 -6 

87-9 

237 

266.8 

122.3 

43 

48.4 

22.4 

108 

121.6 

55-0 

173 

194.8 

88.5 

238 

268.0 

122.8 

44 

49-5 

22.9 

109 

122.7 

55-5 

174 

195-9 

89.0 

239 

269. 1 

123-4 

45 

50.7 

23-4 

no 

123.8 

56-0 

175 

197.0 

89.5 

240 

270.  2 

123-9 

46 

51.8 

23.9 

1 1 1 

125.0 

56-5 

176 

198.1 

90.0 

241 

271.3 

124-4 

47 

52.9 

24.4 

112 

I  26.  I 

S7-0 

177 

199-3 

90 -5 

242 

272. 5 

125.0 

48 

54 -o 

24.9 

113 

127.2 

57-5 

178 

200.  4 

91.1 

243 

273-6 

125-5 

49 

55-2 

254 

114 

128.3 

58.0 

179 

201  .  5 

91  . 6 

244 

274-7 

1  26.0 

50 

56.3 

25.9 

115 

I  29.  6 

58-6 

180 

202.6 

92.1 

24s 

275.8 

126.6 

SI 

57-4 

26.4 

116 

130.6 

59-  I 

181 

203.8 

92.6 

246 

277.0 

127. I 

52 

58.5 

26.9 

117 

131-7 

59-6 

182 

204.9 

93-1 

247 

278.1 

127.6 

53 

59-7 

27.4 

118 

132.8 

60.  I 

183 

206.0 

93-7 

248 

279-2 

128. 1 

54 

60.8 

27.9 

119 

I34-0 

60.6 

184 

207 .  I 

94-2 

249 

280.3 

128.7 

55 

61  .9 

28.4 

120 

I35-I 

61.1 

185 

208.3 

94-7 

250 

281.5 

1  29.  2 

S6 

63.0 

28.8 

121 

136.  2 

61.6 

186 

209.4 

95-2 

251 

282.6 

129.7 

57 

64.  2 

29 -3 

I  22 

137-4 

62.1 

187 

210.5 

95-7 

252 

283-7 

130.3 

S8 

65.3 

29.8 

123 

138.5 

62.6 

188 

211  .7 

96-3 

253 

284-8 

130.8. 

59 

66.4 

30.3 

124 

139-6 

63-1 

189 

212.8 

96.8 

254 

286.0 

131.4 

60 

67.6 

30.8 

125 

140.7 

63-7 

190 

213-9 

97-3 

255 

287.1 

131. 9 

61 

68.7 

31-3 

126 

141.9 

64-  2 

191 

2 1  5  -  0 

97-8 

256 

288.2 

132.4 

62 

69.8 

31.8 

127 

143-0 

64.7 

192 

216.2 

98-4 

257 

289-3 

133-0 

63 

70.9 

32.3 

128 

144.1 

65.2 

193 

217-3 

98-9 

258 

290 .  5 

133-5 

64 

72.1 

32.8 

129 

145-2 

65-7 

194 

218.4 

99-4 

259 

291  .  6 

134-1 

6S 

73-2 

3i-3 

130 

146.4 

66.2 

195 

2195 

100.0 

260 

292.7 

134.6- 

66 

74-3 

33.8 

13  t 

147-5 

66.7 

196 

220.  7 

100. 5 

261 

293.8 

I3S-I 

67 

75.4 

34-3 

132 

148.6 

67.2 

197 

221.8 

101  .0 

262 

295.0 

135.7 

68 

76.6 

34-8 

133 

149-7 

67.7 

198 

222.9 

lor .  5 

263 

296.  1 

136.2 

69 

77-7 

35-3 

134 

150.9 

68.2 

199 

224.0 

102.0 

264 

297  -  2 

136.8 

70 

78.8 

35-8 

135 

152.0 

68.8 

200 

225.2 

102.6 

265 

298.3 

137.3 

71 

79-9 

36.3 

136 

IS3-I 

69-3 

201 

226.3 

103. 1 

266 

299-5 

137-a 

72 

81. I 

36.8 

137 

154-2 

69.8 

202 

227.4 

103-7 

267 

300 . 6 

138-4 

73 

82.2 

37-3 

138 

iSS-4 

70.3 

203 

228.5 

104.  2 

268 

301  .7 

13*^9 

74 

83.3 

37.8 

139 

156-S 

70.8 

204 

229.7 

104-7 

269 

302.8 

139.S 

75 

84.4 

38.3 

140 

157-6 

71.3 

205 

230.8 

105.3 

270 

304.0 

1 40,'.  0 

*  U.  S.  Dept.  of  Agric.  Bur.  of  Chem..  Bui.  65.9    i43 


6.0 


FOOD   INSPECTION   AND   ANALYSIS. 


ALLIHN'S  TABLE  FOR  THE  DETERMINATIOX  OF  DEXTROSE— (Con/mMC(f). 

MilU- 

Milli- 

MiUi- 

Milli- 

Milli- 

Milli- 

Milli- 

MiUi- 

Milli- 

MilU- 

Milli- 

Milli- 

grams 

grams 

grams 

'  grams 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

grams 

of 

of  Cu- 

of 

of 

of  Cu- 

of 

of 

of  Cu- 

of 

of 

of  Cu- 

of 

Cop- 

prous 
Oxide. 

Dex- 

Cop- 

prous 
Oxide. 

Dex- 

Cop- 

prous 
Oxide. 

Dex- 

Cop- 

prous 

Dex- 

per. 

trose. 

per. 

trose. 

per. 

trose. 

per. 

Oxide. 

trose. 

a7i 

30s   I 

140.6 

321 

361  .4 

168. 1 

371 

417-7 

196.3 

421 

474.0 

225.1 

a?* 

306.  2 

141-1 

322 

362.5 

168.6 

373 

418.8 

196.8 

422 

475-6 

225.7 

373 

307.3 

I4I-7 

333 

363 -7 

169.  2 

373 

420.  0 

197-4 

423 

476.2 

226.3 

31* 

308.  S 

143.3 

334 

364 -8 

169-7 

374 

421  .  I 

198.0 

424 

477-4 

226.9 

37S 

309.6 

143.8 

335 

3659 

170.3 

375 

422.  2 

198.6 

42s 

478. 5 

227.5 

276 

310.7 

143 -3 

326 

367-0 

170.9 

376 

4233 

199. 1 

426 

479.6 

228.0 

277 

3>>-9 

143-9 

337 

368.2 

171. 4 

377 

424.5 

199.7 

427 

480.7 

228.0 

278 

3130 

144-4 

328 

369 -3 

172.0 

.^78 

425-6 

200.3 

428 

481.9 

229.  2 

279 

3141 

14S-0 

329 

370-4 

172.5 

379 

426.7 

200. 8 

429 

483.0 

229.8 

2S0 

315-2 

I4S-5 

330 

371-5 

173-t 

380 

427.8 

201 .4 

430 

484.1 

230.4 

281 

316.4 

146.1 

331 

372.7 

173-7 

381 

429.0 

202.0 

431 

485.3 

231  .0 

282 

317-5 

146.6 

332 

373-8 

174-2 

382 

430  •  I 

202.  5 

432 

486.4 

231  .6 

283 

318.6 

147-3 

3i3 

374-9 

174-8 

383 

431-2 

203. 1 

433 

487.5 

232.2 

284 

3>9-7 

147-7 

334 

376.0 

175-3 

384 

432.3 

203.7 

434 

488.6 

232.8 

385 

330.9 

148.3 

335 

377.2 

I7S-9 

385 

433.5 

204.3 

435 

489.7 

233.4 

386 

322.0 

148.8 

336 

378.3 

176. 5 

386 

434.6 

204.8 

436 

490.9 

2339 

287 

3J51 

149-4 

337 

379-4 

177.0 

387 

435.7 

205.4 

437 

492.0 

234.5 

2S8 

324.3 

149.9 

338 

380.5 

177-6 

388 

436.8 

206.0 

438 

493.1 

235-1 

289 

325-4 

150.5 

i       339 

381.7 

178.1 

389 

438.0 

206.  5 

439 

494.3 

235-7 

290 

326.5 

151 .0 

340 

382.8 

178.7 

390 

439.1 

207 .  I 

440 

495.4 

236.3 

291 

327.4 

151-6 

341 

383 -9 

179-3 

391 

440.2 

207.7 

441 

496.5 

236.9 

292 

338.7 

152. I 

342 

385-0 

179-8 

392 

441  .3 

208.3 

442 

497.6 

237.5 

393 

329-9 

152-7 

i      343 

386.2 

180.4 

393 

442.4 

208.8 

443 

498.8 

238.1 

294 

331  -0 

IS3-2 

1      344 

387.3 

180.9 

394 

443.6 

209.4 

444 

499.9 

238.7 

395 

333.1 

153-8 

1      345 

388.4 

181.5 

395 

444.7 

210.0 

445 

501.0 

239.3 

396 

333-3 

IS4-3 

346 

389 -6 

182.1 

396 

445.9 

210.6 

446 

502.  I 

239.8 

297 

334-4 

154-9 

347 

390.7 

182.6 

397 

447.0 

211.2 

447 

503.2 

240.4 

298 

335-5 

155-4 

348 

391.8 

183.2 

398 

448.1 

211.7 

448 

504. 4 

241  .0 

299 

336.6 

156.0 

349 

392.9 

183.7 

399 

449.2 

212.3 

449 

505.5 

241 .6 

JOO 

337.8 

156. J 

350 

394-0 

184.3 

400 

450.3 

212.9 

450 

506.6 

242 .  2 

301 

338.9 

157-I 

351 

395-2 

184-9 

401 

451.5 

213. 5 

451 

507.8 

242.8 

JO  2 

340.0 

157-6 

352 

396.3 

185.4 

402 

452.6 

214.  1 

45  2 

508.9 

243.4 

30 -i 

341 -I 

158.2 

353 

397-4 

186.0 

403 

453-7 

214.  6 

453 

510.0 

244.0 

304 

343.3 

158.7 

354 

398.6 

186.6 

404 

454-8 

215.2 

454 

511.1 

244 . 6 

30s 

343-4 

159-3 

355 

399-7 

187.2 

405 

456.0 

215-8 

455 

512.3 

245.2 

306 

344-5 

159-8 

356 

400.8 

187.7 

406 

457  .1 

216.4 

456 

513. 4 

245.7 

107 

345.6 

160.4 

337 

401  .9 

188.3 

407 

458.2 

217  .0 

457 

514.5 

246.3 

3^-8 

346.8 

160.9 

358 

403-1 

188.9 

408 

459.4 

217-5 

45  8 

515.6 

246.9 

309 

347-9 

161  .5 

359 

404.2 

189.4 

409 

460 .  5 

218. I 

459 

S16.8 

247.5 

310 

349-0 

162.0 

360 

405-3 

190.0 

410 

461 .6 

218.7 

460 

517-9 

248.1 

3" 

3S0.1 

162.6 

1 

1      361 

406.4 

190.6 

411 

462.7 

219-3 

461 

519-0 

248.7 

312 

351-3 

163.1 

1      362 

407 . 6 

191  .  t 

412 

463.8 

219-9 

462 

520.  I 

249.3 

313 

353.4 

163-7 

363 

408.7 

191  .7 

413 

465.0 

220.4 

463 

521-3 

249.9 

314 

353-5 

164.  2 

364 

409.8 

192.3 

414 

466 .  I 

221.0 

31s 

3S4-6 

164.8 

365 

410.9 

193.9 

415 

467.2 

221 . 6 

316 

355-8 

165.3 

366 

412. 1 

193.4 

416 

468.4 

222.  2 

317 

356.9 

165-9 

367 

4'3-2 

194.0 

417 

469.5 

222.8 

318 

358.0 

166.4 

368 

414-3 

194.6 

4.8 

470.6 

223.3 

310 

359- I 

167.0 

369 

4'5.4 

195.  1 

419 

471.8 

223.9 

330 

360.3 

167.5 

370 

416.6 

>95.7 

420 

473.9 

324.5 

is  a  switch,. S",  and  at  either  end  of  the  hard-rubber  plate  is  a  binding 
post,  R,  for  connection  with  the  electric  current.  The  wiring,  which 
i.s  on  the  under  .side  of  the  rubber  yjlate,  is  best  illustrated  by  the  diagram 
in  Fig.  no. 

Four  determinations  may  be  carried  on  simultaneously  in  four  plat- 
inum dishes,  if  desired,  the  wiring  and  the  switches  being  so  arranged 
that  beginning  at  one  end  of  the  plate  either  the  first  dish  or  the  first 


SUGAR   AND  SACCHARINE   PRODUCTS. 


Oil 


K 


K 


Fig.  iio. — Four  Pan  Electrolytic  Apparatus,  shown  (above)  with  Glass-covered  Top 
Partially  Removed,  and  (below)  in  Diagram. 


6i2  FOOD  INSPECTION  /IND   /tN  A  LYSIS. 

two  or  the  first  three  may  be  thrown  in  or  out  of  circuit  at  will  without 
interrupting  the  current  through  the  remaining  dishes.  A  cover  with, 
wooden  sides  and  glass  top  fits  closely  over  the  whole  apparatus  as  a 
protection  from  dust,  but  may  be  easily  lifted  off  to  manipulate  the 
di^hes  when  desired.  The  sides  of  the  cover  are  perforated  to  permit 
the  escape  of  the  gas  formed  during  the  electrolysis. 

The  ordinar}'  street  current  is  used  when  available,  and  the  strength 
of  the  current  may  be  varied  within  wide  limits  by  means  of  a  number 
of  i6  or  32  candle-power  lamps,  K,  coupled  in  multiple,  and  a  rheostat, 
L,  consisting  of  a  vertical  glass  tube  sealed  at  the  bottom,  containing  a 
column  of  dilute  acid,  the  resistance  being  changed  by  var}'ing  the  lengtb 
of  the  acid  column  contained  between  the  two  platinum  terminals  immersed; 
therein,  one  of  which  is  movable.  A  gravity  battery  of  four  cells  may 
be  employed  if  the  laboraton,-  is  not  equipped  with  electric  lights. 

In  using  this  apparatus  for  determining  copper,  as  in  sugar  w^ork,. 
the  plating  process  should  go  on  till  all  the  copper  is  deposited,  requiring 
several  hours  or  over  night  with  a  current  strength  of  about  0.25  ampere.. 
Before  stopping  the  process,  the  absence  of  copper  in  the  solution  should 
be  proved  by  removing  a  few  drops  with  a  pipette,  adding  first  ammonia, 
then  acetic  acid,  and  testing  with  ferrocyanide  of  potassium.  If  no 
brown  coloration  is  produced,  all  the  copper  has  been  plated  out.  Throw 
the  dish  out  of  circuit  by  means  of  the  switch,  pour  out  the  acid  solution 
quickly  before  it  has  a  chance  to  dissolve  any  of  the  copper,  wash  the 
dish  first  with  water  and  then  with  alcohol,  dry,  and  weigh. 

The  copper  may  be  removed  from  the  jjlatinum  dish  by  strong  nitric 
acid. 

Determination  of  Sucrose  by  Fehling's  Solution.* — If  a  polariscope  is 
not  available,  cane  sugar  can  be  determined  as  follows:  First  determine  the 
percentage  of  invert  sugar  present  in  the  sample  by  one  of  the  Fehling 
methods  already  described.  Then  dissolve  i  gram  of  the  sugar  in  about 
1CX3  cc.  of  water  in  a  500-cc.  graduated  flask,  add  3  cc.  of  concentrated 
hydrochloric  acid  and  invert  by  heating  in  water  to  68°  and  cooling  in  the 
regular  manner.  Neutrali/x-  with  sodium  hydroxide  or  sodium  carbonate, 
and  make  up  to  the  mark  with  water.  Determine  the  j)er  cent  of  total 
reducing  sugar  as  invert  sugar  either  by  the  volumetric  or  gravimetric 
Fehling  procc-ss.  Subtract  the  invert  sugar  found  present  in  the  sugar  by 
direct  determination   from  the  total  found  present  after  inversion,  and 


*  Tucker,  Manual  of  Sugar  Analysis,  p.  182. 


SUGAR  AND  SACCHARINE   PRODUCTS.  61.3 

the  remainder  Is  the  invert  sugar  due  to  cane  sugar.     This  figure  multi- 
plied by  0.95  gives  the  j)ercentage  of  cane  sugar. 

For  the  determination  of  sucrose  by  the  gravimetric  Fehling  process  on 
the  inverted  sample,  multiply  the  cupric  oxide  (CuO)  by  the  factor  0.4307, 
or  the  copper  (Cu)  by  the  factor  0.5394. 


ANALYSIS    OF    MOLASSES    AND    SYRUPS. 

First  insure  a  perfectly  homogeneous  samj)le  by  stirring  with  a  rod 
to  evenly  distribute  any  separated  sugar. 

Determination  of  Total  Solids.— (i)  Asbestos  Method. — Weigh  2c 
grams  into  a  loo-cc.  graduated  tlask,  dissolve  in  v\'ater,  and  make  up  to 
the  mark.  Insure  a  uniform  solution  by  shaking.  Measure  10  cc.  of 
this  solution  into  a  tared  platinum  dish  containing  about  5  grams  of 
freshly  ignited,  finely  divided  asbestos  fiber,  and  dry  to  constant  ^veight 
at  70°  in  vacuo,  or  in  a  McGill  oven  (see  p.  586). 

(2)  Sand  Method.'^ — Place  about  15  grams  of  ignited  quartz  sand  and 
a  stirring  rod  in  a  flat-bottom  metal  dish  and  weigh.  Add  2  to  4  grams 
of  the  material  and  sufficient  moisture  to  permit  thorough  mixing.  Dry 
on  a  water  bath  with  stirring  and  finally  in  a  water  oven  until  the  loss  in 
weight  in  one  hour  is  not  more  than  3  mg.  At  least  8  hours'  heating  is 
usually  required. 

(3)  By  Calculation  from  Refractive  Index. — Determine  the  refractive 
index  by  means  of  the  Abbe  refractometer  (p.  108),  and  calculate  the 
total  solids,  using  Geerligs's  tables  (p.  615). 

This  method  is  more  accurate  and  convenient  than  the  specific  gravity 
method  and  employs  a  smaller  quantity  of  material.  The  investigations 
of  StoUef  and  of  Tolman  and  Smith|  have  shown  that  sucrose,  maltose, 
dextrose,  levulose  and  lactose  all  have  practically  the  same  refractive  index. 
Dextrin  has  a  somewhat  higher  refractive  index,  nevertheless  the  solids 
of  commercial  glucose  do  not  give  a  reading  appreciably  higher  than 
the  sugars  named. 

A.  H.  Bryan, §  has  compared  this  method  with  the  method  of  drying 
at  70°  in  vacuo,  with  the  following  results: 

*  v.  S.  Dept.  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  65. 
t  Zeits.  deutsch.  Zucker-Ind.,  1901,  pp.  335,  469.  • 
X  Jour.  Am.  Chem.  Soc,  28,  1906   p.  1476. 
§  Ibid.,  30,  1908,  p.  1443- 


DilTerence  compared 
with  the  Gravimetric  Method. 

—  I 

34  to 

+0 

72 

—  O 

-79  " 

+0 

.62 

—  I 

-53  " 

+0 

•59 

—  I 

•83  " 

— 0 

.07 

—  2 

•52  " 

+0 

.91 

—  O 

■27  " 

+0 

.27 

614  FOOD  INSPECTION  AND  ANALYSIS. 

Material.  Number  of 

Samples. 

Maple  syrup 13 

Cane  table  syruj) 10 

Cane  molasses 17 

Beet  molasses 15 

Honey 24 

Glucose 2 

(4)  B\  Calculation  from  Specific  Gravity. — Weigh  25  grams  of  the 
sample  into  a  loo-cc.  graduated  tlask,  dissolve  in  water,  and  make  up 

20° 
to  the  mark.     Determine  the  specific  gravity,  at  —5  C,  of  the  diluted 

-+ 
solution  by  means  of  a  pycnometcr  or  accurate  hydrometer.    Ascertain 

from  the  table  on  pp.  617  and  618  the  percentage  by  weight  of  solids 

(sugar)  corresponding  to  the  specific  gravity  of  the  diluted  solution,  and 

calculate  the  total  solids  in  the  original  sample  by  the  formula 

Solids  in  original  sample  =  4/^5, 

D  being  the  specific  gravity  of  the  diluted  solution  and  S  the  per  cent 

of  solids  in  the  diluted  solution. 

The  solids  may  also  be  obtained  directly  by  means  of  the  saccha- 
rometer,  also  known  as  the  Bri.x  spindle.  This  instrument  is  a  hydrometer 
graduated  so  as  to  show  the  per  cent  of  sugar  when  the  temperature  of 
the  liquid  is  20°  C. 

If  the  specific  gravity  or  saccharometer  reading  is  taken  at  any  other 
temperature  than  20°  C.  the  necessary  correction  may  be  found  in  the 
table  on  y)age  6iq. 

Determination  of  Ash. — Weigh  from  5  to  10  grams  of  the  sample 
into  a  tared  platinum  dish,  evaporate  to  dryness  on  the  water-bath,  and 
proceed  as  directed  for  ash  of  sugar  (p.  586). 

Polarization  and  Determination  of  Sucrose. — Molasses  and  golden 
syrup  require  the  application  of  clarifying  reagents  before  a  sufficiently 
clear  solution  can  be  obtained  for  reading  on  the  polariscope.  Even 
then  it  is  not  possible  nor  is  it  necessary  to  get  a  water-white  solution,  so 
that  in  this  class  of  products  greater  accuracy  can  usually  be  attained  by 
polarizing  in  a  loo-mm.  tube  (half  the  standard  length)  and  multiplying 
the  reading  by  2.  7'he  clarifier  best  adapted  as  a  rule  for  molasses  and 
golden  syrup  is  lead  subacetate  either  in  solution  (p.  586)  or,  as  first 
proposed  by  Home,*  as  the  anhydrous  salt. 

*  Jour.  Am.  Chem.  Soc,  26,  1904,  p.  186. 

/ 


SUGAR   AND   SACCHARINE    PRODUCTS. 


615 


GEERLIGS'S  TABLE   FOR   DRY  SUBSTANCE    IN  SUGAR-HOUSE   PRODUCTS 
BY   THE   ABBE    REFRACTOMETER,    AT    28°  C* 


Per 

Per 

Refrac- 

Cent 

Decimals  to  be  Added  for 

Refrac- 

Cent 

Decinials  to  be  Added  for 

tive 

Dry 

Fractional  Readings. t 

tive 

?^y 

Fractional  Readings,  t 

Index. 

Sub- 
stance. 

Index. 

Sub- 
stance. 

1-3335 

1 

0.0001=0.05 

0.0010  =  0.75 

1.4083 

45 

0.0004  =  0.2 

0.0015  =  0.75 

1-3349 

2 

0.0002  =  0.1 

0.0011  =  0.8 

1.4104 

46 

0.0005  =  0.25 

0.0016  =  0.8 

1-3364 

3 

0 .  0003  =  0.2 

0.0012  =  0.8 

I. 4124 

47 

0.0006  =  0.3 

0.0017  =  0.85 

1-3379 

4 

0.0004  =  0.23 

0.0013  =  0.85 

I. 4145 

48 

0.0007  =  0.35 

0.0018  =  0.9 

1-3394 

5 

0.0005  =  0.3 

0.0014  =  0.9 

I. 4166 

49 

0 .  0008  =  0.4 

0.0019=0.95 

1.3409 

6 

0 .  0006  =  0.4 

0.0015=1.0 

I. 4186 

50 

0.0009  =  0.45 

0.0020=  1.0 

1-3424 

7 

0.0007  =  0.5 

1.4207 

51 

0.0010  =  0.5 

0.0021  =  1.0 

1-3439 

8 

0 .  0008  =  0.6 

1.4228 

52 

0.0011=0.55 

1-3454 

9 

0 .  0009  =  0.7 

1.4219 

53 

1.3469 

10 

1.4270 

54 

1.3484 

11 

0.0001  =  0.05 

1.4292 

55 

0.0001=0.05 

0.0013  =  0.55 

1-3500 

12 

0.0002  =  0.1 

I-4314 

56 

0.0002  =  0.1 

0.0014  =  0.6 

1-3516 

13 

0 .  0003  =  0.2 

1-4337 

57 

0.0003  =  0.1 

0.0015  =  0.65 

1-3530 

14 

0.0004  =  0.25 

1-4359 

58 

0 .  0004  =  0.15 

0.0016  =  0.7 

1-3546 

15 

0.0005  =  0.3 

1.4382 

59 

0.0005  =  0.2 

0.0017  =  0.75 

T-3562 

16 

0.0006=0.4 

1-4405 

60 

0.0006  =  0.25 

0.0018  =  0.8 

1-3578 

17 

0.0007  =  0.45 

1.4428 

61 

0.0007  =  0.3 

0.0019=0.85 

1-3594 

18 

0 .  0008  =  0.5 

1.4451 

62 

0.0008  =  0.35 

0.0020=0.9 

1.3611 

19 

0.0009=0.6 

1.4474 

63 

0.0009  =  0.4 

0.0021  =  0.9 

1.3627 

20 

0.0010  =  0.65 

1-4497 

64 

0.0010  =  0.45 

0.0022  =  0.95 

1.3644 

21 

0.0011  =  0.7 

1.4520 

65 

0.0011=0.5 

0.0023=1.0 

1.3661 

22 

0.0012  =  0.75 

1-4543 

66 

0.0012  =  0.5 

0.0024=1.0 

1.3678 

23 

0.0013  =  0.8 

1-4567 

67 

1-3695 

24 

0  0014  =  0.85 

I -4591 

68 

1. 3712 

25 

0.0015  =  0.9 

1.4615 

69 

1-3729 

26 

0.0016  =  0.95 

1.4639 
1-4663 
1.4687 

70 

71 
72 

1-3746 
1-3764 

27 
28 

0.0001=0.05 

0.0012  =  0.6 
0.0013  =  0.65 

0.0002^  0.1 

1.3782 

29 

0.0003  =  0.15 

0.0014  =  0.7 

1. 47" 

73 

0.0001  =  0.0 

0.0015  =  0.55 

1.3800 

30 

0.0004  =  0.2 

0.0015  =  0.75 

1-4736 

74 

0.0002  =  0.05 

0.0016  =  0.6 

1.3818 

31 

0.0005  =  0.25 

0.0016  =  0.8 

1.4761 

75 

0.0003  =  0.1 

0.0017  =  0.65 

1-3836 

32 

0 .  0006  =  0.3 

0.0017  =  0.85 

1.4786 

76 

0.0004  =  0.15 

0.0018  =  0.65 

1-3854 

a 

0.0007  =  0.35 

0.0018  =  0.9 

1.4811 

77 

0.0005  =  0.2 

0.0019  =  0.7 

1.3872 

34 

0 .  0008  =  0.45 

0.0019=0.95 

1.4836 

78 

0 .  0006  =  0.2 

0.0020=0.75 

1.3890 

35 

0.0009  =  0.4 

0.0020=1.0 

1.4862 

79 

0.0007  =  0.25 

0.0021  =  0.8 

1-3909 

36 

0.0010  =  0.5 

0.0021=  1.0 

1.4888 

80 

0.0008  =  0.3 

0.0022  =  0.8 

1.3928 

37 

0.0011  =  0.55 

1.4914 

8i 

0.0009  =  0.35 

0.0023  =  0.85 

1-3947 

38 

1.4940 

82 

0.0010  =  0.35 

0.0024  =  0.9 

1.3966 

39 

1.4966 

83 

0.0011  =  0.4 

0.0025  =  0.9 

1.3984 

40 

1.4992 

84 

0.0012  =  0.45 

0.0026=0.95 

1.4003 

41 

1.5019 

85 

0.0013  =  0.5 

0.0027=  1.0 

1 . 5046 

86 

0  0014  =  0.5 

0.0028=1.0 

1-5073 

87 

1.4023 

42 

0.0001  =  0.05 

0.0012  =  0.6 

1.5100 

88 

1-4043 

43 

0.0002  =  0.1 

0.0013  =  0.65 

1.5127 

89 

1.4063 

44 

0.0003  =  0.15 

0.0014  =  0.7 

I   1-5155 

90 

*  Intern.  Sugar  Jour.,  10,  pp.  69-70. 

t  Find  in  the  table  the  refractive  index  which  is  ne.^t  lower  than  the  reading  actually  made 
and  note  the  corresponding  whole  number  for  the  per  cent  of  dry  substance.  Subtract  the  refractive 
index  obtained  from  the  table  from  the  observed  reading;  the  decimal  corresponding  to  this 
difference,  as  given  in  the  column  so  marked,  is  added  to  the  whole  per  cent  of  dry  substance  as 
first  obtained. 


6i5 


FOOD  INSPECTION  ^\D  ANALYSIS. 


TEMP.: "MATURE   CORRECTIONS   FOR    USE   WITH    CEERLIGS'S   TABLE. 
Tempera- 


Drv  Substance. 


ture  of  the 
Prisms  in 

0  1 

5 

10 

15    1 

20 

25    1    30    i    40    1 

50 

60 

70    1 

80 

90 

°C. 

Subtract — 

20 

o-.Vi 

3-54 

0-55 

0.56 

0-57 

0.58 

0.60 

0.62 

0.64 

0.62 

0.61 

3.  60 

0.58 

21 

.46 

■47 

.48 

■49 

-50 

-51 

-52 

-54 

.50 

-54 

•53 

•52 

-50 

22 

-40 

-41 

.42 

-42 

-43 

■  44 

-45 

-47 

.48 

-47 

.40 

•45 

-44 

33 

^?,^ 

•?>?> 

-.S4 

-3.S 

.30 

-37 

-38 

■39 

.40 

-39 

•.S8 

-38 

-38 

24 

.26 

.26 

-27 

.28 

.28 

•29 

-30 

-31 

•32 

•31 

•31 

-30 

-30 

^5 

.20 

.20 

.21 

.21 

.22 

.22 

-23 

-23 

-24 

-23 

-23 

•23 

.22 

26 

.12 

.12 

-13 

-14 

-14 

-15 

-15 

.16 

.16 

.16 

-15 

-IS 

.14 

27 

-07 

.07 

-07 

.07 

.07 

.07 

.08 

.08 

.08 

.08 

.08 

.08 

.07 

Add— 

29 

0.07 

0.07 

0.07 

0.07 

0.07 

0.07 

0.08 

o.o8 

0.08 

0.08 

0.08 

0.08 

0.07 

30 

.12 

.12 

-13 

.14 

.14 

-14 

-15 

■15 

.16 

.16 

.16 

-15 

■14 

31 

.20 

.20 

.21 

.21 

.22 

.22 

•23 

-23 

-24 

-23 

•23 

-23 

.22 

32 

.26 

.26 

■27 

.28 

.28 

-29 

-30 

■31 

-32 

•31 

■31 

-,30 

-30 

33 

■u 

-?,?, 

-34 

-35 

.3b 

-37 

.38 

■39 

.40 

-39 

•38 

-38 

•38 

34 

.40 

-41 

-42 

-42 

•43 

.44 

--I5 

-47 

-48 

-47 

-4ft 

-45 

■  44 

35 

-4b 

■47 

.48 

-49 

-50 

-51 

-52 

-54 

.5<5 

-54 

-53 

-52 

.50 

The  Process. — The  normal  weight,  26  grams,  of  the  molasses  or  S)Tup 
is  dissolved  in  water  in  a  loo-cc.  flask,  and  in  the  case  of  molasses  and 
"golden."  or  "drip"  syrup,  sufficient  subacetate  of  lead  solution  is  added 
to  precipitate  the  coloring  matter.  P>om  5  to  10  cc.  of  the  clarifier 
usually  suffice.  The  flask  is  then  filled  to  the  mark  with  water  and  the 
contents  shaken  thoroughly  and  filtered.  If  on  account  of  air  bubbles 
it  is  difficult  to  make  up  to  the  mark,  the  bubbles  may  usually  be  dis- 
pelled by  a  drop  of  ether.  With  maple  syrup  no  clarifier  is,  as  a  rule, 
necessar}',  though  sometimes  alumina  cream  is  helpful.  With  a  very 
dark-colored  molasses  20  to  30  cc.  of  lead  subacetate  are  required  for 
clarification  and  in  extreme  cases  (though  rarely  with  the  grades  of  molas.ses 
u.'icd  as  food)  it  is  necessary,  after  the  ordinary  filtration,  to  pa.ss  through 
from  5  to  6  grams  of  powdered,  dried  bone  charcoal.* 

.An  excess  of  subacetate  of  lead  .should  be  avoided  on  account  of  the 
fKjssibilitv  of  the  filtrate  becoming  turbid  through  the  formation  of  lead 
carbonate  by  exposure  to  the  air.  A  drop  of  acetic  acid  will  nearly  always 
clear  the  .solution,  if  the  turbidity  is  due  to  carbonate.  If  cloudiness  in 
the  filtrate  persists,  weigh  out  a  fresh  portion  of  the  sample,  dilute,  and 
add  first  the  lead  subacetate  solution,  and  afterwards  enough  of  a  strong 
solution  of  sodium  sulphate  or  common  salt  to  i)recipitate  the  excess  of 
lead;  then  fill  to  the  mark  and  filter.  Polarize,  and  conduct  the  inver- 
sion as  directed  on  p.  588,  using,  however,  a  loo-mm.  tube,  and  multi- 

*  The  treatment  with  Ixjne  char  should  be  used  only  as  a  last  resort,  as,  on  account  of 
slight  aJ>sfjrption  of  sugar,  observed  readings  arc  from  0.4°  to  to  0.5°  too  low. 


SUG/1R   AND  SACCHARINE  PRODUCTS. 


617 


DKNSITV    OF    SOLUTIONS    OF    CAN'E    SL'flAR    AT 


C  !3 

■J  3 

Tenths  of  Per  Cent. 

0 

I 

2 

3 

4 

S 

6 

7 

8 

9 

0 

0.9982 

0 . 9986 

0 . 9990 

0.9994 

0. 9998 

I .0002 

I .0006 

I .0010 

I .0013 

I .001 7 

I 

I .002  I 

I .0025 

I .0029 

I -0033 

I  .0037 

I .0041 

I .0045 

I .0048 

I .0052 

1 .0056 

2 

I .0060 

I .0064 

I  .0068 

I .0072 

I .0076 

I .0080 

I .0084 

I .0088 

I .0091 

I .0095 

3 

I .0099 

I .0103 

I .0107 

1 .01 1 1 

I .01 15 

I .0119 

I .0123 

I .0127 

I .0131 

1-0135 

4 

1  .0139 

I. 0143 

1-0147 

I .0151 

I  O'SS 

I .0159 

I .0163 

I .0167 

I .01 7  I 

10175 

5 

I .0179 

I. 0183 

I .0187 

I .0191 

I. 0195 

T .0199 

I .0203 

I .0207 

I .02  1 1 

I .021 5 

6 

I  .02  19 

I .0223 

I .0227 

I .0231 

I-0235 

1.0239 

I .0243 

I .0247 

I .0251 

1.0255 

7 

I .0259 

I .0263 

I .0267 

I .0271 

I -0276 

I .0279 

1.0283 

I .0287 

I .0291 

I .0295 

8 

I .0299 

1.0303 

I .0308 

1 .03 1 2 

I  -0316 

I .0320 

I .0324 

1-0328 

I -0332 

I  0336 

9 

I .0340 

1.0344 

I -0349 

> -0353 

I  -0357 

I .0361 

I .0365 

1.0369 

1 -0373 

1-0377 

10 

I .0381 

1.0386 

I .0390 

1-0394 

r .0398 

I .0402 

I .0406 

I .0410 

I .0415 

I .0419 

1 1 

I .0423 

1.0427 

I .0431 

I -043s 

1.0440 

I .0444 

1 .0448 

I .0452 

1-0/456 

1 .0460 

12 

I .0465 

I .0469 

r -0473 

I -0477 

I .0481 

1.0486 

I .0490 

I .0494 

I .0498 

1 .0502 

'3 

I  .0507 

I .0511 

I -0515 

1 .0519 

1.0524 

I .0528 

'  0532 

'-0536 

I .0540 

I  -0545 

M 

I .0549 

I.OS53 

1.0558 

1 .0562 

I .0566 

I .0570 

I-OS7S 

I -0579 

1-0583 

1-0587 

rs 

1.0592 

1.0596 

r .0600 

I -0605 

I  .0609 

I .061 3 

I .061  7 

I .0622 

I .0626 

1.0630 

16 

1.0635 

1.0639 

r .0643 

I .0648 

I  .0652 

I .o6s6 

I .0661 

I .0665 

I .0669 

1.0674 

17 

1.0678 

1.0682 

I .0687 

I .0691 

1.069s 

I .0700 

I .0704 

I .0708 

1.0713 

1-0717 

18 

I .072  I 

I .0726 

I .0730 

I  0735 

1-0739 

I -0743 

I .0748 

1.0752 

I-0757 

I .0761 

19 

1.0765 

1.0770 

I .0774 

I  .0779 

1.0783 

1.0787 

I .0792 

I .0796 

1 .0801 

I .0805 

20 

I .0810 

I .0814 

r .0818 

1.0823 

1.0827 

1.0832 

I .0836 

1. 0841 

1.0845 

I .0850 

21 

I .0854 

I .0859 

I .0863 

1.0868 

I .0872 

1.0877 

I .0881 

I .088s 

I .0890 

1.0894 

22 

I .0899 

I .0904 

I .0908 

I .0913 

I .0917 

I  .0922 

I .0926 

I .0931 

I -0935 

I .0940 

23 

I .0944 

1.0949 

'  0953 

r .0958 

I .0962 

I  .0967 

I .0971 

I .0976 

I .0981 

1-0985 

24 

I .0990 

I .0994 

I  .0999 

I . 1003 

I . looS 

I . 1013 

I . lOI 7 

I . 1022 

I . 1026 

1  -  1031 

25 

I  . 1036 

r . 1040 

r .1045 

I .1049 

1-1054 

I. 1059 

I .1063 

I .1068 

I . 1072 

I .1077 

26 

I . 1082 

I .1086 

I .1091 

I . 1096 

1 .  1 100 

I . I los 

I  .  1 1 10 

I . 1 1 14 

I  .  I  I  I  9 

I . 1124 

27 

I  .1128 

I-II33 

1.1138 

I . 1 142 

1.1147 

1.1152 

I .1156 

I . 1161 

I . 1166 

I . 1 1  70 

28 

I.II75 

I. 1 1 80 

1.118s 

I. 1 1 89 

r . 1194 

1. 1 1 99 

I . 1203 

I .1208 

I .1213 

1  .1218 

29 

I  .1222 

I  .  1227 

I. 1232 

I  -1237 

1.1241 

I . 1246 

I .1251 

I .1256 

I . 1260 

I  -  1265 

30 

I  .  1270 

I. 1275 

I .1279 

r .1284 

r.1289 

I .1294 

I. 1299 

1-1303 

I. 1308 

I  •  1313 

31 

1.1318 

1-1323 

1-1327 

I  ■  1332 

I-1337 

I .1342 

I .1347 

1-1351 

11356 

I . 1361 

32 

1. 1366 

1-1371 

I .1376 

I  .1380 

1.1385 

I. 1390 

I -1395 

I . 1400 

1.140s 

I . 1410 

33 

1-1415 

1-1419 

I . 1424 

I .1429 

1-1434 

I. 1439 

I. 1444 

I -1449 

1-1454 

I.I4S9 

34 

1.1463 

I -1468 

I. 1473 

1-1478 

I. 1483 

I. 1488 

I -1493 

I. 1498 

1-1503 

I. I  508 

3S 

1.1513 

r.1518 

1-1523 

I-1528 

I-I533 

I. 1538 

I .1542 

I-1547 

1-1552 

I-1557 

36 

I  .  1562 

1-1567 

1-1572 

1-1577 

1-1582 

I. 1587 

1. 1  592 

I -1597 

I . 1602 

1 . 1607 

37 

I . 1612 

I  .  1617 

I . 1622 

I . 1627 

I .1632 

1-1637 

I .1643 

I .1648 

1-1653 

1.1658 

38 

I. 1663 

I. 1668 

I. 1673 

I. 1678 

I. 1683 

I. 1688 

I .1693 

I .1698 

I .1703 

1 .1708 

39 

1.1713 

1. 1718 

I . 1724 

I.  1729 

I-I734 

1-1739 

I .1744 

I. 1749 

I-I754 

I-I759 

40 

I .1764 

r .1770 

I ■ 1775 

1. 1 780 

1.1785 

I. I  790 

I.I795 

I . I 800 

1.1806 

I.1811 

41 

1.1816 

I .1821 

r.1826 

1.1831 

1-1837 

I .1842 

I. 1847 

1.1852 

1.1857 

1.1863 

42 

r.i868 

1-1873 

I. 1878 

r.1883 

I. 1889 

I. 1894 

I . 1899 

1. 1 904 

1. 1 909 

I.191S 

43 

I  . 1920 

I. 1925 

I. I 930 

r .1936 

I. 1941 

I .1947 

I .1951 

I-I957 

1 . 1962 

I .1967 

44 

1. 1972 

I. 1978 

I. 1983 

I .1988 

1. 1 994 

I. 1999 

I . 2004 

I .2009 

I  -20 IS 

I  .  2020 

45 

I . 2025 

I .2031 

t . 2036 

I .2041 

I .2047 

I  .  2052 

1.2057 

I .2063 

I  .2068 

1.2073 

46 

1.2079 

I .2084 

I . 2089 

I .2095 

I  . 2  too 

I  .  2 105 

I  .  21 1 1 

I  .  2116 

1.2122 

1.2127 

47 

1.2132 

1-2138 

I -2143 

I .2149 

I .2154 

I  -2159 

I .2165 

I . 2170 

I .2176 

1 .2181 

48 

I .2186 

I .2192 

I -2197 

I .2203 

r .2208 

I  .2214 

I  .  2219 

1.2224 

I . 2230 

1.223s 

49 

I  .2241 

I .2246 

1.2252 

1.2257 

I .2263 

1.2268 

I .2274 

1.2279 

1.2285 

1 . 2290 

50 

I . 2296 

I. 2301 

I .2307 

I .2312 

I. 2318 

1-2323 

1.2329 

I -2334 

1.2340 

I-234S 

*  According  to  Dr.  F.  Plato  (Kaiserlichen  Normal-Eichungs-Kommission,  Wiss.  Abh.,  2,  1900. 
p.  153).  This  table  is  given  by  the  U.  S.  Bureau  of  Standards  (Circular  19,  pp.  12  and  13)  as  the  basis 
for  standardizing  hydrometers,  indicating  per  cent  of  sugar  at  20^.  known  as  saccharometers  or  Brix 
spindles.  The  table  is  also  useful  in  calculating  the  per  cent  of  sugar  from  the  specific  gravity  as 
•determined  by  the  pycnometer.     Temperature  corrections  are  given  on  page  619. 


(5l8 


FOOD   INSPECTION  MND  ANALYSIS. 


DENSITY    OF   SOLl'TIOXS    OF   CANE   SUGAR    AT 


C. — Continued 


Tenths  of  Per  Cent. 

p. 

0 

I 

2 

3 

4 

5 

() 

7 

8 

9 

50 

I .3390 

1 .3301 

1.2307 

1  -2312 

1.2318 

1-2323 

I  2329 

I  2334 

1.2340 

1-2345 

SI 

I23SI 

1.2356 

I  .2362 

1-2367 

1-2373 

1-2379 

1 .2384 

1.2390 

1-2395 

I  .  2401 

S3 

1 .340b 

I .2412 

1 .2418 

I .2423 

I .2429 

I  -2434 

I  .2440 

1.2446 

I .2451 

1-245/ 

S3 

I . 3463 

1 .2468 

I -3474 

I .2479 

1.2485 

I .2490 

1 . 2496 

I . 2502 

1.2507 

1-2513 

54 

I ■25'9 

I .2524 

'■2530 

1-2536 

1.2541 

1.2547 

1-2553 

1-2558 

1.2564 

I .2570 

SS 

12575 

1-2581 

1.2587 

1 .2592 

I .2598 

I . 2604 

I . 2610 

I .2615 

I .2621 

I . 2627 

St 

1.2633 

I .2638 

I .2644 

I .2650 

1-2655 

1 .2661 

I . 26O7 

I -2673 

I .2678 

I .2684 

57 

1 . 3690 

I .2696 

I .2701 

1 .2707 

I-2713 

I. 2719 

I  .2725 

I  -2730 

I  .2736 

I  .2742 

58 

1.3748 

1.2754 

I -2759 

1.2765 

I .2771 

1.2777 

1.2783 

I .2788 

I .2794 

I . 2800 

59 

1 .3806 

I .2812 

I .2818 

1.2823 

1.2829 

1-2835 

1 .2841 

I .2847 

1-2853 

I .2859 

ho 

I  .2865 

1 .2870 

1.2876 

1 .2882 

1.2888 

1.2894 

I .2900 

I . 2906 

I . 2912 

I .2918 

61 

1.3934 

1.2929 

1-2935 

I .2941 

1.2947 

1 -2953 

I -2959 

1.2965 

1-2971 

I .2977 

62 

1.3983 

I . 2989 

I -2995 

I .3001 

1.3007 

I-3013 

I -3019 

I -3025 

I -3031 

I  3037 

63 

J  3043 

1  3049 

I -3055 

I .3061 

I .3067 

1-3073 

I -3079 

I  3085 

I -3091 

1-3097 

64 

1-3103 

1. 3109 

I-3115 

I .3121 

I .3127 

1-3133 

1-3139 

I  -3145 

1-3151 

1-3157 

65 

1-3163 

1.3169 

1-3175 

1.3182 

1.3188 

1-3194 

I .3200 

1  .3206 

I .3212 

1.3218 

66 

1.3334 

I  -3230 

I -3236 

1 .3243 

I -3249 

1-3255 

I .3261 

1.3267 

1-3273 

1-3279 

67 

1.3286 

1.3292 

1.3298 

1.3304 

I-3310 

I  3316 

1-3322 

1-3329 

I-333S 

I-334I 

68 

1-3347 

1-3353 

1-3360 

1.3366 

I -3372 

i-.'!3  78 

I  3384 

I -3391 

I -3397 

1  3403 

69 

1-3409 

1.3416 

I .3422 

1.3428 

1-3434 

I  .3440 

1-3447 

I -3453 

I -3459 

1-3465 

70 

1-3472 

1-3478 

1.3484 

1 -3491 

I -3497 

1-3503 

1-3509 

1-3516 

1-3522 

1.3528 

71 

I -3535 

I-3541 

I -3547 

1-3553 

1-3560 

I  .3566 

1-3S72 

I-3S79 

I-3S85 

I-3591 

72 

1-3598 

1.3604 

I .3610 

I .3617 

I .3623 

1  .3630 

1-3636 

I  .3642 

1.3649 

1-3655 

73 

I .3661 

1.3668 

1-3674 

1.3681 

1.3687 

I -3693 

I .3700 

I .3706 

1 -3713 

I-37I9 

74 

1-3725 

1-3732 

1-3738 

1-3745 

I -3751 

I  -3757 

I  3764 

1-3770 

I  -3777 

1-3783 

75 

1-3790 

1-3796 

1-3803 

I -3809 

1.3816 

I .3822 

1.3829 

1-3835 

1.3841 

1,3848 

76 

1-3854 

1.3861 

1.3867 

1-3874 

1.3880 

1.3887 

I  3893 

I  -3900 

1-3907 

1-3913 

77 

1 -3930 

I  3926 

1-3933 

1-3939 

I  3946 

1-39S2 

1-3959 

1  -3965 

I  -3972 

I  3978 

78 

1-3985 

I -3992 

1-3998 

1 .4005 

I . 40 1 1 

I .4018 

1.4025 

1-4031 

I -4038 

I  .4044 

79 

1.4051 

1 .4058 

I .4064 

I -4071 

1.4077 

I .4084 

I .4091 

I -4097 

I .4104 

I . 41 1 1 

80 

I -4117 

1 -4124 

I .4130 

1-4137 

I .4144 

I .4150 

1-4157 

I .4164 

I .4170 

I. 4177 

81 

1.4184 

1 .4190 

I .4197 

1.4204 

I . 4210 

I .4217 

1  .4224 

I .4231 

' -4237 

I .4244 

83 

1 .4251 

' -4257 

I .4264 

1 .4271 

I .4278 

1 .4284 

I .4291 

I .4298 

1-4305 

1  -  43 1 1 

83 

1-4318 

'  4325 

1-4332 

I .4338 

I  -4.345 

I -43  52 

I -4359 

1-4365 

1-4372 

1-4379- 

84 

1.4386 

1 -4393 

1 -4399 

1.4406 

1 .4413 

I .4420 

1 .4427 

1-4433 

I .4440 

1-4447 

8s 

1-4454 

1 .4461 

1.4468 

1.4474 

I .4481 

1 .4488 

1 -449S 

1.4502 

1-4509 

I-45IS 

86 

1-4522 

I -4529 

1-4536 

1.4543 

I -4550 

I -4557 

1.4564 

1.4570 

1-4577 

I .4584 

87 

I -4591 

I .4598 

1-4605 

I .4612 

1 .4619 

I . 4626 

1-4633 

I .4640 

I . 4646 

1  4653 

88 

1 .4660 

I .4667 

1.4674 

I .4681 

I .4688 

1.469s 

1 .4702 

1.4709 

I .4716 

I -4723 

89 

1-4730 

1-4737 

1-4744 

1.4751 

1.4758 

1.4765 

1.4772 

1.4779 

1.4786 

I -4793 

90 

1.4800 

1.4807 

1.4814 

I .4821 

I .4828 

1-4835 

I .4842 

1.4849 

I . 4856 

I  4863 

91 

1.4870 

1.4877 

1.4884 

1.4891 

I . 4898 

1 -4905 

I  .4912 

I-4919 

I .4926 

I -4934 

9* 

1.4941 

1.4948 

1-495S 

1 . 4962 

1.4969 

1  4976 

1.4983 

1.4990 

1-4997 

I  -S0O1 

93 

1 .  5012 

1,5019 

1 .5026 

1 • S033 

I . 5040 

I-SO47 

1-5054 

1 .5061 

I .5069 

I -5076 

94 

1  S083 

I . 5090 

1-5097 

1-5104 

15112 

1.5119 

I .5126 

15133 

I  .5140 

I  5147 

95 

1-5155 

1 .5162 

1.5169 

1-5176 

15183 

1-5191 

1.5198 

1-5205 

I  .5212 

I  .5219 

96 

1.5227 

1.5234 

1-5241 

1-5248 

15255 

1-5263 

1-5270 

i-52ff7 

1.5284 

1.5292 

97 

I  .5299 

I ■ 5306 

1-5313 

1 -5321 

1-5328 

1  53^5 

1-5342 

I  5350 

5-.S357 

1-5364 

98 

1  5372 

1-5379 

1 . 5386 

1-5393 

1.5401 

I .5408 

I  -541S 

I  5423 

I  5430 

1-5437 

99 

1-5445 

15452 

1-5459 

1.5467 

I -5474 

1 .5481 

I -5489 

1-5496 

I-SS03 

'5511 

100 

I-55I8 

SUGAR   AND  SACCHARINE  PRODUCTS. 


619 


TEMPERATURE   CORRECTIOx\S   TO    SACCHAROMETER   READINGS 
(STANDARD  AT  20°  C.)* 


Tempera- 
ture in 
Degrees 
Centigrade. 


15.56 
(60'' F.) 


26 

27 
28 


40 
AS 
50 

ss 
60 


Observed  Per  Cent  of  Sugar. 


10         IS  20         2S         30         35     I     40         45  50  SS  60  70 


Subtract  from  Observed  Per  Cent. 


0 

30 

0 

49 

0 

65 

0 

77 

0 

«9 

0 

99 

I 

08 

I 

16 

I 

24 

. 

31 

1 

3  7 

I 

41 

I 

44 

0 

36 

0 

47 

0 

56 

0 

65 

0 

73 

0 

80 

0 

8(. 

0 

91 

0 

97 

I 

01 

I 

05 

1 

08 

I 

10 

0 

12 

0 

18 

0 

43 

0 

48 

0 

52 

0 

S7 

0 

60 

0 

04 

0 

67 

0 

70 

0 

72 

0 

74 

0 

7  5 

0 

11 

0 

IS 

0 

40 

0 

44 

0 

48 

0 

5' 

0 

55 

0 

58 

0 

00 

0 

03 

0 

6t 

0 

66 

0 

68 

0 

29 

0 

32 

0 

3  b 

0 

40 

0 

43 

0 

40 

0 

50 

0 

52 

0 

54 

0 

50 

0 

58 

0 

59 

0 

60 

0 

26 

0 

29 

0 

32 

0 

35 

0 

38 

0 

41 

0 

44 

0 

46 

0 

48 

0 

49 

0 

51 

0 

52 

0 

53 

0 

24 

0 

2C. 

0 

29 

0 

31 

p 

34 

0 

3C 

0 

3« 

0 

40 

0 

41 

0 

42 

0 

44 

0 

45 

0 

46 

0 

20 

0 

22 

0 

24 

0 

26 

0 

28 

0 

30 

0 

32 

0 

M 

0 

34 

0 

36 

0 

3t 

0 

3  7 

0 

38 

0 

17 

0 

18 

0 

20 

0 

22 

0 

23 

0 

25 

0 

2b 

0 

27 

0 

28 

0 

28 

0 

29 

0 

30 

0 

31 

0 

11 

0 

14 

0 

I  S 

0 

16 

0 

18 

0 

19 

0 

20 

0 

20 

0 

21 

0 

21 

0 

2: 

0 

23 

0 

23 

0 

oq 

0 

10 

0 

10 

0 

1 1 

0 

I  2 

0 

13 

0 

13 

0 

M 

0 

14 

0 

14 

0 

I  c 

0 

>5 

0 

15 

0 

OS 

0 

05 

0 

05 

0 

06 

0 

o() 

0 

06 

0 

07 

0 

07 

0 

07 

0 

07 

0 

oi- 

0 

c« 

0 

08 

0 

I  I 

0 

I  2 

0 

12 

0 

14 

0 

I  5 

0 

16 

0 

Tft 

0 

I  7 

0 

I  7 

0 

18 

0 

li 

0 

19 

0 

19 

0 

18 

0 

2C 

0 

22 

0 

24 

0 

2( 

0 

28 

c 

29 

0 

3C 

0 

30 

0 

3: 

0 

^i 

0 

^?, 

0 

34 

Add  to  Observed  Per  Cent. 


o .  46 
o-  54 
0.61 

o .  99 

1 .4-' 

1 .91 

2  .  4(5 
30 

3  ■<>9 
O.4.- 


1-45 
1  .94 
2.48 
307 
3  •  72 
0.44 


0.23 
0.3c 

o.3f 
o .  42 
o.  45 
o.5f 
0.63 

I  .02 

I  .4 

I  .  96 

2.50 

3    09 

3  -73 

o.4( 


0.17 
o .  24 
0-3I 


0-51 
O.S9 
0.66 

I  .06 

1  -51 

2  .  00 
2.53 
312 
3-73 
0.48 


0.06 
0.12 
o.  19 
o.  26 
0.32 

o .  40 
o .  46 
O.S4 
o  .6t 
0.68 


1-54 
2  03 
2.56 
3-12 
3-72 
o.  5C 


o  .07 
0.13 
o .  20 
0.27 

0.34 

o .  40 

0.48 
0.56 
0.63 
o.  71 

T  .  13 

1  -5 
2.05 

2  ■  5 

312 

3  •  70 
0.52 


0.07 
0.14 
0.21 
0.28 
0.35 

0.42 
0.50 
0.58 
0.66 
0.73 

I  .  16 

1  .  60 

2  .07 
2.5 
3.12 
3<>7 
o.  54 


o .  07 

O.  I.^ 

0.21 
o .  29 
o..?f 

0.44 

o .  52 
0.6c 

0.68 

o.  76 

1  .  18 
1.62 

2  .  09 
2.59 
3-  " 
3-65 
o .  56 


0.62 
0.5s 


39 
•32 
•  24 
.16 
.08 


0  .  07 
0.15 
0.22 
0  .  30 
0.38 

o.c8 
o.is 
0.23 
0.31 
0.38 

c.c8 

C.lt 
0.  2/ 
0.32 
0.39 

c.c8 
c.  le 
0.2^ 
0.32 
°-3? 

o.c8 
0 .  16 
0.24 
0.32 
0.40 

0  .  46 
O.S4 
0.61 
0  .  70 
0.78 

0.47 
O.S4 
0  ,  62 
0.  70 
0  .  78 

0.47 
0.55 
0.63 
0.71 
0.79 

o./)8 
0.  56 
0  .6j 
0.72 
0.8c 

0.48 
0.  56 
o.6j 
0.72 
0.8c 

I  .  20 

I  .  21 

I  .  22 

I  .  22 

123 

1.64 

1.65 

I  .65 

1.65 

I  .66 

2.10 

2  .  10 

2  .  IC 

2.1c 

2  .  10 

2-59 

2.58 

2.5^ 

2.57 

2.56 

3- 10 

308 

3  07 

3.05 

3  03 

3.62 

3.60 

3-57 

3-54 

3  50 

0.58 

0.58 

0.59 

0 .  60 

0  .60 

0.32 
039 

0.48 
0.56 
0.64 

0.  72 
o.Sr 

1 .  22 
1. 6s 
2.08 
2.52 
2.97 
3-43 
o  .  60 


*U.  S.  Dept.  of  Commerce  and  Labor,  Bur.  of  Standards,  Circular  19,  1909,  p.  11.  This  table  is 
calculated  using  the  data  on  thermal  expansion  of  sugar  solutions  by  Plato  (Wiss.  Abh.  der  Kaiser- 
lichen  Normal-Eichungs-Kommission,  2,  1900,  p.  140),  assuming  the  instrument  to  be  of  Jena  16'" 
glass.  The  table  should  be  used  with  caution  and  only  for  approximate  results  V/hen  the  tempera- 
ture differs  much  from  the  standard  temperature  or  from  the  temperature  of  the  surrounding  air. 


620  FOOD   INSPECTION   AND   ANALYSIS. 

plying  the  reading  by  2,  Ixnh  direct  and  invert.*     Use    Clerget's   formula 
fi)r  ealcuhition  of  the  sucrose. 

P\)r  medium-  or  light-colored  grades  of  molasses,  which  yield  but 
a  sma"!  precipitate  with  lead  subacetate,  the  above  method  of  simple 
polarization,  both  direct  and  invert,  gives  results  sufficiently  accurate 
for  ordinary  work.  For  dark-colored,  or  "  black-strap  "  molasses,  or 
wherever  extreme  accuracy  is  recjuired,  the  solution  should  be  first 
made  up  to  the  mark  and  then  clarified  by  the  addition  of  a 
slight  excess  of  anhydrous  lead  subacetate  (]).  587),  as  proposed  by 
Home,  or  else  the  double  dilution  method  of  Wiley  should  be  em- 
ployed. Both  methods  make  due  allowance  for  the  volume  of  the  pre- 
cipitate. 

Doiillc  Dilution  Miihod.f — Take  half  the  normal  weight  of  the  sample 
and  make  up  the  solution  to  100  cc,  using  the  appropriate  clarifier.  Take 
the  normal  weight  of  the  sample  and  make  up  a  second  solution  with  the 
clarifier  to  100  cc.  Filter  and  obtain  direct  polariscopic  readings  of 
both  solutions.  Invert  each  in  the  usual  manner  and  obtain  the  invert 
reading  of  the  two. 

The  true  direct  polarization  of  the  sample  is  the  product  of  the  two 
direct  readings  divided  by  their  difference.  The  true  invert  polariza- 
tion is  the  product  of  the  two  invert  readings  divided  by  their  dif- 
ference. 

Determination  of  RafRnose  in  Beet  Sugar  Molasses. — For  the  deter- 
mination of  sucrose  and  rallinosc  when  present  in  the  same  solution,  use 
the  following  formulas  of  Creydt :  | 

0.5188^  — & 
Sucrose  = (i) 

0.8454  ^  ^ 

a—S 
and  Raffinose  =  — -— , (2) 

1.85 

where    a=direct    reading,  i  =  reading    after  inversion,  and  6'  =  pcr  cent 
of  sucrose. 


*  The  short  tube  fioo  mm.)  is  preferred  for  polarizing  molasses,  not  only  on  account  of 
the  more  or  less  rleep  color  of  the  c  larified  solution,  hut  also  because  a  molasses  sample  con- 
taining <  onsiflerable  commercial  glucose  would  not  read  wilhin  the  scale  limits,  if  the  200- 
jnm   tube  were  employefi. 

t  Wiley  and  Klwell,  Analyst,  1896,  21,  p.  184. 

X  t'   S.  iJept.  Agrif  .  P.ur  of  Ch<  m  ,  Bui.  107  (rev),  p.  43. 


SUGAR   .-IND   SACCHARINE  RRODUCTS.  621 

DavoU  *  recommends  for  purposes  of  clarification  of  the  molasses  the 
use  of  powdered  zinc  after  inversion  of  the  molasses  sample  according  to 
Clerget's  method.  He  adds  i  gram  of  the  zinc  to  the  sample  after  in- 
version v/hile  at  the  temperature  of  69°  C,  allowing  it  to  act  for  three  to 
four  minutes  at  that  temperature,  after  which  he  cools  and  filters,  with 
the  production  of  an  almost  colorless  solution. 

Determination  of  Reducing  Sugar. — (Estimated  as  Dextrose.) — Dilute 
5  grams  of  molasses  or  syrup  with  water  in  a  loo-cc.  graduated  flask, 
using  2  to  5  cc.  normal  lead  acetate.  Make  up  to  100  cc,  filter,  take 
an  ahquot  part  of  the  filtrate  (25  to  50  cc.j  and  make  this  up  to  100 
cc,  the  amount  taken  being  such  that,  when  diluted,  the  solution  will 
contain  not  more  than  ^%  of  dextrose.  Since  lead  acetate  has  been 
used  to  clarify,  add  to  the  aliquot  part  taken  and  before  dilution,  enough 
sodium  sulphate  to  precipitate  the  excess  of  lead,  then  filter  and  make 
up  to  the  100  cc.  mark. 

Determine  the  reducing  sugar  in  this  solution  by  either  volumetric 
or  gravimetric  Fehling  processes. 

U.  S.  Standard  Molasses  is  molasses  containing  not  more  than  25% 
of  water,  nor  more  than  5%  of  ash. 

Adulteration  of  Molasses  and  Syrups. — A  common  adulterant  of  all 
these  products  is  commercial  glucose.  From  its  water-white  color  anfl 
inert  sweetness,  no  less  than  from  its  cheapness,  it  forms  an  admirable 
adulterant  for  dark-colored  or  low-grade  molasses  and  syrups,  counter- 
acting to  a  great  extent  by  its  smoothness  the  strong  and  often  disagree- 
able taste  of  the  inferior  products  with  which  it  is  mixed.  Thus  a  grade 
of  molasses  too  cheap  to  be  ordinarily  used  for  food  purposes  can  be 
made  to  assume  the  appearance,  and  to  some  extent  the  taste,  of  the 
higher-priced  and  light-colored  grades,  by  admixture  with  commercial 
glucose. 

Tin  salts  are  also  used  to  improve  the  color  of  low-grade  or  dark 
molasses,  and  bleaching  agents,  such  as  sulphurous  acid,  are  frequently 
employed.  Copper  is  sometimes  found,  due  to  utensils  or  vessels  used 
in  processes  of  manufacture. 

Lead  may  occur  in  maple  syrup,  due  to  the  leaden  plugs  or  spigots 
through  which  the  sap  is  sometimes  drawn  from  the  trees. 

Detection  and  Determination  of  Commercial  Glucose. f — From  the 
direct  polarization  of  a  normal  solution  of  molasses  or  syrup  the  presence 

*  Jour.  Am.  Chem.  Soc,  25  (1903),  p.  1019. 
t  Leach,  ibid.,  p.  982. 


62  2  FOOD  INSPECTION  AND   ANALYSIS. 

or  absence  of  commercial  glucose  can  usually  be  established.  The  direct 
polarization  of  a  normal  solution  of  pure  molasses  should  not  be  much  in 
excess  of  50°  on  the  Soleil-Ventzke  scale,  while  a  pure,  dark-colored  molas- 
ses should  polarize  well  under  40°.  Golden  syrup  and  maple  syrup 
reatl  higher  than  molasses,  and  a  normal  solution  of  pure  maple  syrup 
may  have  a  direct  j^olarization  as  high  as  65°,  being  more  often  than  not 
above  60°. 

An  excessively  high  direct  polarization  is  at  once  an  indication  of 
the  presence  of  commercial  glucose,  while  an  in\ert  reading  at  ordinary 
room  temperature  to  the  right  of  the  zero-point  is  an  almost  positive 
proof  of  its  presence  in  either  of  the  above  products. 

The  optically  active  constituents  of  commercial  glucose,  viz.,  dextrin, 
maltose,  and  dextrose,  are  present  in  such  varying  amounts,  that  it  is 
impossible  to  determine  accurately  the  exact  amount  of  this  adulterant 
in  complex  saccharine  products  which  themselves  contain  components 
common  to  glucose.  Its  approximate  amount  can,  however,  be  very 
satisfactorilv  estimated  in  molasses  and  syrups  by  the  use  of  the  follow- 
ing formula: 

(a-5)ioo 
^  = 7^. * 

where  G=per  cent  of  commercial  glucose,  a  =  direct  polarization,  and 
5  =  per  cent  of  cane  sugar  previously  obtained  from  the  Clerget  formula 
(p.  588).  A  large  amount  of  invert  sugar  present  affects  the  accuracy 
of  this  formula.  It  is  especially  ap])licablc  to  maple  syrup,  wherein  the 
per  cent  of  invert  sugar  is  small,  but  may  be  applied  also  to  molasses 
and  golden  syrup,  wherein  the  amount  of  invert  sugar  is  not  so  large 
but  that  results  may  be  obtained  as  close  as  could  be  expected  from  an 
empirical  formula. f 

In  saccharine  products  containing  considerable  invert  sugar  the 
invert  reading  at  87°  C.  obtained  as  directed  on  page  639,  is  divided  by 

♦  Leach,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  48. 

t  This  formula  is  leased  on  the  assumption  that  42°  Be.  mixing  glucose,  the  grade 
sijccially  made  and  used  for  admixture  with  molasses,  syrups,  and  honey,  has  a  maximum 
polarization  of  175°  V.  It  was  adopted  as  a  result  of  investigations  made  some  years  ago 
by  the  author,  but  subsequently  it  appeared  that  42°  B<i.  mixing  glucose  po'.rrizes  lower 
than  formerly.  Thus  a  sample  recently  examined  by  the  author  polarized  at  162./^  V. 
Pending  further  investigations  it  seems  best  for  the  present  tf)  retain  the  old  formula,  for, 
while  it  undoubtedly  gives  low  results,  especially  with  higher  admixtures  of  glucose,  it 
approxim-^'es  the  truth  more  closely  than  would  be  expected,  perhaps  because  it  tends  To 
compensate  for  the  error  due  to  substances  in  genuine  molasses  and  honey  that  polarize 
to  the  nght  after  inversion.  Furthermore,  it  has  been  adopted  by  the  A.  O.  A.  C.  To 
avoid  misunderstanding,  express  results  in  terms  of  glucose  polarizing  at  that  factor. 


SUGAR    AND    SACCHARINE  PRODUCTS. 


623 


the  api)roprialc  factor  (163)  to  obtain  ihr  ixTCcntagc  of  commercial 
glucose. 

While  theoretically  pure  molasses  and  syru[)s  would  be  expected  to 
show  no  rotation  when  polarized  at  87°  C.  after  inversion,  as  a  matter 
of  fact  most  samples  exhibit  a  decidedly  righldianded  reading  at  that 
temperature.  Occasionally  a  zero  reading  is  noted,  and  in  rare  instances 
a  slight  leftdianded  rotation  occurs  under  the  abo\'e  conditions. 

Dextro-rotation  is  undoubtedly  caused  by  some  form  of  decom])Osition 
or  fermentation.  It  may  be  due  to  a  preponderance  of  dextrose  in  the 
reducing  sugars,  since  levulose  is  more  easily  decomposed  than  dextrose, 
or  it  may  be  caused  by  the  decomposition  products  formed  when  the  raw 
juice  is  being  defecated  with  lime,  or  again  it  might  result  from  a  special 
fermentation   forming  dextran. 

The  following  table  shows  results  by  A.  H.  Bryan*  of  polarization  of 
samples  of  Louisiana  molasses  and  syrup  of  known  purity,  showing 
especially  the  invert  readings  at  87°  C: 

POLARIZATION    OF   LOUISIANA   MOLASSES   AND    SYRUP, 


MOLASSES. 

SYRUP. 

Direct 
Polariza- 

Corrected Invert 

Direct 

Corrected  Invert 

Polarization — 

Dry 

Polariza- 

Polarization— 

Dry 

Substance. 

tion 
at  20°  C. 

Substance 

tion 
at  20°  C. 

At  20°  C. 

At  87°  C. 

At  20°  C. 

At  87°  C. 

°  V. 

°  V. 

°  V. 

Per  Cent. 

°  V. 

°  V. 

°  V. 

Per  Cent. 

40.8 

—  20.24 

+  2.2 

80.8 

48.4 

-17.6 

+  1.98 

74-3 

24.6 

-20.9 

+  2.2 

76.8 

54-0 

-18.7 

+  3-3° 

68.3 

26.0 

-18.26 

+  3-52 

76.8 

50.2 

—  12. 1 

+  6.i6t 

42.4 

-16.94 

+  2.42 

78.2 

50-4 

-14-3 

+  1.76 

52.4 

-16.28 

+  2.20 

69.1 

61.8 

-16.5 

+  2.20 

55-6 

-13-59 

+  4-18 

69.6 

39-6 

—  18.04 

+  2.20 

80.8 

39-6 

-17.82 

+  2.20 

79.0 

Average . 

+  2.65 
+  6.16 

;       44.0 

—  17.16 

+  2.64 

72.0 

Maximu 

n 

42.0 

—  1 7 . 60 
-17.27 

+  2.42 
+  3-52 

73-8 
76.1 

Minimur 

n 

0.00 

42.4 

^ 

41 .6 

-16.94 

+  3-96 

74.0 

52.4 

—  17.60 

+  3-52 

76.1 

26.6 

-19-8 

0.00 

78.1 

i     50.8 

-25.08 

+  1.10 

87-5 

22.6 

—  16.72 

+  3-96 

84.1 

41 .6 

-14.74 

+  1.10 

75-0 

45-6 

-15-4 

+  2.20 

78.0 

*  A.  O.  A.  C.  Proc,  1908,  U.  S.  Dept.  of  -Vgric,  Bur.  of  Chem.,  Bui.  122,  p.  182. 
f  Sample  ropy  and  badly  fermented. 


02  4 


FOOD  INSPECTION  AND  ANALYSIS. 


TYPICAL  ANALYSES    OF  MOLASSES   AND   SYRUPS    ADULTERATED   WITH 

COMMERCIAL  GLUCOSE. 


Polarization. 


^3 


i  go.- 


mQ 


v'^i 


(a)  Molasses 

W     "    

(c)     "    

(a)  Golden  drip  svrup . . 
(6)  "  "  '«'  .. 
(O       "        "  '*     .. 

(a)  Maple  s>Tup 

(ft)      "        ■"    

(0    "      "  


62 

98.7 
109.7 

73-5 
100.4 
143-6 
76-3 
77-9 
87.0 


+  36-3' 
+  71.9' 
-f  90 
+  3Q-8' 
+  87.6: 
+  136.0, 
+  7-6, 
+  24  I 
+  30.6 


17° 
18° 

17° 

18.4° 

18.6° 

X9° 

22.4° 


10 
19.9 

14-5 
2? 

16.9 
5-6 

51 
40. 1 

42-5 


30.03 
27.62 

31.61 
33-44 
38-17 


16. ()0 


24.6 
45 -o 
54-4 
27.7 
52.8 

78.5 
14.4 
21.6 

25-4 


29.36 
27.98 
22.02 
23.67 
24.48 
21.52 
31-91 
23-44 
28.80 


■83 
•53 
.67 

■04 


1. 00 
0.65 

i.oS 


Determination  of  Dextrin.  —  According  to  Beckman's  method  a 
weighed  amount  of  the  honey  or  molasses  is  diluted  with  an  equal  vokuTie 
of  water  and  from  ten  to  twelve  times  its  volume  of  methyl  alcohol  is 
added.  The  precipitated  dextrin  is  collected  in  a  tared  filter  and  thor- 
oughly washed  with  methyl  alcohol,  after  which  it  is  dried  and  weighed. 

Reduction  of  Saccharine  Products  to  an  Ash  for  Mineral  Analysis. 
— If  a  considerable  quantity  of  molasses,  syrup,  or  other  saccharine  sub- 
stance is  to  be  burnt  to  an  ash,  it  is  both  tedious  and  annoying  to  ignite 
directly,  by  reason  of  the  excessive  swelling  and  frothing  of  such  substances 
during  ignition.  Small  quantities  of  molasses,  syrup,  or  honey  may  with 
care  be  reduced  to  an  ash  by  the  method  described  on  page  586. 

If  a  readily  controlled  electric  current  is  available,  it  may  be  utilized 
as  follows:*  Mix  100  grams  (f  molasses,  syrup,  or  other  saccharine 
solution,  which  should  be  evaporated  to  syrupy  consistency  if  not  already 
such,  with  about  35  grams  of  concentrated  suljjhuric  acid  in  a  large 
porcelain  evaporating-dish.  An  electric  current  is  then  passed  through 
it  while  stirring,  by  placing  one  platinum  electrode  in  the  bottom  of  the 
dish  near  one  side  and  attaching  the  other  to  the  lower  end  of  the  glass 
rod,  wth  which  the  contents  are  stirred.  Begin  with  a  current  of  about 
I  ampere  and  gradually  increase  to  4-1     In  from  ten  to  fifteen  minutes 

*  I>cach,  32d  An.  Rcpt.  Mass.  Slate  Board  of  Hcaltb  (1900),  p.  653.  Reprint,  p.  37. 
This  methofi  is  preferred  to  the  ordinary  method  of  heating  with  sulphuric  acid,  especially 
in  case  of  molasses,  because,  if  properly  manipulated,  it  so  quietly  comes  into  the  form  of  a 
\crv  finely  divided  char  or  powder,  especially  adapted  for  subsequent  quick  ignition. 

t  M'xlifierl  from  method  of  Budde  and  Schou  for  determining  nitrogen  dcctrolylically. 
Ztschr.  anal.  Chem.,  38  ''1899),  p.  345. 


SUGAR  AND  SACCHARINE  PRODUCTS.  625 

the  mass  is  reduced  to  a  fine,  dr}'  char,  which  may  then  be  readily  burnt 
to  a  white  ash  in  the  original  dish  over  a  free  flame  or  in  a  muffle. 

Or,  100  grams  of  the  molasses  or  syrupy  solution  to  be  ashed  may 
be  first  evaporated  to  dryness  and  afterward  mixed  with  from  10  to  20  cc. 
of  concentrated  sulphuric  acid  in  a  j)orcelain  evaporating-dish,  or  if  the 
substance  to  be  ashed  be  a  dry  sugar  or  confectioner)-,  20  grams  are 
mixed  with  the  above  amount  of  acid.  Heat  is  gently  applied  by  means 
of  the  gas  flame  till  the  swelling  and  frothing  have  ceased,  which  usually 
requires  only  a  few  minutes.  The  final  ignition  is  then  accomplished 
in  the  usual  manner,  nitric  acid  being  added  if  necessary  to  completely 
destroy  the  organic  matter. 

Determination  of  Tin  in  Molasses. — Fuse  the  ash  from  a  weighed 
portion  of  the  sample  with  sodium  hydroxide  in  a  silver  crucible,  dis- 
solve in  water,  and  acidulate  wdth  hydrochloric  acid;  filter  and  precipi- 
tate the  tin  from  this  solution  with  hydrogen  sulphide;  wash  the  pre- 
cipitate on  a  filter  and  dissolve  it  in  an  excess  of  ammonium  sulphide. 
Filter  this  solution  into  a  tared  platinum  dish,  and  deporit  the  tin  directly 
in  the  dish  by  electrolysis,  using  a  current  of  0.05  ampere  and  the  appa- 
ratus described  on  page  608. 

Distinction  between  Invert  Sugar,  Maltose,  and  Lactose.* — All  these 
sugars  reduce  Fehling's  solution.  Dextrose  and  levulose  (invert  sugar) 
when  boiled  with  Barfoed's  copper  acetate  solution  (14  grams  crj^stal- 
lized  copper  acetate  and  5  cc.  acetic  acid  in  200  cc.  water)  v.'ill  form 
a  precipitate  of  cuprous  oxide,  while  neither  maltose  nor  lactose  will 
do  this.  The  solution,  which  has  thus  been  tested  for  invert  sugar  and 
found  to  be  free,  or  the  filtrate  from  the  cuprous  oxide  precipitate,  is 
treated  with  an  excess  of  basic  lead  acetate,  filtered,  and  to  the  filtrate 
is  added  an  excess  of  sodium  sulphate  solution  to  precipitate  the  lead. 
The  solution  is  again  filtered  and  treated  with  copper  sulphate  solution, 
if  not  already  blue.  It  is  then  made  alkaline  ^^•ith  sodium  hydroxide 
and  heated  to  boiling.  A  red  precipitate  of  cuprous  oxide  at  tliis  stage 
indicates  either  lactose  or  maltose  or  both. 

A  solution  of  the  sugar,  made  strongly  ammoniacal,  is  then  mixed 
with  alkaline  bismuth  solution  f  and  the  container  is  set  in  a  water- 
bath  at  60°  C.     l^.Ialtose  soon  reduces  the  bismuth,  but  lactose  does  not. 

To  test  for  lactose,  add  strong  nitric  acid  to  the  solid  sugar  residue 

*  Bartley  and  Alayer,  Merck's  Report,  12  (1903),  p.  100. 

t  This  reagent  is  prepared  as  follows:    Bismuth  subnitrate,  2  grams;    Rochelle  salt,  4 
grams;  sodium  hydroxide,  8  grams;   dissolved  in  100  cc.  of  water  b}'  the  aid  of  heat. 


626  FOOD  INSPECTION  AND  ANALYSIS. 

and  warm  gently  till  red  fumes  come  off.  Then  set  the  container  in  hot 
water  and  cool  gradually.  Crystals  of  mucic  acid  appear  after  a  time 
if  aiiv  appreciable  amount  of  lactose  be  present. 

Determination  of  Lactose  or  Maltose. — Either  sugar,  if  in  solution 
free  from  other  reducing  sugars,  ma\'  be  determined  by  the  volumetric 
Fehling  method  (-p.  5Q1)  or  by  the  Defren  method,  using  the  table  on 
page  595. 

For  thj  determination  of  maltose  in  commercial  glucose,  sec  page  630. 

Estimation  of  Cane  Sugar  and  Dextrose  in  Mixtures.— Obtain  true 
direct  and  invert  readings  of  a  normal  solution  of  the  mixture.  Deter- 
mine the  per  cent  of  sucrose  by  Clerget's  formula  (p.  588),  This  figure 
represents  the  right-handed  rotation  due  to  sucrose.  Subtracting  this 
from  the  direct  polarization,  the  difference  represents  the  right-handed 
rotation  due  to  dextrose.  The  specific  rotary  power  of  sucrose  is  66.5 
and  that  of  dextrose  52.3. 

Calling  d  the  percentage  of  dextrose  and  R'  the  right-handed  rota- 
tion due  to  dextrose  as  above  obtained,  if  the  Soleil-Ventzke  scale  is  used, 


whence 


Determination  of  Levulose.* — On  page  589  attention  was  called  to 
the  variation  in  the  rotar}'  power  of  levulose  with  the  temperature.  This 
variation  is  constant,  and  i  gram  of  levulose  in  100  cc.  of  water  produces 
a  decrease  in  left-handed  reading  of  0.0357°  ^^  ^^^  cane  sugar  (Ventzke) 
scale  for  each  1°  C.  increase  in  temperature.  Therefore,  the  weight 
of  levulose  present  in  a  given  solution  can  be  calculated  from  the  polari- 
scopic  readings  at  two  temperatures,  using  a  water- jacketed  tube,  as 
described  on  page  639. 

R-R' 


L  = 


0-0357  it-l'f 


where  L  =  weight  of  levulose, 

i?  =  reading  at  higher  temperature  /, 
i?'  =  reading  at  lower  temperature  I'. 

The  percentage  of  levulose  present  in  the  solution  may  readily  be  cal- 
culated as  follows: 

*  Wiley,  Agric.  Anal.,  p.  272. 


SUGAR   AND  SACCHARINE  PRODUCTS.  627 

If  L'  =  percentage  of  levulose, 

L  =  weight  of  levulose  in  solution, 
IF  =  weight  of  sugar  sample  made  up  to  100  cc, 
_LXioo 

In  a  normal  solution  1^  =  26.048. 

ANALYSIS   OF   MAPLE   PRODUCTS. 

Determination  of  Moisture. — This  is  accomplished  by  direct  drying 
with  sand,  or  by  calculation  from  the  specific  gravity,  or,  preferably  from 
the  refractive  index.     See  molasses  methods,  page  613. 

Determination  of  Ash. — Burn  5  grams  in  a  platinum  dish  by  the  usual 
method,  observing  the  precautions  given  for  molasses,  page  614. 

Soluble  and  Insoluble  AsJi."^ — To  the  platinum  dish  containing  the 
ash  add  40  cc.  of  hot  water  and  boil  gently  for  two  minutes.  Filter  through 
a  small  ashless  filter,  and  wash  with  hot  water  until  the  filtrate  amounts 
to  100  cc.  Return  the  filter  to  the  dish  used  for  ashing,  burn  at  a  low 
red  heat,  cool  and  weigh,  thus  obtaining  the  insoluble  ash.  The  soluble 
ash  is  obtained  by  difference,  subtracting  the  weight  of  insoluble  from 
that  of  total  ash. 

Alkalinity  of  Soluble  Ash.'f — Allow  the  filtrate  from  the  above  deter- 
mination to  cool,  then  titrate  with  tenth-normal  hydrochloric  acid,  using 
methyl  orange  as  an  indicator. 

Alkalinity  of  Insoluble  Ash.'f — Add  excess  of  tenth-normal  hydrochloric 
acid  (usually  10  to  15  cc.)  to  the  ignited  insoluble  ash  in  the  platinum 
dish,  heat  to  the  point  of  boiling  over  an  asbestos  plate,  allow  to  cool, 
and  titrate  excess  of  hydrochloric  acid  with  tenth-normal  sodium  hydroxide, 
using  methyl  orange  as  an  indicator. 

Express  the  alkalinity  in  each  case  as  the  number  of  cubic  centimeters 
of  tenth-normal  acid  used  on  the  ash  of  i  gram  of  sample. 

Polarization. — Sec  page  614. 

Determination  of  Reducing  Sugar. — See  page  621. 

Determination  of  Malic  Acid  Value. — Modified  Leach  and  Lyihgoe 
Method. I — Weigh  6.7  grams  of  the  sample  into  a  200  cc.  beaker,  and  add 

*  A.  H.  Bryan,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  No.  40,  p.  6. 
t  U.  S.  Dept.  of  Agric  ,  Bur.  of  Chem.,  Bui.  107  (rev.),  p.  69. 

X  Jour.  Am.  Chem.  Soc,  26,  1904,  pp.  380  and  1536;  U.  S.  Dept.  of  .A.gric.,  Bur.  of 
•Chem.,  Bui.  107  (rev.),  p.  74. 


628  FOOD    INSPECTION  AND   ANALYSIS. 

water  to  make  a  volume  of  20  cc.  Add  2  drops  of  ammonium  hydroxide 
(specific  gravity,  0.90),  i  cc.  of  a  lo^c  solution  of  calcium  chloride,  and 
oo  cc.  of  959c  alcohol.  Cover  the  beaker  with  a  watch  glass,  heat  for 
one-half  hour  on  a  water  bath,  then  turn  off  the  tlame  and  allow  the 
beaker  to  stand  overnight.  Filter  the  material  in  the  beaker  through 
good  quality  filter  paper,  wash  the  precipitate  with  hot  75%  alcohol  until 
the  filtrate  measures  100  cc,  dry  and  ignite.  Add  from  15  to  20  cc.  of 
tenth-normal  hydrochloric  acid  to  the  ignited  residue,  thoroughly  dissolve 
the  lime  by  heating  carefully  to  just  below  boiling,  cool  and  titrate  the 
excess  of  acid  with  tenth-normal  sofljum  hydroxide-,  using  m.cthvl  orange 
as  an  indicator.  One-tenth  of  the  number  of  cubic  centimeters  of  acid 
neutralized  by  the  ignited  residue  expresses  the  malic  acid  value.  Run 
blank  determinations  on  reagents,  using  the  same  amounts,  particularly  of 
ammonium  hydroxide,  as  were  used  in  the  original  determination,  and 
makf  the  necessary  correction. 

Determination  of  Lead  Number.  —  Winton  Method.'*-  —  Weigh  25 
grams  of  the  material  (or  26  grams  if  a  ])ortion  of  the  fihrate  is  to 
be  used  for  polarization)  and  transfer  by  means  of  boiled  water  into  a 
loo-cc.  flask.  Add  25  cc.  of  standard  lead  subacetate  solution,  fill  to 
the  mark,  shake,  allow  to  stand  at  least  three  hours  and  filter  through 
a  dr)'  filter.  From  the  clear  filtrate  pipette  off  10  cc,  dilute  to  50  cc, 
add  a  moderate  excess  of  sulphuric  acid,  and  100  cc  of  95%  alcohol. 
Let  stand  over  night,  filter  on  a  Gooch  crucible,  wash  with  95%  alcohol, 
dry  at  a  moderate  heat,  ignite  at  low  redness  for  three  minutes,  taking 
care  to  avoid  the  reducing  cone  of  the  flame,  cool,  and  weigh.  Calcu- 
late the  amount  of  lead  in  the  precipitate,  using  the  factor  0.6831,  subtract 
this  from  the  amount  of  lead  in  2.5  cc.  of  the  standard  solution,  multiply 
the  remainder  by  100,  and  divide  by  2.5,  thus  obtaining  the  lead  number. 

The  standard  lead  subacetate  is  prepared  by  diluting  one  part  of 
the  ordinarv'  solution  (page  586)  with  four  volumes  of  water,  filtering  if 
not  clear.  It  is  standardized  by  a  blank  determination  conducted  as 
above  described.  The  solution  deposits  a  slight  precipitate  on  standing, 
but  this  does  not  usually  appreciably  affect  its  strength. 

Ross  Modification. '\ — This  process  is  specially  adapted  for  the  exam- 
ination of  mixtures  of  maple  and  cane  sugar  syrups,  as  the  results  are 
proportional  to  the  per  cent  of  maple  syrup  present,  which  is  not  true 
of  the  Winton   method.     The  lead   numbers  of  pure  maple  syrup  range 

*  Jour.  Am.  Chem.  S<jc.,  28,  1906,  p.  1204. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Qhem.,  Circular  53. 


SUGAR   AND  SACCHARINE   PRODUCTS.  629 

from  1.8  to  3.0,  whereas  by  the  Winton  method  they  range  from  1.2 
to  2.5. 

Transfer  25  grams  of  the  syrup  to  a  loo-cc.  flask,  using  about  25  cc. 
of  freshly  boiled  water,  add  10  cc.  of  potassium  sulphate  solution  (7  grams 
per  liter),  then  25  cc.  of  lead  subacetate  solution  of  the  strength  employed 
in  the  foregoing  method.  Make  up  to  the  mark  with  boiled  water  and 
proceed  as  in  the  Winton  method. 

Run  the  blank  in  exactly  the  same  way,  substituting  25  grams  of  pure 
cane  sugar  syrup  (66  grams  of  sucrose  dissolved  in  34  grams  of  water) 
for  the  maple  syrup. 

Determination  of  Hortvet  Number.* — Apparatus. — (t)  A  tube,  15.3 
cm.  in  length,  consisting  of  a  wide  cylindrical  portion  3  cm.  in  diameter, 
narrowed  at  the  top  to  a  neck  2  cm.  in  diameter,  and  at  the  bottom  to  a 
stem  graduated  in  tenths  to  5  cc. 

(2)  A  holder,  made  of  pine  or  white  wood,  of  a  size  adapted  to  carry 
the  tube  in  the  shield  of  the  centrifuge.  The  holders  and  tubes  should 
be  arranged  in  balanced  pairs  in  the  centrifuge. 

Procedure. — Introduce  5  cc.  of  syrup  or  5  grams  of  sugar  into  the 
tube.  Add  10  cc.  of  water,  and  dissolve  completely.  Next  add  10  drops 
of  alumina  cream,  and  1.5  cc.  of  lead  subacetate.  Shake  thoroughly, 
and  allow  to  stand  from  forty-five  to  sixty  minutes.  Place  the  tube  in 
its  holder  in  the  centrifuge  shield,  and  run  six  minutes.  If,  after  the 
end  of  this  time,  any  material  adheres  to  the  sides  of  the  wide  part  of  the 
tube,  loosen  with  a  small  wire  or  by  giving  the  tube  a  slight  twisi.  then 
run  the  tube  six  additional  minutes,  and  finally  read  the  volume  of  the 
precipitate  in  the  stem,  estimating  to  o.oi  cc. 

Run  a  blank  with  the  above  reagents  in  water,  subtracting  the  blank 
reading  from  that  of  the  precipitate.  In  the  case  of  syrup,  reduce  to 
the  5 -gram  basis  by  dividing  by  the  specific  gravity  of  the  sample.  If 
the  sugar  content  of  the  sample  is  known,  the  specific  gravity  can  be 
calculated  from  the  table  on  page  6-17.  For  pure  maple  syrup  1.33  is 
very  nearly  correct. 

The  centrifuge  used  by  Hortvet  had  a  radius  of  18.5  cm.  and  was  run 
at  a  speed  of  1600  revolutions  per  minute.  The  corresponding  velocity 
in  cm.  per  second  (v)  and  revolutions  per  minute  (R)  for  any  given  centri- 
fuge with  a  radius  of  r  cm.  may  be  calculated  by  the  following  formulae : 


v='s/  '^20,ooor,  R  =  6ov/27tr. 


Jour.  Am.  Chem.  Sor.,  26,  1904.  p.  1532. 


630  FOOD   INSPECTION  AND  ANALYSIS. 

Results  by  Hortvet  on  pure  maple  syrups  vary  from  1.2  cc.  to  about 
2.5  cc,  and  on  pure  maple  sugars  from  1.8  cc.  to  4  cc. 

Commercial  brands  of  adulterated  syrups  and  sugars  give  such  pre- 
cipitates as  o.co  cc,  0.02  cc,  0.05  cc,  and  0.08  cc  Hortvet  regards  with 
suspicion  a  syrup  testing  lower  than  1.2  cc,  and  when  the  result  is  below 
I  cc,  the  sample  is  positively  condemned  as  being  mixed  with  refined 
cane  sugar.  In  the  case  of  sugar,  a  somewhat  higher  minimum  figure 
is  adopted  than  with  syrup.  In  view  of  the  fact  that  the  speed  has  much 
to  do  with  the  volume  of  the  precipitate,  the  analyst  should  make  a  series 
of  similar  experiments  with  his  own  centrifuge,  and  work  out  his  own 
standards.  Results  may  be  better  compared  with  each  other,  if  calculated 
on  the  water-free  basis. 

In  case  of  doubt,  and  in  fact  in  ;«ll  cases  at  first,  it  would  be  well 
to  make  confirmatory  tests,  such  as  determining  the  ash  and  reducing 
sugar. 

Sy's  Lead  Method.* — In  a  25-cc  graduated  cylinder  introduce  5  cc. 
of  syrup,  or  5  grams  of  sugar  which  is  afterwards  dissolved  in  a  httle 
water.  Add  water  to  the  15  cc.  mark  and  2  cc.  of  lead  subacetate  solution. 
Shake  thoroughly  and  allow  the  mixture  to  stand  twenty  hours.  Then 
read  the  volume  of  the  precipitate,  which  for  pure  maple  products  should 
be  at  least  3  cc  and  is  usually  over  5  cc. 

ANALYSIS    OF    COMMERCIAL    GLUCOSE, 

Wileyt  has  worked  out  a  method  for  calculating  the  percentage  of 
dextrin,  maltose,  and  dextrose  present  in  commercial  glucose,  based 
on  the  specific  rotary  power  of  these  substances  and  on  the  reducing 
y)Ower  of  maltose  and  dextrose.  To  apply  this  method,  the  operator, 
if  he  has  a  polariscope  reading  in  sugar  scale  degrees,  must  ascertain 
the  equivalent  readings  in  angular  degrees  from  the  table  on  page  583; 
and  calculate  the  specific  rotary  power  in  each  case  from  the  formula 

W)d  =  —^^  page  584. 

Thus,  if  he  possesses  a  Schmidt  and  Haensch  instrument,  he  should 
multiply  the  true  reading,  as  obtained  on  that  instrument,  with  a  normal 

*  Jour.  Am.  Chem.  Soc.  30,  1908,  p.  14.30. 

t  Chem.  News,  46,  p.  175;  Agric.  Anal.,  3,  pp.  288-290. 


SUGAR  AND  SACCHARINE  PRODUCTS.  631 

^solution  of  the  given  sugar  or  mixture,  by  the  factor  0.3468,  to  convert 
the  reading  into  circular  degrees  from  which  to  figure  the  specific  rotary- 
power  as  above. 

The  specific  rotarj-  power  of  dextrin  is  fixed  at  193,  that  of  maltose 
138,  and  that  of  dextrose  at  53. 

Then  if  P  =  total  polarization  of  the  mixture  in  terms  of  specific 
rotary  power,  c/  =  per  cent  dextrose,  w==per  cent  maltose,  and  i'=per 
cent  dextrin, 

^  =  53^^+138^+193^' (i) 

The  value  of  P  is  obtained  from  observation  and  calculation  as  above 
described  on  a  known  solution  of  the  sample,  say  10  grams  in  100  cc. 
The  reducing  sugars,  maltose  and  dextrose,  are  then  removed,  prefer- 
ably by  oxidation  with  cyanide  of  mercur\',  as  follows:* 

Prepare  the  reagent  by  dissolving  120  grams  mercuric  cyanide  and 
120  grams  sodium  hydroxide  in  water,  mixing  the  two  solutions,  and 
making  up  to  1,000  cc.  Remove  any  precipitate  that  may  gather  by 
filtration. 

Make  a  solution  of  10  grams  of  the  glucose  sample  in  100  cc.  and 
take  10  cc.  of  this  solution  in  a  50-cc.  graduated  flask.  Add  sufficient 
mercuric  cyanide  solution  to  have  an  excess  of  reagent  after  the  oxidation 
'(from  20  to  25  cc),  and  boil  for  three  minutes  under  a  hood  with  a  good 
draft.  Cool  and  neutralize  the  alkali  with  concentrated  hydrochloric 
acid,  adding  the  latter  till  the  brown  color  is  discharged.  By  this  method 
the  optical  activity  of  the  maltose  and  dextrose  is  discharged,  while  that 
of  the  dextrin  remains  unaffected.  From  the  polariscope  reading  cal- 
culate as  above  the  specific  rotar}-  power  of  the  dextrin  {P').      Then 

^^'  =  193^' (2) 

The  reducing  power  on  Fehling's  solution  of  dextrose  is  to  that  of 
maltose  as  100  is  to  62.  Whence,  if  i?  =  reducing  sugar  (reckoned  as 
dextrose)  we  have 

R  =  d-\- 0.62m (3) 

Subtracting  equation  (2)  from  eciuation  (i)  we  have 

P-P'  =  53^ri38m .     (4) 

*  Wilc)-,  Agric.  Analysis,  p.  290. 


(■32  FOOD    INSPECTION   AND    ANALYSIS 

Multiplying  equation  (})  by  53  and  subtracting  from  equation  (4), 

P-P'  =  53^+ 138m, 

53  ^  =  53^+   32.86W, 

P-P'- 53/?  =  105.14m (5) 

Therefore 

P-P'-S?>R  ... 

m= , (6) 

105.14      '  ^  ^ 

d  =  R— 0.62m, (7) 

P' 
d'  =  — (8) 

193 

Determination  of  Dextrin  in  Commercial  Glucose. — One  volume  of 
the  sample  is  well  shaken  with  about  10  volumes  of  90%  alcohol,  and 
the  precipitated  dextrin  is  separated  by  filtration  through  a  tared  filter, 
washed  thoroughly  with  strong  alcohol,  dried  at  100°,  and  weighed. 

Qualitative  Tests  for  Commercial  Glucose.  —  Several  confirmatory 
chemical  tests  may  be  employed  for  commercial  glucose,  aside  from 
the  optical  test  with  the  polariscope.  Thus  a  ])recipitate  of  dextrin 
by  treatment  of  the  sample  with  an  excess  of  strong  alcohol,  in  the  absence 
of  mineral  salts  insoluble  in  alcohol,  is  strongly  indicative  of  commercial 
glucose.  An  excess  of  sodium  chloride  in  the  ash  also  points  strongly  to 
the  presence  of  glucose. 

Determination  of  Ash. — Formerly  when  sulphuric  acid  was  used  for 
conversion  of  the  starch  the  ash  consisted  largely  of  calcium  sulphate,  but 
at  present  when  hydrochloric  acid  is  almost  exclusively  used  the  mineral 
matter  is  almost  entirely  common  salt,  formed  by  the  neutralization  of  the 
acid. 

Determine  ash  by  burning  in  a  platinum  dish  at  dull  redness  as  in  the 
case  of  other  saccharine  products.  Qualitative  or  cjuantitative  tests 
may  be  made  for  chloride,  in  the  latter  case  calculating  the  ecjuivalent 
amount  of  sodium  chloride.  If  the  amount  of  sodium  chloride  found 
does  not  equal  the  total  ash,  sulphates  may  be  looked  for. 

Determination  of  Sulphurous  Acid.  —  At  the  present  time  glucose 
usually  is  free  from  an  appreciable  amount  of  sulphurous  acid  which 
formerly  was  extensively  employed  for  bleaching.  It  may  be  determined 
by  distillation,  oxidation  to  sulphuric  acid,  and  precipitation  with  barium 
chloride  as  described  on  page  840. 


SUGAR    AND   S/tCCHARINE   PRODUCTS.  633 

Detection  of  Arsenrc. — Since  the  Manchester  epidemic  of  arsenical 
poisoning,  due  to  the  consumption  of  beer  prepared  from  glucose  con- 
taminated through  the  sulphuric  acid  with  this  poison, it  is  highly  important 
that  both  the  acid  used  for  conversion  and  the  glucose  be  frequently 
tested  for  this  contamination. 

The  tests  may  be  made  on  2  to  5  grams  of  the  materials  without  charring 
or  destruction  of  the  organic  matter,  by  the  Marsh  test  or  the  Sanger- 
Black-Gutzeit  test  as  described  under  general  methods  on  pages  74  to  77. 

The  English  limit  of  one  and  one-half  parts  per  million  calculated 
as  metallic  arsenic  should  not  be  exceeded. 

HONEY. 

Composition  and  Occurrence. — Honey  is  the  saccharine  product 
deposited  by  bees  {Apis  mellifica  and  A.  dorsata)  in  the  cells  of  honey 
comb,  which  the  insect  forms  out  of  wax  secreted  by  its  body.  Honey 
has  its  source  chiefly  in  the  nectaries  of  flowers,  from  which  the  bees 
abstract  it,  also  in  the  juices  of  ripe  fruits  and  the  exudations  of  leaves 
(honeydew).  While  in  the  honey-sac  of  the  bee,  the  sucrose,  which 
forms  the  chief  constituent  of  the  fruit  juice  or  nectar,  becomes  for  the 
most  part  inverted,  forming,  in  the  honey,  dextrose  and  K-vulose.  The 
evaporation  to  a  syrupy  consistency  is  effected  in  the  hive  by  exposure 
to  a  current  of  air,  produced  by  fanning  of  the  wings  of  the  bees. 

The  flavor  of  honey  varies  considerably,  according  to  its  source. 
Besides  water,  the  sugars,  and  mineral  matters,  i)ollen  is  usually  present, 
derived  from  the  flowers,  also  as  a  rule  a  small  (quantity  of  wax,  and 
nearly  always  appreciable  amounts  of  various  organic  acids.  Fincke  f 
states  real  honey  may  or  may  not  contain  formic  acid. 

European  Honey. — Neufeld*  gives  the  following  limits  for  pure 
honey : 

Water 8.30  to  33.59% 

Protein 0.03   "     2.67% 

Invert  sugar 49-59  "  93-96% 

Sucrose o.  10  "   10. 12% 

Dextrin 0.99  "     9.70% 

Formic  acid 0.03   ''     0.21% 

Ash 0.02  "     0.68% 

*  Der  Nahrungsmittelchemiker  als  Sachverstandiger.,  Berlin,  1907,  p.  275. 
t  Zeits.  Unters.  Nahr.  Genussm.,  23,  iqi2,  p.  255. 


19 

28 

7 

64% 

78 

8% 

33% 

o 

50% 

6^4  FOOD  INSPECTION  /IND  /IN A  LYSIS. 

Canadian  Honey. — A  large  number  of  samples  of  genuine  honey 
analyzed  in  1807  for  the  Department  of  Inland  Revenue,  Canada  (BuL 
47),  showed  the  following  variations: 

Direct  polarization —   2.4  to     — 

Invert           "          —10.2  "      — 

Sucrose  (by  Clerget) 0.5  " 

Invert  sugar 6o-37  " 

Water 12  '* 

Ash 0.03  " 

American  Honey. — Browne*  has  examined  97  samples  of  American 
and  Hawaiian  honey,  representing  the  product  made  from  the  nectar 
of  numerous  flowers  as  well  as  honeydew.  Maxima  and  minima  of 
polarizations  and  analyses  of  some  of  the  more  important  kinds,  and  of 
all  the  levorotatory  and  the  dextrorotatory  samj)les  are  given  in  the  table 
on  page  635. 

As  regards  the  chemical  characteristics  of  honey  from  different  flowers^ 
Browne  states  that  alfalfa  honey  usually  has  less  dextrin  and  undetermined 
matter — the  so-called  '  impurities  " — and  more  sucrose  than  the  other 
varieties,  although  the  low  amount  of  impurities  is,  to  some  extent,  char- 
acteristic of  the  honey  of  the  whole  family  (leguminosa?).  The  compositae 
yield  honey  with  about  the  average  amount  of  organic  non-sugars;  the 
rosaceic  yield  a  product  low  in  dextrin,  but  high  in  undetermined  m  t^.er. 
Buckwheat  and  other  polygonaceous  honeys  contain  almost  no  sucrose, 
but  give  tests  for  tannins.  Basswood  honey  is  relatively  high  in  dextrin, 
and  that  from  poplar,  oak,  hickory  and  other  trees,  all  of  which  contain 
considerable  quantities  of  honeydew,  are  rich  in  both  dextrin  and  ash. 
Pronounced  tannin  reactions  are  obtained  in  honey  gathered  from  the 
flowers  or  plants  of  the  sumac,  hop  and  others  rich  in  tannin.  Tupelo, 
mangrove  and  sage  honeys  are  distinguished  by  their  high  levulose  content. 

Browne  found  the  average  per  cent  of  water  in  honey  from  the  arid 
states  of  .Arizona,  Nevada,  Utah,  and  Colorado  was  15.60,  and  from  the 
humid  states  of  Minnesota,  Wisconsin,  Illinois,  Missouri  and  Iowa  was 
18.88. 

Hawaiian  Honey. — This  is  characterized  by  its  high  ash  and  the 
presence  of  decided  amounts  of  chlorides  in  the  ash.     Van  Dinef  states 

*  U.  S.  Dep'i.  of  Agric,  Bur.  of  Chem.,  Bui.  no  (1908). 
t  Ibid.,  p.  52. 


SUG/IR  AND  SACCHARINE    PRODUCTS. 


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636 


FOOD  INSPECTION  AND   ANALYSIS. 


that  the  floral  honey  of  Hawaii  is  largely  from  the  blossoms  of  the  algarroba 
{Prosopis  julifera),  while  the  honeydew  honey,  which,  together  with 
mixtures  of  honeydew  and  floral  honey  forms  about  two-thirds  of  the 
prtxlucl  of  the  Hawaiian  Islands,  comes  largely  from  the  exudations  of 
the  sugar-cane  leaf -hopper  [Pcrkinsidla  saccltaricida),  and  the  sugar- 
cane aphis  [Aphis  sacchari).  Honeydew  honey  is  dextrorotatory,  and 
for  this  reason  has  often  been  condemned  as  adulterated.  It  has  a  strong 
molasses-like  odor,  and  often  a  very  dark  color.  Bakers  prefer  it  to 
algarroba  honey,  because  of  its  baking  and  boiling  jjroperties. 

The  variation  in  the  composition  of  Hawaiian  honey  is  shown  in  the 
table  on  ])age  635,  compiled  from  Browne's  data. 

Dextrorotatory  Honey. — The  U.  S.  standards  detme  honey  as  levo- 
rotatory,  thus  excluding  the  larger  part  of  the  Hawaiian  product,  and  also 
unimportant  kinds  of  honey  made  from  certain  trees.  Pure  floral  honey 
•with  no  admixture  of  honeydew  is  seldom  if  ever  dextrorotatory. 

The  following  are  the  results  obtained  by  Browne  in  the  examination 
of  delrorotatory  honeys: 


2^ 


>. 

0 

c 

^ 

K 

+   3-6 

+    7-8 

-    2.5 

+   3-4 

+  20.9 

-1-26.6 

17.02 

16.05 

65.80 

65.89 

3.10 

2.76 

0.76 

0.78 

10.19 

12.95 

3-13 

1.57 

0.19 

0.12 

63.04 

63.12 

Hawaiian. 


Sugar 
Cane 
Honey- 
dew. 

Honeydew 
and 
Flowers 

-t-17.8 

+   3-6 

+  13-5 
+  34-8 
15-46 
64.84 

+    1-9 

+  23-7 
16.29 
67.81 

5-27 

2-57 

1.29 

10.01 

3-13 

1.02 

9-65 
2.66 

0.15 

0.14 

62.12 

64.96 

Direct  poiarization  at  20°  C.*.. . 
Invert  polarization  at  20°  C.  .  .  . 
Invert  p<jlarizati(jn  at  87°  C.  .  .  . 

Water [^r  cent 

Invert  sugar " 

Sucrose " 

Ash " 

Dextrin " 

Undertcrmined " 

Free  arid  as  formic  ....       " 
Reducing    sugar    as    dextrose, 
per  cent 


4-17.0 
-I-15.0 

+  35-0 
16.44! 
71.69 
0.61I 

0.29J 
6.02 

4-95; 
0.05 

68.68 


-l-ii. 

+    5- 
+  28. 

13- 

65- 

4- 

o. 

10. 

4- 


0.08 


63.11 


+   5-3 
+   1.9 
+  23.4 
17.80 
66.85 
2.41 
0.80 
8.62 
3-52 
0-13 

64.04 


*  Constant. 


Adulteration  of  Honey. — The  most  common  adulterants  of  honey 
are  cane  sugar,  cfjmmercial  invert  sugar,  and  commercial  glucose.  Some- 
times two  or  more  adulterants  are  emj^loycfl  in  the  same  sample.  Gelatin 
is  alst)  said  to  be  u.sed.  It  appears  to  be  a  fact  that  bees  may  be  made 
to  feed  ujxjn  cane  syrup  or  commercial  glucose,  if  the.se  materials  are 
placed  in  proximity  to  their  hives,  .so  that  in  some  in.stances  the  adulterant 


SUGAR    AND  SACCHARINE   PRODUCTS.  637 

may  be  sui)plicd  through  the  medium  of  the  bee.  Sophisticated  honey 
IS  often  put  up  in  tumblers  or  jars  containing  pieces  of  honeycomb,  so 
that  presence  of  the  comb  is  b\-  no  means  proof  of  its  purity.  Comb-honey, 
sold  in  the  frame  as  sealed  by  the  bees,  is  never  adulterated,  excei)t  when 
the  bees  are  fed  upon  glucose  or  cane  sugar. 

Cane  Sugar. — The  following  are  typical  analyses  of  honey  adulterated 
with  cane  sugar: 

A.  B.  C. 

Direct  polarization.  .. .    +34.7  +12  +   1.2 

Invert  "  ....    —24  —17.6  "21.5 

Temperature 14°  15°  i9-5° 

Sucrose  (Clerget) 43-i6%         21.8%  17.07% 

Invert  sugar 42.48%        60.03%        67.2% 

Water 42.42%         21.15%,         i5-56%o 

Ash .11%  0.06%, 

A  strong  right-handed  polarization  before  inversion,  coupled  with  a 
left-handed  invert  reading  at  20°,  is  evidence  of  adulteration  with  cane 
sugar,  or  a  product  containing  cane  sugar. 

Honey  stored  by  bees  fed  on  cane  sugar  is  also  characterized  by  its 
right-handed  polarization.  Although  the  bee  inverts  the  larger  part  of 
the  cane  sugar  in  its  body,  this  inversion  is  never  as  complete  as  in  the 
case  of  nectar  honey. 

Glucose. — The  following  are  typical  analyses  of  honey  adulterated 
with  commercial  glucose: 

A.*  B.  C. 

Direct  i)olarizat ion.  .     4-147  -t-66.9  -fioi.5 

Invert  "  ..     4-135.2  +61.9  +   99.0 

Temperature 18°  20°  22° 

Sucrose  (Clerget)....  8.83%  3.76%  0.0% 

Invert  sugar 46.18%         74.66%  49.87% 

Water 15-19%         2i.4o%.t        23.7% 

Ash 0.03% 

Care  should  be  taken  not  to  confuse  honeydew  honey  with  honey 
adulterated  with  glucose.  Browne  gives  the  following  means  of  distinction : 
(i)  the  difference  in  invert  polarization  between  20  and  87°,  corrected  to 
77%  invert  sugar,   (2)    Beckman's  iodine  test   (page  641),  and   (3)   the 

*  Both  commercial  glucose  and  added  cane  sugar. 


63S 


FOOD  INSPECTION  AND  ANALYSIS. 


Kimig  and   Karsch   test    (page   642).     He   also   finds   the   quantity   and 
character  of  the  ash,  the  acidity,  and  microscopic  examination  of  value. 

The  following  analyses  of  mixtures  of  commercial  glucose  and  honey 
were  made  bv  A,  H.  Brvan.* 


Mixture. 

Constant 

Invert  Polarization — 

Polariza- 

Invert Sugar 

Calculated  Glucose. 

100  — 

Direct 

tion 

I 

Invert 

(Correct- 

Glucose 

Honey. 

Polariza- 
tion at 

20°  c. 

At  20^  C. 

At  87°C. 

Differ- 
ence 
(87°- 

20°). 

Before 
Inver- 
sion. 

After 
Inver- 
sion. 

Polariza- 
tion at 
87°- 
1.63. 

Polariza- 
tion at 

(20°C.-|- 

17.5)- 

1.93. 

ed  Polar- 
ization 
Differ- 
ence X 

lOO-J- 

26.7) 

% 

% 

°V. 

°V. 

°v. 

°V. 

% 

% 

% 

% 

% 

100 

+  153-8 

+  153-34 

+  144-32 

30.02 

30-45 

88.5 

88.5 

50 

50 

+    67.0 

+    65.67 

+  73-81 

8.14 

53.67 

54. 5t 

45-3 

43-1 

56-9 

20 

80 

+    15-4 

+    13-42 

+   Z3-°° 

19.58 

69.00 

70-3: 

20.2 

16.0 

19.2 

10 

90 

-      2.4 

-      4-84 

+    18.59 

23-43 

74.42 

74.1- 

11.4 

6.6 

8.8 

5 

95 

-    "-5 

-    14-31 

+    11.66 

25.96 

75-74 

77.8c 

7.2 

1.6 

3-8 

3 

97 

-   14.2 

-    16.94 

+     9-13 

26.07 

76.62 

78.01 

5-6 

0.29 

3-7 

2 

98 

—    16.0 

-    18.70 

+     8.14 

26.84 

76.64 

78-3. 

5-0 

0.00 

1 .2 

I 

99 

-    18.2 

—    20 .  90 

+     6.93 

27-83 

77.20 

78.87 

4-2 

0.00 

0.0 

100 

-    19-5 

—    22.11 

+     5-94 

28.05 

77.68 

78-9. 

3-2 

0.00 

0.0 

Commercial  Invert  Sugar  is  the  mo.st  difficult  of  detection  of  all  the 
adulterants.  Herzfeld's  processf  for  the  manufacture  of  invert  sugar 
syrups  consists  in  boiling  for  thirty  to  forty-five  minutes  i  kilogram  of 
refined  sugar  in  300  cc.  of  water  with  i.i  gram  of  tartaric  acid.  Brownjl 
gives  the  following  analysis  of  the  j)roduct  made  by  this  process: 

Direct  polarization  at  20° —  6.2 

Constant  j)olarization  at  20° —   9.5 

Invert  polarization  at  20° — 16.9 

Invert  polarization  at  87° +   4.8 

Water 16.32% 

Invert  sugar 73-38% 

Sucro.sc 4.36% 

A.sh o.oc% 

Dextrin 4-86% 

100.00 
Acids  as  formic 0.06% 

♦A.  O.  A.  C.  Proc.,  1908,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bull.  122,  p.  181. 
t  Zeits.  ver.  d.  Zucker-Ind.,  31,  p.  1988. 
Xloc.  cii.,  page  64. 


SUGAR  AND  SACCHARINE  PRODUCTS.  639 

This  adulterant  is  best  detected  by  Browne's  test  (page  642).  Ley's 
test*  has  value  in  confirming  the  results  of  Browne's  test,  but  should  be 
used  with  caution,  as  American  honeys  do  not  react  like  the  Eurojjcan, 

Gelatin  is  indicated  if  a  precipitate  occurs  in  the  diluted  sample  with 
a  solution  of  tannic  acid. 

ANALYSIS    OF    HONEY. 

Preparation  of  Sample. — In  the  case  of  strained  honey,  stir  with  a  rod 
till  any  sej)aratcd  sugars  are  evenly  distributed  throughout  the  mass,  or, 
if  the  honey  has  become  solidified  wholly  or  in  i)art  by  crystallization,  use 
a  gentle  heat  on  a  closed  water-bath  to  restore  it  to  fluid  form. 

In  the  case  of  comb  honey,  cut  with  a  knife  across  the  top  of  the  comb 
if  sealed,  and  separate  completely  from  the  comb  by  straining  through 
a  40-mesh  sieve. 

Determination  of  Moisture. f^Weigh  2  grams  into  a  flat-bottom 
metal  dish  27  inches  in  diameter,  which,  together  with  10  to  15  grams 
of  fine  quartz  sand  and  a  short  stirring  rod,  has  been  previously  tared, 
add  5  to  10  cc.  of  water,  stir  until  the  whole  has  been  thoroughly  incor- 
porated, and  dry  to  constant  weight  at  65  to  70°  C.  in  a  vacuum  oven. 
Honeys  of  high  purity  usually  dry  in  twelve  hours,  while  those  of  the 
honeydew  class  rich  in  dextrin  and  gum  require  thirty-six  hours,  or  longer. 

Determination   of  Ash. — See  page  614. 

Polarization. — Direct  and  Invert  at  20°  C. — Proceed  as  directed  under 
molasses  (page  614),  except  that  only  alumina  cream  is  used  as  a  clarifier. 
To  destroy  birotation  add  a  drop  or  two  of  ammonia  before  making  up 
to  the  mark.  J 

Invert  at  87°  C. — Invert  a  half  normal  portion  in  the  usual  manner  in 
a  loo-cc.  flask,  cool,  add  a  few  drojjs  of  ])henolphthalein  and  enough 
sodium  hydroxide  to  neutralize;  discharge  the  pink  color  with  a  few  drops 
of  dilute  hydrochloric  acid,  add  from  5  to  10  cc.  of  alumina  cream, 
make  up  to  the  mark  and  filter.  Polarize  in  a  200-mm.  tube  at  87°,  and 
multiply  reading  by  2. 

Polarization  at  the  temperature  of  87°  can  most  readily  be  etTected 
by  the  use  of  a  water-jacketed  tube,  as  shown  in  Fig.  in.  An  all-metal 
tube,  the  interior  of  which  is  heavily  gold-plated  to  avoid  corrosion  by 
acid,  is  preferable  to  one  in  which  the  inner  tube  is  glass  with  a  metal 


*  Pharm.  Zeits.,  47,  1902,  p.  603. 

t  Browne,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  no,  p.  i8. 

X  Frtihling,  Zeits.  offentl.  Chemie,  4,  1898,  p.  410. 


6-^0  FOOD  INSPECTION  AND  ANALYSIS. 

jacket,  as  in  the  latter  leaky  joints  are  liable  to  occur,  due  to  uneven 
expansion.  A  tubulure  is  provided  in  the  outer  tube  for  a  thermometer, 
so  that  the  exact  tem])erature  may  be  noted.  A  tank  of  boiling  water 
placed  on  a  shelf  above  the  polariscope  is  connected  by  rubber  tubing 
with  tlie  jacketed  tube  as  it  rests  in  the  j)olariscope,  as  shown  in  Fig.  in. 

Determination  of  Reducing  Sugars. — Determine  by  Allihn's  method 
(page  608)  in  an  aliijuot  of  25  cc.  of  a  solution  obtained  by  making  10  cc. 
of  the  solution  prepared  for  polarization  up  to  250  cc.  If  desired  the 
sugar  may  be  determined  by  the  volumetric  Fehling  process  (page  591). 

The  reducing  sugars  may  be  calcukUed  as  dextrose  as  obtained  from 
Allihn's  table,  or  as  levulose  by  multiplying  the  dextrose  by  1.044. 

Determination  of  Levulose. — Wiley's  Method.*' — This  may  be  calcu- 
lated ap{)ro\iraately  by  the  following  formula: 

100(1.0315/1—0)      100(1.031571—0) 
(2.3919)26  62.19  ' 

in  which  /  =  levulose,  a=the  direct  polarization  at  20°  of  a  solution  of  the 
normal  quantity  of  honey  made  up  to  100  cc.  at  20°,  and  ^  =the  direct 
])olarization  of  the  same  solution  at  87°  C,  2.39T9  =  the  variation  in 
polarization  of  i  gram  of  levulose  in  100  cc.  of  solution  between  20  and 
87°  C,  and  r.03i5=the  factor  for  converting  the  volume  of  the  solution 
at  20"^  into  that  at  87°  C. 

Determination  of  Dextrose. f — Multiply  the  percentage  of  levulose 
as  obtained  in  the  preceeding  section  by  0.915, thus  obtaining  the  equivalent 
dextrose,  and  subtract  this  from  the  per  cent  of  reducing  sugars  expressed 
as  dextrose. 

Determination  of  Sucrose. —  Owing  to  the  inaccuracies  of  Clerget's 
metiiod  a.-i  aijj)lied  to  honey,  Browne  recommends  the  following:  Neutralize 
the  free  acid  of  10  cc.  of  the  solution  used  for  invert  polarization  with 
sodium  carbonate,  make  up  to  250  cc.  anrl  determine  the  reducing 
sugars  by  Allihn's  method.  Subtract  from  the  invert  sugar  thus  obtained 
the  invert  sugar  found  before  inversion,  and  multiply  the  difference  by 
0.95. 

Determination  of  Dextrin. — Browne^s  MeiJwd.lf — Weigh  8  grams  of 
honey  directly  into  a  loo-cc.  flask,  add  4  cc.  of  water,  and  finally  with 

*  Principles  and  Practice  of  Agricultural  Analysis,  1897,  III,  p.  267.     Browne,  loc.  ciL, 
p.  17. 

t  Browne,  loc.  cil.,  p.  17.     Jour.  Am.  Chcm.  .Soc,  28,  1906,  p.  446. 


SUGAR   AND   SACCHARINE   PRODUCTS.  ^4' 

continual  agitation  sufficient  absolute  alcohol  to  fill  to  the  mark.  Shake 
thoroughly  and  allow  to  stanrl  twenty-four  hours,  or  until  the  dextrin  is 
deposited  on  the  bottom  and  sides  of  the  flask  and  the  liquid  is  perfectly 
clear.  Decant  on  a  filter  and  wash  the  precii)itate  in  the  flask  with  lo  cc. 
of  cold  95%  alcohol,  pouring  the  liquid  finally  on  the  filter.  Dissolve 
the  precipitate  in  the  flask  and  on  the  filter  in  a  little  boiling,  distilled 
water,  collecting  the  solution  in  a  tared  platinum  dish.  Evaporate  the 
liquid,  and  dry  to  constant  weight  at  ioo°  C.  If  the  alcohol  ])recii)iiate 
is  considerable,  it  shoukl  be  dried  at  70°  C.  in  vacuo.  After  weighing, 
dissolve  in  water  and  make  uj)  to  a  definite  volume  according  to  the 
weight  as  follows: 

Residue,  grams.  0-0.5  0.5-1.0  i. 0-1.5  1.5-2.0  2.0-2.5  2.5-3.C 
Volume,  cc.  .  ..      50  100  150  200  250  30c 

Filter,  determine  invert  sugar  and  sucrose  in  aliejuots  by  copper  reduction 
before  and  after  inversion,  and  subtract  the  sum  of  these  sugars  from  the 
total  alcohol  precipitate. 

Determination  of  Acids. — Dissolve  10  grams  of  the  honey  in  water 
and  titrate  with  tenth-normal  sodium  hydroxide,  using  phenolphthalein 
as  indicator.     Express  result  as  formic  acid. 

Beckman's  Test  for  Glucose.* — Treat  a  mixture  of  equal  parts  of 
honey  and  water  with  a  solution  of  iodine  in  potassium  iodide.  If  glucose 
is  present,  a  red  or  violet  color  (due  to  erythro-  or  amylo-dextrin)  appears, 
the  shade  and  intensity  depending  on  the  nature  and  amount  of  the 
glucose  present. 

Determination  of  Commercial  Glucose  in  Honey. — Except  for  rough 
work,  the  method  described  on  page  622  for  calculating  the  per  cent  of  com- 
mercial glucose  from  the  sucrose  and  from  the  direct  polarization  is  not 
recommended  for  use  with  honey  and  other  products  wherein  the  invert 
sugar  is  so  large  as  to  considerably  affect  its  accuracy.  In  this  case,  it 
is  best  after  inversion  to  polarize  the  sample  at  87°  C,  the  temj)erature  at 
which  the  reading  due  to  invert  sugar  would  theoretically  be  o.  At 
this  temperature,  any  considerable  right-handed  polarization  can  be 
accounted  as  due  to  commercial  glucose.  (See  page  639.) 

As  in  the  case  of  molasses,  the  writer  advocates  assuming  175°  as  the 
direct  polarization  of  the  glucose  used,  this  being  about  the  maximum 
reading  for  a  normal  solution  of  42°-Be.  glucose.     Lythgoe  has  shown 

*  Zeits.  Anal.  Chem.,  35,  1896,  p.  267. 


642  FOOD  INSPECTION   AND   ANALYSIS. 

that  in  polarizing  at  high  tomi)craturcs  samples  of  saccharine  products 
containing  commercial  glucose,  certain  precautions  have  to  be  observed 
not  necessary  when  cane  or  invert  sugar  are  the  only  sugars  present. 
Thus,  a  normal  solution  of  glucose,  when  polarized  at  87°  C,  has  a  lower 
reading  than  in  the  cold,  the  ditTerencc  being  doubtless  due  partly  at 
least  to  llic  cxpansi(m  of  the  liquid.  Again,  on  subjecting  a  normal 
solution  of  glucose  to  inversion  with  acid,  as  in  Clerget's  process,  and 
heating  to  87°  C,  it  will  be  found  impossible  to  get  a  constant  reading, 
but  the  reading  will  drop  rapidly,  due  to  a  partial  hydrolysis  of  the  maltose 
or  dextrin. 

In  honey  and  other  preparations  containing  much  invert  sugar  and 
commercial  glucose,  it  is  best  to  proceed  as  follows:  Divide  the  polariza- 
tion at  87°  by  163*  and  mull i ply  the  result  by  100  for  the  percentage  of 
commercial  glucose  in  terms  of  glucose  polarizing  at  175°.  It  should  be 
borne  in  mind  that  the  results  by  even  this  method  are  only  approximate, 
as  genuine  honey  is  more  or  less  dextrorotatory  at  87°  C. 

ft+17.5 

The  following  formula  is  used  bv  Euro[)ean  chemists:  G— in 

1-93 
which  G^the  per  cent  of  commercial   glucose,  and  6  =  the   polarization 

after  inversion  at  20°  C. 

Browne's  Test  for  Commercial  Invert  Sugar. f — Reagent. — This 
should  be  freshly  prepared  each  time  before  using.  Shake  5  cc.  of  c.  p. 
anilin  with  5  cc.  of  water,  and  add  sutlicient  glacial  acetic  acid  (2  cc)  to 
just  clear  the  emulsion. 

Process. — Treat  5  cc.  of  a  i :  i  solution  of  the  honey  in  a  test  tube 
with  I  to  2  cc.  of  the  anilin  reagent,  allowing  the  latter  to  flow  down  the 
walls  of  the  tube  so  as  to  form  a  layer  upon  the  honey  solution.  If,  when 
the  tube  is  gently  agitated,  a  red  ring  forms  beneath  the  anilin  solution, 
this  color  becoming  gradually  imjjarted  to  the  whole  layer,  artificial 
invert  sugar  is  present.  This  reaction  is  due  to  furfural  formed  during 
the  high  temperature  employed  in  the  commercial  processes  of  inversion. 
Boiling  genuine  honey  also  causes  the  formation  of  furfural,  but  this  treat- 
ment imjjairs  the  fiax'or  and  is  y^robably  never  practiced. 

Distinction  of  Honeydew  and  Glucose  Honeys. — Method  of  Konig 
and  Karsch.X — Dissolve  40  grams  of  honey  in  a  cylinder  in  water,  and 

*  The  true  [>f>larization  at  87°  C.  of  a  normal  solution  of  glucose  subjected  to  inversion 
and  neutralization  as  above  (but  without  the  use  of  the  ciarifier),  will  be  about  93%  that 
of  the  direct  fK)larization  of  the  sample  in  the  cold.     Hence  175X0.93  =  162.7. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  no,  p.  68. 

X  Zeits.  anal.  Chem.,  34,  1895,  P-  '■     ^-  ^-  I^<^pl-  '^f  Agric,  Bur.  of  Chem.,  Bui.  1 10,  p.  63. 


SUGAR    AND   SACCHARINE    I'RODUCTS. 


643 


make  up  to  40  cc.  Transfer  20  cc.  of  the  homogeneous  solution  to  a 
250-cc.  flask  and  fill  to  mark  with  absolute  alcohol  with  slow  addition  and 
constant  shaking,  and  then  allow  to  stand  two  or  three  days,  with  occasional 
agitation.  At  the  end  of  this  time  all  the  dextrin  has  settled  out.  After 
shaking  the  solution,  filler  and  evaporate  100  cc.  of  the  filtrate  undl  free 
from  alcohol.  To  the  liquid  residue  add  a  little  subacetate  of  lead  and 
sodium  sulphate,  make  up  to  20  cc.  with  water,  and  polarize  the  filtered 
solution.  Dextrorotatory  natural  honeys  show  by  this  method  a  le\o- 
rotation;  honevs  adulterated  with  dextrose  or  glucose  to  the  extent  of 
25%  or  more,  a  dextrorotation.  In  case  the  honey  contains  a  large 
amount  of  sucrose,  the  solution  should  be  inverted  with  hydrochloric  acid 
before  polarizing. 

Beeswax. — The  purity  of  beeswax  is  best  established  by  determining 
its  melting-point,  its  specific  gravity,  its  saponification  equivalent,  and 
its  refractometric  reading.  The  melting-point  of  pure  wax  is  about 
64°  C,  while  that  of  paraflin,  its  chief  adulterant,  is  from  52  to  55°  C. 
Its  saponification  equivalent  should  be  from  87.8  to  107,  while  that  of 
paraffin  is  o. 

Method  of  Determining  Specific  Gravity  of  Beeswax* — Place  a  weighed 
rod  of  the  wax,  about  i  to  1.5  cm.  long  by  0.5  cm.  diameter,  in  an  accurately 
marked  50-cc.  flask,  and  run  in  water  from  a  burette  till  the  water  level 
reaches  the  mark.  50  cc.  minus  the  burette  reading  represent  the  vol- 
ume occupied  by  the  wax.  The  rod  should  be  made  to  lie  flat  on  the 
bottom  of  the  flask,  so  that  the  incoming  w^ater  will  force  its  end  against 
the  sides  and  prevent  the  end  from  rising  above  the  mark.  The  weight 
of  the  rod,  divided  by  its  volume  gives  its  specific  gravity.  The  specific 
gravity  of  various  mixtures  of  wax  of  0.969  specific  gravity  and  paraffin 
of  0.871  are  given  in  the  following  table,  prepared  by  Wagner,  so  that 
from  the  specific  gravity  of  the  mixture  the  percentage  of  parafTin  can  be 
calculated : 


Wax 
(Percentage). 

Paraffin 
(Percentage). 

Specific 
Gravity. 

Wax 
(Percentage). 

Paraffin 
(Percentage). 

Specific 
Gravity. 

25 
50 

100 

75 
50 

.871 

■893 
.920 

75 

80 

100 

25 
20 

-942 
-948 
.969 

The  Refractometer  Reading  is  most  useful  in  establishing  the  purity 
of  wax.     Observations  with  this  instrument  are  best  made  at  65°  and 


*  U.  S.  Dept.  of  Agric,  Div.  of  Chem.,  Bui.  13,  p.  842. 


641 


FOOD  INSPECTION   y4ND   .4 N. 4 LYSIS. 


great  care  should  be  taken  in  the  case  of  the  Zeiss  butyro-refractometer 
not  to  exceed  this  temperature,  or  injur)-  to  the  instrument  may  resuh^ 
The  Abb^  refractometer  may  be  used  with  j>erfect  safety  and,  when 
available,  is  to  be  preferred  for  the  examination  of  beeswax.  Many 
food  laboratories  are,  however,  not  equipped  with  the  Abbe,  but  nearly 
all  find  the  butyro-refractometer  indispensable.  The  latter  instrument 
was  primarily  designed  for  such  substances  as  butter  and  lard,  so  that  the 


I-  IG.   1 1 1 . — Apparatus  for  Polarizing  at  High  Temperatures. 


manufacturers  did  not  intcnrl  it  to  be  subjected  to  as  high  a  temperature 
as  65°.  They  have,  however,  assured  the  author  that  if  care  be  taken 
to  bring  the  temperature  very  slowly  and  gradually  to  the  required  degree, 
65°,  and  to  avoid  also  sudden  'Cooling,  the  cement  that  secures  the  prisms 
in  place  will  not  be  appreciably  affected;  otherwise  cracking  or  loosening 
of  the  cement  would  be  liable  to  occur  after  a  time. 


SUGAR   AND   SACCHARINE   hRODUCTS.  645 

At  65°  C.  i)urc  l)eeswax  should  have  a  reading  on  the  butyro-refrac- 
tomeler  of  30  to  31.5,*  while  that  of  parafhn  is  from  11  to  14.5.! 


CONFECTIONERY. 

The  composition  of  confectionery-  is  more  complex  than  that  of  the 
saccharine  products  hitherto  considered.  As  a  rule,  cane  sugar,  or  one 
of  its  products,  as  molasses,  forms  the  basis  of  most  of  the  confections. 
Commercial  glucose  is  also  a  common  ingredient,  while  a  large  variety 
of  such  materials  as  eggs,  butter,  chocolate,  various  flavoring  extracts, 
spices,  nuts,  and  fruits,  enter  into  the  composition  of  confectionery. 

U.  S.  Standard  Candy  is  candy  containing  no  terra  alba,  barytes, 
talc,  chrome  yellow,  or  other  mineral  substances  or  poisonous  colors  or 
flavors,  or  other  ingredients  injurious  to  health. 

Adulteration. — Of  late  the  adulteration  of  confectioner)-  has  been 
held  largely  in  check  by  the  National  Confectioners'  Association  of  the 
United  States,  which  has  fixed  high  standards  of  purity,  and  has  been 
very  zealous  in  restricting  the  use  of  harmful  adulterants. 

Commercial  glucose  is  not  regarded  as  an  adulterant  of  confectionery 
by  the  above-named  association  and  by  but  few  of  the  state  laws.  On  the 
contrary,  any  ingredient,  other  than  color,  that  has  no  food  value,  may 
logically  be  considered  as  an  adulterant.  Under  this  head  are  included 
such  substances  as  parafhn,  as  well  as  make-weight  mineral  matters,  such 
as  terra  alba,  talc,  or  calcium  sulphate. 

B.  H.  Smith  %  has  called  attention  to  the  presence  of  arsenic  in  shellac 
used  to  coat  certain  kinds  of  confectionery. 

Colors  in  Confectionery. — A  very  wide  range  of  colors  is  necessarily 
employed  in  the  manufacture  of  confectioner}-,  and  the  almost  endless 
variety  of  coal-tar  dyes  now  available  lend  themselves  most  readily  to 
the  confectioner's  needs.  Elsewhere,  under  "colors,"  lists  of  injurious 
and  non-injurious  dyes  are  given  as  compiled  by  the  National  Confec- 
tioners' Association,  though  it  is  not  always  readily  apparent  how  the  lines 
are   drawn. 

The  tinctorial  power  of  these  dyes  is  so  high  that  the  actual  amoi.nt 
of  substance  contained  in  a  thin  coating  of  the  cok)r  on  the  outside  of  the 
candy  is  exceedingly  small,  so  that  it  is  doubtful  whether  serious  cases  of 
injury  have  ever  arisen  from  their  use. 

*  no,  1.4452  to  1.4463-  t  «D,  1.43T0  to  1.4335. 

X  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  91,  1912. 


^46  FOOD   INSPECTION  AND   ANALYSIS. 

Such  was  not  the  case  formerly,  before  the  ])revalencc  of  the  coal-tar 
dyes,  when  such  poisonous  mineral  j^igments  as  ehromate  of  lead  were 
frequently  used.  Only  one  or  two  instances  of  the  use  of  lead  chromate 
in  candy  have  come  to  the  author's  attention  within  ten  years,  since  more 
satisfactor}'  and  harmless  yellow  colors  among  the  azo-dyes  are  now 
obtainable. 

Analysis  of  Confectionery.— The  following  have  been  submitted 
by  the  author  as  ])rovisional  methods  of  procedure  for  the  A.  O.  A.  C.:* 

(i)  Products  of  Practically  Uniform  Composition  Throughout. — • 
(a)  Lozenges  and  Oilier  Pulverizable  Products. — Grind  in  a  mortar  or 
mill  to  a  fine  powder.  For  total  solids,  weigh  from  2  to  5  grams  of  the 
powdered  sample  in  a  tared  platinum  dish,  and  dry  in  a  McGill  oven 
to  constant  weight. 

For  .45//,  ignite  the  residue  from  total  solids  in  the  original  dish, 
observing  the  precautions  given  under  sugar  (p.  586),  and  molasses 
(p.  624). 

(b)  Semi- plastic,  Syrupy,  or  Pasty  Products. — Weigh  50  grams  of 
the  sample  into  a  250-cc.  graduated  flask,  mix  thoroughly  or  dissolve, 
if  soluble,  in  water,  and  fill  to  the  mark.  Be  sure  that  the  solution  is 
uniform,  or,  if  insoluble  material  is  present,  that  it  is  evenly  mixed  by- 
shaking  before  taking  aliquot  parts  for  the  various  determinations.  For 
total  solids  and  ash,  measure  25  cc.  of  the  above  solution  or  mixture  into 
a  tared  platinum  dish,  and  proceed  as  directed  under  (a). 

(2)  Confectionery  in  Layers  or  Sections  of  Different  Composition. — 
When  it  is  desired  to  examine  the  (lilTerent  portions  separately,  they 
should  be  separated  mechanically  with  a  knife,  when  possible,  and  treated 
as  directed  under  (i). 

(3)  Sugar-coated  Fruit,  Nuts,  etc. — In  case  of  a  saccharine  coating 
inclosing  fruit,  nuts,  or  any  less  readily  soluble  material,  dissolve  or 
wash  off  the  exterior  coating  in  water,  which  may,  if  desired,  be  evaporated 
to  dr}'ness  for  weighing,  and  ]>roceed  as  in  fi). 

(4)  Candied  or  Sugared  Fruits. — Proceed  as  in  the  examination  of 
fruits  rChay^tcr  XXI). 

Detection  of  Mineral  Adulterants. — As  in  the  case  of  molasses,  a 
considerable  quantity,  say  100  grams,  should  be  reduced  to  an  ash  for 
examination  for  mineral  adulterants,  such  as  talc,  calcium  sulphate,  and 

iron  oxide,  which  are  detected  by  regular  qualitative  tests. 

^i 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  44. 


SUGAR  AND   SACCHARINE   PRODUCTS.  647 

Detection  of  Lead  Chromate. — Fuse  the  ash  in  a  porcelain  crucible 
with  a  mixture  of  sodium  carbonate  and  potassium  chlorate,  boil  the 
fused  residue  with  water,  neutraliz.e  with  acetic  acid,  fiUer,  and  treat  the 
filtrate  with  barium  chloride  or  lead  acetate  solution.  A  yellow  pre- 
cipitate indicates  a  chromate.  Treat  the  insoluble  part  of  the  fusion 
with  nitric  acid,  and  test  for  lead  in  the  usual  manner. 

If  a  drop  of  ammonium  sulphide  be  applied  to  a  piece  of  confectionery 
colored  with  lead  chromate,  it  will  produce  a  black  coloration. 

Determination  of  Ether  Extract. — The  ether  extract  includes  the  fat 
derived  from  chocolate,  eggs,  or  butter,  as  well  as  any  paraffin  present. 
Measure  25  cc.  of  the  20%  solution  (i)  (b)  (p.  646)  into  a  very  thin, 
readily  frangible  glass  evaporating-shell  (Hoffnieister's  Schdlchen),  con- 
taining 5  to  7  grams  of  freshly  ignited  asbestos  fiber;  or,  if  impossible  to 
thus  obtain  a  uniform  sample,  weigh  out  5  grams  of  the  mixed,  finely 
divided  sample  into  a  dish,  and  wash  with  water  into  the  asbestos  in  the 
evaporating-shell,  using,  if  necessary,  a  small  portion  of  the  asbestos 
fiber  on  a  stirring-rod  to  transfer  the  last  traces  of  the  sample  from  dish 
to  shell.  Dry  to  constant  weight  at  100°,  after  which  cool,  wrap  loosely 
in  smooth  paper,  and  crush  into  rather  small  fragments  between  the 
fingers,  carefully  transferring  the  pieces  with  the  aid  of  a  camel's-hair 
brush  to  an  extraction-tube,  or  to  a  Schleicher  and  Schull  cartridge  for 
fat  extraction.  Extract  with  anhydrous  ether  or  with  petroleum  ether  in 
a  continuous  extraction  apparatus  for  at  least  twenty-five  hours.  Trans- 
fer the  solution  to  a  tared  flask,  evaporate  the  ether,  dr)'  in  an  oven  at 
100°  C.  to  constant  weight,  and  weigh. 

Determination  of  Paraffin. — Add  to  the  ether  extract  in  the  flask,  as 
above  obtained,  10  cc.  of  95%  alcohol,  and  2  cc.  of  i :  i  sodium  hydroxide 
solution,  connect  the  flask  with  a  reflux  condenser,  and  heat  for  an  hour 
on  the  water-bath  or  until  saponification  is  complete.  Remove  the  con- 
denser, and  allow  the  flask  to  remain  on  the  bath  till  the  alcohol  is  evapo- 
rated off,  and  a  dry  residue  is  left.  Treat  the  residue  with  about  40  cc. 
of  water,  and  heat  on  the  bath,  with  frequent  shaking,  till  ever\1;hing 
soluble  is  in  solution.  Wash  into  a  separatory  funnel,  cool,  and  extract 
with  four  successive  portions  of  petroleum  ether,  which  are  collected  in 
a  tared  flask  or  capsule.  Remove  the  petroleum  ether  by  evaporation,  and 
dr}^  in  the  oven  to  constant  weight. 

It  should  be  noted  that  any  phytosterol  or  cholesterol  present  in  the 
fat  would  come  dowTi  with  the  paraffin,  but  the  amount  would  be  so 
insignificant  that,  except  in  the  most  exacting  work,  it  may  be  disregarded. 


64S  l-'OOD   INP3ECTON  ^ND  /IN /i LYSIS. 

The  characicr  i)f  ihc  final  residue  should,  however,  be  confirmed  bv 
determining  is  melting-pt)in!  and  sj)ecifie  gravi  y,  and  by  subjecting  it 
to  examinaiion  in  the  butyro-refraciomeler.  The  melting-point  of  par- 
alTm  is  about  54-5°  C. ;  its  specific  gravity  at  15.5°  C.  is  from  0.868  to  0.915, 
and  on  the  butyro-refractomcter  the  reading  at  65°  C.  is  from  11  to  14.5. 

Determination  of  Starch. — Measure  gradually  25  cc.  of  a  20%  aqueous 
soluiion  or  uniform  mixture  of  the  sample  into  a  hardened  filter  or  Gooch 
crucible,  or  transfer  by  washing  5  grams  of  the  finely  ])owdered  substance 
to  the  filter  or  Gooch,  and  allow  the  residue  on  the  I'llter  to  become  air- 
dried.  Extract  with  I'lve  successive  porJons  of  10  cc.  of  ether,  then 
wash  with  150  cc.  of  lo^,'  alcohol,  and  fmally  with  20  cc.  of  strong  alcohol. 
Transfer  the  residue  to  a  large  flask  and  boil  gently  for  four  hours  with 
200  cc.  of  water  and  20  cc.  of  hydrochloric  acid  (specific  gravity  1.125), 
the  flask  being  provided  with  a  reflux  condenser.  Cool,  neutralize  with 
sodium  hydroxide,  add  5  cc.  of  alumina  cream,  and  make  up  the  volume 
to  250  cc.  with  water.  Fiher  and  determine  the  dextrose  in  an  aliquot 
part  of  the  filtrate  by  any  of  the  various  Fehling  methods.  The  weight 
of  the  dextrose  multi])licd  by  0.9  gives  the  weight  of  the  starch. 

Polarization  of  Confectionery. — As  a  clarifier  use  either  alumdna 
cream  or  subacelate  of  lead,  according  to  the  nature  and  opacity  of  the 
sample.  Ordinarily  alumina  cream  is  best,  but  in  dark-colored  samples, 
or  those  in  which  molasses  has  been  used,  it  is  sometimes  necessary  to 
employ  the  subacetate.  When  starch  is  absent,  and  the  sample  is  practi- 
cally soluble,  polarize  and  invert  in  the  usual  manner  (p.  588).  Where 
considerable  starch  or  insoluble  matter  is  present,  use  the  double-dilution 
method  of  Wiley  and  Ewell  (p.  620),  thus  making  due  allowance  for 
the  volume  of  the  ijrecijMtate. 

Cane  sugar,  invert  sugar,  and  drxlrin,  are  determined  as  directed 
for  honey. 

Commercial  glucose  is  roughly  determined  by  polarizing  the  sample 
at  87°  C,  as  in  the  case  of  honey  (p.  639). 

Confectionery  is  made  in  such  a  wide  variety  of  forms,  and  these  differ 
in  consistency  to  such  an  extent  that  commercial  glucose  of  all  available 
degrees  of  density  can  Ix-  utih'zed  to  advantage  in  one  product  or  another. 
In  this  respect  confectionery  is  unlike  lioney  and  molasses,  wherein  a 
fairly  uniform  grade  of  commercial  glucose  is  necessarily  used  for 
mixing,  this  grade  Vx'ing  naturally  selected  with  reference  to  its  similarity 
in  density  to  the   molasses.     On   this  account   the-  glucose  factor  used 


SUGAR    AND   SACCHARINE  PRODUCTS.  649 

for  honey  and  molasses  (175)  may  in  some  varieties  of  confectionery  be 
loo  high. 

Determination  of  Alcohol  in  Syrups  Used  in  Confectionery. — (Brand y- 
drops.) — Open  each  drop  by  cutting  off  a  section  with  a  sliarp  knife,  and 
collect  in  a  beaker  the  syrup  of  from  15  to  25  of  the  drops,  which 
will  usually  yield  from  30  to  50  grams  of  syrup.  Strain  the  syrup  into 
a  tared  beaker  through  a  perforated  porcelain  filter-plate  in  a  funnel 
to  separate  from  particles  of  the  inclosing  shell,  and  ascertain  the  weight 
of  the  syrup.  Wash  into  a  distilling-flask,  dilute  with  half  its  volume 
of  water,  and  distil  off  into  a  tared  receiving-flask  a  volume  equal  to  the 
original  volume  of  syrup  taken.  Ascertain  the  weight  of  the  distillate 
and  its  specific  gravity  by  means  of  a  pycnometer.  Multiply  the  per- 
centage by  weight  of  alcohol  corresponding  to  the  specific  gravity,  as 
found  in  the  tables  on  page  661  et  seq.,  by  the  weight  of  the  distillate,  and 
divide  this  by  the  weight  of  syrup  taken.  The  result  is  the  per  cent  by 
weight  of  alcohol  in  the  syrup. 

Detection  of  Colors. — It  is  sometimes  necessary  to  macerate  a  con- 
siderable mass  of  the  material  to  remove  the  color,  which  is,  however, 
in  the  majority  of  cases  readily  soluble.  The  insoluble  colors  are  nearly 
all  mineral  pigments  to  be  looked  for  in  the  ash,  as  in  the  case  of  chromate 
of  lead  (p.  647).  Frequently  the  coloring  matter  is  confined  to  a  thin 
outer  layer,  which  is  readily  washed  off. 

The  solution  of  the  dyestufif  is  examined  as  directed  under  colors. 

Detection  of  Arsenic. — Arsenic  may  be  present  through  impure 
coloring-matter.  If  the  color  is  confined  to  an  exterior  coating,  this 
should  be  washed  off  and  examined.  If  distributed  through  the  mass, 
a  solution  of  the  whole  should  be  taken.  Examine  for  arsenic  by  the 
Gutzeit  or  Marsh  method,  as  directed  on  pp.  74  to  77. 


650  FOOD   INSPECTION  AND    ANALYSIS. 


REFERENCES    ON    SUGARS. 

Babington,    F.    \V.     Sugars,    Syrups,  and   Molasses.     Can.    Inl.    Rev.    Dept.,  BuL 

25- 

Maple  S}Tup.     Can.  Inl.  Rev.  Dept.,  Bui.  45. 

B.^RTLEY,  E.  H.,  and  Mayer,  J.  L.     Identification  of  Carbohydrates.     Merck's  Report, 

12,  1903,  p.  100. 
Brown,  H.  T.,  Morris,  G.  H.,  and  Millar,  J.  H.    Experimental  Methods  Employed' 

in  the  Examination  of  the  Products  of  Starch  Hydrolysis  by  Diastase.     Jour. 

Chem.  See.  Trans.,  71  (1897),  p.  72. 
Browne,  C.  A.     The  Analysis  of  Sugar  Mixtures.     Jour.  Am.  Chem.   Soc,  28,  1906, 

P-  439- 
Chemical  Analysis  and  Composition  of  American  Honeys.     U.  S.  Dept.  of  Agric.,, 

Bur.  of  Chem.,  Bui.  no. 

The  Unification  of  Saccharimetric  Observations.    A.O.  A.C.  Proc.  1908,  p.  221. 

A  Handbook  of  Sugar  Analysis.      New  York,  191 2. 

Bryan,     X.     H.       The     Estimation     of     Dry    Substance     by    the    Refractometer 

in     Liquid     Saccharine    Food   Products.     Jour.    Am.    Chem.    Soc,    30,  1908, 

p.  1443. 
Methods  for  the  .\nalysis  of  Maple  Products  and  the  Detection  of  Adulterants,. 

together  with  the  Interpretation  of  Results  Obtained.     U.  S.  Dept.  of  Agric,. 

Bur.  of  Chem.,  Circ.  No.  40. 

Maple  Sap  Sirup.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  134. 

Chemical  .Analyses  and  Composition  of  Imported  Honey  from  Cuba,  Mexico, 

and  Haiti.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  154,  191 2. 
DoOLiTTLE,  R.  E.,  and  Seeker,  .\.  F.     TTie  Possibilities  of  Muscovado  Sugar  as  an 

.•\flultcrant  for  Maple  Products.     A.  O.  A.  C.  Proc.  1908.     U.  S.  Dept.  of  Agric, 

Hur.  of  Chem.,  Bui.  122,  p.  196. 
Notes  on  the  Winton   Lead  Number  of  Mixtures  of  Cane  and   Maple  Syrup. 

Ibid.,  p.  198. 
Fresenius,  W.     Der  Starkesirup  bei  Zubereitung    von  Nahrungs-  und  Genussmitteln. 

Zeits.  Unters.  Nahr.  Genuss.,  2,  1899,  pp.  35  u.  279. 
Fruhlino,   R.     .^nleitung  zur  Untersuchung  der  fiir  die  Zuckerindustrie.     6th  ed. 

Braun.sweig,  1903. 
Hiltner,    K.    S.,  and   Thatcher,    R.    W.     An    Imj)rove(i    Method   for   the   Rapid 

Estimation    of     Sugar    in      Beets.       Jour.    Am.    Chem.    Soc,    23,     1901,    p. 

299. 
HORNE,  W.  D.     The  Chemical  Determination  of  Sulphites  in  Sugar  Products.     U.  S. 

Dept.  of  .Agric,  Bur.  of  Chem.,  Bui.  105,  1906,  p.  125. 
HoRT\T.T,  J.     The  Chemical  Comfxjsition  of  MajjJe-Syrup  and  Maple-Sugar,  Methods 

of  .Analysis,  and  Detection  of  .Adulteration.     Jour.  Am.  Chem.  Soc,  26,  1904, 

P-  1523- 


SUGAR   AND  SACCHARINE    PRODUCTS.  651 

Jones,  C.  H.     Detection  of  Adulteration  in  Maple  Sugar  and  Nfaple  Syrup.     Vt.  Agric. 

Exp.  Sta.  Rep.,  1903,  p.  446. 
Maple    Syrup    and    Maple    Sugar    Investigations    with    Particular    Reference 

to    the     Detection    of   Adulteration.      Vt.    Agric.    E.xp.    Sta.    Rep.,    1904,    p. 

315- 
Landolt,    H.       Handbook    of    the     Polariscope     and     its     Practical     Applications, 

1882. 
• Trans,    by    Long,    J.    H.     Optical    Rotation    of    Organic    Substances.     Easton, 

1902. 
Leach,  A.  E.     The  Determination  of  Commercial  Glucose  in  Molasses,  Syrups  and 

Honey.     Jour.  Am.  Chem.  Soc,  25,  1903,  p.  982. 

Saccharine  Products.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  43. 

Lock  and  Newlands.     A  Handbook  for  Planters  and  Refiners.     London,  1888. 

Macfarlane,  T.     Honey.     Can.  Inl.  Rev.  Dept.,  Bui.  45. 

MuNSON,  L.  S.,  and  Walker,  P.  H.     The  Unification  of  Reducing  Sugar  Methods. 

Jour.  Am.  Chem.  Soc,  28,  1906,  p.  663. 
Robin,  L.     Sucres.     Analyse  des  Matieres  Alimentaires  (Girard  et  Dupre),  p.  525. 

Paris,  1894. 
Ross,   S.   H.     Suggested  Modification  of  the  Winton    Lead    Number,    Especially  as. 

Applied  to  Mixtures  of  Maple  and  Cane  Sugar  Sirups.     U.  S.  Dept.  of  Agric, 

Bur.  of  Chem.,  Circ.  53. 
Roth,  H.  L.     A  Guide  to  the  Literature  of  Sugar.     London,  1890. 
Sachsse,  R.     Die  Chemie  der  Kohlenhydrate.     Leipzig,  1877. 
Sawyer,  H.  E.     The  Commercial  Analysis  of  Molasses.     Jour.  Am.  Chem.  Soc,  27, 

1905,  p.  691. 
Shutt,  F.  F.,  and  Charron,  A.  T.     Determination  of  Moisture  in  Honey.     Trans. 

Royal  Soc.  Canada,  2d  Series,  1902-3,  7,  Section  3. 
Sidersky,  D.     Traite  d'Analyse  des  Matieres  Sucrees.     Paris,  1890. 
Spencer,    G.   L.     Handbook   for   Sugar   Manufacturers  and   their   Chemists.     New 

York,  1905. 
Steydn,    E.     Die   Untersuchung   des    Zuckers   und   Zuckerhaltiger   StofTe.     Leipzig, 

1893. 
Sy,  a.  p.     Note  on  the  Examination  of  Maple  Products — The  Lead  Value.     J.  Frank. 

Inst.,  162,  p.  71. 
■ Three  New  Preliminary  Tests  for  Maple  Products.     Jour.  Am.  Chem.  Soc,  30, 

1908,  p.  1429. 
ToLLENS,  B.     Handbuch  der  Kohlenhydrate.     Breslau,  1888. 
ToLMAN,  L.  M.,  and  Smith,  W.  B.     Estimation  of  Sugars   by  Means  of  the  Refrac- 

tometer.     Jour.  Am.  Chem.  Soc,  28,  1906,  p.  1476. 
Tucker,  J.  H.     Manual  of  Sugar  Chemistry.     New  York,  1890. 
Walker,  P.  H.     The  Unification  of  Reducing  Sugar  Methods.     Jour.  Am.   Chem. 

Soc,  29,  1907,  p.  541. 
Weichmann,  F.  S.     Sugar  Analysis.     New  York,  1890. 
Wein,  E.     Tabellen  zur  quantitativen  Bestimmung  der  Zuckerarten. 
~ Trans,  by  Frew,  W.     Tables  for  the  Quantitative  Estimation  of  the  Sugars- 
London,  i8q6. 


652  FOOD  INSPECTION   AND  ANALYSIS. 

\\\ix\,  H.  W  .     Sugar,  Molasses  and  Syrup,  Confections,  Hineyand  Beeswax.    U.S. 

Depth  of  Agric,  Div.  of  Chem.,  Bui.  13.  ])art  6. 
The    Influence    of    Temperature    on    the    Specific    Rotation     of    Sucrose    and 

Method    of     Correcting    Readings    of    Compensating    Polariscopes    Therefor. 

Jour.  Am.  Chem.  Soc.  21.  i8qo,  P-  568. 
AViNTON,  .■\.  L.,  and  Kreider,  J.  Lehn.     A  Method  for  the  Determination  of  Lead 

Number  in  Maple  Syrup  and  Maple  Sugar.     Jour.  Am.  Chem.  Soc,  28,  1906, 

p.  1204. 
YoPER,  P.  A.     l'el)er  das  \'orkommen  von  Formaldehvd  in  ZAickcrfabriks-erzeugnissen. 

Zeits.  Unters.  Nahr.  Genuss.,  20,  1910,  p.  208. 
A  Polariscopic  Method  for  the  Determination  of  Malic  Acid  and  its  Applica- 
tion in  Cane  and  Maple  Products.     Jour.  Ind.  Eng.  Chem.,  3,  1911,  p.  563. 
Notes  on  the  Determination  of  Acids  in  Cane  Juice.     Jour.  Ind.  Eng.  Chem., 

3,  lOI I,  p.  640. 
YouN'G.  W.  J.     .\  Miscroscopic  Study  of  Pollen.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem., 

Bui.  no. 


CHAPTER  XV. 

ALCOHOLIC  BEVERAGES. 

Alcoholic  Fermentation. — In  a  broad  sense  all  alcoholic  liquors  are 
saccharine  products,  in  that  they  are  essentially  the  result  of  the  fermen- 
tation of  sugar.  In  the  case  of  fruits,  the  sugar  already  exists  as  such 
in  their  juices,  which,  when  expressed,  almost  immediately  on  exposure 
to  the  air  begin  to  undergo  spontaneously  the  process  of  alcoholic  fermen- 
tation, in  accordance  with  the  reaction: 

(1)  C9H,206=2C2H«0+2C02. 

Dextrose  or         Alcohol  Carbon 

grape  sugar  dioxide 

In  the  case  of  grains  the  process  is  more  complex,  involving  a  preliminar\' 
saccharous  fermentation,   whereby  the   starch  is  first   transformed   into 
sugar. 
Thus 

(2)  2CeHioO,+  H20  =  CeHioO,  +  CsH^Oe. 

Starch  Dextrin  Dextrose 

(3)  CeH,o05+H20  =  C«H,30e. 

Dextrin  Dextrose 

The  process  of  alcoholic  or  vinous  fermentation  is  largely  dependent 
upon  the  presence  of  various  species  of  yeasts,  which  either  exist  from 
the  first  in  the  expressed  juices  themselves,  as  in  the  case  of  wines,  being 
derived  from  the  skins  of  the  grapes  and  from  the  air,  or  are  introduced 
with  some  degree  of  selection,  as  in  the  case  of  beer. 

In  the  juices  of  most  fruits  the  sugar  exists  in  the  form  of  sucrose, 
mixed  with  variable  amounts  of  invert  sugar  resulting  from  the  inver- 
sion of  the  sucrose  due  to  the  action  of  ferments,  such  as  invertase,  a 
soluble  ferment  of  yeast.  The  invert  sugar  nearly  always  predominates, 
and  in  some  juices,  as  for  instance  the  grape,  nearly  all  the  sugar  has  been 
inverted. 

653 


654  FOOD  INSPECTION  AND  ANALYSIS. 

The  above  reaction,  No.  i,  illustrating  the  splitting  up  of  grape  sugar 
into  alcohol  and  carbon  dioxide,  does  not  represent  the  practical  yield 
of  alcohol  under  ordinary'  conditions  that  occur  in  vinous  fermentation, 
for,  as  a  matter  of  fact,  instead  of  51.11  parts  of  alcohol  and  48.89  parts 
carbon  dioxide.,  which  would  theoretically  result  as  above  from  the  fer- 
mentation of  ICO  parts  of  dextrose,  only  about  g^%  of  the  theoretical 
yield  can  be  obtained,  so  that  in  practice  it  is  possible  to  form  but  about 
48.5%  alcohol  and  A^-^^c  carbon  dioxide.  The  balance,  amounting 
to  some  5%,  consists  chiefly  of  glycerin,  succinic  acid,  and  traces  of 
various  compounds,  including  some  of  the  higher-boiling  alcohols  (propyl, 
butyl,  and  amyl)  and  their  ethers,  which  form  the  fusel  oil  of  the  dis- 
tilled  liquors. 

Vinous  fermentation  takes  place  most  readily  in  slightly  acid  liquids, 
at  a  temperature  ranging  from  25°  to  30°  C. 

It  is  convenient  to  divide  alcoholic  beverages  into  two  main  groups, 
first  the  fermented  and  second  the  distilled  liquors.  The  fermented 
liquors  naturally  subdivide  themselves  into  {a)  the  products  of  the  direct 
spontaneous  fermentation  of  saccharine  fruit  juices,  such,  for  example, 
as  those  of  the  apple  and  the  grape,  to  form  cider  and  wine  respectively, 
and  {h)  the  malted  and  brewed  liquors,,  such  as  beer  and  ale,  produced 
by  the  conversion  of  the  starch  of  grain  into  sugar,  and  the  fmal  alcoholic 
fermentation  of  the  latter. 

The  distilled  liquors  include  such  products  as  whiskey,  brandy,  rum, 
and  gin,  wherein  alcoholic  infusions  prepared  by  previous  fermentation 
in  various  ways  are  further  subjected  I0  distillation. 

Alcoholic  Liquors  and  State  (or  Municipal)  Control. — The  mere 
adulteration  of  liquors  does  not  constitute  the  only  feature  which  brings 
them  within  the  scope  of  the  public  analyst's  work  and  renders  them 
especially  amenable  to  stringent  laws.  Indeed,  it  is  often  a  far  more 
im[j<jrtant  question  for  the  analyst  to  decide  by  his  results  whether  or 
not  the  samples  submitted  to  him,  by  police  seizure  or  otherwise,  are 
sold  in  violation  of  the  regulations  in  force  in  his  particular  locality  govern- 
ing the  liquor  trafiic. 

A  common  regulation  in  no-license  localities  fixes  the  maximum  per 
cent  of  alcohol  which  shall  decide  whether  or  not  a  liquor  is  legally  a 
temperance  drink,  and  can  be  sold  as  such  with  imj)uniiy.  From  its  low 
content  in  alcohol,  an  analyst's  findings  regarding  a  certain  sample  may 
exonerate  the  dealer  suspected  of  \iolating  this  law,  while  yet  by  the 
very  reason  of  its  being  low  in  alcohol  the  same  sample  would  be  placed 


ALCOHOLIC  BEi/ER/tGES.  O55 

in  the  adulterated  list  as  regards  non-conformance  to  a  standard  of  purity. 
While  the  raising  of  revenue  is  one  j)urpose  for  the  existence  of  these 
laws  bearing  on  liquor  license,  an  equally  important  object  sought  to  be 
gained  is  doubtless  the  repression  of  intemperance. 

Toxic  Effects. — A  popular  impression  seems  to  exist  that  the  toxic 
effects  of  an  adulterated  licjuor  are  far  worse  from  a  temperance  stand- 
point than  those  of  a  sample  of  good  standard  quality,  and  it  is  a  common 
experience  of  the  public  analyst  to  have  submitted  to  him  by  well-mean- 
ing temperance  advocates  sam])les  which  are  alleged  to  have  caused 
the  worst  forms  of  intoxication,  and  are  thus  suspected  of  being  impure. 
As  a  matter  of  fact  the  chief  adulterants  of  liquors  are  water,  sugar,  and, 
in  the  case  of  beer,  various  bitter  principles  and  vegetable  extractives, 
none  of  which  are  on  record  as  being  in  themselves  actively  toxic* 

Alcohol  is  the  one  ingredient  of  liquor  which,  more  than  any  other, 
produces  a  marked  physiological  effect.  ]\Iany  liquors,  especially  those 
of  the  distilled  variety  classed  as  adulterated,  are  so  considered  by  reason 
of  their  low  alcoholic  content  through  watering  or  otherwise,  hence  this 
commonest  form  of  adulteration,  far  from  being  detrimental  in  itself,  is 
actually  helpful  to  the  temperance  cause. 

Details  of  Liquor  Inspection. — The  same  precautions  should  be 
carefully  observed  by  officers  making  seizures  of  liquors  for  analysis, 
as  by  food  inspectors,  regarding  safe  deliver)^  of  the  samples  to  the 
analyst.  The  following  instructions  are  circulated  by  the  State  Board 
of  Health  of  Massachusetts,  which  has  in  charge  the  inspection  of  liquors, 
concerning  the  taking  of  samples  in  that  state  and  the  transmission  to 
the  analyst: 

DIRECTIONS    FOR   TAKING    SAMPLES    FOR   ANALYSES. 

The  officer  making  a  seizure,  or  taking  samples  of  beer,  should  note 
at  the  time  of  such  seizure  the  general  appearance  of  the  liquor, — as  to 
whether  it  is  clear  or  cloudy,  whether  it  is  still  or  has  a.  strong  head. 

If  the  liquor  is  in  bottles,  take  at  least  one  pint  bottle;  if  in  barrels, 
draw  a  pint  bottle  from  each.  Request  the  owner  to  seal  each  sample 
taken.  If  the  bottles  have  cork  stoppers,  cut  the  stoppers  off  level  with 
the  top  of  the  bottle  and  cover  with  wax;  if  with  patent  stoppers,  a  little 
wax  placed  upon  the  wire  at  the  point  where  it  lays  against  the  neck  of 
the  bottle  is  sufficient.     If  the  owner  refuses  to  seal  it,  then  the  officer 

*  The  writer  refers  to  substances,  intentionally  added,  and  not  to  accidental  impurities, 
such  as  arsenic,  etc.,  that  are  occasionally  *'ound.  '    -  -       \ 


656  FOOD  INSPECTION  AND  AN /t LYSIS. 

should  seal  it  in  his  presence,  calling  his  attention  to  the  fact.  Before 
leaving  the  premises,  place  upon  the  bottle  a  label  or  tag,  with  the  date, 
the  name  of  the  owner,  and  the  name  of  the  officer  upon  it,  and  also  the 
name  of  the  town  or  city.  Then  place  in  a  box,  with  the  certilicate 
required  by  law,  and  forward  without  delay  to  the  analyst. 

FORM   OF   LABEL. 

Town 

Date  of  seizure 19 

Owner 

Kind  of  liquor 

Brewer 

Accompanying  each  sample  is  a  certilicate  litie  the  following,  the 
first  part  of  which  is  filled  out  and  signed  by  the  ofiicer,  wliile  the  second 
part,  containing  the  data  of  analysis,  is  filled  out  and  signed  by  the  analyst 
and  returned  by  him  to  the  officer.  Such  a  certificate  is  nearly  always 
accepted  as  evidence  in  court  without  the  personal  appearance  of  the 
analyst. 

.' ss  19    . 

To  the  State  Board  of  Health: 

I  send  herewith  a  sample  of 

taken  from  liquors  seized  by  me 19     . 

Ascertain  the  percentage  of  alcohol  it  contains,  by  volume,  at  sixty 
degrees  Fahrenheit,  and  return  to  me  a  certificate  herewith  upon  the 
annexed  form. 
Seized  from 


Officer. 

COMMONWEALTH  OF  MASSACHUSETTS. 

No 

Office  of  the  State  Board  of  Health. 

Boston, 19     . 

This  is  to  certify  that  the received  by  me 

with  the  above  statement  contains I)er  cent  of  alcohol, 

by  volume,  at  sixty  degrees  Fahrenheit.  '^^ 

Received 19     • 

Analysis  made 19     . 


[seal.]  Analyst  State  Board  of  Health. 


ALCOHOLIC  BEVERAGES.  657 

A  convenient  method  for  recording  analyses  is  by  the  emplc-yment 
of  numbered  library  cards,  which  bear  the  same  number  as  the  certificates 
and  are  kept  by  the  analyst. 

The  following  is  a  convenient  form: 


No Analyzed 

County Wt.  flask  and  ale 

City  or  town Wt.  flask 

Officer Wt.  ale 

Defendant Sj).  gr.  ak .  (60^) 

Address Per  ct-nt  alcohol 

Kind  of  li(iuor Reported 

Seized 

Received 

How  delivered 

Sealed 

Condition 

Kind  of  bottle 

Registered 

METHODS    OF   ANALYSIS    COMMON   TO   ALL   LIQUORS. 

Specific  Gravity. — This  should  be  taken  at  15.6°  or  calculated  to 
that  temperature.  The  most  convenient  mode  of  procedure  is  to  bring 
the  temperature  of  the  sample  somewhat  below  that  point  by  allowing 
the  flask  containing  it  to  stand  in  cold  water,  and  to  have  everything  in 
readiness  to  make  the  determination  when  15.6°  temperature  has  been 
reached,  either  by  the  hydrometer  spindle  in  a  glass  cylinder,  by  the 
Westphal  balance,  or  by  the  pycnometer.  The  latter  is  by  far  the  most 
accurate,  especially  if  it  is  of  the  form  which  is  fitted  with  a  thermometer- 
stopper. 

Detection  of  Alcohol. — It  is  rarely  necessan,-  to  make  a  qualitative 
test  for  alcohol  in  liquors,  since  it  is  almost  invariably  present  even  in 
many  of  the  so-called  temperance  drinks,  at  least  in  small  amount. 
Indeed  in  many  localities  a  beverage  is  legally  a  temperance  drink  that 
contains  not  more  than  1%  alcohol  by  volume. 

The  Iodoform  Test. — Alcohol,  when  present  in  aqueous  solution  to 
the  extent  of  0.1%  or  more,  may  be  detected  by  the  iodoform  test.  The 
solution  is  warmed  in  a  test-tube  with  a  few  drops  of  a  strong  solution 
of  iodine  in  potassium  iodide,  after  which  enough  sodium  hydroxide 
solution  is  added  to  nearly  decolorize.  On  standing  for  some  time  a 
yellow  precipitate  of  iodoform  will  appear  if  alcohol  be  present,  or  at 
once  if  there  is  a  considerable  amount,  and  the  characteristic  odor  of 
iodoform  will  be  rendered  apparent,  even  when  the  precipitate  is  so  slight 
as  to  be  almost  imperceptible.  This  iodoform  precipitate  is  crystalline, 
showing  under  the  microscope  as  star-shaped  groups  or  hexagonal  tablets. 


e-i'''.  FOOD  INSPECTION  /iND  /ANALYSIS. 

It  should  not  be  forgotten  thai  other  substances  than  alcohol  give  the 
reaction,  as  lactic  acid,  acetone,  and  various  aldehydes  and  ketones. 

Pure  methyl  or  amy]   alcohol  or  acetic  acid  do  not  thus  react. 

Bcrthclot  recommends  benzoyl  chloride  as  a  reagent  for  detecting 
alcohol.  By  warming  a  mixture  of  a  few  drops  of  benzoyl  chloride  wath 
the  solution  to  be  tested,  and  adding  a  little  sodium  hydroxide,  ethyl 
benzoate  is  formed,  recognizable  by  its  distinctive  odor.  This  reaction 
is  delicate  to  o.i^c  alcohol.  The  presence  of  other  alcohols  than  ethyl 
produces  ethers  of  characteristic  odor. 

Hardy  s  Tcsl  jor  Alcohol  consists  in  shaking  the  aqueous  solution 
with  some  powdered  guaiacum  resin,  filtering,  and  adding  to  the  filtrate 
a  little  hydrocyanic  acid  and  a  drop  of  dilute  copper  sulphate  solution. 
A  blue  coloration  considerably  deeper  than  that  due  to  the  copper  salt 
is  indicative  of  alcohol. 

Methyl  Alcohol  in  spirits  is  tested  for  as  described  on  pp.  749-752. 

Determination  of  Alcohol. — In  the  case  of  carbonated  lic^uids  it  is 
necessary  to  first  expel  the  free  carbon  dioxide,  which  is  readily  accom- 
plished by  pouring  the  liquor  back  and  forth  from  one  beaker  to  another, 
from  time  to  time  removing  the  excess  of  froth  from  the  top  of  the  vessel 
b}-  the  aid  of  the  hand.  Or,  the  sample  may  be  shaken  vigorously  in  a 
large  separatory  funnel,  and  the  still  liquor  drawn  off  from  below  the 
froth,  repeating  the  operation  several  times  if  necessary.  In  either 
case  the  mechanical  treatment  should  be  continued  till  the  liquor  is  com- 
paratively quiet  and  free  from  foam. 

(i)  By  Distillation. — This  is  by  far  the  most  accurate  method  of 
determining  alcohol,  and  should  be  carried  out  in  all  cases  where  any 
legal  controversy  is  apt  to  be  involved.  Into  a  flask  of  250  to  400  cc. 
capacity  introduce  a  convenient  cjuanlity  of  the  liquor,  which  should  be 
accurately  weighed  or  measured,  according  to  whether  the  ])ercentage 
by  weight  or  measure  is  desired.  The  following  are  suitable  quantities; 
Distilled  liquors,  25  grams  or  cc;  cordials,  25  to  50  grams  or  cc;  wines, 
ciders,  and  malt  licjuors,  100  grams  or  cc.  In  the  case  of  wines  or 
ciders  which  have  undergone  acetic  fermentation,  add  o.i  to  0.2  gram  of 
precipitated  calcium  carbonate  or  neutralize  with  standard  alkali. 

Dilute  the  liquid  to  1 50  cc.  and  distil  into  a  loo-cc  flask.  Nearly 
all  alcoholic  liquors,  if  comi)aralively  free  from  carbon  dioxide,  will 
boil  without  undue  frothing  or  foaming.  New  wine  will  occasionally 
give  trouble  in  this  regard,  but  foaming  may  usually  be  prevented  in  this 


/ILCOHOUC  nnyERAGES.  659 

case  by  the  addition  of  tannic  acid.  In  case  of  wine,  cider,  and  beer 
all  the  alcohol  will  have  passed  over  in  the  first  75  cc.  of  the  distillate, 
or  three-fourths  the  original  measured  volume,  but  with  distilled  liquors 
high  in  alcohol  the  process  had  better  be  continued  till  nearly  100  cc.  or 
the  original  volume  taken  have  passed  over.  If  the  condenser  is  of  glass, 
one  can  observe  when  all  the  alcohol  has  been  distilled  over,  for  the  reason 
that  the  mixed  alcohol  and  water  vapors  in  the  upper  portion  of  the  con- 
denser present  a  striated  or  wavy  appearance,  readily  apparent  so  long 
as  the  alcohol  is  passing  over,  while  after  all  the  alcohol  has  been  distilled, 
the  condenser-tube  appears  perfectly  clear.  The  distillation  is  thus 
continued  for  some  time  after  this  striated  appearance  has  ceased.  The 
distillate  in  the  receiving  glass  is  finally  made  up  to  the  mark  or  to  the 
original  volume  of  the  liquor  taken.  Strictly  speaking,  the  measure- 
ments before  and  after  distillation  should  be  made  at  15.6°  C,  but,  except- 
ing in  case  of  distilled  liquors,  no. appreciable  error  resuhs  from  making 
both  measurements  at  the  same  or  room  temperature.  Another  precau- 
tion formerly  thought  necessary  w^as  to  have  the  delivery-tube  from  the 
condenser  pass  below  the  level  of  a  little  water  in  the  receiving-flask 
from  the  start,  but  equally  accurate  results  have  been  obtained  by  simply 
allowing  the  end  of  the  condenser-tube  to  enter  the  narrow-necked  flask. 

Fig.  112  shows  a  bank  of  six  stills  of  the  kind  used  in  the  author's 
laboratory  for  alcohol  determination  in  liquors.  In  each  still  the  verti- 
cal glass  worm-condenser,  the  round-bottomed  distilling-fiask,  and  the 
lamp,  are  supported  by  rings  held  by  a  single  upright  rod.  The  receiving- 
flask  is  readily  connected  with  the  condenser  by  means  of  a  single  bent 
tube  provided  with  a  rubber  stopper.  The  cold-water  pipe  supplving 
the  condensers  is  shown  at  the  top,  and  the  gas-supply  pipe  at  the  bottom. 

The  distillate,  made  up  to  100  cc,  is  thoroughly  shaken  and  its 
specific  gravity  taken  at  exactly  15.6°  in  a  pycnometer,  or  by  the  Westphal 
balance.  From  the  specific  gravity  the  corresponding  percentage  of 
alcohol  by  weight  or  volume,  or  the  grams  per  100  cc.  in  the  distillate, 
is  ascertained  by  reference  to  the  accompanying  tables. 

To  obtain  percentage  of  alcohol  by  weight  in  the  sample,  multiply 
the  per  cent  by  weight  in  the  distillate  by  the  weight  of  the  distillate,  and 
divide  by  the  weight  of  the  sample  taken;  to  obtain  per  cent  by  volume, 
multiply  the  per  cent  by  volume  in  the  distillate  by  100,  and  divide  by 
the  volume  of  the  sample  used. 

(2)  From  the  Specific  Gravily  of  the  Sample. — In  the  case  of  dis- 
tilled li(]uors  having  very  little   residue,   an  approximation  to  the  true 


66o 


FOOD  INSPECTION  AND  ANALYSIS. 


percentage  of  alcohol  may  be  obtained  by  using  the  alcohol  table  in  con- 
nection with  the  specific  gravity  of  the  liquor  itself.  The  accuracy  of 
this  method  depends  largely  on  the  freedom  from  residue,  being  absolutely 
correct  for  mixtures  of  alcohol  and  water  only. 

(3)  By  Evaporation.— D^itrmmc  the  specific  gravity  of  the  sample, 
evaporate  a  measured  portion  of  the  liquor  (50  or  100  cc.)  in  a  porcelain 


FiG.   1 1  2. — Bank  of  Stills  for  Alcohol  Determination. 

dish  over  the  water-bath  to  one-fourth  its  bulk,  make  up  to  its  original 
volume  with  distilled  water,  and  determine  the  specific  gravity  of  this 
second  or  dealcoholized  portion.  Add  i  to  the  original  specific  gravity, 
and  from  this  subtract  the  second  specific  gravity.  The  difference  is 
the  specific  gravity  corresponding  to  the  alcohol  in  the  liqutjr,  the  per 
cent  of  which  is  found  from  the  table. 

Example. — .Suppose  the  specific  gravity  of  the  original  sample  to  be 
0.9900  while  that  of  the  dealcoholized  sample  is  1.0009.  Then  1.9900  — 
1.0009  =  0.989 r.     •'•  P  r  Cent  by  volume  of  alcohol  =  8. 10. 


y4LCOHOUC  BEyER^GES. 


661 


SPECIFIC  GRAVITY  AND  PERCENTAGE  OF  ALCOHOL. 
(According  to  Hehner.) 


Spec. 

Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Grav. 

at 
15.6°  C. 

Per 
Cent 

Per 
Cent 

Grams 

Grav. 

at 
13.6°  C. 

Per 
Cent 

Pel 

Cent 

Grams 

Grav. 

at 
iS.6°C. 

Per 
Cent 

Per 
Cent 

Grams 

by 

by  Vol- 

per 
100  cc. 

by 

by  Vol- 

per 

by 

by  Vol- 

per 

Weight 

ume. 

Wejo;ht 

ume. 

Weight 

ume. 

1 00  cc 

I .0000 

0.00 

0.00 

0.00 

0.9999 

0.05 

0.07 

0.05 

0-9959 

2-33 

2-93 

2.32 

0.9919 

4.69 

5-86 

4-65 

8 

O.II 

0.13 

O.II 

8 

2-39 

3.00 

2-38 

8 

4-75 

5-94 

4.71 

7 

0.16 

0.20 

0.16 

7 

2-44 

3-07      2.43 

7 

4.81 

6.02 

4-77 

6 

0.21 

0.26 

0.21 

6 

2.50 

3.14      2.49 

6 

4-87 

6.10 

4-83 

5 

0.26 

0-33 

0.26 

5 

2.56 

3-21      2.55 

5 

4-94 

6.17 

4.90- 

4 

0.32 

0.40 

0.32 

4 

2.61 

3-28 

2.60 

4 

5.00 

6.24 

4-95 

3 

0-37 

0.46 

0.37 

3 

2.67 

3-35 

2.65 

3 

5.06 

6.32 

5.01 

2 

0.42 

0-53 

0.42 

2 

2.72 

3-42 

2.70 

2 

5-12 

6.40 

5-07 

I 

0.47 

0.60 

0.47 

1 

2.78 

3-49      2.76 

I 

5-19 

6.48 

5-14 

0 

0-53 

0.66 

0-53 

0 

2.83 

3-55      2-81 

0 

5-25 

6-55 

5.20 

0.9989 

0.58 

0-73 

0.58 

0.9949 

2.89 

3.62      2.87 

0.9909 

5-31 

6.63 

5-26 

8 

0.63 

0.79 

0.63 

8 

2.94 

3.69      2.92 

8 

5-37 

6-71 

5-32 

7 

0-68 

0.86 

0.68 

7 

3.00 

3-76 

2.98 

7 

5-44 

6-78 

5-39 

6 

0-74 

0-93 

0.74 

6 

3.06 

3-83 

3-04 

6 

5-50 

6.86 

5-45 

5 

0.79 

0.99 

0.79 

5 

3.12 

3-90 

3.10 

5 

5-56 

6-94 

5-51 

4 

0.84 

1.06 

0.84 

4 

3.18 

3-98 

3.16 

4 

5.62 

7.01 

5-57 

3 

0.89 

I-13 

0.89 

3 

3-24 

4-05 

3-22 

3 

5-69 

7.09 

5-64 

2 

0-95 

1. 19 

0-95 

2 

3-29 

4.12      3.27 

2 

5-75 

7.17 

5-70 

I 

1. 00 

1.26 

1. 00 

I 

3-35 

4-20          T,.7,^ 

I 

5-81 

7-25 

5-76 

0 

1.06 

1-34 

1.06 

0 

3-41 

4-27      3-39 

0 

5-87 

7-32 

5.81 

0.9979 

1. 12 

1.42 

1. 12 

0.9939 

3-47 

4-34 

3-45 

0.9899 

5-94 

7.40 

5-88 

8 

1. 19 

1-49 

1. 19 

8 

3-53 

4-42 

3-51 

8 

6.00 

7-48 

5-94 

7 

1-25 

1-57 

1-25 

7 

3-59 

4-49 

3-57 

7 

6.07 

7-57 

6.01 

6 

I-31 

1.65 

1-31 

6 

3-65 

4-56      3-(>3 

6 

6.14 

7.66 

6.07 

5 

1-37 

1-73 

1-37 

5 

3-71 

4-63 

3-69 

5 

6.21 

7-74 

6.14 

4 

1-44 

1. 81 

1-44 

4 

3-76 

4.71 

3-74 

4 

6.28 

7-83 

6.21 

3 

1-50 

1.88 

1-50 

3 

3.82 

4.78 

3-80 

3 

6.36 

7-92 

6.29 

2 

1-56 

1.96 

1.56 

2 

3-88 

4-85 

3-85 

2 

6.43 

8.01 

6.36 

1 

1.62 

2.04 

1. 61 

I 

3-94 

4-93 

3-91 

I 

6.50 

8.10 

6.43 

0 

1.69 

2.12 

1.68 

0 

4.00 

5.00 

3-97 

0 

6.57 

8.18 

6.50 

0.9969 

I -75 

2.20 

1-74 

0.9929 

4.06 

5 -08 

4-03 

0.9889 

6.64 

8.27 

6-57 

8 

1. 81 

2.27 

1.80 

8 

4.12 

5-16 

4.09 

8 

6.71 

8-36 

6.63 

7 

1.87 

2-35 

1.86 

7 

4.19 

5-24 

4.16 

7 

6.78 

8-45 

6.70 

6 

1-94 

2.43 

1-93 

6 

4-25 

5-32 

4.22 

6 

6.86 

8.54 

6.78 

5 

2.00 

2.51 

1-99 

5 

4-31 

5-39 

4.28 

5 

6-93 

8-63 

6.85 

4 

2.06 

2.58 

2.05 

4 

4-37 

5-47 

4-34 

4 

7.00 

8.72 

6.92 

3 

2. II 

2.62 

2.10 

3 

4-44 

5-55 

4.40 

3 

7.07 

8.80 

6-99 

2 

2.17 

2.72 

2.16 

2 

4-50 

5-63 

4.46 

2 

7-13 

8.88 

7-05 

1 

2.22 

2-79 

2.21 

I 

4-56 

S-71 

4-52 

I 

7  20 

8.96 

7.12 

0 

2.28 

2.86 

2.27 

0 

4.62 

5-78 

4-58 

0 

7.27 

9.04 

7.19 

6b2 


FOOD  INSPECTION  AND  ANALYSIS. 


SPECIFIC  GR.WITY  .VXD  PERCENTAGE  OF  ALCOHO'L— (Continued). 


Absolute  Alcohol. 

Absolute  Alcohol. 

0      LJX                 ' 

1 

Absolute  Alcohol. 

Spec. 

opec. 

;   Spec. 

1               ,              ' 

Grav. 

at 

Per 

Cent 

Per 
Cent 

Grams 

Grav. 

at 
15.6°  C. 

Per 

Cent 

Per 

Cent 

Grams 

i  Grav. 
at 

Per 

Cent 

Per 

Cent 

Grama 

15.6°  C. 

bv 

by  Vol- 

per 

by 

b>'  Vol- 

per 

15-6° C. 

by 

by  Vol- 

per 

Weight 

ume. 

100  cc. 

Weight 

ume. 

100  cc. 

Weight 

ume. 

100  cc. 

O.9S79    7.33 

9-13 

7.24 

0.9829 

10.92 

13-52 

10.73 

0.9779 

14-91 

18.36 

14-58 

8 

7.40 

9.21 

7-31 

8 

11.00 

13.62 

10. 8i 

8 

15.00 

18.48 

14.66 

7 

7-47 

9.29 

7-37 

7 

11.08 

13-71 

10.89 

7 

15.08 

18.58 

14-74 

6 

7-53 

9-37 

7-43 

6    11-15 

13-81 

10-95 

6 

15-17 

18.68 

14-83 

5 

7.60 

9-45 

7-50 

5    11-23 

13-90 

11.03 

5 

15-25 

18.78 

14.90 

4 

7.67 

9-54 

7-57 

4    11-31 

13-99 

11. II 

4 

15-33 

18.88 

14.98 

3 

7-73 

9.62 

7-63 

3    11.38 

14.09 

II. 18 

3 

15-42 

18.98 

15-07 

2 

7.80 

9.70 

7.70 

2    11.46 

14.18 

11.26 

2 

15-50 

19.08 

15-14 

I    7-87 

9-78 

7-77 

I    11.54 

14.27 

11-33 

I 

15-58 

19.18 

15.21 

0    7-93 

9.86 

7-83 

0 

11.62 

14-37 

II. 41 

0 

15-67 

19.28 

15-30 

0.9869    8.00 

9-95 

7.89 

0.9819 

11.69 

14.46 

11.48 

0.9769 

15-75 

19-39 

15-38 

8,  8.07 

10.03 

7.96 

8 

11.77 

14.56 

11.56 

8 

15-83 

19.49 

15-46 

7 

8.14 

10.12 

8.04 

7 

11.85 

14-65 

11.64 

7 

15-92 

19-59 

15-54 

6 

8.21 

10.21 

8.10 

6 

11.92 

14-74 

11.70 

6 

16. oc 

19.68 

15.62 

5 

8.29 

10.30 

8.17 

5 

12.00 

14.84 

11.78 

5 

16.08 

19-78 

15-70 

4 

8.36 

10.38 

8.24 

4 

12.08 

14-93 

11.85 

4 

16.15 

19-87 

15-76 

3 

8.43 

10.47 

l-^l 

3 

12.15 

15.02 

11.92 

3 

16.23 

19.96 

15-84 

2 

8.50 

10.56 

8.38 

2 

12.23 

15.12 

12.00 

2 

16.31 

20.06 

15-90 

I    8-57 

10.65 

8.45 

I 

12.31 

15.21 

12.08 

I 

16.38 

20.15 

15-99 

0   8.64 

10.73 

8-52 

0 

12.38 

15-30 

12.14 

0 

16.46 

20.24 

16.06 

0.9859    8.71 

10.82 

8.58 

0.9809 

12.46 

15.40 

12.22 

0.9759 

16-54 

20.33 

16.13 

8    8.79 

10.91 

8.66 

8 

12.54 

15-49 

12.30 

8 

16.62 

20.43 

16.21 

7    8.86 

11.00 

8-73 

7 

12.62 

15-58 

12-37 

7 

16.69 

20.52 

16.28 

6   8.93 

11.08 

8.80 

6 

12.69 

15.68 

12.44 

6 

16-77 

20.61 

16.35 

5    9-00 

II. 17 

8.87 

5 

12.77 

15-77 

12.51 

5 

16-85 

20.71 

16.43 

4   9-07 

11.26 

8.93 

4 

12.85 

15-86 

12-59 

4 

16.92 

20.80 

16.50 

3'  9-14 

"•35 

9.00 

3 

12.92 

15.96 

12.66 

3 

17.00 

20.89 

16.57 

2    9.21 

11.44 

9-07 

2 

13.00 

16.05 

12.74 

2 

17.08 

20.99 

16.65 

I    9.29 

11.52 

9.14 

I 

13.08 

16.15 

12.81 

I 

17-17 

21.09 

16.74 

0   9.36 

II. 61 

9.22 

0 

13-15 

16.24 

12.89 

0 

17-25 

21.19 

16.81 

.0.9849    9-43 

11.70 

9.29 

0-9799 

13-23 

16-33 

12.96 

0.9749 

17-33 

21.29 

16.89 

8    9.50 

11.79 

9-35 

8 

13-31 

16.43 

13-03 

8 

17-42 

21.39 

16.97 

7    9-57 

11.87 

9-42 

7 

13-38 

16.52 

13.10 

7 

17-50 

21.49 

17-05 

6   9.64 

11.96 

9-49 

6 

13-46 

16.61 

13-18 

6 

17-58 

21-59 

17-13 

5    9-71 

12.05 

9-56 

5 

13-54 

16.70 

13-26 

5 

17.67 

21.69 

17.20 

4   9-79 

12.13 

9.64 

4 

13.62 

16.80 

13-33 

4 

17-75 

21-79 

17.29 

3   9-86 

12.22 

9.71 

3 

13.69 

16.89 

13-40 

3 

17-83 

21.89 

17-37 

2    9-93 

12.31 

9-77 

2 

13-77 

16.98 

13-48 

2 

17-92 

21.99 

17-46 

ilio.oo 

12.40 

9-84 

I 

13-85 

17.08 

13-56 

1 

18.00 

22.09 

17-54 

c'10.03 

12.49 

9.92 

0 

13-92 

17.17 

13-63 

0 

18.08 

22.18 

17.61 

'©•9839  10-15 

12.58 

9-99 

0.9789 

14.00 

17.26 

13-71 

0.9739 

18. T5 

22.27 

17-68 

8;  10. 23 

12.68 

10.06 

8 

14.09 

17-37 

13-79 

8 

18-23 

22.36 

17-76 

710.31 

12.77 

10.13 

7 

14.18 

17.48 

13.88 

7' 

18.31 

22.46 

17.82 

610.38 

12.87 

10.20 

6 

14.27 

17-59 

13.96 

6 

18.38 

22-55 

17.90 

5  10-46 

12.96 

10.28 

5 

14.36 

17.70 

14.04 

5 

18.46 

22.64 

17.97 

4  10.54  1 

13-05 

10.36 

4 

14-45 

17.81 

14-13 

4 

18.54 

22-73 

18.05 

3 10.62 

13-15 

10.44 

3 

14-55 

17.92 

14-23 

3 

18.62 

22.82 

18.13 

3 10.69 

13-24 

10.51 

2 

14.64 

18.03 

14-32 

2 

18.69 

22.92 

18.19 

1  10.77   ; 

13-34 

10.59 

I 

14-73 

18.14 

14-39 

I 

18.77 

23.01 

18.27 

e  10.85 

13-43 

10.67 

0! 

14.82 

18.25 

14.48 

0 

18.85 

21.10 

18.34 

ALCOHOLIC  BE y BRUGES.  663 

SPECIFIC  GRAVITY  AND  PERCENTAGE  OF  ALCOHOL— (Conlinued). 


Absolute  Alcohol. 

Spec. 

Absolute  Ale 

■ohol. 

Absolute  AlcohoL 

Spec. 

Spec. 

•Grav. 

at 

Per 

Lent 

Per 
Cent 

Grams 

Grav. 
at 

Per 
Cent 

Per 
Cent 

Grams 

Grav. 
at 

Per 
Cent 

Per 
Cent 

Grams 

JS-O^C. 

bv 

by  Vol- 

per 

15.6°  C. 

bv 

by  Vol- 

per 

13.6"  C. 

by 

by  Vol- 

per 

Weight 

ume. 

100  cc. 

Weight 

ume. 

100  cc. 

Weight 

ume. 

100  cc. 

0.9729 

18.92 

23-19 

18.41 

0.9679 

22.92 

27-95 

22.18 

0.9629 

26.60 

32.27 

25.61 

8 

19.00 

23.18 

18.48 

8 

23.00 

28.04 

22.26 

8 

26.67 

32-34 

25-67 

7 

19.08 

23-38 

18.56 

7 

23.08 

28.13 

22.33 

7 

26.73 

32-42 

25-73 

6 

19.17 

23.48 

18.65 

6 

23-15 

28.22 

22.40 

6 

26.80 

32-50 

25  -  79 

5 

19-25 

23-58 

18.73 

5 

23-23 

28.31 

22.47 

5 

26.87 

32-58 

25-85 

4 

19-33 

23.68 

18.80 

4 

23-31 

28-41 

22.54 

4 

26.93 

32-65 

25-91 

3 

19.42 

23-78 

18.88 

3 

23-38 

28.50 

22.61 

3 

27.00 

32-73 

25-98 

2 

19-50 

23.88 

18.95 

2 

23.46 

28.59 

22.69 

2 

27.07 

32-81 

26.04 

I 

19-58 

23.98 

19-03 

I 

23-54 

28.68 

22.76 

I 

27.14 

32.90 

26.10 

0 

19.67 

24.08 

19.12 

0 

23.62 

28.77 

22.83 

0 

27.21 

32.98 

26.17 

0.9719 

19-75 

24.. x8 

19.19 

0.9669 

23.69 

28.86 

22.90 

0.9619 

27-29 

33-06 

26.25 

8 

19-83 

24.28 

19.27 

8 

23-77 

28.95 

22.97 

8 

27.36 

33-15 

26.31 

7 

19.92 

24.38 

19-36 

7 

23-85 

29.04 

23-05 

7 

27-43 

33-23 

26.37 

6 

20.00 

24.48 

19-44 

6 

23.92 

29-13 

23-11 

6 

27-50 

33-3^ 

26.43 

5 

20.08 

24-58 

19-51 

5 

24.00 

29.22 

23-19 

5 

27-57 

33-39 

26.51 

4 

20.17 

24.68 

19-59 

4 

24.08 

29-31 

23-27 

4 

27.64 

33-48 

26-57 

3 

20.25 

24-78 

19.66 

3 

24-15 

29.40 

23-33 

3 

27.71 

33-56 

26.64 

2 

20.33 

24-88 

19-74 

2 

24-23 

29-49 

23.40 

2 

27.79 

33-64 

26.71 

1 

20.42 

24.98 

19-83 

1 

24-31 

29.58 

23.48 

I 

27. 86 

33-73 

26.78 

0 

20.50 

25-07 

19.90 

0 

24-38 

29-67 

23-55 

0 

27-93 

33-81 

26.84 

0.9709 

20.58 

25-17 

19.98 

0.9659 

24.46 

29-76 

23.62 

0.9609 

28.00 

33-89 

26.90 

8 

20.67 

25-27 

20.07 

8 

24-54 

29.86 

23-70 

8 

28.06 

33-97 

26.96 

7 

20.75 

25-37 

20.14 

7 

24.62 

29-95 

23-77 

7 

28.12 

34-04 

27.01 

6 

20.83 

25-47 

20.22 

6 

24-69 

30.04 

23-84 

6 

28.19 

34-11 

27.07 

5 

20.92 

25-57 

20.30 

5 

24-77 

30-13 

23-91 

5 

28.25 

34-18 

27-13 

4 

21.00 

25-67 

20.33 

4 

24-85 

30.22 

23-99 

4 

28.31 

34-25 

27.18 

3 

21.08 

25.76 

20.46 

3 

24.92 

30-31 

24-05 

3 

28.37 

34-33 

27.24 

2 

21.15 

25-86 

20.52 

2 

25.00 

30.40 

24.12 

2 

28.44 

34-40 

27-31 

I 

21.23 

25-95 

20.59 

1 

25-07 

30.48 

24-19 

I 

28.50 

34-47 

27.36 

0 

21.31 

26.04 

20.67 

0 

25.14 

30.57 

24.26 

0 

28.56 

34-54 

27.42 

0.9699 

21.38 

26.13 

20.73 

0.9649 

25.21 

30-65 

24-32 

0.9599 

28.62 

34-61 

27-47 

8 

21.46 

26.22 

20.81 

8 

25.29 

30-73 

24-39 

8 

28.69 

34-69 

27-53 

7 

21.54 

26.31 

20.89 

7 

25-36 

30.82 

24.46 

7 

28.75 

34-76 

27-59 

6 

21.62 

26.40 

20.96 

6 

25-43 

30.90 

24-53 

6 

28-81 

34-83 

27.64 

5 

21.69 

26.49 

21.03 

5 

25-50 

30.98 

24-59 

5 

28.87 

34-90 

27.70 

4 

21.77 

26.58 

21. II 

4 

25-57 

31-07 

24.66 

4 

28.94 

34-97 

27.76 

3 

21.85 

26.67 

21.18 

3 

25.64 

S^'-'S 

24-72 

3 

29.00 

35-05 

27.82 

2 

21.92 

26.77 

21.25 

2 

25-71 

31-23 

24-79 

2 

29.07 

35-12 

27.89 

I 

22.00 

26.86 

21-33 

1 

25-79 

31-32 

24.86 

I 

29-13 

35-20 

27-95 

0 

22.08 

26.95 

21.40 

0 

25-86 

31-40 

24-93 

0 

29.20 

35-28 

28.00 

0.9689 

22.15 

27.04 

21.47 

0.9639 

25-93 

31.48 

24.99 

0.9589 

29.27 

35-35 

28.07 

8 

22.23 

27-13 

21.54 

8 

26.00 

31-57 

25.06 

8 

29-33 

35-43 

28.12 

7 

22.31 

27.22 

21.61 

7 

26.07 

31-65 

25-12 

7 

29.40 

35-51 

28.18 

6 

22.38 

27-31 

21.68 

6 

26.13 

31.72 

25.18 

6 

29-47 

35-58 

28.24 

5 

22.46 

27.40 

21.76 

5 

26.20 

31.80 

25-23 

5 

29-53 

35.66 

28.30 

4 

22.54 

27.49 

21.83 

4 

26.27 

31.88 

25-30 

4 

29.60 

35  •  74 

28.36 

3 

22.62 

27-59 

21.90 

3 

26.33 

31.96 

25-36 

3 

29.67 

35-81 

28-43 

2 

22.69 

27.68 

21.96 

2 

26.40 

32-03 

25-43 

2 

29-73 

35-89 

28.48 

I 

22.77 

27.77 

22.01 

I 

26.47 

32.11 

25.49 

I 

29.80 

35-97 

28.54 

0 

22.85 

27.86 

22.12 

0 

26.53 

32-19 

25-55 

0 

29.87 

36.04 

28.61 

664 


f^OOD  INSPECTION  AND  ANALYSIS. 


SPECIFIC  GR.WITV  .\ND  PERCENTAGE  OF  ALCOHOL— (Co«//wMfrf). 


Spec. 
Grav. 

at 
15.6°  c. 

Absolute  Alcohol. 

Spec. 
Grav. 

at 
15.6°  C. 

Absolute  Alcohol. 

Spec. 
Grav. 

at 
I5.6°C. 

Absolute  Alcohol. 

Per 

Cent 

bv 

Weight 

Per 
Cent 
by  Vol- 
ume. 

Grams 
per 

100  cc. 

Per 

Cent 

by 

Weight 

Per 
Cent 
by  Vol- 
ume. 

Grams 
per 

100  cc. 

Per 

Cent 

by 

Weight 

Per 
Cent 
by  Vol- 
ume. 

Grams- 

per 
100  cc- 

0.9579 

29-93 

36.12 

28.67 

0.9529 

32.94 

39-54 

31.38 

0.9479 

35-55 

42.45 

33-70 

8 

30.00 

36.20 

28.73 

8 

33.00 

39-61 

31.43 

8 

35-60 

42.51 

33-75 

7 

30.06 

36.26 

28.78 

7 

33-06 

39-68 

31.48 

7 

35-65 

42.56 

33.79 

6 

30.11 

36.32 

28.82 

6 

2,3--^^ 

39-74 

31.53 

6 

35-70 

42.62 

33-83 

5 

30-17 

36.39 

28.88 

5 

33-18 

39-8' 

31.59 

5 

35-75 

42.67 

33-88 

4 

30.2^ 

36.45 

28.92 

4 

33-24 

39-87 

31.63 

4 

35-80 

42-73 

33-92 

3 

30.28 

36.51 

28.98 

3 

Zi-2^ 

39-94 

31.69 

3 

35-85 

42-78 

33-97 

2 

3,°-i^ 

36.57 

29-03 

2 

iZ-iS 

40.01 

31-74 

2 

35-90 

42.84 

34.01 

I 

30 -3^ 

36.64 

29.08 

I 

33-41 

40.07 

31.80 

1 

35-95 

42.89 

34.05 

0 

30-44 

36.70 

29-13 

0 

33-47 

40.14 

31.86 

0 

36.00 

42.95 

34-09- 

0.9569 

30.50 

36.76 

29.18 

0.9519 

33-53 

40.20 

31-91 

0.9469 

36.06 

43.01 

34-14 

8 

30..';  6 

36.83 

29-23 

8 

33.59 

40.27 

31.96 

8 

36-11 

43-07 

34-09 

7 

30.61 

36.89 

29.27 

7 

33.65 

40-34 

32.01 

7 

36-17 

43.13 

34-24 

6 

30-67 

36-95 

29-33 

6 

33-71 

40-40 

32.07 

6 

36-22 

43-19 

34-28 

5 

30-72 

37-02 

29.38 

5 

33-76 

40.47 

32.12 

5 

36-28 

43.26 

34-34 

4 

30.78 

37-08 

29-43 

4 

33.82 

40-53 

32-17 

4 

36-33 

43-32 

34-38 

3 

30.83 

37-14 

29.48 

3 

33-88 

40.60 

32.22 

3 

36-39 

43-38 

34-44 

2 

30-89 

37.20 

29-53 

2 

33-94 

40-67 

32.27 

2 

36-44 

43-44 

34-48 

I 

30-94 

37.27 

29.58 

I 

34.00 

40.74 

32.32 

1 

36-50 

43-50 

34-54 

0 

31.00 

37.34 

29.63 

0 

34-05 

40.79 

32-37 

0 

36.56 

43.56 

34-58 

0.9559 

31.06 

37.41 

29.69 

0.9509 

34-10 

.40.84 

32.41 

0.9459 

36.61 

43-63 

34-63 

8 

31.12 

37-48 

29-74 

8 

34-14 

40.90 

32-45 

8 

36.67 

43-69 

34-69 

7 

31-19 

37-55 

29.81 

7 

34.19 

40-95 

32-49 

7 

36-72 

43-75 

34-73 

6 

31-25 

37-62 

29.86 

6 

34-24 

41.00 

32-54 

6 

36.78 

43.81 

34-79 

5 

ii-i^ 

37-69 

29.91 

5 

34-29 

41.05 

32-59 

5 

36-83 

43-87 

34-!| 

4 

31-37 

37-76 

29-97 

4 

34-33 

41. II 

32-63 

4 

36-89 

43-93 

34.88 

3 

31-44 

37-83 

30-03 

3 

34-38 

41.16 

32-67 

3 

36-94 

44-00 

34-92 

2 

31-50 

37-90 

30-09 

2 

34-43 

41.21 

32.71 

2 

37-00 

44.06 

34-96 

I 

31-56 

37.97 

30-14 

I 

34-48 

41.26 

32-75 

I 

37-06 

44.12 

35-02 

° 

31.62 

38.04 

30.20 

0 

34.52 

41.32 

32-79 

0 

37-" 

44.18 

35-07 

0.9349 

31.69 

38.11 

30.26 

0.9499 

34.57 

41.37 

^^■li 

0.9449 

37-17 

44-24 

35-12 

8 

31-75 

38.18 

30-31 

8 

34.62 

41.42 

32.88 

8 

37-22 

44-30 

35-16 

7 

31.81 

38.25 

30.36 

7 

34.67 

41.48 

32.92 

7 

37-28 

44-36 

35-21 

6 

31-87 

38-33 

30.42 

6 

34.71 

41.53 

32.96 

6 

37-33 

44-43 

35 -2<? 

5 

31-94 

38.40 

30.48 

5 

34-76 

41.58 

33-00 

5 

37-39 

44-49 

35-31 

4 

32.00 

38-4; 

30.53 

4 

34-81 

41.63 

33-04 

4 

37-44 

44-55 

35-35 

3 

32.06 

38.53 

30.59 

3 

34.86 

41.69 

33-09 

3 

37-50 

44.61 

35-41 

2 

32.12 

38.60 

30.64 

2 

34.90 

41.74 

33--iZ 

2 

37-56 

44.67 

35-46 

I 

32-19 

38.68 

30.71 

1 

34-95 

41.79 

ii'-^l 

I 

37.61 

44-73 

35.51 

0 

32-25 

38.75 

30-77 

0 

35-00 

41.84 

3i-2i 

0 

37-67 

44-79 

35-56 

0-9539 

32.31 

38.82 

30.81 

0.9489 

35-05 

41.90 

32.26 

0.9439 

37-73 

44.86 

35-60 

8 

32-37 

38.89 

30.87 

8 

35-10 

41.95 

33-30 

8 

37-78 

44.92 

35-65 

7 

32.44 

38.96 

30.93 

7 

35-15 

42.01 

33-34 

7 

37-83 

44.98 

35-70 

6 

32-50 

39.04 

30.99 

6 

35-20 

42.06 

33-39 

6 

37-89 

45-04 

35-75 

5 

52.56 

39." 

31-05 

5 

35-25 

42.12 

33-43 

5 

37-49 

45- 10 

35-80 

4 

32.62 

39.18 

31.10 

4 

.35-30 

42.17 

33-48 

4 

38-00 

45.16 

35-85 

3 

32.69 

39.25 

31.15 

3 

35-35 

42.23 

33-53 

3 

38.06 

45.22 

35-90 

2 

32-75 

39-32 

31.20 

2 

35-40 

42-29 

33-57 

2 

38.11 

45.28 

35-95 

1 

32.81 

39-40 

31.26 

I 

35-45 

42.34 

33-61 

I 

38-17 

45-34 

36.00^ 

0 

32-87 

39-47 

3»-32 

0 

35-50 

42.40 

33-65 

0 

38.22 

45.41 

36.04. 

ALCOHOLIC  BEyERAGES.  6fD5 

SPECIFIC  GRAVITY  AND  PERCENTAGE  OF  W.COliOl.— (Continued). 


Spec. 

Absolute  Alcohol. 

Spec. 

Absolute  -A.lcohol. 

Absolute  Alcohol. 

1 

Spec. 

Grav. 

at 
15.6°  C. 

Per 

Cent 

Per 
Cent 

Grams 

Grav. 

at 
IS.6°C. 

Per 
Cent 

Per 

Cent 

Grams 

Grav. 

at 

Per 

Cent 

Per 
Cent 

Grams 

by 

by  Vol- 

per 

by 

by  Vol- 

per 

15.6°  C. 

by 

by  Vol- 

per 

Weight 

ume. 

lOO  cc. 

Weight 

ume. 

100  cc. 

Weight 

ume. 

100  cc. 

0.9429 

38.28 

45-47 

36.08 

0-9379 

40.85 

48.26 

38.31 



0.9329 

43-29 

50-87 

40.38 

8 

38.33 

45-53 

36 

13 

8 

40.90 

48.32 

38.35 

8 

43 

32, 

50.92 

40.42 

7 

38-39 

45  -  59 

36 

18 

7 

40.95 

48.37 

38.39 

7 

43 

39 

50.97 

40.46 

6 

38-44 

45-65 

36 

23 

6 

41.00 

48-43 

38.44 

6 

43 

43 

51.02 

40.50 

5 

38-50 

45-71 

36 

28 

5 

41.05 

48.48 

38.48 

5 

43 

48 

51.07 

40.54 

4 

38-56 

45-77 

36 

2,3, 

4 

41.10 

48.54 

38.52 

4 

43 

52 

51.12 

40.58 

3 

38.61 

45-83 

36 

38 

3 

41-15 

48.59 

38.58 

3 

43 

57 

51-17 

40.62 

2 

38.67 

45-89 

36 

43 

2 

41.20 

48.64 

38.62 

2 

43 

62 

51.22 

40.66 

I 

38.72 

45-95 

36 

48 

I 

41-25 

48.70 

38.66 

I 

43 

67 

51-27 

40.70 

0 

38.78 

46.02 

36 

53 

0 

41.30 

48.7s 

38.70 

0 

43 

71 

51-32 

40.74 

0.9419 

38-83 

46.08    36 

57 

0.9369 

41-35 

48.80 

38.74 

0.9319 

43 

76 

51.38 

40.78 

8 

38.89 

46.14    36 

62 

8 

41.40 

48.86 

38.78 

8 

43 

81 

51-43 

40.81 

7 

38-94 

46.20'  36 

67 

7 

41-45 

48.91 

38.82 

7 

43 

86 

51.48 

40.85 

6 

39.00 

46.26    36 

72 

6 

41-50 

48.97 

38.87 

6 

43 

90 

51.53 

40.89 

5 

39-05 

46.32'  36 

76 

5 

41-55 

49-02 

38.91 

5 

43 

95 

51-58 

40-93 

4 

39.10 

46.371  36 

80 

4 

41.60 

49.07 

38.95 

4 

44 

00 

51-63 

40.97 

3 

39-15 

46.42'  36 

85 

3 

41-65 

49.13 

38.99 

3 

44 

05 

51.68 

41.01 

2 

39.20 

46.481  36 

89 

2 

41.70 

49.18 

39-04 

2 

44 

09 

51-72 

41.05 

I 

39-25 

46.53!  36 

94 

I 

41-75 

49-23 

39.08 

I 

44 

14 

51-77 

41.09 

0 

39-30 

46.59    36 

98 

0 

41.80 

49.29 

39-13 

0 

44 

18 

51.82 

41    13 

0  9409 

39.35 

46.64    37 

02 

0.9359 

41.85 

49.34 

39.17 

0.9309 

44 

23 

51-87 

41-17 

8 

39-40 

46.70 

37 

07 

8 

41-90 

49  40 

39-21 

8 

44 

27 

51-91 

4I-20 

7 

39-45 

46.75 

37 

II 

7 

41.95 

49-45 

39-25 

7 

44 

32 

51.96 

41-24 

6 

39-50 

46.80 

37 

15 

6 

42.00 

49  50 

39-30 

6 

44 

36 

52.01 

41.28 

5 

39-55 

46.86 

37 

19 

5 

42.05 

49-55 

39-34 

5 

44 

41 

52.06 

41-31 

4 

39.60 

46.91 

37 

23 

4 

42.10 

49.61 

39-38 

4 

44 

46 

52. 10 

41.35 

•3 

39-65 

46.97 

37 

27 

3 

42.14 

49.66 

39-42 

3 

44 

50 

52.15 

41.49 

2 

39-70 

47.02 

37 

32 

2 

42.19 

49.71 

39.46 

2 

44 

55 

52.20 

41-43 

1 

39-75 

47-08 

37 

36 

I 

42.24 

49.76 

39.50 

I 

44 

59 

52.25 

41.47 

0 

39-80 

47.13 

37 

41 

0 

42.29 

49.81 

39.54 

0 

44 

64 

52.29 

41.51 

0.9399 

39-85 

47.18 

37 

45 

0.9349 

42.33 

4Q.86 

39.58 

0.9299 

44 

68 

52.34 

41-55 

8 

39-90 

47-24 

37 

49 

8 

42.38 

49.91 

39.62 

8 

44 

73 

52.39 

41.59 

7 

39-95 

47-29 

37 

53 

7 

42.43 

49.96 

39.66 

7 

44 

77 

52.44 

41-63 

6 

40.00 

47-35 

37 

58 

6 

42.48 

50.01 

39-70 

6 

44 

82 

52.48 

41.67 

5 

40.05 

47.40 

37 

62 

5 

42.52 

CO.  06 

39-74 

5 

44 

86 

52.53 

41-70 

4 

40.10 

47-45 

37 

67 

4 

42.57 

50.11 

39-78 

4 

44 

91 

52.58 

41.74 

3 

40.15 

47-51 

37 

71 

3 

42.62 

50.16 

39.82 

3 

44 

96 

52.63 

41-77 

2 

40.20 

47-56 

37 

75 

2 

42.67 

50.21 

39.86 

2 

45 

00 

52.68 

41.81 

I 

40.25 

47.62 

37 

80 

I 

42.71 

50.26 

39-90 

I 

45 

05 

52.72 

41.85 

0 

40.30 

47-67 

37 

84 

0 

42.76 

50.31 

39-94 

c 

45 

09 

52.77 

41.89 

0.9389 

40.35 

47.72 

37 

88 

0.9339 

42.81 

50.37 

39.98 

0.9289 

45 

.14 

52.82 

41.93 

8 

40.40 

47.781  37 

92 

8 

42.86 

50.42 

40.02 

8 

45 

18 

52.87 

41.97 

7 

40.45 

47-83!  37 

96 

7 

42.90 

50.47 

40.06 

7 

45 

23 

52.91 

42-OO 

6 

40.50 

47.89^  38 

00 

6 

42.95 

50.52 

40.10 

6 

45 

27 

52.96 

42.04 

5 

40.55 

47.94;  38 

05 

5 

43.00 

50.57 

40.14 

5 

45 

32 

53-01 

42.08 

4 

40.60 

47-99    38 

09 

4 

43.05 

50.62 

40. 18 

4 

45 

36 

53-06 

42.12 

3 

40.65 

48.051   38 

13 

3 

43.10 

50.67 

40.22 

3 

45 

41 

53- 10 

42.16 

2 

40.70 

48.10    38 

18 

2 

43.13 

50.72 

40.26 

2 

45 

46 

53-15 

42.19 

I 

40.75 

48-16    38 

22 

I 

43.19 

50.77 

40.30 

I 

45 

50 

53-20 

42.23 

0 

40.80 

48.21    38 

27 

0 

43-24 

50.82 

40.34 

0 

45-55 

53-24 

42.27 

666  FOOD  ISSPECTION  JND  ANALYSIS. 

SPECIFIC  GRA\1TY  AND  rERCEXTAGE  OF  ALCOHOL— (Con/mi^ed). 


Spec. 

Absolute 

AlcohoL 

Spec. 

.Absolute  Alcohol.      , 

Spec. 

Absolute  Alcohol. 

1 

Grav. 

Per 

Per 

Grav. 

at 

Per 

Per 

Grav. 
at 

Per 

Per 

h"  •' 

Cens 

Cent 

15.6°  C. 

Cent 

Cent 

15.6°  C. 

Cent 

Cent 

15.         \^ 

by 

by  Vol- 

by 

by  Vol- 

by 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

Weight. 

ume. 

0.9279 

45-59 

53-29 

0.9229 

47-86 

55-65      1 

0.9179 

50-13 

57-97 

8 

45-64 

53-34 

8 

47-91 

55-69 

8 

50-17 

58-ot 

7 

45.68 

53-39 

7 

47-96 

55-74     ! 

7 

50.22 

58-06 

6 

45-73 

53-43 

6 

48.00 

55-79 

6 

50.26 

58.10 

5 

45-77 

53-48 

5 

48.05 

55-83 

5 

50-30 

58-14 

4 

45-S2 

53-53 

4 

48.09 

55-88 

4 

50-35 

58.19 

3 

45.86 

53-58 

3 

48-14 

55-93 

3 

50-39 

58-23 

2 

45-91 

53-62 

2 

48.18 

55-97 

2 

50-43 

58.28 

I 

45-96 

53-67 

I 

48.23 

56.02 

I 

50.48 

58-32 

0 

46.00 

53-72 

0 

48.27 

56-07 

0 

50-52 

58-36- 

0.9269 

46.05 

53-77 

0.9219 

48.32 

56-11     , 

0.9169 

50-57 

58.41 

8 

46.09 

53-81 

8 

48.36 

56.16     ' 

8 

50.61 

58-45 

7 

46.14 

53-86 

7 

48.41 

56.21 

7 

50-65 

58.50 

6 

46.18 

53-91 

6 

48.46 

56.25 

6 

50-70 

58-54 

5 

46.23 

53- --5 

5 

48.50 

56-30 

5 

50-74 

58-5& 

4 

46.27 

54.00 

4 

48.55 

56-35 

4 

50-78 

58-63 

3 

46.32 

54-05 

3 

48.59 

56-40 

3 

50.83 

58-67 

2 

46.36 

54-10 

2 

48.64 

56-44 

2 

50.87 

58-72 

I 

46.41 

54-14 

I 

48.68 

56-49 

I 

50-91 

58.76 

0 

46.46 

54-19 

0 

48.73 

56-54 

0 

50.96 

58.80 

0.9259 

46.50 

54-24 

0.9209 

48-77 

56.58 

0.9159 

51.00 

58-85 

8 

46.55 

54-29 

8 

48.82 

56.63 

8 

51-04 

58.89 

7 

46.59 

54.33 

7 

48.86 

56.68 

7 

51-08 

58-93 

6 

46.64 

54-38 

6 

48.91 

56.72 

6 

51-13 

58-97 

5 

46.68 

54-43 

5 

48.96 

56-77 

5 

51-17 

59-OI 

4 

46.73 

54-47 

4 

49.00 

56.82 

4 

51.21 

59-05 

3 

46.77 

54-52 

3 

49-04 

56.86 

3 

51-25 

59-09 

2 

46.82 

54-57 

2 

49-08 

56.90 

2 

51-29 

59-14 

I 

46.86 

54-62 

I 

49-12 

56-94 

I 

51-33 

59-18 

0 

46.91 

54-66 

0 

49-16 

56-98 

0 

51-38 

59-22 

0.9249 

46.96 

54-71 

0.9199 

49-20 

57.02 

0.9149 

51-42 

59.26 

8 

47-00 

54-76 

Proof  8 

49-24 

57.06 

8 

51-46 

59-30 

7 

47-05 

54-80 

7 

49-29 

57-10 

7 

51-50 

59-34 

6 

47-09 

54-85 

6 

49-34 

57-15 

6 

51-54 

59-39 

5 

47-M 

54-90 

5 

49-39 

57-20 

5 

51-58 

59-43 

4 

47.18 

54.95 

4 

49-44 

57-25 

4 

51-63 

59-47 

3 

47-23 

54-99 

3 

49-49 

57-30 

3 

51-67 

59-51 

2 

47-27 

55-04 

2 

49-54 

57-35 

2 

51-71 

59-55 

I 

47-32 

55-09 

I 

49-59 

57-40 

I 

51-75 

59-59 

0 

47-36 

55-13 

0 

49-64 

57-45 

0 

51-79 

59-63 

0.9239 

47-41 

55-18 

i  0.9189 

49-68 

57-49 

0.9139 

51-83 

59.68 

8 

47-46 

55-23 

!             8 

49-73 

57-54 

8 

51.88 

59-72 

7 

47-50 

55-27 

7 

49-77 

57-59 

7 

51-92 

59-76 

6 

47-55 

55-32 

6 

49-82 

57-64 

6 

51.96 

59.80 

5 

47-59 

55-37 

5 

49.86 

57-69 

5 

52-00 

59-84 

4 

47-64 

55-41 

4 

49-91 

57-74 

4 

52-05 

59-89 

3 

47-68 

55-46 

3 

49-95 

57-79 

3 

52-09 

59-93 

2 

47-73 

55-51 

2 

50.00 

57-84 

2 

52-14 

59-98- 

I 

47-77 

55-53 

I 

50.04 

57.88 

I 

52.18 

60.02 

0 

47-82 

55.60 

0 

50.09 

58.92 

0 

52-23 

60.07 

jILcoholic  beverages. 


667 


SPECIFIC  GRAVITY  AND  PERCENTAGE  OF  ALCOHOL— (Con/wwei). 

Spec. 

Absolute 

Alcuhul. 

Spec. 

Absolute 

1 
Alcohol. 

Absolute  AlcohoL 

Spec. 

Grav. 

at 
15.6°  C. 

Per 

Per 

Grav. 

at 
15.6°  c. 

Per 

Per 

Grav. 

Per 

Per 

Cent 

Cent 

Cent 

Cent 

at 
15.0°  C. 

Cent 

Cent 

by 

by  Vol- 

by 

by  Vol- 

by 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

WeiKbt. 

ume. 

O.9K129 

52.27 

60.12 

0.9079 

54-52 

62.36 

0.9029 

56.82 

64.63 

8 

52-32 

60.16 

8 

54-57 

62.41 

8 

56.86 

64.67 

7 

52-36 

60.21 

7 

54-62 

62.45 

7 

56.91 

64.71 

6 

52.41 

60.25 

6 

54-67 

62.50 

6 

56-95 

64-76 

5 

52-45 

60.30 

5 

54-71 

62.55 

5 

57.00 

64.80 

4 

52-50 

60.34 

4 

54-76 

62 .  60 

4 

57-04 

64-85 

3 

52-55 

60.39 

3 

54-81 

62.65 

3 

57-08 

64.89 

2 

52-59 

60.44 

2 

54.86 

62.69 

2 

57-13 

64-93 

I 

52.64 

60.47 

I 

54-90 

62.74 

I 

57-17 

64-97 

0 

52.68 

60.52 

c 

54-95 

62.79 

0 

57-21 

65-01 

0.9119 

52-73 

60.56 

0.9069 

55-00 

62.84 

0.9019 

57-25 

65-05 

8 

52-77 

60.61 

8 

55.05 

62.88 

8 

57-29 

65.09 

7 

52.82 

60.65 

7 

55.09 

62.93 

7 

57-33 

65-13 

6 

52.86. 

60.70 

6 

55.14 

62.97 

6 

57-38 

65-17 

5 

52-91 

60.74 

5 

55-18 

63.02 

5 

57-42 

65.21 

4 

52-95 

60.79 

4 

55-23 

63.06 

4 

57-46 

65-25 

3 

53-00 

60.85 

3 

55.27 

63.11 

3 

57-50 

65-29 

2 

53-04 

60.89 

2 

55.32 

63-15 

2 

57-54 

65-33 

1 

53-09 

60.93 

I 

55.36 

63-20 

I 

57-58 

65-37 

0 

53-13 

•    60.97 

0 

55.41 

63-24 

0 

57-63 

65.41 

0.9109 

53-17 

61.02 

0.9059 

55.45 

63.28 

0.9009 

57-67 

65-45 

8 

53-22 

61.06 

8 

55.50 

63-33 

8 

57-71 

65-49 

7 

53-26 

61.10 

7 

55.55 

63-37 

7 

57-75 

65-53 

6 

53-30 

61.15 

6 

55.59 

63-42 

6 

57-79 

65-57 

5 

53-35 

61.19 

5 

55.64 

63.46 

5 

57-83 

65.61 

4 

53-39 

61-23 

4 

55.68 

63-51 

4 

57-88 

65-65 

3 

53-43 

61.28 

3 

55-73 

63-55 

3 

57-92 

65.69 

2 

53-48 

61.32 

2 

55-77 

63.60 

2 

57-96 

65-73 

I 

53-52 

61.36 

I 

55.82 

63-64 

I 

58.00 

65-77 

0 

53-57 

61.40 

0 

55-86 

63-69 

0 

58-05 

65.81 

0.9099 

53-61 

61.45 

0.9049 

55. 9T 

63-73 

0.8999 

=^8.09 

65.85 

8 

53-65 

61.49 

8 

55-95 

63-78 

8 

58.14 

65  .90 

7 

53-70 

61-53 

7 

56.00 

63.82 

7 

^8.i8 

65  .94 

6 

53-74 

61.58 

6 

56-05 

63-87 

6 

58-23 

65  -99 

5 

53-78 

61.62 

5 

56-09 

63.91 

5 

58-27 

66.03 

4 

53-83 

61.66 

4 

56.14 

63-96 

4 

58-32 

66.07 

3 

53-87 

61.71 

3 

56.18 

64.00 

3 

58.36 

66.12 

2 

53-91 

61-75 

2 

56.23 

64-05 

2 

58.41 

66.16 

I 

53-96 

61.79 

I 

56.27 

64.09 

I 

58-45 

66.21 

0 

54-00 

61.84 

0 

56.32 

64.14 

0 

58-50 

66.25 

0.9089 

54-05 

61.88 

0.9039 

56-36 

64.18 

0.89S9 

58-55 

66.29 

8 

54- 10 

61.93 

8 

56.41 

64.22 

8 

58-59 

66.34 

7 

54-14 

61.98 

7 

56-45 

64-27 

7 

58-64 

66.38 

6 

54-19 

62.03 

6 

56-30 

64.31 

6 

58.68 

66.43 

5 

54.24 

62.07 

5 

56-55 

64.36 

5 

58-73 

66.47 

4 

54-29 

62.12 

4 

56-59 

64.40 

4 

58-77 

66. sr 

3 

54-33 

62.17 

3 

56.64 

64-45 

3 

58.82 

66.56 

2 

54-38 

62.22 

2 

56. 68 

64.49 

2 

i;8.86 

66.60 

1 

54-43 

62.26 

I 

56-73 

64.54 

I 

'=^8.91 

66.65 

0 

54-48 

62.31 

0 

56-77 

64-58 

0 

1 

58-95 

66.09 

66i  FOOD   INSPECTION  AND   ANALYSIS. 

SPECIFIC  (.'.R.WITY  AND   PERCENTAGP:  OF  ALCOHOL— (Con/znwetf). 


1 

Absolute  Alcohol.      | 

Spec. 

.Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Spec. 

Grav.    1 
at       1 
IS.6»C. 

Per 

Per 

Grav. 
at 

Per 

Per 

Grav. 

at 

Per 

Per 

Cent 

Cent 

15.6°  C. 

Cent 

Cent 

15.0°  C. 

Cent 

Cent 

by 

by  Vol- 

by 

by  Vol-    1 

.r^y. 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

Weight. 

ume. 

0.8979 

59.00 

66.74 

0.8929 

61.13 

68.76 

0.8879 

63-30 

70.81 

8 

59-04 

66.78 

8 

61.  17 

68.80 

8 

63-35 

70.85 

7 

5909 

66.82 

7 

61.21 

68.83 

7 

63-39 

70.89 

6 

59-13 

66.86 

6 

61.25 

68.87 

6 

63-43 

70-Q3 

5 

59-17 

66.90 

5 

61.29 

68.91 

5 

63.48 

70.97 

4 

59.22 

66.94 

4 

61-33 

68.95 

4 

63-52 

71.01 

3 

59.26 

66.99 

3 

61.38 

68.99 

3 

63-57 

71-05 

2 

59-30 

67  03 

2 

61.42 

69.03 

2 

63.61 

71.09 

I 

59-35 

67-07 

I 

61.46 

69.07 

I 

63-65 

71-13 

0 

59-39 

67.11 

0 

61  .50 

69.  II 

0 

63.70 

71.17 

©.8969 

59-43 

67-15 

0.8919 

61.54 

69.15 

0.8869 

63-74 

71.22 

8 

59-48 

67. 19 

8 

61. =58 

69.19 

8 

63.78 

71.26 

7 

59-52 

67.24 

7 

61.63 

69.22 

7 

63-83 

71-30 

6 

59-57 

67.28 

6 

61.67 

69.26 

6 

63.87 

71-34 

5 

59 -61 

67.32 

5 

61.71 

69.30 

5 

63.91 

71-38 

4 

59-65 

67.36 

4 

61-75 

69-34 

4 

63.96 

71.42 

3 

59-70 

67-40 

3 

61.79 

69.38 

3 

64.00 

71.46 

2 

59-74 

67.44 

2 

61.83 

69.42 

2 

64.04 

71-50 

I 

59-78 

67-49 

I 

61.88 

69.46 

I 

64.09 

71-54 

0 

59-83 

67-53 

0 

61.92 

69.50 

0 

•64.13 

71-58 

0.8959 

59-87 

67-57 

0.8909 

61.96 

69-54 

0.8859 

64.17 

71.62 

8 

59-91 

67.61 

8 

62.00 

69.58 

8 

64.22 

71.66 

7 

59-96 

67.65 

7 

62.05 

69.62 

7 

64.26 

71.70 

6 

60.00 

67.69 

6 

62.00 

69.66 

6 

64.30 

71.74 

5 

60.04 

67-73 

5 

62.14 

69.71 

5 

64.35 

71.78 

4 

60.08 

67-77 

i            ■^ 

62.18 

69-75 

4 

64-39 

71.82 

3 

60.13 

67.81 

!             3 

62.23 

69.79 

3 

64-43 

71.86 

2 

60.17 

67.85 

2 

62.27 

69.84 

2 

64.48 

71.90 

I 

60.21 

67.89 

I 

62.32 

69.88 

I 

64.52 

71.04 

0 

60.26 

67-93 

0 

62.36 

69.92 

0 

64-57 

71.98 

0.8040 

60.29 

67-97 

0.8899 

62.41 

69.06 

0.8849 

64.61 

72.02 

8 

60.33 

68.01 

8 

62.45 

70.01 

8 

64.65 

72.06 

7 

60.38 

68.05 

7 

62.:;o 

70.05 

7 

64.70 

72.10 

6 

60.42 

68.09 

6 

62.55 

70.00 

6 

64.74 

72.14 

s 

60.46 

68.1.3 

1            5 

62.59 

70.14 

5 

64.78 

72.18 

4 

60.50 

68.17 

4 

62.64 

70.18 

4 

64.83 

72.22 

3 

60.54 

68.21 

1             3 

62.68 

70.22 

3 

64.87 

72.26 

2 

60.58 

68.25 

2 

62.73 

70.27 

2 

64.91 

72.30 

I 

60.63 

68  29 

1             I 

62.77 

70-31 

I 

64.96 

72-34 

0 

60.67 

68.33 

1             0 

62.82 

70-35 

0 

65.00 

72-38 

••8939 

60.71 

68.36 

0.8889 

62.86 

70.40 

0.8839 

65.04 

72.42 

8 

60.76 

68.40 

8 

62.91 

70.44 

8 

65.08 

72.46 

7 

60.79 

68.44 

7 

62.95 

70.48 

7 

65.13 

72.50 

6 

60.83 

68.48 

6 

63 .  00 

70.52 

6 

65-17 

72-54 

5 

60.88 

68.52 

5 

63.04 

70-57 

5 

1      65.21 

72.58 

4 

i     60.92 

68.56 

4 

63.09 

70.61 

4 

65.25 

72.61 

3 

60.96 

68.60 

3 

63-13 

70.65 

3 

65-29 

72.65 

3 

61.00 

68.64 

2 

63-17 

i      70.69 

2 

65-33 

72.69 

I 

61.04 

68.68 

I 

63.22 

i      70.73 

I 

65-38 

72-73 

0 

• 

61.08 

68.72 

0 

63.26 

1      70.77 

0 

65.42 

72.7} 

/ll.COHOUC  BF.yilRAGES.  669 

SPECIFIC  GRAVITY  AND   PERCENTAGE  OF  .KLCOHOl.— {Continued). 


i 

Absolute  Alcohol. 

Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Spec. 

1 

Spec. 

Grav. 

Per        1 

Per 

Grav. 

Per 

Per 

Grav. 

Per 

Per 

at 
15.6"  C. 

Cent 

Cent 

at 
15.6"  C. 

Cent 

Cent 

at 
15.6°  C. 

Cent 

Cent 

by 

by  Vol- 

by 

by  Vol- 

bv 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

Weight. 

ume. 

0.8829 

65.46 

72.80 

0.8779 

67.58 

74-74 

0.8729 

69.67 

76.61 

8 

65-50 

72.84 

8 

67-63 

74.78 

8 

69.71 

76.65 

7 

65-54 

72.88 

7 

67.67 

74-82 

7 

69-75 

76.68 

6 

65-58 

72.92 

6 

67.71 

74.86 

6 

69-79 

76.72 

5 

65-63 

72.96 

5 

67-75 

74.89 

5 

69.83 

76.76 

4 

65.67 

72.99 

4 

67.79 

74-93 

4 

69.88 

76.80 

3 

65-71 

73-03 

3 

67.83 

74-97 

3 

69.92 

76.83 

2 

65-75 

73-07 

2 

67.88 

75-or 

2 

69.96 

76.87 

I 

65-79 

73-11 

1 

67.92 

75-04 

I 

70.00 

76.91 

0 

65.83 

73-15 

0 

67.96 

75.08 

0 

70.04 

76.94 

0.8819 

65.88 

73-19 

0.8769 

68.00 

75-12 

0.8719 

70.08 

76.98 

8 

65.92 

73.22 

8 

68.04 

75-16 

8 

70. 12 

77.01 

7 

65.96 

73.26 

7 

68.08 

75-19 

7 

70.  16 

77-05 

6 

66.00 

73-30 

6 

68.13 

75-23 

6 

70.20 

77.08 

5 

66.04 

73-34 

5 

68.17 

75-27 

5 

70.24 

77.12 

4 

66.09 

73-38 

4 

68.21 

75-30 

4 

70.28 

77-15 

3 

66.13 

73-42 

3 

68.25 

75-34 

3 

70.32 

77.19 

2 

66.17 

73-46 

2 

68.29 

75-38 

2 

70.36 

77.22 

I 

66.22 

73-50 

I 

68.33 

75-42 

I 

70.40 

77-25 

0 

66.26 

73-54 

0 

68. 38 

75-45 

0 

70.44 

77.29 

-0.8809 

66.30 

73-57 

0.8759 

68.42 

75-49 

0.8709 

70-48 

77-32 

8 

66.35 

73-61 

8 

68.46 

75-53 

8 

70-52 

77-36 

7 

66.39 

73-65 

7 

68.50 

75-57 

7 

70.56 

77-39 

6 

66.43 

73-69 

6 

68.54 

75 -60 

6 

70.60 

77-43 

5 

66.48 

73-73 

5 

68.58 

75-64 

5 

70.64 

77.46 

4 

66.52 

73-77 

4 

68.63 

75.68 

4 

70.68 

77-50 

3 

66.57 

73-81 

3 

68.67 

75-72 

3 

70.72 

77-53 

2 

66.61 

73-85 

2 

68.71 

75-75 

2 

70.76 

77-57 

I 

66.65 

73-89 

I 

68.75 

75-79 

I 

70.80 

77.60 

0 

66.70 

73-93 

0 

68.79 

75-83 

0 

70.84 

77-64 

0.8799 

66.74 

73-97 

0.8749 

68.83 

75-87 

0.8699 

70.88 

77-67 

8 

66.78 

74.01 

8 

68.88 

75-90 

8 

70.92 

77.71 

7 

66.83 

74-05 

7 

68.92 

75-94 

7 

70.96 

77-74 

6 

66.87 

74.09 

6 

68.96 

75.98 

6 

71.00 

77-78 

5 

66.91 

74-13 

5 

6g.oo 

76.01 

S 

71.04 

77-82 

4 

66.96 

74-17 

4 

69.04 

76-05 

4 

71.08 

77-85 

3 

67.00 

74.22 

3 

69.08 

76.09 

3 

71-13 

77-89 

2 

67.04 

74-25 

2 

69.13 

76-13 

2 

71.17 

77-93 

I 

67.08 

74.29 

I 

69.17 

76.16 

I 

71.21 

77.96 

0 

67-13 

74-33 

0 

69.21 

I     76.20 

0 

71-25 

78.0c 

0.8789 

67.17 

74-37 

0.8739 

69.25 

76.24 

0.8689 

71.29 

78.04 

8 

67.21 

74-40 

8 

69.29 

76.27 

8 

71-33 

78.07 

7 

67.25 

74-44 

7 

69-33 

76-31 

7 

71-38 

78.11 

6 

67.29 

74.48 

6 

69-38 

!    76-35 

6 

71.42 

78.14 

5 

67-33 

74-52 

5 

69.42 

'    76.39 

5 

71.46 

78.18 

4 

67.38 

74-55 

4 

69.46 

76.42 

4 

71.50 

78.22 

3 

67.42 

74-59 

3 

1     69.50 

76.46 

3 

71-54 

78-25 

2 

67.46 

74-63 

2 

69.54 

76-50 

2 

71-58 

78.29 

I 

67.50 

74-67 

I 

'     69.58 

76-53 

I 

71-63 

''l-H 

0 

67-54 

74.70 

0 

j 

69.63 

76.57 

0 

71.67 

78.36 

670  FOOD  INSPECTION  AND  ANALYSIS. 

SPECIFIC  GRAVITY  AXD  PERCENTAGE  OF  ALCOHOL— (CowZ/Hz/^-rf), 


Spec. 
Grav. 

at 
1  f.-t"  C. 

Absolute  Alcohol. 

Spec. 
Grav. 

at 

Absolute  Alcohol. 

Spec. 

Grav. 

at 

Absolute  Alcohol. 

Per 

Per 

Per 

Per 

Per 

Per 

Cent 

Cent 

15.6'  C. 

Cent 

Cent 

15.0°  C. 

Cent 

Cent 

by 

by  Vol- 

by 

by  Vol- 

by 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

Weight. 

ume. 

0.8679 

71.71 

78.40 

0.8629 

73.83 

80.26 

0.8579 

76.08 

82.23 

8 

71-75 

78.44 

8 

73-88 

80.30 

8 

76.13 

82.26 

7 

7I-7Q 

78-47 

7 

73-92 

80.33 

7 

76.17 

82.30 

6 

71-83 

78.51 

6 

73-96 

80.37 

6 

76.21 

'^2-3,i 

5 

71. SS 

78.55 

5 

74.00 

80.40 

5 

76-25 

82.37 

4 

71.92 

78.58 

4 

74-05 

80.44 

4 

76.29 

82.40 

3 

71.96 

!     78.62 

3 

74-09 

80.48 

3 

76.33 

82.44 

2 

72.00 

78.66 

2 

74-14 

80.52 

2 

76.38 

82.47 

1 

72.04 

78.70 

I 

74.18 

80.56 

I 

76.42 

82.51 

0 

72.09 

78.73 

0 

74-23 

80.60 

0 

76.46 

82.54 

0.8669 

72-13 

78-77 

0.8619 

74-27 

80.64 

0.8569 

76.50 

82.58 

8 

72.17 

78.81 

8 

74-32 

80.68 

8 

76.54 

82.61 

7 

72.22 

78.85 

7 

74-36 

80.72 

7 

76.58 

82.65 

6 

72.26 

78.89 

6 

74.41 

80.76 

6 

76.63 

82.69 

5 

72-30 

78.93 

5 

74-45 

80.80 

5 

76.67 

82.72 

4 

72.35 

78.96 

4 

74-50 

80.84 

4 

76.71 

82.76 

3 

72.39 

79.00 

3 

74-55 

80.88 

3 

76.75 

82.79 

2 

72-43 

79.04 

2 

74-59 

80.92 

2 

76.79 

82.83 

I 

72.48 

79.08 

I 

74-64 

80.96 

I 

76.83 

82.86 

0 

72.52 

79.12 

0 

74.68 

81.00 

0 

76.88 

82.90 

0.8659 

72-57 

79.16 

0.8609 

74-73 

81.04 

0.8559 

76.92 

82.93 

8 

72.61 

79.19 

8 

74.77 

81.08 

8 

76.96 

82.97 

7 

72-65 

79-23 

7 

74.82 

81.12 

7 

77.00 

83.00 

6 

72.70 

79-27 

6 

74.86 

8r.i6 

6 

77.04 

83.04 

5 

72-74 

79-31 

5 

74.91 

81.20 

5 

77.08 

83.07 

4 

72.78 

79-35 

4 

74.95 

81.24 

4 

77-13 

83.11 

3 

72.83 

79-39 

3 

75-00 

81.28 

3 

77-17 

83.14 

2 

72.87 

79-42 

2 

75-05 

81.32 

2 

77.21 

83.18 

I 

72.91 

79.46 

1 

75-09 

81.36 

I 

77-25 

83.21 

0 

72.96 

79 -.so 

0 

75-14 

81.40 

0 

77-29 

83-25 

0.8649 

73.00 

79-54 

0.8599 

75-18 

81.44 

0.8549 

77-33 

83.28 

8 

73-04 

79-57     ; 

8 

75-23 

81.48 

8 

77-38 

83-32 

7 

73.08 

79.61     I 

7 

75-27 

81.52 

7 

77-42 

83.36 

6 

73-13 

79-65     i 

6 

75-33 

81.56 

6 

77.46 

83-39 

5 

73-17 

79.68 

5 

75-36 

81.60 

5 

77-50 

83-43 

4 

73-21 

79.72 

4 

75-41 

81.64 

4 

77-54 

83.46 

3 

73-25 

79.75 

3 

75-45 

81.68 

3 

77-58 

83-50 

2 

73-29 

79.79 

2 

75-50 

81.72 

2 

77-63 

83-53 

I 

73-33 

79.83 

I 

75-55 

81.76 

I 

77-67 

83-57 

0 

73-38 

79.86 

0 

75-59 

81.80 

0 

77-71 

83.60 

0.8639 

73-42 

79.90 

0.8589 

75-64 

8r.84 

0.8539 

77-75 

83.64 

8 

7346 

79.94 

8 

75.68 

81.88 

8 

77-79 

83.67 

7 

73-50 

79-97 

7 

75-73 

81.92 

7 

77-83 

83-71 

6 

73-54 

80.01 

6 

75-77 

81.96 

6 

77.88 

83-74 

5 

73-58 

So.  04 

5 

75.82 

82.00 

5 

77-02 

83-78 

4 

73-63 

80.08 

4 

75.86 

82.04 

4 

77-96 

83.81 

3 

73 -'>7 

80.12 

3 

75-91 

82.08 

3 

78.00 

83-85 

3 

73-71 

80.15 

2 

75-95 

82.12 

2 

78.04 

83.88 

I 

73-75 

80.19 

I 

76.00 

82.16 

I 

78.08 

83.91 

0 

73-79 

80.22 

0 

76.04 

82.19 

0 

78.12 

83-94 

ALCOHOLIC  BEVERAGES.  671 

SPECIFIC  GRAVITY  AND  PERCENTAGE  QF  ALCOHOL— (Co«//M«ed). 


Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Spec. 

Grav. 

Per 

Per 

Grav. 

Per 

Per 

Grav. 

Per 

Per 

at 
15.6°  C. 

Cent 

Cent. 

at 
iS.6°C. 

Cent 

Cent 

at 
15.6°  C. 

Cent 

Cent 

by 

by  Vol- 

by 

by  Vol- 

by 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

Weight. 

ume. 

0.8529 

78.16 

83.98 

0.8479 

80.17 

85-63 

0.8429 

82.19 

87.27 

8 

78.20 

84.01 

8 

80.21 

85.66 

8 

82.23 

87.30 

7 

78.24 

84.04 

7 

80.25 

85.70 

7 

82.27 

87-34 

6 

78.28 

84.08 

6 

80.29 

85-73 

6 

82.31 

87-37 

5 

78.32 

84.11 

5 

80.33 

85-77 

5 

82.35 

87.40 

4 

78.36 

84.14 

4 

80.38 

85.80 

4 

82.38 

87-43 

3 

78.40 

84.18 

3 

80.42 

85.84 

3 

82.42 

87.46 

2 

78.44 

84.21 

2 

80.46 

85-87 

2 

82.46 

87.49 

I 

78.48 

84.24 

I 

80.50 

85. 90 

I 

82.50 

87.52 

0 

78-52 

84.27 

0 

80.54 

85  .94 

0 

82.54 

87.55 

C.8519 

78. s6 

84.31 

0.8469 

80.58 

85.97 

0.8419 

82.58 

87.58 

8 

78.60 

84-34 

8 

80.6^ 

86.01 

8 

82.62 

87.61 

7 

78.64 

84-37 

7 

80.67 

86.04 

7 

82.65 

87.64 

6 

78.68 

84.41 

6 

80.71 

86.08 

6 

82.69 

87.67 

5 

78.72 

84-44 

5 

80.75 

86.11 

5 

82-73 

87.70 

4 

78.76 

84-47 

4 

80.79 

86.15 

4 

82.77 

87-73 

3 

78.80 

84.51 

3 

80.8^ 

86.18 

3 

82.81 

87-76 

2 

78.84 

84.54 

2 

80.88 

86.22 

2 

82.85 

87-79 

I 

78.88 

84-57 

I 

80.92 

86.25 

I 

82.88 

87.82 

0 

78.92 

84.60 

0 

80.96 

86.28 

0 

82.92 

87.85 

0.8509 

78.96 

84.64 

0.84^0 

81.00 

86.32 

0.8400 

82.96 

87.88 

8 

79.00 

84.67 

'8 

81.04 

86.35 

8 

83.00 

87.91 

7 

79.04 

84.70 

7 

81.08 

86.38 

7 

83.04 

87.94 

6 

79.08 

84.74 

6 

81.12. 

86.42 

6 

83.08 

87.97 

5 

79.12 

84.77 

5 

81.16 

86.45      i 

5 

83.12 

88.00 

4 

79.16 

84.80 

4 

81.20 

86.48      i 

4 

83-15 

88.03 

3 

79.20 

84.83 

3 

81.24 

86.51    ! 

3 

83.19 

88.06 

2 

79.24 

84.87 

2 

81.28 

86.54    1 

2 

83-23 

88.09 

I 

79.28 

84.90 

I 

81.32 

86.58 

1 

83-27 

88.13 

0 

79-32 

84.93 

0 

81.36 

86.61 

0 

83-31 

88.16 

0,8499 

79-36 

84-97 

0.8449 

81.40 

86.64 

0.8399 

83-35 

88.19 

8 

79.40 

85.00 

8 

81.44 

86.67 

8 

83-38 

88.22 

7 

79-44 

85-03 

7 

81.48 

86.71 

7 

83.42 

^^'5 

6 

79.48 

85.06 

6 

81.52 

86.74 

6 

83.46 

88.28 

5 

79-52 

85.10 

5 

81.56 

86.77 

5 

83-50 

88.31 

4 

79-56 

85-13 

4 

81.60 

86.80 

4 

83-54 

88.34 

3 

79.60 

85.16 

3 

81.64 

86.83 

3 

83.58 

88.37 

2 

79.64 

85.19 

2 

81.68 

86.87 

2 

83.62 

88.40 

I 

79.68 

85-23 

I 

81.72 

86.90 

I 

83.65 

88.43 

0 

79.72 

85.26 

0 

81.76 

86.93 

0 

83.69 

88.46 

C.8489 

79.76 

85.29 

0.8439 

81.80 

86.96 

0.8389 

83.73 

88.49 

8 

79.80 

85-33 

8 

81.84 

86.99 

8 

83.77 

88.52 

7 

79.84 

85-36 

7 

81.88 

87.03 

7 

83.81 

88.55 

6 

79.88 

85-39 

6 

81.92 

87.06 

6 

83.85 

88.58 

5 

79.92 

85.42 

5 

81.96 

87.09 

5 

83.88 

88.61 

4 

79.96 

85.46 

4 

82.00 

87.12 

4 

83-92 

88.64 

3 

80.00 

85.49 

3 

82.04 

87.15 

3 

83-96 

88.67 

2 

80.04 

85-53 

2 

82.08 

87.18 

2 

84.00 

88.70 

1 

80.08 

85-56 

1 

82.12 

87.21 

1 

84.04 

88.7^ 

0 

80.13 

85-59 

0 

82.15 

87.24 

0 

84.08 

88.76 

t>72 


FOOD  INSPECTION  AND  ANALYSIS. 


SPECIFIC  GRAVITY  AND   PERCENTAGE  OF  XLCO^lOl.— {Continued). 


Absolute  Alcohol.      1 

Spec. 

Grav. 

at 

Absolute  Alcohol.      j 

1 

Absolute  Alcohol. 

Spec. 
Grav. 

Per 

Per 

Per 

Per 

opec 

Grav. 

at 

Per 

Per 

at 
15.6°  C. 

Cent 

Cent 

y  e  ffi  C 

Cent 

Cent 

15.6°  c.  1 

Cent 

Cent. 

by 

by  Vol- 

15.*^    ^. 

by 

by  Vol- 

by 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

1 

Weight. 

ume. 

0.8379    , 

84. 12 

SS.79     j 

0.8329 

86.08      1 

90.32      1 

0.8279   1 

88.00 

91.78 

s 

S4.16 

88.83 

8 

86.12     • 

90.35      ' 

8 

88.04 

91.81 

7 

84.20 

88.86 

7 

86.15 

90.38      ' 

7 

88.08 

91.84 

6 

84.24 

88.89 

6 

86.19 

90.40 

6 

88.12 

91.87 

5 

84.28 

88.92 

5 

86.23 

90.43 

5 

88.16 

91.90 

4 

84.32 

88.95 

4 

86.27     1 

90.46 

4 

88.20 

91-93 

3 

84.36 

88.98 

3 

86.31 

90.49 

3 

88.24 

91.96 

2 

84.40 

89.01 

2 

86.35 

90.52 

2 

88.28 

91.99 

I 

84.44 

89.05 

I 

86.38 

90-55 

I 

88.32 

92.02 

0 

84.48 

89.08 

0 

86.42 

\ 

90.58 

0 

88.36 

92.05 

0.8369 

S4-52 

89.11 

0.8319 

86.46 

90.61 

0.8269 

88.40 

92.08 

8 

84.56 

89.14 

8 

86.50     1 

90.64 

8 

88.44 

92.12 

7  1 

84.60 

89.17 

7 

86.54     1 

90.67 

7 

88.48 

92.15 

6' 

84.64 

89.20 

6 

86.58 

90-70 

6, 

88.52 

92.18 

5 

84.68 

89.24 

5 

86.62 

90-73 

5  i 

88.56 

92.21 

4 

84.72 

89.27 

4 

86.65 

90.76 

4  1 

88.60 

92.24 

3 

84.76 

89.30 

3 

86.69 

90.79 

3 

88.64 

92.27 

2 

84.80 

89-33 

2 

86.73 

90.82 

2 

88.68 

92.30 

I 

84.84 

89-36 

I 

86.77 

90.85 

I 

88.72 

92-33 

0 

84.88 

89-39 

0 

86.81 

90.88 

0 

88.76 

92.36 

0.8359 

84.92 

89.42 

'  0.8309 

86.85 

90.90 

0.8259 

88.80 

92-39 

8 

84.96 

89.46 

8 

86.88 

90-93 

8 

88.84 

92.42 

7 

85.00 

89.49 

7 

86.92 

90.96 

7 

88.88 

92-45 

6 

85.04 

89  52 

6 

86.96 

90.99 

6 

88.92 

92.48 

5 

85-08 

89.55 

5 

87.00 

91.02 

5 

88.96 

92-51 

4 

85.12 

89.58 

4 

87.04 

91.05 

4 

89.00 

92-54 

3 

85-15" 

89.61 

3 

87.08 

91.08                      3 

89.04 

92-57 

2 

85.19 

89.64 

2 

87.12 

91. II                      2 

89.08 

92.60 

I 

85-23 

89.67 

I 

87-15 

91.14                      I 

89.12 

92.63 

0 

85-27 

89.70 

0 

87.19 

91.17                      0 

89.16 

92.66 

0.8349 

85-31 

89-72 

0.8299 

87-23 

91.20 

0.8249 

89.19 

92.68 

8 

85-35 

89-75 

8 

87.27 

91-23 

8 

89.23 

92.71 

7 

85-38 

89.78 

7 

87-31 

91-25 

'            7 

89.27 

92.74 

6 

85-42 

89.81 

6 

87-35 

91.28 

6 

89.31 

92-77 

5 

85.46 

89.84 

5 

87.38 

91-31 

5 

89-35 

92.80 

4 

85-50 

89.87 

4 

87.42 

91-34 

4 

89.38 

92.83 

3 

85-54 

89 .  90 

3 

87.46 

91-37 

3 

89.42 

92.86 

2 

85 -.58 

89-93 

2 

87.50 

91.40 

2 

89.46 

92.89 

I 

85.62 

89.96 

r 

87-54 

91-43 

I 

89.50 

92.91 

0 

85-65 

89.99 

0 

1 

87.58 

91.46 

0 

89-54 

92-94 

0-8339 

85.69 

90.02 

1'  0.8289 

87.62 

91.49 

0.8239 

89.58 

92-97 

8 

85-73 

,     9005 

'              8 

87.65 

91-52 

8 

89.62 

93.00 

7 

85-77 

j     90.08 

7 

87.69 

91-55 

7 

89.65 

93-03 

6 

85.81 

90.11 

6 

87-73 

1     91-57 

6 

89.69 

93.06 

.      5 

85-85 

90.14 

i             5 

87-77 

91.60 

5 

89-73 

93-09 

4 

'      85.88 

90.17 

4 

87.81 

91.63 

4 

89.77 

93-" 

3 

'       85. Q2 

90.20 

3 

87-85 

91.66 

;         3 

89.81 

93-14 

3 

85.06 

,     90.23 

2 

87.88 

91.69 

:      2 

89.85 

93-17 

I 

1       86.00 

90.26 

I 

87.92 

91.72 

I 

89.88 

93-20 

0 

,       86.04 

90.29 

0 

87-96 

91-75 

0 

1 

89.92 

93-23 

ALCOHOLIC  BEl/ERACES.  673 

SPECIFIC  GRAVITY  AND  PERCENTAGE  OF  M.COHO'L— {Continued). 


Absolute  Alcohol.      j 

Absolute  Alcohol. 

Absolute  Alcohol. 

Spec. 

Spec. 

Spec. 

Grav. 

at 

Per 

Per 

Grav. 

at 

Per 

Per 

Grav. 
at 

Per 

Per 

15.6°  C. 

Cent 

Cent 

iS.6°C. 

Cent 

Gent 

15.6°  C. 

Cent 

Cent 

by 

by  Vol- 

by 

by  Vol- 

by 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

Weight. 

ume. 

0.8229 

89.96 

93^26 

0.8179 

91-75 

94-53 

0.8129 

93-59 

95-84 

8 

90.00 

93-29 

8 

91.79 

94-56 

8 

93-63 

95-87 

7 

90.04 

93-31 

7 

91.82 

94-59 

7 

93-67 

95-90 

6 

90.07 

93-34 

6 

91.86 

94.61 

6 

93-70 

95-92 

5 

90.11 

93-36 

5 

91.89 

94.64 

5 

93-74 

95-95 

4 

90.14 

93-39 

4 

91-93 

94.66 

4 

93-78 

95-97 

3 

90.18 

93-41 

3 

91.96 

94.69 

3 

93-81 

96.00 

2 

90.21 

93-44 

2 

92.00 

94.71 

2 

93-85 

96.03 

1 

90.25 

93-47 

I 

92.04 

94-74 

I 

93-89 

96.05 

0 

90.29 

93-49 

0 

92.07 

94.76 

0 

1 

93-92 

96.08 

0.8219 

90.32 

93-52 

0.8169 

92.11 

94-79 

0.8119  1 

93-96 

96.11 

8 

90.36 

93-74 

8 

92-15 

94.82 

8 

94-00 

96.13 

7 

90-39 

93-57 

7 

92.18 

94-84 

7  ' 

94-03 

96.16 

6 

90-43 

93-59 

6 

92.22 

94.87 

6 

94-07 

96.18 

5 

90.46 

93.62 

5 

92.26 

94-90 

5  1 

94.10 

96.20 

4 

90.50 

93-64 

4 

92.30 

94.92 

4 

94.14 

96.22 

3 

90-54    ' 

93-67 

3 

92-33 

94-95 

3 

94.17 

96.25 

2 

90-57    i 

93-70     1 

2 

92-37 

94.98 

2 

94-21 

96.27 

I 

90.61    ' 

93-72 

I 

92.41 

95.00 

I 

94-24 

96.29 

0 

90.64 

93-75 

0 

92.44 

95-03 

0 

94.28 

96.32 

0.8209 

90.68 

93-77 

0.8159 

92.48 

95.06 

0.8109 

94-31 

96-34 

8 

90.71 

93.80 

8 

92.52 

95-08 

8 

94-34 

96.36 

7 

90-75 

93.82 

7 

92-55 

95-11 

7 

94.38 

96-39 

6 

90-79 

93-85 

6 

92-59 

95-13 

6 

94.41 

96.41 

5 

90.82 

93-87 

5 

92.63 

95.16 

5 

94-45 

96-43 

4 

9c.  86 

93-90 

4 

92.67 

95-19 

4 

94-48 

96.46 

3 

90.89 

93-93 

3 

Q2.70 

95-21 

3 

94-52 

96.48 

2 

90-93 

93-95 

2 

92.74 

95-24 

2 

94-55 

96.50 

I 

90.96 

93-98 

I 

92.78 

95-27 

I 

94-59 

96-53 

0 

91.00 

94-00 

0 

92.81 

95-29 

0 

94 .  62 

96-55 

0.8199 

91.04 

94-03 

0.8149 

92-85 

95-32 

0.8099 

94-65 

96 -.17 

8 

91.07 

94-05 

8 

92.89 

95-35 

8 

94-69 

96.60 

7 

91.11 

94.08 

7" 

92.92 

95-37 

7 

94-73 

96.62 

6 

91.14 

94.10 

6 

92.96 

95-40 

6 

94-76 

96.64 

5 

91.18 

94-13 

5 

93-00 

95.42 

5 

94.80 

96.67 

4 

91 .21 

94-15 

4 

93-04 

95-45 

4 

94-83 

96.69 

3 

91-25 

94.18 

3 

93-07 

95.48 

3 

94.86 

96.71 

2 

91.29 

94.21 

2 

93-11 

95-50 

2 

94.90 

96.74 

I 

91.32 

94-23 

I 

93-15 

95-53 

I 

94-93 

96.76 

0 

91.36 

94.26 

0 

93-18 

95-55 

0 

94-97 

96.78 

0.8189 

91-39 

94-28 

0.81^9 

93.22 

95 -.'?8 

0.8089 

95.00 

96.80 

8 

91-43 

94-31 

'8 

93.26 

95.61 

8 

95.04 

,     96-83 

7 

91.46 

94-33 

7 

93-30 

95-63 

7 

95-07 

1     06. 8<; 

6 

91.50 

94-36 

6 

93-33 

95.66 

6 

95 . 1 1 

!     96.88 

5 

91-54 

]     94-38 

5 

93-37 

95-69 

5 

05-14 

1     96.90 

4 

91-57 

94-41 

4 

93-41 

95-71 

4 

05.18 

96-93 

3 

91.61 

94-43 

3 

93-44 

95-74 

3 

95.21 

1     96-95 

2 

91.64 

94.46 

2 

93  -48 

95.76 

2 

95-25 

1     96.98 

i: 

91.68 

94-48 

I 

93-52 

95  •  79 

I 

95.29 

97.00 

0 

91.71 

94-51 

0 

93-55 

95.82 

0 

05-32 

97.02 

674  FOOD  INSPECTION  AND  ANALYSIS. 

SPECIFIC  GRAVITY  AND  PERCENTAGE  OF  .\LCOYlO\.— {Continued). 


Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Spec. 

Absolute  Alcohol. 

Spec. 

Orav 

Per 

Per 

Grav. 

Per 

Per 

Grav. 

Per 

Per 

at 
iS.6'C. 

Cent 

Cent 

at 
15.6°  C. 

Cent 

Cent 

at 
15.6°  C. 

Cent 

Cent 

by 

by  Vol- 

by 

by  Vol- 

bv 

by  Vol- 

Weight. 

ume. 

Weight. 

ume. 

Weight. 

ume. 

0.8079 

95-36 

97-05 

0.8029 

97.07 

98.18 

0.7979 

98.69 

99.18 

Q 

95-39 

97.07 

8 

97.10 

98.20 

8 

98 

72 

99 

20 

7 

95-43 

97.10 

7 

97-13 

98.22 

7 

98 

75 

99 

22 

6 

95.46 

97.12 

6 

97.16 

98.24 

6 

98 

78 

99 

24 

S 

95  -  50 

97-15 

5 

97.20 

98.27 

5 

98 

81 

99 

26 

4 

95-54 

97-17 

4 

97-23 

98.29 

4 

98 

84 

99 

27 

3 

95-57 

97.20 

3 

97.26 

98.31 

3 

98 

87 

99 

29 

2 

95.61 

97.22 

2 

97-30 

98.33 

2 

98 

91 

99 

31 

I 

95.64 

97-24 

I 

97-33 

98-35 

I 

98 

94 

99 

33 

0 

95-68 

97.27 

0 

97-37 

98.37 

0 

98 

97 

99 

35 

0.8069 

95-71 

97.29 

0.8019 

97-40 

98.39 

0.7969 

99 

00 

99 

37 

8 

95-75 

97-32 

8 

97-43 

98.42 

8 

99 

03 

99 

39 

7 

95-79 

97-34 

7 

97.46 

98.44 

7 

99 

06 

99 

41 

6 

95.82 

97-37 

6 

97-50 

98.46 

6 

99 

10 

99 

43 

5 

95-86 

97-39 

5 

97-53 

98.48 

5 

99 

13 

99 

45 

4 

95-89 

97.41 

4 

97-57 

98.50 

4 

99 

16 

99 

47 

3 

95-93 

97-44 

3 

97.60 

98.52 

3 

99 

19 

99 

49 

2 

95-96 

97-46 

2 

97-63 

98-54 

2 

99 

23 

99 

51 

I 

96.00 

97-49 

I 

97.66 

98.56 

I 

99 

26 

99 

53 

0 

96.03 

97-51 

0 

97-70 

98-59 

0 

99 

.29 

99 

-55 

0.8059 

96.07 

97-53 

0.8009 

97-73 

98.61 

0-7959 

99 

■32 

99 

•57 

8 

96.10 

97-55 

8 

97.76 

98.63 

8 

99 

36 

99 

■59 

7 

96.13 

97-57 

7 

97.80 

98.65 

7 

99 

39 

99 

.61 

6 

96.16 

97-60 

6 

97-83 

98.67 

6 

99 

42 

99 

-63 

5 

96.20 

97.62 

5 

97.87 

98.69 

5 

99 

45 

99 

-65 

4 

96.23 

97-64 

4 

97.90 

98.71 

4 

99 

48 

99 

.67 

3 

96.26 

97.66 

3 

97-93 

98.74 

3 

99 

52 

99 

69 

2 

96.30 

97.68 

2 

97.96 

98.76 

2 

99 

55 

99 

71 

I 

96-33 

97-70 

I 

98.00 

98.78 

I 

99 

58 

99 

73 

0 

96.37 

97-73 

0 

98.03 

98.80 

0 

99 

61 

99 

75 

0.8049 

96.40 

97-75 

0.7999 

98.06 

98.82 

0.7949 

99 

65 

99 

77 

8 

96-43 

97-77 

8 

98.09 

98.83 

8 

99 

68 

99 

80 

7 

96.46 

97-79 

7 

98.12 

98.85 

7 

99 

71 

99 

82 

6 

96.50 

97.81 

6 

98.16 

98.87 

6 

99 

74 

99 

84 

5 

96.53 

97-83 

5 

98.19 

98.89 

5 

99 

78 

99 

86 

4 

96.57 

97.86 

4 

98.22 

98.91 

4 

99 

81 

99 

88 

3 

96.60 

97.88 

3 

98.25 

98-93 

3 

99 

84 

99 

90 

2 

96.63 

97.90 

2 

98.28 

98.94 

2 

99 

87 

99 

92 

I 

96.66 

97.92 

I 

98.31 

98.96 

I 

99 

90 

99 

94 

0 

96.70 

97-94 

0 

98-34 

98.98 

0 

99.94 

99.96 

0.8039 

96.73 

97.96 

0.7989 

98-37 

99.00 

0-7939 

99-97 

99.98 

8 

96.76 

97.98 

8 

98.41 

99.02 

7 

96.80 

98.01 

7 

98.44 

99.04 

Abs. 

Ale. 

6 

96.83 

98.03 

6 

98-47 

99-05 

0.7938 

100.00 

100.00 

5 

96.87 

98.05 

5 

98.50 

99.07 

4 

96.90 

98.07 

4 

98-53 

99-09 

3 

96-93 

98.09 

3 

98-56 

99.11 

2 

96 .  96 

98.11 

2 

98.59 

99-13 

1- 

97.00 

98.14 

I 

98.62 

99-15 

0 

97-03 

98.16 

0 

98.66 

99.16 

y4LC0H0LIC   RRyF.RAGFS. 


675 


(4)  Determination  of  Alcohol  by  tJie  Ebullioscope  or  Vaporimeter 
is  based  on  the  variation  in  boilin^-])oint  of  mixtures  of  alcohol  and  water, 
in  accordance  with  the  amount  of  alcohol  |>resent.  There  are  various 
forms  of  this  instrument,  one  of  the  simplest  and  most  convenient  being 
that  of  Salleron,  Fig.  113,  the  apparatus  being  known  in  France  as  an 


0 

a. 

H 

0 

z 

<  2 

£0 

0 

z  z 

IOIt 

0 

0- 

hoo- 

-0 

^M^ 

- 

2— 

-   -- 

—2 

\n\ 

4- 

\ir{ 

-4 

r96-i 

- 

6— 

^  "^ 

—8 

r96-= 

8- 

N*i 

-8 

r93-i 

"~ 

10- 

-10 

^^ 

— 

12- 

= ■■_ 

-12 

;-9i-: 

— 

14- 

i-    -: 

-14 

16- 

roo^ 

-16 

18- 

^89i 

-18 

20- 

I — = 

-20 

=-881 

NH 

— 

25- 

^86i 

-25 

0 

li 

Fig.  113. — Salleron 's  Ebullioscope  and  Scale  for  Calculation  of  Results. 

ebulliometer.  This  consists  of  a  jacketed  metallic  reservoir,  heated  by 
a  lamp  placed  beneath,  and  fitted  with  a  return-flow  condenser  at  the 
top  and  with  a  delicate  thermometer  graduated  in  tenths  of  a  degree. 

As  the  boiling-point  of  water  varies  with  the  atmospheric  pressure, 
it  is  necessary  to  determine  the  actual  boiling-point  corresponding  with 
the  barometric  conditions  each  time  a  series  of  determinations  are  made. 


676  FOOD  INSPECTION   AND   ANALYSIS. 

This  is  done  by  boiling  a  measured  portion  of  distilled  water  in  the  reser- 
voir, and  carefully  noting  the  temperature  when  it  becomes  constant. 

The  reservoir  is  then  rinsed  out  with  a  little  of  the  liquor  to  be  tested^ 
after  which  a  measured  amount  of  this  liquor  is  boiled  in  the  reservoir 
and  the  temperature  again  noted.  A  sliding  scale  (Fig.  113)  accompanies 
the  instrument,  having  three  graduated  parts  as  shown.  The  central 
movable  portion  is  graduated  in  degrees  and  tenths  of  a  degree  centi- 
grade, the  part  at  the  left  has  the  per  cent  of  alcohol  corresponding  to 
the  temperature  in  the  case  of  simple  mixtures  of  alcohol  and  water, 
while  the  part  at  the  right  is  used  for  reading  the  per  cent  in  the  case  of 
wine,  cider,  beer,  etc.,  which  have  a  considerable  residue.  The  movable- 
scale  bearing  the  degrees  of  temperature  is  first  set  with  the  actual  tem- 
perature of  boiling  water  (as  ascertained)  opposite  the  o  mark  on  the- 
stationar}'  scale.  Suppose  the  temperature  of  boiling  water  has  been 
found  to  be  100.1°.  The  scale  is  in  this  case  set  as  shown  in  Fig.  113. 
Suppose  also  the  temperature  of  boiling  of  the  wine  to  be  tested  is 
found  to  be  89.3°.  From  the  right-hand  scale  the  corresponding  per  cent 
of  alcohol  is  found  to  be  17.2. 

When  the  licjuor  to  be  tested  contains  more  than  25%  of  alcohol,  it 
is  necessary  to  dilute  with  a  measured  amount  of  distilled  water  and 
calculate  the  per  cent  from  the  dilution. 

When  once  the  boiling-point  of  water  has  been  determined  for  a  given 
barometric  pressure,  it  is  unnecessar}-  to  change  the  position  of  the  slid- 
ing scale  during  a  series  of  alcohol  determinations  unless  that  pressure 
changes. 

Expression  of  Results. — Some  confusion  is  caused  by  the  three  ways 
of  expressing  results  of  the  alcohol  determination,  whether  as  per  cent  by 
weight,  per  cent  by  volume,  or  grams  per  100  cc.  The  particular  mode 
adopted  should  depend  upon  the  nature  of  the  case  and  upon  the  prevail- 
ing custom.  In  laboraton,-  analyses,  unless  otherwise  fjualified,  the  simple 
expression  of  "jK-r  cent"  usually  implies  ])er  cent  by  weight,  and  for 
the  reason  that  this  conforms  with  other  determinations,  the  adoption 
of  the  weight-percentage  plan  is  perhaps  most  natural  to  the  chemist  on 
the  grounds  of  uniformity. 

In  enforcing  the  laws  regulating  the  liquor  trafTic,  the  custom  leans 
to  volume  percentage,  and  many  of  the  laws  are  based  on  the  "volume 
of  alcohol  at  60°  F."  (see  p.  656). 

In  recent  years  many  European  analysts  have  adoj^tcd  the  custom  of 
expressing  results  of  analyses  ; of  wines  and  other  lj(iuors  in  grams  per 


ALCOHOLIC  BEVER/IGES.  677 

100  cc.  and,  in  order  to  have  a  common  basis  of  comparison  belwccn 
the  composition  of  American  and  of  European  wines,  this  manner  of 
expression  has  to  some  extent  been  adoj^tcd  in  the  United  States. 

Proof-spirit  in  the  United  States  is  an  alcoholic  liquor  containing  50% 
of  absolute  alcohol  by  volume  at  15.6°  C.  A  common  method  of  express- 
ing alcohol  is  in  "degree  proof"  or  simply  ''  proof,"  which  in  the  United 
States  is  twice  the  per  cent  of  alcohol  by  volume.  Thus,  yi.3  proof  or 
degree  proof  is  the  same  as  45.65%  alcohol  by  volume. 

English  Proof-spirit  differs  from  that  in  the  United  States  in  tliat  it 
contains  49.24%  by  weight,  or  57.06%  by  volume  of  absolute  alcohol  at 
15.6°  C.  Strength  is  expressed  in  degrees  over  or  under  proof.  Thus 
liquor  20°  under  proof  has  80  parts  by  volume  of  proof-spirit  and  20  parts 
of  water  at  15.6°  C,  while  20°  over-proof  means  that  100  volumes  of  the 
liquor  have  to  be  diluted  to  120  volumes  with  water  to  yield  proof-spirit. 
To  calculate  the  per  cent  by  volume  of  English  proof-spirit  from  the  per 
cent  of  alcohol  by  volume,  divide  the  latter  by  0.5706,  or  multii)ly  it  by 

^•7525- 

Direct  Determination  of  Extract. — In  lic^uors  having  a  high  sugar 
content,  the  extract  or  total  solids  cannot  be  determined  accurately  by 
evaporation  at  the  temperature  of  boiling  water,  owing  to  the  dehydra- 
tion of  the  reducing  sugars  at  temperatures  exceeding  75°.  When  extreme 
accuracy  is  required,  such  liquors  should  be  dried  in  vacuo  at  75°,  or  in 
a  McGill  oven  (p.  586). 

Approximate  results  satisfactor}'  in  most  cases  are  obtained  by  heat- 
ing for  two  and  one-half  hours  10  grams  of  the  liquor  in  a  tared  platinum 
dish  at  the  temperature  of  boiling  water.  If  the  results  are  to  be  expressed 
in  grams  per  100  cc,  instead  of  weighing  out  10  grams,  10  cc.  of  the  liquor 
are  measured  by  a  pipette  into  a  tared  dish.  With  distilled  liquors  having 
low  residues,  accurate  results  are  obtainable  by  direct  evaporation  at 
100°,  using  preferably  25  grams  or  25  cc.  according  as  the  result  is  to  be 
expressed  in  per  cent  by  weight  or  grams  per  100  cc. 

Extract  in  wine  and  beer  is  more  readily  calculated  indirectly  from 
their  specific  gravity  as  noted  elsewhere. 

Determination  of  Ash. — The  residue  from  the  determination  of  the 
extract  is  incinerated  to  a  white  ash  in  the  original  dish  at  a  low  red  heat, 
either  over  a  Bunsen  flame  or  in  a  muffle.  The  dish  is  finally  cooled  in 
a  desiccator  and  weighed. 

Preservatives  and  Artificial  Sweeteners  in  liquors  are  identified  as. 
described  in  Chapters  XVIII  and  XIX. 


67S 


FOOD  INSPECTION  AND  ANALYSIS. 


FERMENTED  LIQUORS. 

The  fermented  juices  of  many  varieties  of  fruits  and  berries  furnish 
beverage?  more  or  less  popular  in  various  localities,  especially  for  home 
consumption,  though,  with  the  exception  of  the  products  of  the  apple  and 
the  grape,  few  of  them  arc  found  on  the  market.  The  following  table 
shows  the  average  percentage  of  sugar  and  free  acid  in  the  expressed 
juice  or  must  of  fruits,  according  to  Fresenius,  arranged  in  the  order 
of  their  sugar  content: 


Peaches 

Apricots 

Plums 

Green  gages  . .  . 
Raspberries.  .. . 
Blackberries.  . . 
Strawberries.  . . 

Currants 

German  prunes 
Gooset)erries.  .. 

Pears 

Apples 

Mulberries 

Sour  cherries.  .. 
Sweet  cherries.  . 
GrajK-s 


Per  Cent  Sugar. 

Per  Cent  Free 
Acid  as  Malic. 

1-99 

0.85 

2-13 

1.29 

2.80 

1.72 

4.18 

0.67 

4.84 

1.80 

5-32 

1.42 

6.89 

1-57 

7-30 

2-43 

7.56 

1.08 

8.00 

1.63 

8.43 

0.09 

9.14 

0.82 

10.00 

2.02 

10.44 

1.^2 

15-30 

0.88 

16.15 

0.80 

CIDER. 

Cider  is  the  expressed  juice  of  the  apple.  When  fresh  and  before 
fermentation  has  set  in,  it  is  known  as  sweet  cider,  but  it  does  not  long 
remain  in  this  condition,  developing  after  a  good  fermentation  from  3  to 
6  [K-r  cent  of  alcohol  by  volume. 

The  predominating  yeast  under  the  influence  of  which  the  fermenta- 
tion of  cider  takes  place  is  Saccharomyces  apiculaius,  found  in  consider- 
able quantity  on  the  outside  of  the  apples  as  well  as  in  the  soil  in  which 
the  trees  grow. 

Process  of  Manufacture. — The  best  cider  is  made  from  ripe  fruit, 
taking  care  to  avoid  the  green  and  the  rotten  apples,  both  of  which  impair 
the  quaHty  of  the  product.  After  gathering,  the  apples  are  best  allowed  to 
Stand  in  piles  until  perfectly  ripe,  being  kept  under  cover.  If  exposed 
to  the  weather,  certain  of  the  yeast  organisms  found  on  the  skins  of  the 
apples  that  are  useful  in  promoting  subsequent  fermentation  would  be 


ALCOHOLIC  BEVER/IGES.  679 

washed  off.  As  a  rule  the  apples  commonly  used  by  farmers  for  cider- 
making  are  those  that  are  unsalable  or  unfit  for  other  purposes,  being 
chiefly  windfalls  or  bruised  and  imperfect  fruit.  The  apples  are  usually 
first  crushed  in  a  mill  to  a  coarse  pulp,  which  is  afterward  subjected  to 
pressure  in  a  suitable  press  and  the  juice  thus  extracted. 

In  this  country  but  little  attention  is  paid  to  the  after  processes,  the 
juice  being  usually  transferred  directly  to  barrels,  which  are  not  always 
particularly  clean,  and  allowed  to  ferment  spontaneously  in  a  convenient 
place,  subject  to  changes  in  tcmj)erature.  There  is  little  wonder  that 
cider  so  made  will  keep  but  a  short  time  and  quickly  goes  over  into  vinegar, 
unless  salicylic  acid  or  other  antiseptic  is  added. 

In  France  more  care  is  taken  to  regulate  the  temperature  of  fermen- 
tation, to  insure  absolute  cleanness  of  all  receptacles,  and  to  separate 
out  contaminating  impurities.  A  preliminary  fermentation  is  usually 
given  to  the  juice  in  open  vats,  during  which  the  yeast  spores  are 
developed,  while  impurities  separate  out  both  by  rising  to  the  surface 
and  by  settling  to  the  bottom,  care  being  taken  to  avoid  the  develop- 
ment of  acetic  fermentation.  At  the  proper  time  the  juice  is  "racked 
off"  or  drawn  from  the  clear  portion  between  the  top  and  bottom,  trans- 
ferred to  scrupulously  clean  barrels,  and  allowed  to  undergo  a  second 
fermentation  at  a  lower  temperature  than  before. 

Sometimes  the  "racking  off"  is  repeated,  and  the  juice  is  further 
clarified  by  "fining"  or  treating  with  isinglass,  which  carries  down  certain 
albuminous  substances. 

Cider  thus  made  is  capable  of  keeping  a  very  long  time. 

In  England  cider  is  sometimes  "fined"  by  treatment  with  milk,  one 
quart  of  the  latter  being  added  to  eighteen  gallons  of  cider. 

The  apple  pomace,  left  as  a  residue,  is  generally  steeped  in  water 
and  repressed.  The  juice  from  the  second  pressing  is  occasionally  added 
to  the  first  for  cider  manufacture,  but  more  often  is  concentrated  and 
made  into  apple  jelly,  or  used  as  a  fortifier  for  vinegar  to  make  up 
deficiency   in   solids. 

Composition  of  Cider.— The  following  tables,  due  to  Browne,*  show 
the  chemical  composition  of  the  freshly  expressed  juice  of  several 
American  varieties  of  apple,  as  well  as  that  of  a  few  fermented  samples 
of  cider  of  known  purity. 

*  Penn.  Dept.  of  Agric,  BuL  58. 


b:-^o 


FOOD  INSPECTION  AND   ANALYSIS. 
APPLE   JUICES. 


Red  astrachan 

Early  han-cst 

Yellow  transparent . 
Early  strawberry.  . . 

Sweet  bough 

Baldwin,  green 

' '  ripe 

Ben  Davis 

Belltlower 

Tulpahocken 

Unknown 


I -05317 
1.05522 
1.05020 
1.04949 
1-04079 
1.04882 
1.07362 

1-05389 
1.06270 
1.05727 
I. 05901 


Cfl 


*>;; 


>  5 


3 " 


11.78  6.87  3.63 

13-29  7-49  3-97 

II. 71  8.03  2.10 

II. 81  5.474.21 

11.87;  7-61   3.08 

11.36!  6.961  1.63 

16.82!  7.97I  7.05 

12.77I  7. 11!  3.85 

14.90  9.06,  4.32 

13.94  9-68^  3. II 
13.75  10.52   2.31 


10.50 
11.46 
10. 14 
9.68 
10.69 

8-59 
15.02 
10.96 

13-38 
12.79 
12.83 


10.69 
II  .67 
10.24 

9.00 
10.85 

8.68 

15-39 
II. 16 
13.61 
12-95 
12-95 


a^ 


1. 14 
0.90 
0.86 
0.78 

O.IO 

1.24 

0.67 
0.46 

0.58 

0.26 

0.44 


0-37 
0.28 

0.27 
0.24 


0.31 

0.26 

0.28 
0.28 

0.24 
0.26 


0.77 
0.65 
0.44 

I. II 


1.22 
0.87 
1.07 
0.66 
0.49 
0.22 


^  V  y 

o  c  «^iJ 

5     -     •   OJ 

.S  j;  I'.S 
&P  o  o 


23.72 
24.32 

19.24 
39-40 
36.16 

49.  OO' 

39 .  20 

48.20 
44.18 


FERMENTED  CIDER  (MIXED  APPLES). 


Rotation, 

Specific 
Gravity. 

Solids. 

Invert 
Sugar. 

Malic 
Acid. 

Acetic 
Acid, 

Alcohol. 

Pectin. 

Ash. 

400-mm. 

Tube, 
Ventzke 

Scale. 
Degrees 

to  the 

Left. 

A... 

1  .o'>805 

1-94 

0. 19 

0.21 

0.24 

6.85 

0.03 

0.25 

2.30 

B... 
C... 

I. 00122 
1.00525 

2.71 
3,26 

0.19 
0.89 

0.24 
0.30 

0.42 
0.48 

5-13. 
4.67 

0.03 
0.05 

0.32 
0.29 

2.49. 
5.28 

E... 

I. 00071 
I. 00512 

1.93 
2.71 

0.34 
0.24 

0.27 
0.29 

0.21 
1.96 

4-95 
4.26 

0.05 
0.06 

0.23 
0.36 

2.00 
1.76 

The  following  are  summaries  of  the  results  of  a  large  number  of 
analyses  of  European  apple  juices  made  by  Truelle,  the  quantities  being 
e.xpressed  in  grams  per  liter: 


Mean. 


Minimum. 


Maximum. 


Sfx-cifu  gravity 

Invert    ugar 

Sucrose 

Total  fermentable  sugars  (as  dextrose)  . . 

Tannin 

Pectin  and  albuminous  substances 

Acidity  ^sulphuric  acid) 


1.0760 

135-85 

25.01 

162.18 

2.90 

12 

2.14 


1-0573 
108.38 

5-58 
119.22 
0.26 
o 
0.69 


1. 1 100 
181. 81 
71.7 

231-57 
8.07      ' 

23 
7.41 


ALCOHOLIC  BEyER/iGES. 


68 1 


In  the  municipal  laboratory  of  Paris,  Sangle  Fcrriere  has  analyzed 
eleven  samples  of  known-purity  cider  with  the  following  results: 


Density. 

Si 

Sugar  per 
Liter. 

c" 

.2 

|3 

Alkalinity  of 
Ash,  as 
KoCOs  per 
Liter. 

Af  i.litv  a-; 
H.SOj. 

0  >  5 

"5 

•6 

Mean 

Maximum 

Minimum.  . . 

I. 0159 
1. 0410 

I. 0012 

3-9 
6.2 
I.I 

52.67  21.31 
114.00  59.40 

22.62  Trace 

21.62 
60.80 

Trace 

-4°.  26 

-II°.20 

0 

3.26 

4.32 
2.48 

2.56 
3-68 

2.C4 

5-27 
6-59 
4.20 

2-5S 
2.94 
1-47 

Six  samples  of  bottled  "sweet"  cider  purchased  in  ISIassachusclts 
were  analyzed  in  the  Food  and  Drug  Laboratory  of  the  Board  of  Health 
with  the  following  results: 


Maximum 
Minimum 
.'Average . . 


Per  Cent 

Alcohol  by 

Weight. 


8.00 

3-55 
5-71 


Per  Cent 
Acid  as 
Malic. 


0.72 
0.48 
0.58 


Per  Cent 
Extract. 


7.82 
2.42 
4.19 


Browne  gives  the  following  as  the  composition  of  the  mixed  ash  of 
several  varieties  of  apple: 


Ingredient. 


Potash  (K2O) 

Soda(Na,0) 

Lime  (Cab) 

Magnesia  ( MgO) 

Oxide  of  iron  (  FejO.,) 

Oxide  of  aluminum  (AUOj) 

Chlorine  (CI) .* 

Silica  (SiOj) 

Sulphuric  acid  (SO.,) 

Phosphoric  acid  (PoOj) 

Carbonic  acid  (CO^) 

Deduct  oxj'gen  equivalent  to  CI. 
Total 


Per- 
cent- 
age. 


55-94 
0.31 

4-43 
3-78 

0-95 
0.80 

0-39 
0.40 
2.66 
8.64 
21.60 


99.90 
.09 


99.81 


3 


Ingredient. 


Potassium  carbonate  (KjCOg)... 
Potassium  yihosphate  (K3PO4).  .. 

Sodium  chloride  (NaCl) 

Calcium  sulphate  (CaSO^) 

Calcium  oxide  (CaO) 

Magnesium  phosphate  (MgjP^O^) 

Magnesium  oxide  (MgO) 

Ferric  oxide  (FcjO.,) 

Aluminum  oxide(AU03) 

Silica  (SiOj) '. 


Total. 


Per- 
cent- 
age. 


6.85 

14-55 
0.60 

4.52 
2-57 
6.97 
0.59 
0.95 
0.80 
0.40 


99.80 


682  FOOD  INSPECTION  /iND  ANALYSIS. 

Burckor  *  gives  the  following  composition  of  the  ash  of  cider: 

Per  Cent. 

Silica o  •  94 

Phosphoric  acid 1 2 .68 

Lime 2-77 

^Magnesia 2 .05 

Oxides  of  iron  and  manganese o.  94 

Potash 53.74 

Soda 1 .  10 

Carbonic  acid 25 .  78 


100.00 


Adulteration  of  Cider. — The  Committee  on  Standards  of  the  A.  O.  A.  C, 
have  submitted  for  adoption  the  following  standards  for  cider:  Alcohol 
not  more  than  8%,  extract  not  less  than  1.8%  determined  by  evaporation 
in  an  open  vessel  at  ordinary  atmospheric  pressure  and  at  the  tempera- 
ture of  boiling  water;    ash  not  less  than  0.2%. 

Entirely  factitious  cider  made  from  other  than  apple  stock  is  rarely 
found,  though  the  product  as  sold  is  frequently  of  inferior  quality  and 
adulterated.  The  chief  adulterants  are  water  and  sugar,  and  the  use  of 
antiseptics  is  common,  especially  of  salicylic  and  sulphurou.-,  acids,  sodium 
bcnzoate,  and  occasionally  beta-naphthol. 

Sodium  carbonate  is  sometimes  added  to  cider  to  neutralize  the  acid 
and  thus  prevent  acetic  fermentation.  An  abnormally  high  ash  (say 
in  excess  of  0.35%)  would  point  toward  the  presence  of  added  alkali. 

Watering  is  apparent  when  the  content  of  alcohol,  solids,  and  ash  of 
the  suspected  sample  are  found  to  be  considerably  below  the  corre- 
sponding constants  of  pure  cider.  According  to  Sangle  Ferriere,  the 
following  are  the  minimum  figures  for  these  constants  in  a  pure  cider, 
so  that  a  sample  may  safely  be  pronounced  as  watered  if  they  all 
nm  distinctly  below: 

Alcohol 3%  by  volume 

Extract 1.8% 

Ash 0.17% 

Besides  these  determinations,  it  is  useful  also  to  determine  the  fixed 
and  volatile  acids. 

Caramel  is  to  be  looked  for,  especially  in  watered  samples.     Other 

♦  Les  Falsifications  dcs  Substances  Alimcntaires,  p.  176. 


ALCOHOLIC  BEVERAGES. 


685 


adulterants  alleged  to  be  of  frequent  oceurrence  in  French  cider,  but 
not  commonly  found  in  this  country  are  commercial  glucose,  tartaric  acid 
(to  increase  the  acidity  of  a  watered  product),  and  coal-tar  colors. 

Absence  or  deficiency  of  malates  is  conclusive  evidence  of  fraud, 
indicating  the  admixture  of  notable  quantities  of  the  juice  of  the  second 
pressing  of  pomace. 

Sugar  is  rendered  apparent  by  the  right-handed  polarization  of  the 
sample,  pure  cider  always  polarizing  well  to  the  left.  If  after  inversion 
of  a  dextro-rotary  cider  the  polarization  is  still  to  the  right,  commercial 
glucose  is  indicated;  if  the  reading  after  inversion  is  to  the  left,  cane 
sugar  has  undoubtedly  been  added. 

Frequently  the  analyst  has  only  to  determine  the  alcohol,  especially 
in  cases  of  seizure,  to  ascertain  whether  or  not  there  has  been  violation 
of  the  liquor  laws. 

PERRY  OR  PEAR  CIDER. 

This  is  a  common  French  product,  but  is  rarely  if  ever  found  on  sale 
in  this  country,  though  sometimes  made  for  home  consumption.  In 
composition  and  in  method  of  manufacture  it  much  resembles  apple 
cider.     It  is  also  subject  to  the  same  forms  of  adulteration. 

The  following  table  summarizes  a  number  of  analyses  made  by 
Truelle  on  pear  juice,  or  must,  amounts  being  expressed  in  parts  per 
thousand : 


Specific  gravity 

Invert  sugar 

Sucrose 

Total  fermentable  sugars  (as  dextrose) 

Tannin 

Pectin  and  albuminous  substances  — 
Acidity  (as  sulphuric  acid) 


Mean. 


1.0845 

145-64 

,36.74 

18.^.14 

1.78 

13.08 

1.47 


Maximum. 


1.0675 

108.10 

16. 6<) 

143-78 

1 .01 

?, 
o.  76 


Minimum. 


I .0980 
200 

61 .41 
220 

3.20 


2.40 


The  following  analysis  of  champagne  perry  is  taken   from  the  Lancel 
of  October  i,  1892: 

Alcohol  by  weight i  -  45 

Alcohol  by  volume i  -80 

Solids 1 1 .00 

Ash 0.35 


684  FOOD  INSPECTION  AND  ANALYSIS. 


WINE. 


Wine  in  its  broadest  sense  is  the  fermented  expressed  juice  of  any 
fruit,  though  the  term,  unless  otherwise  restricted,  is  generally  understood 
to  apply  to  the  juice  of  the  grape. 

The  organism  present  in  grape  juice  that  plays  the  chief  part  in  its 
alcoholic  fermentation  is  the  Saccharomyces  cllipsoideiis,  a  yeast  which 
exists  on   the  skins  of  the  grape. 

Process  of  Manufacture.— The  grapes,  which  should  be  fully  ripe, 
are  picked  and  sometimes  sorted,  according  to  the  care  that  is  taken  in 
grading  the  product.  They  are  also  sometimes  freed  from  the  stems, 
which  contain  considerable  tannic  acid,  and  which  when  crushed  with  the 
grapes  impart  a  certain  astringency  to  the  final  product.  The  grapes  are 
crushed  either  by  machinery  or  by  the  bare  feet,  and  the  juice  is  pressed 
-out  from  the  pulp  in  various  ways,  by  screw  or  hydraulic  press,  or  by  the 
centrifugal  process. 

A  certain  amount  of  juice  runs  off  from  the  preliminary  crushing 
known  as  the  first  run,  and  makes  the  choicest  wune.  The  product  from 
the  pressure  constitutes  the  second  run,  after  which  the  pomace,  by  steep- 
ing in  water  and  repressing,  is  made  to  yield  an  inferior  juice  used  in 
vinegar-making. 

Red  wines  are  made  from  dark  grapes  by  fermenting  the  pulp,  before 
pressing,  with  the  skins,  which  by  this  treatment  yield  up  their  rich  color 
(oenocyanin)  to  the  juice.  Besides  the  color,  the  skins  contain  also  tannin. 
White  wine  is  made  from  the  pressed  pulp,  freed  from  the  skins  at  once, 
or  from  the  pulp  of  white  grapes.  The  unfcrmented  must  constitutes 
from  60  to  80  per  cent  of  the  weight  of  the  grape. 

Fermentation  progresses  most  rapidly  at  a  temperature  between  25° 
and  30°  C,  but  wine  having  a  much  finer  bouquet  is  produced  by  slower 
fermentation,  hence  the  must  is  allowed  to  ferment  in  open  vats  or  tubs 
in  cool  cellars,  at  a  temperature  of  from  5°  to  1 5°  till  it  settles  out  com- 
paratively clear,  special  care  being  taken  to  avoid  development  of  acetic 
fermentation.  At  the  end  of  the  first  or  active  fermentation,  the  wine 
is  drawn  off  and  allowed  to  undergo  a  second  or  slow  fermentation  in 
casks,  during  which  most  of  the  lees  or  crude  argols,  composed  of  potas- 
sium bitartrate,  settle  out,  being  insoluble  in  alcohol,  and  the  characteristic 
bouquet  or  flavor  of  the  wine  is  developed.  Occasionally  during  this 
process  the  wine  is  racked  or  drawn  off. 

Undesirable   fermentations   and   vegetaljlc    fungus  growth,  which  are 


ALCOHOLIC  BEl/ERAGES.  685 

liable  to  occur  at  this  time,  are  avoided  as  much  as  possible  by  usint^ 
especially  clean  casks,  which  are  frequently  "sulphured"  (or  burnt  out 
with  sulphur)  before  being  used.  The  wine  is  also  sometimes  clarified, 
or  "fined,"  by  treatment  with  gelatin,  which  mechanically  removes  many 
impurities  by  precipitation,  or  is  subjected  to  pasteurization  before  finally 
being  bottled  or  stored  in  casks. 

Classification  of  Wines. — Wines  are  either  natural  or  jorti/ied.  Nat- 
ural wines  are  those  which  contain  no  added  sugar  or  alcohol,  but  which 
Are  exclusively  the  product  of  the  simple  juice,  fermcntcri  under  the  best 
conditions,  cither  till  the  sugar  has  been  used  u}),  or  till  the  yeast  food 
is  exhausted,  or  until  the  yeast  growth  has  been  checked  by  the  strength 
of  the  alcohol  developed.  When  the  alcohol  content  amounts  to  14% 
by  weight  there  can  be  no  further  fermentation  due  to  yeast,  so  that  this 
is  the  highest  limit  for  natural  wine.  Examples  of  natural  wines  are 
hock  and  claret  and  many  California  wines. 

Fortified  wines  are  those  to  which  alcohol  has  been  added,  usually  before 
the  natural  fermentation  has  been  allowed  to  proceed  to  a  finish.  For 
this  reason  considerable  sugar  is  usually  left,  and  such  wines  arc  more 
often  sweet.     Examples  of  fortified  wines  are  IVIadeira,  sherry,  and  port. 

Volatile  ethers  (products  of  volatile  acids)  predominate  as  a  rule  in 
natural  wines,  while  fixed  ethers  (from  the  fixed  acids  as  tartaric)  are 
most  characteristic  in  fortified  wines. 

Wines  are  also  variously  classified  according  to  characteristic  proper- 
ties possessed  by  them,  as  still  or  sparkling,  red  or  white,  "dry''  or  sweet, 

etc. 

Still  wines  are  those  in  v.'hich  there  is  but  little  carbon  dioxide  remain- 
ing, so  that  they  do  not  effervesce.  Sparkling  wines  are  more  or  less 
heavily  charged  with  carbon  dioxide,  either  naturally,  as  in  the  case  of 
champagne,  wherein  the  gas  is  formed  by  after-fermentation  of  added 
sugar  in  the  corked  bottle,  or  artificially,  by  carbonating  them  in  a  similar 
manner  to  "soda-water." 

Among  the  best-known  red  wines  are  those  of  Burgundy  and  the 
Bordeaux  wines  or  clarets,  w^hile  the  Rhenish  and  Moselle  wines  and  the 
Sautemes  are  examples  of  white  wine. 

"Dry"  wines  are  those  in  which  the  sugar  has  been  exhausted  by 
fermentation,  while  sweet  wines  possess  a  considerable  amount  of  unfer- 
mented  sugar.  Whether  or  not  an  excess  of  sugar  is  left  after  fermenta- 
tion has  stopped  depends  upon  the  amount  of  yeast  food  or  nitrogenous 
substance  present  in  the  wine.     When  the  proteins  are  exliausted  by  the 


6S6 


FOOD  INSPECTION  /IND  ANALYSIS. 


yeasi,  fermentation  ceases,  and  for  this  reason  gelatin  and  other  nitrog- 
enous bodies  are  sometimes  added  to  e.xtend  the  period  of  fermentation. 
Sweet  wines  are  often  reinforced  by  the  addition    of   sugar.      ^Madeira, 
both  red  and  white,  are  samples  of  dry  wine,  while  port  wine  is  one  of" 
the  sweet  variety. 

WTiile  most  of  our  finer  wines  still  come  from  France  and  Germany, 
large  quantities  of  California  wines  are  now  being  produced  of  an  extremely 
high  grade  and  of  many  varieties. 

Composition  of  Grape  Must  and  of  Wine. — Konig's  analyses  of  a. 
large  number  of  grape  musts  from  different  sources  arc  thus  summarized: 


Specific 
Gravity. 

WatPr        Nitroge- 

Sugar. 

Acid. 

Other 
Non-ni- 
trogenous 
Material. 

Ash. 

^linimum 

1.0690 

1.2075 
I. 1024 

51-53        0-" 
82.10        0.57 

74.49      0.28 

12.89 

35-45 
19.71 

0.20 
1. 18 
0.64 

1.68 

11.62 

4.48 

0. 20 

Maximum 

0.6- 

0.40 

Typjical  analyses  of  German,  French,  Austrian,  Russian,  Italian,  and 
Spanish  wines  arc  shown  in  the  following  table,  also  due  to  Konig: 


Germany: 

Moselle 

Rhine 

Tladen 

Wurtemburg,  white  wine. 
' '  red  wine  . . 

Alsace 

Lorraine,  red  wine 

France : 

Red  wine 

White  wine 

Austria: 

Tyrol,  red  wine 

'•       white  wine 

Russia: 

Red  wine 

White  wine 

Italy 

Spain : 

Ordinary  red  wine 

S«veei  wine 


5< 


00 


0.9964 
1.0005 


0-9995 


0.9967 


0.9982    7.80 

9963!  8.30 


7-99 
8.00 
6.65 
6.10 
4-73 
6.59 
8.08 


9940 
0.99271 


9.08 


0.9939J10.76 
11.96 
10.61 


0-9931 


12.30 
1.0233  12.78 


2.24 
2.60 
2.16 
2.27 
2.64 
2.07 
2.27 

2.56 
3-03 

2.34 
1.87 

2.76 

2.568 

3-44 

3-53 
9.69 


-5. 


0.79 
0.81 
0.91 

0-95 
1.14 
0.696 
0.56 

0-57 
0.66 

C.62 
0-59 

0.56 
0.49 


0.49 

0.59 


0.018 
0.095 
0.091 
0.018 
0.032 


0.20 

0-358 
0.262 
0.026 
0.168 


0.052 


0.I42I 
o.iool 


0.031. 
0.095. 

o.o88. 
0.30. 


0.458 
1-44 

0.38 

6.55 


ALCOHOLIC   Br.yER/IGES. 


687 


Germany: 

Moselle 

Rhine 

Baden 

Wurtemburg,  white  wine. 
"  red  wine.  . 

Alsace 

Ivorraine,  red  wine 

France: 

Red  wine 

White  wine 

Austria: 

Tyrol,  red  wane- 

' '       white  wine 

Russia: 

Red  wine 

White  wine 

Italy 

Spain: 

Ordinars'  red  wine 

Sweet  wine 


0.72 
0.85 
0.49 
0-57 
o.4(- 

0-55 
0.5c 


0-73 
0.97 

0.65 
0.65 

0.64 
2-59 
0-45 

i.og 
0.63 


0.02s 
0.019 


0.043 


0.23 

0.207 

0.25 

0.25 

0.229 

0.185 

0.248 
0.25 


.021    0.222 
.020    0.175 


0.036 
0.026 


0.267 
0.204 
0.29 

0.61 
0.74 


0.036 
0.046 
0.025 
0.043! 
0.040 
0.038 
0.030 

0.030I 
0.032' 


0.068 
0.085 

0.1 15 
0.108 


.106 
.09S 


0.0271 

0.022    0.077 

0.027  O.III 
0.030  0.086 
0.032I  0.1 15 


.027 
-039 


.242 
.296 


O.OII 

0.017 


0.024 


0.02      0.012' 
0.022,  0.02c 


I  0.009    0.021 

O.OIO     o.oS    I 


.101 

.010 


0.009 
0.008 


.018 


0.017 


0.008 

0-033 
0.038 

0.023 
0.023 


0.221 
0.212 


On  page  688  arc  given  summaries  of  analyses  of  American  wines 
compiled  from  tables  of  analyses  made  by  Bigelow.* 

Varieties  of  Wine. — Champagne  is  a  selected,  sweet,  white  wine, 
clarified  with  gelatin,  bottled  with  the  addition  of  cane  sugar,  mi.xed  with 
a  little  brandy,  and  tightly  corked.  Sometimes  a  small  amount  of  yeast 
is  also  introduced.  Fermentation  is  allowed  to  go  on  at  a  temperature 
of  about  24°  C,  during  which  the  wane  is  highly  charged  with  carbon 
dioxide.  The  bottles  are  set  on  their  side  for  some  months,  after  which 
they  are  inverted  till  the  sediment  gathers  above  the  cork,  which  by  careful 
manipulation  is  quickly  removed  so  as  to  throw  out  the  sediment,  and  is 
afterward  replaced  and  secured.  Champagne  contains  from  8  to  :o 
per  cent  of  alcohol  and  is  high  in  sugar. 

Claret  is  a  light,  red  wine  of  a  deep  color,  and  is  somewhat  acid  and 
astringent.  In  alcohol  it  varies  from  8  to  13  per  cent  by  volume.  It  has 
ver)-  little  sugar  and  is  high  in  volatile  ethers. 

Madeira  is  a  strong,  white  wdnc,  possessing  a  refined,  nutty,  aromatic 
flavor  wdien  fully  aged.  It  is  generally  forlified,  containing  from  17  to 
20  per  cent  of  alcohol.     It  is  named  from  the  island  which  produces  it. 

Sherry  is  a  deep,  amber-colored,  sweet,  Spanish  wine,  high  in  alcohol 


*  U,  S.  Dept.  of  .Agric,  Bur.  of  Chem.,  Bui.  59. 


688 


FOOD   INSPECTION  AND   ANALYSIS. 


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ALCOHOLIC  BEVERAGES.  6«9 

(sometimes  containing  over  20%),  being  usually  fortified.  It  is  slightly 
acid  and  possesses  much  fragrance.     Sherry  is  nearly  always  "plastered." 

Hocks  are  white  German  wines,  mildly  acid,  containing  9  to  12  per 
cent  of  alcohol  by  volume.  They  have  very  little  sugar,  and  rank  among 
:he  highest  of  natural  wines.  The  best-known  varieties  are  Hockheimer 
and  Johanisberger. 

Port  {Vinum  portense  of  the  1870  Pharmacopoeia)  is  a  dark-purple, 
astringent  wine,  almost  always  fortified,  and  hence  high  in  alcohol  (from 
15  to  18  per  cent  by  \-olume).  It  is  much  imj)r(n-ed  Ijy  aging,  during 
which  it  looses  considerable  of  its  astringency.  It  contains  a  large  amcjunt 
of  extract,  from  2  to  6  per  cent  of  the  wine  being  sugar.  The  fi.xed  ethers 
predominate  over  the  volatile. 

Standards  of  Purity  for  Wine. — The  ratio  of  volatile  to  fixed  acids  in 
pure  wine  should  not  exceed  1:3.  A  higher  proportion  of  volatile  acid 
shows  the  fact  that  acetic  fermentation  has  set  in. 

The  presence  of  any  considerable  free  tartaric  acid  would  indicate 
the  addition  of  this  substance  to  the  wine. 

The  Uni;ed  States  Pharmacopoeia  has  prescribed  the  following  require- 
ments in  the  case  of  wines:  For  white  wine  {Vinum  album)  the  specific 
gravily  at  15.6°  should  not  be  less  than  o.qqo  nor  more  than  i.oio;  the 
extract  or  residue  at  100°  should  not  be  less  than  1.3  nor  more  than  3%;  as 
indicating  the  amount  of  free  acid,  not  less  than  3  nor  more  than  5.2  cc. 
normal  potassium  hydroxide  should  be  recjuired  to  neutralize  50  cc.  of 
the  wine,  using  phenolphthalein  as  an  indicator;  it  should  contain  not  less 
than  7  nor  more  than  12  per  cent  by  weight  of  absolute  alcohol;  it  should 
contain  only  traces  of  tannin. 

For  red  wine  (Vinum  ruhum)  the  specific  gravity  at  \^.b°  should 
not  be  less  than  0.989  nor  more  than  i.oio;  the  extract  should  not 
be  less  than  1.6%  nor  more  than  s.^{  ;  its  limits  as  to  acidity  are 
the  same  as  with  white  wine,  eosin  or  fiuorescin,  however,  being  used 
as  an  indicator;  in  alcoholic  strength,  it  should,  like  whiti-  wine,  come 
within  the  limits  of  7  and  12  per  cent  alcohol  by  weight.  It  should 
not  be  artificially  colored,  but  should  show  the  presence  of  tannic 
acid. 

The  following  are  U.  S.  standards  for  wines:  Wine  is  the  product 
made  by  the  normal  alcoholic  fermentation  of  the  juice  of  .sound,  ripe 
grapes,  and  the  usual  cellar  treatment,  and  contains  not  less  than  7 
nor  more  than  16  ])er  cent  of  alcohol,  by  volume,  and,  in  100  cc.  {20°  C), 


690  FOOD  INSPECTION  AND   ANALYSIS. 

not  more  than  o.i  gram  of  sodium  chloride  nor  more  than  0.2  gram 
of  jx)tassium  sulphate;  and  for  red  wine  not  more  than  0.14  gram,  and 
for  white  wine  not  more  than  0.12  gram  of  volatile  acids  produced  by 
fermentation  and  calculated  as  acetic  acid.  Red  wine  is  wine  contain- 
ing the  red  coloring  matter  of  the  skins  of  grape.  White  wine  is  wine 
made  from  white  grapes  or  the  expressed  fresh  juice  of  other 
grajx's. 

Dry  wine  is  wine  in  which  the  fermentation  of  the  sugars  is  practically 
complete,  and  which  contains,  in  100  cc.  (20°  C),  less  than  i  gram  of 
sugars,  and  for  dry  red  wine  not  less  than  0.16  gram  of  grape  ash  and 
not  less  than  1.6  grams  of  sugar-free  grape  solids,  and  for  dry  white 
wine  not  less  than  0.13  gram  of  grape  ash  and  not  less  than  1.4  grams 
of  sugar-free  grape  solids. 

Fortified  dry  wine  is  dry  wine  to  which  brandy  has  been  added, 
but  which  conforms  in  all  other  particulars  to  the  standard  of  dry 
wine. 

Sweet  wine  is  wine  in  which  the  alcoholic  fermentation  has  been 
arrested,  and  which  contains,  in  100  cc.  (20°  C),  not  less  than 
1  gram  of  sugars,  and  for  sweet  red  wine  not  less  than  0.16  gram  of 
grape  ash,  and  for  sweet  white  wine  not  less  than  0.13  gram  of 
grape  ash. 

Fortified  sweet  wine  is  sweet  wine  to  which  wine  spirits  have  been 
added.  By  act  of  Congress,  "  sweet  wine  "  used  for  making  fortified 
sweet  wine  and  "  wine  spirits  "  used  for  such  fortification  are  defined 
as  follows  (sec.  43,  Act.  of  October  i,  1890,  26  Stat.  567,  as  amended 
by  section  68,  Act  of  August  27,  1894,  28  Stat.  509,  and  further 
amended  by  Act  of  Congress,  approved  June  7,  1906):  "That  the 
wine  spirits  mentioned  in  section  42  of  this  act  is  the  ])roducl  resulting 
from  the  distillation  of  fermented  grape  juice  to  which  water  may  have 
been  added,  prior  to,  during,  or  after  fermentation,  for  the  sole  j)urpose 
of  facilitating  the  fermentation,  and  economical  distillation  thereof,  and 
shall  be  held  to  include  the  products  from  grapes  or  their  residues,  com- 
monly known  as  grape  brandy;  and  the  pure  sweet  wine,  which  may 
be  fortified  free  of  tax,  as  provided  in  said  section,  is  fermented  grape 
juice  only,  and  shall  contain  no  other  substance  whatever  introduced 
before,  at  the  time  of,  or  after  fermentation,  except  as  herein  expressly 
provided;  and  .such  sweet  wine  shall  contain  not  less  than  4  per  cent 
of   saccharine   matter,   which    saccharine    .strength    may   be    determined 


ALCOHOLIC  BEVERAGES.  691 

by  testing  with  Balling's  saccharometcr  or  must  scale,  such  sweet  wine, 
after  the  evaporation  of  the  spirits  contained  therein,  and  restoring  the 
sam[)le  tested  to  original  volume  by  addition  of  water:  Provided,  That 
the  addition  of  pure  boiled  or  condensed  grape  must,  or  pure  crystallized 
cane  or  beet  sugar,  or  pure  anhydrous  sugar  to  the  jjure  grape  juice 
aforesaid,  or  the  fermented  product  of  such  grape  juice  prior  to  the 
fortification  provided  by  this  act,  for  the  sole  purpose  of  perfecting 
swctl  wine  according  to  commercial  standard,  or  the  addition  of  water 
in  such  quantities  only  as  may  be  necessary  in  the  mechanical  operation 
of  gra])e  conveyors,  crushers,  and  ])ipes  leading  to  fermenting  tanks, 
shall  not  be  excluded  by  the  definition  of  pure  sweet  wine  aforesaid: 
Provided,  however,  That  the  cane  or  beet  sugar,  or  pure  anhydrous  sugar, 
or  water,  so  used  shall  not  in  either  case  be  in  excess  of  10%  of  the 
weight  of  the  wine  to  be  fortified  under  this  act:  And  provided  further, 
That  the  addition  of  water  herein  authorized  shall  be  under  such  regula- 
tions anrl  limitations  as  the  Commissioner  of  Internal  Revenue,  with 
the  approval  of  the  Secretary  of  the  Treasury,  may  from  time  to  time 
prescribe;  but  in  no  case  shall  such  wines  to  which  water  has  been 
added  be  eligible  for  fortification  under  the  provisions  of  this  act  where 
the  same,  after  fermentation  and  before  fortification,  have  an  alcoholic 
strength  of  less  than  5%  of  their  volume." 

Sparkling  wine  is  wine  in  which  the  after  part  of  the  fermentation  is 
completed  in  the  bottle,  the  sediment  being  disgorged  and  its  place 
supplied  by  wine  or  sugar  liquor,  and  which  contains  in  100  cc.  (20°  C), 
not  less  than  0.12  gram  of  grape  ash. 

Modified  wine,  ameliorated  wine,  corrected  wine,  is  the  product  made 
by  the  alcoholic  fermentation,  with  the  usual  cellar  treatment,  of  a 
mixture  of  the  juice  of  sound,  ripe  grapes  with  sugar  (sucrose),  or  a 
syrup  containing  not  less  than  65%  of  sugar  (sucrose),  and  in  quantity 
not  more  than  enough  to  raise  the  alcoholic  strength  after  fermentation, 
to  11%  by  volume. 

Raisin  wine  is  the  product  made  by  the  alcoholic  fermentation  of 
an  infusion  of  dried  or  evaporated  grapes,  or  of  a  mixture  of  such 
infusion,  or  of  raisins  with  grape  juice. 

Adulteration  of  Wine. —  Beverages  purporting  to  be  wine  are 
sometimes  found  on  sale  that  are  entirely  spurious,  in  that  they  con- 
tain little  if  any  fermented  grape  juice.  Api)le  cider  is  not  infreciuently 
the  basis   of  such   artificial  products,  and    the    following    recipes  givea 


6  >2  FOOD    INSPECTION   AND   ANALYSIS. 

bv  Brannt  may  be  taken  as  typical  of  the  composition  of  these  wine 
substitutes: 

Burgundy. — Bring  into  a  barrel  40  quarts  of   apple  juice,  5  pounds 
of  bruised  raisins,  ]   pound  of  tartar,   i  quart  of  bilberry  juice,  and  3. 
pounds  sugar.     Allow   the   whole   to  ferment,   filling  constantly  up  with 
cider.     Then  clarify  with  isinglass,  add  about  i  ounce  of  essence  of  bitter 
almonds,  and  after  a  few  weeks  draw  off  into  bottles. 

Malaga  Wine. — Apple  juice,  40  quarts;  crushed  raisins,  10  pounds; 
rectified  alcohol,  2  quarts;    sugar  solution,    2  quarts;   elderberry  flowers, 

1  quart;  acetic  ether,  i  ounce  and  2  drachms.  The  desired  coloration  is 
effected  by  the  addition  of  bilberry  or  elderberry  juice;  otherwise  the 
j)rocess  is  the  same  as  given  for  Burgundy, 

Sherry   Wine. — Apple  juice,   50   quarts;    orange-flower    water,  about 

2  drachms;  tartar,  2  ounces  and  4  drachms;  rectified  alcohol,  3  quarts; 
crushed  raisins,  10  pounds;  acetic  ether,  i  ounce  and  2  drachms.  The 
process  is  the  same  as  for  Burgundy. 

Claret  Wine. — Apple  juice,  50  quarts;  rectified  alcohol,  4  quarts; 
black  currant  juice,  2  quarts;  tartar,  2  ounces  and  4  drachms.  Color 
with  bilberry  juice.  The  further  process  is  the  same  as  for  Bur- 
gundy. 

Artificial  products  similar  in  nature  to  the  above  are  also  mixed  in 
varying  jjroportions  with  pure  wine. 

Presence  of  malates,  as  well  as  absence  or  diminution  of  total  tartaric 
acid,  is  also  indicative  of  cider. 

If  the  ash  of  the  wine  be  submitted  to  the  flame  test,  the  sodium 
light  will  predominate  in  the  case  of  pure  wine,  while  if  the  basis  of  the 
sample  be  largely  or  wholly  apple  stock,  the  potash  flame  will  be  readily 
ajjparent. 

Wines  are  most  frequently  adulterated  by  "plastering,"  by  watering; 
bv  the  addition  of  excessive  amounts  of  sugar  or  glucose,  by  various  flavor- 
ing ])rinciples,  by  coal-tar  and  vegetable  colors,  by  antise})lics,  and  by 
added  alcohol. 

Plastering.— By  this  term  is  understood  the  addition  of  gypsum  or 
plaster  of  Paris  to  the  must  before  fermentation,  a  practice  in  vogue  in 
parts  of  France,  Italy,  and  Si)ain.  The  reaction  which  takes  place  with 
the  potassium  bitartratc  present  in  the  wine  is,  accfjrding  to  Chancel, 
as  follows: 


/ILCOHOLIC  BEVERAGES.  69$ 

2KHC,H,06  +  CaSO,  =  CaC,H,Oe+  H,C,H/36+  K,SO,. 

Potassium  Calcium  Calcium  Tartaric  Potassium 

bitartrate  sulphate  tartrate  acid  sulphat* 

Various  advantages  arc  said  lo  result  from  this  practice.  The  wine 
is  clarified  by  the  precipitation  of  the  calcium  tartrate,  which  mechan- 
ically carries  down  with  it  many  impurities,  the  color  of  the  wine  is 
improved,  since  the  solubility  of  the  coloring  principle  present  in  the 
skins  is  increased,  the  fermentation  is  rendered  more  rapid  and  complete, 
and  the  keeping  qualities  of  the  wine  are  enhanced.  The  practice  is, 
however,  considered  objectionable  on  account  of  the  potassium  sulphate 
which  is  left  in  solution  in  the  wine,  and  in  some  countries  plaster- 
ing is  forbidden,  or  the  amount  of  ])otassium  sulj>hate  limited  by 
statute. 

The  following  are  analyses  of  two  Spanish  wines  made  from  the  same 
grape  juice,  one  of  which  was  plastered.  The  results  are  expressed  in 
grams  per  liter. 


Xot  Plastered. 

Plastered. 

Color 

Yellow 

23-3 
0.66 
2.06 

1.29 
0.41 

Bright  red 

27-3 
0.61 

5-38 

0.17 
5 

Extract  dried  at  100° 

Insoluble  ash 

Soluble  ash 

The  soluble  ash  containing 

Potassium  carbonate 

"          sulphate.  . .. 

The  effect  of  plas'.cring  is  thus  seen  to  distinctly  increase  the  extract 
and  the  soluble  ash.  Any  considerable  amount  of  potassium  sulphate 
is  an  indication  of  plastering. 

Addition  of  Cane  Sugar. — ^The  term  "chaptalizing"  is  applied  in 
France  to  the  addition  to  the  must  of  cane  sugar  for  the  i)urpose  of 
increasing  the  yield  in  alcohol.  The  addition  of  1,700  grams  of  sugar 
to  1,000  liters  of  must  is  said  to  increase  the  alcoholic  strenglh  by  1%. 
It  was  formerly  customary  to  add  with  the  sugar  calcium  carbonate, 
to  partially  neutralize  the  acidity,  but  this  is  rarely  practiced  at  present. 

The  European  wine-raising  countries  are  not  disposed  to  regard  the 
reinforcement  of  wine  by  added  cane  sugar  in  the  must  as  in  itself  a  fraud, 
unless  water  is  also  added,  or  unless  some  other  form  of  adulteration  is 
practiced  at  the  same  time.    In    I'rr.nce,  however,  the  addition   of  cane 


6  14  FOOD  JXSPECTION  ^ND  JN^ LYSIS. 

sugar  is])ermitkHl  only  in  \\inefor  local  consumption,  and  is  restricted  in 
-amount. 

The  use  of  commercial  glucose  in  wine  instead  of  cane  sugar  is  not 
regarded  with  as  much  favor,  in  view  of  the  fact  that  glucose  contains 
more  or  less  unfermentable  matter,  and  introduces  dextrin  and  various 
mineral  sahs  into  the  wine. 

To  ascertain  the  nature  and  extent  of  the  sugars  ])resent  in  wine  is 
frequently  of  great  importance.  Much  information  may  be  gained  from 
the  direct  and  invert  polarization  of  the  sample,  as  well  as  frcjm  the  deter- 
mination of  reducing  sugars. 

Invert  sugar  is  the  only  legitimate  sugar  that  should  be  present  in 
genuine  wine.  In  normal  fermentation  the  dextrose  is  more  quickly 
destroyed  than  the  le\ailose,  hence  the  polarization  of  pure  wine  is  always 
left-handed,  unless  all  the  sugar  has  been  fermented,  in  which  case  the 
reading  should  be  zero. 

Seventy-five  samples  of  California  red  wines,  chiefly  claret,  Burgundy, 
Rhine,  and  southern  France  types,  analyzed  in  the  Bureau  of  Chemistry  * 
of  the  U.  S.  Department  of  Agriculture,  polarized  from  —0.5  to  —2.1. 
Upwards  of  eighty  samples  of  California  white  wine  (of  the  types  of 
Burgundy,  Sauteme,  and  southern  France)  were  submitted  to  polariza- 
tion and  all  but  four  were  left-handed.  These  four  (evidently  abnormal) 
polarized  from  o.  to  -f  i.     Most  of  them  varied  from  — o.i  to  —3.5. 

Thirteen  of  the  port  wine  types  (California)  had  a  left-handed  polariza- 
tion of  from  —14.7  to  —27.1.  These  apparently  contained  large  quan- 
tities of  unfermented,  inverted  cane  sugar. 

A  sharp,  right-handed  polarization  would  indicate  the  presence  of 
either  commercial  glucose  or  cane  sugar.  After  inversion,  if  the  reading 
is  still  right-handed,  glucose  is  apparent,  while  if  inversion  changes  the 
reading  from  right  to  left,  cane  sugar  has  undoubtedly  been  added.  By 
application  of  Clcrget's  formula  the  amount  of  cane  sugar  can  be  estimated. 

The  Watering  of  Wine,  unless  excessive  in  degree,  is  not  always  easy 
to  pnne,  by  reason  of  the  varjing  composition  of  pure  wine,  and  because 
the  practice  is  usually  accompanied  by  other  forms  of  sophistication 
intended  to  cover  up  evidences  of  watering.  Considerable  quantities 
of  adderl  water  alone  would  usually  be  rendered  apparent  by  a  propor- 
tionate and  abnormal  lowering  of  the  alcohol,  extract,  ash,  acidity,  and, 
indeed,  nearly  all  the  constants. 

Gautier  in  his  Traile  sur  la  Sophislicalion  el  V Analyse  des  Vins  claims 

""  *  Bui.  59.  " 


ALCOHOLIC  BE l^E RAGES.  695 

that  the  sum  of  the  weight  in  grams  of  alcohol  in  100  cc.  and  the  Icjlal 
.acidity,  expressed  in  grams  of  sulphuric  acid  per  liter,  varies  within  very 
narrow  limits  in  pure  wines,  rarely  being  below  13  or  alcove  17.  A  large 
num!:)cr  of  analyses  made  by  Gautier  and  others  would  seem  to  confirm  this, 
so  thai  in  the  majority  of  cases,  added  water  would  be  strongly  indicated  if 
the  sum  of  these  two  constants  was  materially  reduced  below  13.  It  is 
more  conservative  to  adopt  12.5  as  a  minimum  limit  for  the  sum  of  the 
alcohol  and  total  acid  expressed  as  above. 

Detection  of  Added  Alcohol. — As  a  result  of  the  findings  of  a  com- 
mittee appointed  in  France  to  determine  the  matter  of  added  alcohol, 
it  was  submitted  that  a  relation  existed  between  the  weight  of  the  extract 
and  that  of  the  alcohol  in  pure  wine.  In  the  case  of  red  wines,  if  the 
weight  of  the  alcohol,  divided  by  the  weight  of  the  extract  (both  expressed 
in  grams  per  100  cc.)  exceeds  4.6,  the  addition  of  alcohol  is  strongly  indi- 
cated. With  white  wines,  the  quotient  obtained  by  dividing  the  weight 
of  alcohol  by  weight  of  extract  should  not  exceed  6.6.  If  it  does,  added 
alcohol  is  to  be  suspected. 

In  the  case  of  plastered  wines  containing  sulphate  of  potassium,  or 
wines  having  added  sugar,  it  is  necessary  to  deduct  from  the  total  extract 
the  weight  of  the  reducing  sugar  and  of  the  potassium  sulphate  as  found 
(less  0.1  gram  for  each  of  these  substances),  the  difference,  or  reduced 
extract  as  it  is  called,  being  used  in  this  case  in  obtaining  the  ratio. 

Fruit  Wines  other  than  Grape. — Wines  mostly  of  domestic  manufac- 
ture are  sometimes  made  from  small  fruits,  such  as  raspberries,  straw- 
berries, blackberries,  gooseberries,  elderberries,  and  currants,  as  well  as 
from  cherries,  plums,  and  apricots.  Wines  made  from  most  of  these 
fruits  readily  undergo  acetic  fermentation  unless  antiseptics  are  added, 
or  unless  extreme  care  is  taken  in  their  manufacture  and  keeping.  Fre- 
quently mixtures  of  various  fruit  juices  are  made  to  yield  excellent  wine. 
Most  of  the  sour  fruits  require  a  liberal  admixture  of  sugar  to  produce 
an  acceptable  wine. 

The  following  analysis  of  currant  wine  is  due  to  Frcsenius: 

Alcohol   o io.ci% 

Free  acid o. 79% 

Sugar 11-94% 

Water 77-26% 

The  alcoholic  content  of  other  fruit  wines  is  thus  shown  by  Brannt: 

Gooseberr)'  wine 11. 84%  alcohol 

Elderberry  wine ,     8 .  79%      ' ' 

Orange  wine 11.26%      " 


6q6  food  inspect  JON   ^ND   ANALYSIS. 

METHODS  OF  ANALYSIS  OF  WINE  AND  CIDER. 

For  determination  of  specific  gravity,  alcohol,  extract  (by  direct 
method),  and  ash.  see  pp.  657-676. 

Calculation  of  the  Extract  in  Wine. — Attention  has  already  been  called 
to  the  ditlkulty  in  accurately  determining  the  extract  of  sweet  wines 
gravimetricallv  by  evaporation.  An  approximate  determination  of  the 
extract  may  be  obtained  by  calculation  from  the  specific  gravity  of  the 
dealcoholized  liquor,  or  one  may  use  for  this  purpose  the  tables  compiled 
,  bv  Windisch,  and  based  on  ex])erimcnts  made  on  drying  wine  in  vacuo 
at  75°  C.  In  wines  high  in  sugar,  with  more  than  69c  of  extract,  this 
method  is  far  more  accurate  than  drying  at  100°,  and  is  to  be  recommended. 

Evaporate  a  measured  portion  of  the  wine  on  the  water-bath  to 
one-fourth  its  volume,  and  dilute  with  water  to  exactly  the  volume 
measured.  Determine  the  specific  gravity  of  this  dealcoholized  liquid 
at  15.6°,  and  from  the  following  table  ascertain  the  extract  corre- 
sponding. 

Determination  of  Total  Acidity. — Carbonated  beverages  are  first 
freed  from  carbon  dioxide  by  agitatioi.  as  described  on  page  658,  after 
which  25  cc.  of  the  sample  are  heated  just  to  the  boiling-point  and  titrated 
with  tenth-normal  sodium  hydroxide,  using  in  the  case  of  while  wine 
or  cider  phenolphthalein  as  an  indicator.  With  red  wine  delicate  litmus 
paper  should  be  used.  Total  acidity  is  usually  expressed,  in  the  case 
of  cider  as  malic,  and  of  wine  as  tartaric  acid.  Each  cubic  centimeter 
of  tenth-normal  alkali  corresponds  to  0.0067  gram  malic,  or  0.0075  gram 
tartaric  acid.  Some  chemists  express  total  acidity  in  terms  of  sulj)huric 
acid,  each  cubic  centimeter  of  tenth-normal  alkali  being  equivalent  to 
0.0049  gram  of  sulphuric  acid. 

Volatile  Acids  in  all  liquors  are  usually  expressed  as  acetic,  although 
traces  of  propionic  and  other  volatile  acids  may  be  present.  50  cc.  of 
the  cider  or  wine  and  a  little  tannic  acid  are  transferred  to  a  distilling- 
flask,  Fig.  115,  the  stopper  of  which  is  provided  with  two  tubes,  one  of 
which  connects  with  the  condenser,  while  the  other,  arranged  to  reach 
nearly  to  the  bottom  of  the  distilling-flask,  communicates  with  a  second 
flask  which  contains  about  300  cc.  of  water.  The  contents  of  both  fiasks 
are  brought  to  boiling,  after  which  the  flame  under  the  distilling-flask 
is  lowered,  and  steam  from  the  water-flask  is  jjassed  through  the  wine 
till  abfjul  200  cc.  of  distillate  have  collected  in  the  receiving-flask. 
Titrate  this  with  tenth-normal  sodium  hydroxide,  using  phenolphthaleiik 


JLCOHOLIC  BEyERAGES. 


697 


EXTRACT  IN  WINE, 
[According  to  Windisch.] 


Specific 

Ex-  1 

1 
Specific  1 

Ex- 

Specific 

Ex- 

Specific 

Ex- 

Specific 

Ex- 

Specific 

Ex- 

Gravity. 

tract. 

Gravity. 

tract. 

Gravity. 

tract. 

Gravity. 

tract. 

Gravity. 

tract. 

Gravity. 

tract. 

I . 0000 

0.00 

I .0065  ' 

1.68 

1 .0130 

3.36 

1.019s 

5. 04 

I .0260 

6.72 

1.0325 

8.40 

1 .000 1 

0.03  1 

1 .0066  j 

1.70 

1 .0131 

3.38 

I .0196 

5  06 

I .0261 

6-75 

I .0326 

8-43 

I .0002 

o.os  1 

I .0067 

1-73 

t .0132 

3.41 

I. 0197 

5  09 

I .0262 

6.77 

1.0327 

8.46 

I .0003 

0.08 

I .0068 

1.76 

I  0133 

3-43 

1 .0198 

5. II 

1 .0263 

6.80 

I .0328 

8.48 

I .0004 

0. 10 

I .0069 

1.78 

1. 0134 

3.46 

I .0199 

5.14 

I .0264 

6.82 

1.0329 

8. SI 

I .0005 

0.13 

I .0070 

1. 81 

I013S 

3-49 

1 .0200 

5-17 

1.0265 

6.85 

1.0330 

8.53 

I .0006 

0.15 

I .0071 

1.83 

I .0136 

3.51 

1 .0201 

5. 19 

I .0266 

6.88 

1.0331 

8.56 

I .0007 

0.18 

1.0072 

1.86 

1.0I37 

3-54 

I .0202 

S.22 

I .0267 

6.90 

1033a 

8.59 

I .0008 

0.  20  I 

1.0073 

1.88 

1 .0138 

3.56 

I .0203 

5-25 

I .0268 

6.93 

10333 

8.61 

I .0009 

0.23 

I .0074 

1. 91 

I. 01 39 

3.59 

I .0204 

5-27 

1 .0269 

6.95 

I  0334 

8.64 

I  0010 

0.  26 

1.0075 

1 .94 

I .0140 

3.62 

I .0205 

S.30 

I .0270 

6.98 

I  0335 

8-66 

I .0011 

0.2« 

I .0076 

I  .  q6 

I .0141 

3.64 

I .0206 

5-32 

1 .0271 

7.01 

I  0336 

8.69 

I  .OOI  2 

0.31 

1.0077 

1.99 

I .0142 

3.67 

I .0207 

5-35 

1 .0272 

7.03 

1  0337 

8.72 

I .0013 

0.34 

I .0078 

2.01 

I. 0143 

3.69 

1 .0208 

5.38 

1.0273 

7  .06 

10338 

8.74 

1 .0014 

0.36  ! 

I .0079 

2.04 

I .0144 

3-72 

I .0209 

5.40 

1.0274 

7.08 

1.0339 

8.77 

1 .  00 1 5 

0-39 

I .0080 

2.07 

I.OI4S 

3.75 

1 .0210 

5. 43 

1.027s 

7-11 

1.0340 

8.79 

I .0016 

0.  41 

I .0081 

2.09 

I  . 0 1 46 

3.77 

1 .021 1 

5. 45 

I .0276 

7-13 

1.0341 

8.83 

I .0017 

0-44 

I .0082 

2.12 

10147 

3.80 

1 .0212 

5.48 

1.0277 

7.16 

I  0342 

8.85 

I .0018 

0.46 

I .0083 

2.14 

I  .0148 

3.82 

I. 0213 

5.51 

I .0278 

7.19 

I  0343 

8.87 

I .0019 

0.49 

I .0084 

2.17 

I  . 0 1 49 

3.8s 

1 .0214 

5.53 

1.0279 

7.21 

1.0344 

8.90 

I .0020 

°-52 

I .0085 

2.19 

I .0150 

3.87 

1 .0215 

5. 56 

1 .0280 

7-24 

1.0345 

8.92 

I .0021 

0.54 

I .0086 

2.  22 

1.0151 

3.90 

1 .0216 

5.58 

I .0281 

7.26 

1 .0346 

8.95 

I  .0022 

O.S7 

I .0087 

2.25 

I .0152 

3.93 

I .0217 

5.61 

I .0282 

7.29 

1.0347 

8.97 

1 .  00  2 ,5 

0.59 

1.0088 

2.27 

1.0I53 

3. 95 

I .0218 

5.64 

1.0283 

7-32 

1 .0348 

9.00 

I  .0024 

0.62 

I .0089 

2.30 

I. 0154 

3.98 

I .0219 

S.66 

I .0284 

7-34 

1-0349 

9.03 

1.0025 

0.  64 

I .0090 

2.32 

i-oiSS 

4.00 

1 .O220 

5.69 

1.028s 

7-37 

1-0350 

9 -OS 

I  .0026 

0.67 

I .0091 

2-35 

1 . 0 1 5  6 

4.03 

I .0220 

5.71 

1.0286 

7-39 

I -035 1 

9.08 

I  .0027 

0.  69 

I .0092 

2.38 

I -0157 

4.06 

I .0222 

5.74 

I .0287 

7.42 

1-0352 

9.  10 

I .0028 

0.72 

I .0093 

2  .40 

1 .0158 

4.08 

1 .0223 

5-77 

I .0288 

7-4S 

1-0353 

9-13 

I .0029 

0.7s 

I .0094 

2.43 

1.0159 

4. II 

1 .0224 

5.79 

1 .0289 

7-47 

1-0354 

9. 16 

I .0030 

0.77 

I .0095 

2.45 

r .0160 

4.13 

I .0225 

5. 82 

I .0290 

7.50 

I-03S5 

9-i3 

I .0031 

0.80 

I .0096 

2.48 

I .0161 

4- 16 

I .0226 

S-84 

I .0291 

7.52 

1-0356 

9.21 

1.0032 

0.82 

I .0097 

2.50 

I .0162 

4.  19 

1 .0227 

S.87 

I .0292 

7.55 

1-0357 

9-23 

1.0033 

0.85 

I .0098 

2.53 

I .0163 

4.21 

I  .  0  2  28 

5- 89 

1.0293 

7.58 

1.0358 

9.  26 

1.0034 

0.87 

I .0099 

2.56 

I .0164 

4.24 

I .0229 

5. 92 

I .0294 

7.60 

1-0359 

9.29 

1.0035 

0  .90 

I .0100 

2.s8 

I. 0165 

4-  26 

I .0230 

5.94 

1.029s 

7.63 

1 .0360 

9.31 

I .0036 

0.93 

1 .0101  1 

2.61 

I .0166 

4.29 

I .0231 

5-97 

1 .0296 

7-65 

1 -0361 

9-34 

1.0037 

0-95 

I .0102 

2.63 

I .0167 

4.31 

I .0232 

6.00 

I .0297 

7.68 

1 -0362 

9-36 

1 .0038 

0.98 

1.0103 

2.66 

I. 0168 

4.34 

I.0233 

6.02 

1 .0298 

7.70 

1  0363 

9  39 

1 .0039 

I  .00 

1 .0104 

2.69 

I .0169 

4.37 

I  .0234 

6.05 

1 .0299 

7-73 

1-0364 

9  42 

I  0040 

1.03 

1 .0105 

2.71 

I .0170 

4-39 

I -0235 

6.07 

I .0300 

7-76 

1-0365 

9-44 

I  0041 

I. OS 

I .0106 

2.74 

I .0171 

4-42 

I .0236 

6.!0 

1.0301 

7-78 

I .0366 

9-47 

I .0042 

I  .08 

I .0107 

2.76 

I. 0172 

4.44 

I .0237 

6.12 

I .0302 

7-81 

1.0367 

9-49 

I .0043 

I  .11 

I .0108 

2.79 

1.0173 

4-47 

1  .0238 

6.15 

I  0303 

7-83 

1.0368 

9.52 

I .0044 

I  •  13 

I .0109 

2.82 

1.0174 

4.50 

1.0239 

6.18 

1.0304 

7-86 

[  0369 

955 

I .0045 

1. 16 

I .0110 

2.84 

1.017s 

4.52 

I .0240 

6.  20 

1.0305 

789 

1.0370 

9-57 

I . 0046 

1. 18 

1 .01 1 1 

2.87 

1 .0176 

4.55 

I .0241 

6.23 

1 .0306 

7-91 

1.0371 

900 

I .0047 

I  .  21 

I .01 12 

2.89 

I. 0177 

4-57 

I .0242 

6.25 

1.0307 

7-94 

I .0372 

9-62 

I .0048 

1.24 

1 .0113 

2.92 

I .0178 

4.  60 

I .0243 

6.28 

I .0308 

7-97 

1 -0373 

9-65 

I .0049 

I  .  26 

I .0114 

2.94 

1. 0179 

4.63 

I .0244 

6.31 

I .0309 

7-99 

1-0374 

9-68 

I .0050 

1.29 

I .0115 

2.97 

1 . 0 1  So 

4.6s 

1.0245 

6.33 

1 .0310 

8.02 

1-0375 

9-70 

1. 005 1 

1.32 

I  .on6 

3  -oo 

1 .0181 

4.68 

I .0246 

6.36 

I .0311 

8.04 

I .0376 

9-73 

I  .0052 

1.34 

I .0117 

3.02 

1 .0182 

4.70 

1.0247 

6.38 

1 .0312 

8.07 

1-0377 

9-75 

1.0053 

1-37 

I .01 18 

3.0s 

I .01S3 

4.73 

I .0248 

6.41 

I  0313 

8.09 

1.0378 

9-78 

1.0054 

1.39 

I  .01 19 

3-07 

I .0184 

4.75 

1  1 .0249 

6.44 

1-0314 

8.12 

1-0379 

9-80 

I .0055 

1.42 

I .01 20 

3.IO 

1.018s 

4.78 

1 .0250 

6.46 

1-031S 

8.14 

I .0380 

9  83 

I .0056 

I.4S 

I .0121 

3-12 

1.0186 

4.81 

I .0251 

6.49 

1-0316 

8.17 

I -0381 

9.86 

1.0057 

1.47 

I .01 22 

31S 

I .0187 

4.83 

I .0252 

6.51 

10317 

8.20 

1 .0382 

9.88 

I .0058 

1.50 

I .01 23 

3.18 

1.0188 

4.86 

I.02S3 

6.54 

1 .0318 

8.22 

1-0383 

9.91 

1.0059 

1-52 

I .01 24 

3.20 

I .0189 

4.88 

I .0254 

6.56 

1. 03 1 9 

8.25 

1-0384 

9. 93 

I  .0060 

1-55 

I .0125 

3-23 

1 . 0 1 90 

4.91 

'  0255 

6.59 

1 -0320 

8.27 

1.038s 

9.96 

I  .0061 

1-57 

I .01 2b 

3.26 

I  .0191 

4  94 

I .0256 

6.62 

1 -0321 

8.30 

I .0386 

9.99 

I  .0062 

I  .60 

I .01 27 

3.28 

r .0192 

4.96 

I .0257 

6.64 

I .0322 

8.33 

I .0387 

10. Ol 

I .0063 

1.63 

I .01 28 

3.31 

I .0193 

4  99 

1  .0258 

6.67 

1-0323 

8-35 

1.0388 

10.04 

I .0064 

i.6s 

I .0129 

iSi 

I .0194 

501 

1.0259 

6.70 

1.0324 

8.38 

I .0389 

10.06 

69"^ 


FOOD  INSPECTION  ^ND   ^N.^ LYSIS. 


EXTRACT  IX  \\lXF.—{ConliiiueJ). 


Specific 

Ex- 

Specific ;  Ex- 

Specific 

Ex- 

Specific 

E.X- 

Specific 

Ex- 

Specific 

Ex- 

Gra\-ity. 

tract.  ] 

Gravity.;  tract. 

Gravity. 

tract. 

Gravity. 

tract. 

Gravity. 

tract. 

Gravity. 

tract. 

X  .OJiOO 

10.09 

1.045s 

11.78 

1.0520 

13.47 

1.0585 

15.16 

I .0650 

16.86 

1 .0715 

18.56 

i.o30t 

10. 11 

1 .0456 

11.81 

I. 0521 

1 3  ■  49 

1.05S6 

IS. 19 

I. 0651 

16.88 

1 .0716 

18.58 

1  0301 

10.14 

1.0457 

11.83 

1 .0522 

13-52 

1.0,87 

15.22 

I .0652 

16.91 

1.0717 

18.61 

1.0393 

10.17 

1.0458 

11.86 

1.0523 

13.55 

1.05SS 

15.24 

1.0653 

16.94 

1.0718 

18.63 

1.0394 

10.19 

I. 0459 

11.88 

1.0524 

13.57 

1.0589 

15.2- 

I .0054 

16. 96 

I. 0719 

18.66 

1.039s 

10.33 

1 .0460 

11.91 

1.052s 

1 3 .  60 

1.0590 

15.29 

I .0655 

16.99 

I .0720 

18.69 

1.0396 

10.  25 

1 .0461 

11.94 

1.0526 

13-62 

I. 0591 

15.32 

I .0O56 

17.01 

I .0721 

1S.71 

1 .0397 

10.27 

1 .0462 

11 .96 

1.0527 

13.65 

1.0592 

15-35 

1.0657 

17.04 

I .0722 

1S.74 

I .0398 

10.30 

1  1.0463 

11.99 

I .0528 

13-68 

1.0593 

15-37 

1.0658 

17.07 

1.0723 

18.76 

1.0399 

10.32 

1.0464 

12.01 1 

1.0529 

13.70 

I. 0594 

iS-40 

1.0659 

17.09 

1.0724 

18.79 

1 .0400 

10.3s 

1.046s 

12.04 

1.0530 

13-73 

I.OS95 

lS-42 

I .0660 

17.12 

1.0725 

18.82 

I .0401 

10.37 

1 .0466 

12  .06 

I. 0531 

13-75 

1.0596 

15-45 

I .0661 

17.14 

1 .0726 

18.84 

1.040J 

10.40 

I  1.0467 

12.09 

1.0532 

13.78 

1.0597 

15-48 

I .0602 

17.17 

1.0727 

18.87 

1.0403 

10.43 

1.0468 

12.12 

1.0S33 

13-81 

1-0598 

15-50 

I .0663 

17.  20 

I .0728 

18.90 

1 . 0404 

10.45 

1  1.0469 

12. 14 

1.0534 

13.83 

1-0599 

15-53 

1  1 .0664 

ly .  22 

1.0729 

18.92 

I .0405 

10.48 

1.0470 

12.17 

I. 053s 

13.86 

I .0600 

15-55 

I .0665 

17.25 

1.0730 

18. 95 

I  .0406 

10.51 

1.0471 

12. 19 

1.0536 

13-89 

I . 060 I 

IS -58 

I .0666 

17.27 

1 .0731 

18.07 

1.0407 

10. S3 

1.0472 

12.22 

1.0537 

13.91 

I .0602 

i5-6i 

I .0667 

17.30 

1.0732 

19. 00 

I  .0408 

10.56 

1  1.0473 

12.25 

1.0538 

13-94 

I .0603 

15-63 

1.0668 

17.33 

1.0733 

19. OJ 

1.0409 

10.58 

1.0474 

12.27 

I. 0539 

13.96 

I . 0604 

15-66 

I .0669 

17.35 

1.0734 

19.05 

■  1 .0410 

10.61 

•  1.047s 

12.30 

1.0540 

13.99 

1.0605 

15-68 

I .0670 

17.38 

1.0735 

19. oS 

1.0411 

10.63 

'  1.0476 

12.32 

I. 0541 

14.01 

I .0606 

1S-71 

I .0671 

17.41 

1 .0736 

19. 10 

1.0412 

10.66 

1.0477 

12.35 

1.0542 

14.04 

I .0607 

15-74 

I .0672 

17-4,? 

1.0737 

19.13 

1.0413 

10.69 

1  1.0478 

12.38 

1.0543 

14.07 

I .0608 

IS -76 

1.0673 

17.46 

1.0738 

IQ.  i6 

1.0414 

10.71 

1  1.0479 

12.40 

1.0544 

14.09 

I .0609 

15-79 

I .0674 

17.48 

1.0739 

19.  18 

1.041s 

10.74 

1  I .0480 

12.43 

I. 054s 

14. 12 

1  I .0610 

15-81 

1.0675 

17.51 

I .0740 

19.21 

1.0416 

10.76 

j  1.0481 

12.4s 

1.0546 

14.14 

I .061 1 

iS-84 

I .0676 

17.54 

1.0741 

19.23 

1  .0417 

10.79 

{  1.0482 

12.48 

1.0547 

14.17 

I. 0612 

15-87 

I .0677 

17.56 

1.0742 

19.  26 

1  .0418 

10.82 

'[  1.0483 

12.51 

1.0548 

14.  20 

I .0613 

15.89 

1.0678 

17.59 

1.0743 

19.29 

1.0419 

10.84 

1.0484 

12.53 

1.0549 

14.22 

I .0614 

15-92 

I .0679 

j 

17.62 

1.0744 

19-31 

1  .0420 

10.87 

!  1.048s 

12.56 

I. 05 SO 

14-25 

I .0615 

15-94 

'  1.0680 

17.64 

1.0745 

19.34 

I  .0421 

10.90 

1 .0486 1 12.58 

i.ossi 

14.28 

I .0616 

15-97 

I . 06S I 

17.67 

1 .0746 

19.37 

1 .0422 

10.92 

1 .0487  12. 6i 

1.0552 

14-30 

I .0617 

16.00 

1  1.0682 

17.69 

1.0747 

19.39 

I .0423 

10.9s 

1.0488  1  12.64 

1.0553 

14-33 

1. 0618 

16.02 

1.0683 

17.72 

1 .0748 

19.42 

1.0424 

10.97 

j  I .0489  12.66 

I.OSS4 

14-35 

I .0619 

16.05 

'  1.0684 

17.75 

1.0749 

19.44 

I  .0425 

11 .00 

1 .0490  1  12.69 

I.05SS 

14-38 

1 .0620 

16.07 

1  1.0685 

17.77 

1.0750 

19.47 

I  .0426 

1 1  .03 

1.0491   12.71 

1.0556 

14.41 

I .0621 

16. 10 

1  1.0686 

17.80 

1 .0751 

19.50 

1.0427 

11.05 

1.0492  1  12.74 

1.0557 

14-43 

I .0622 

16.13 

;  1.0687 

17.83 

1.0752 

19-52 

I  .0428 

11.08 

1.0493  !  12.77 

1.0558 

14.46 

1.0623 

16.15 

1.0688 

17.85 

1.0753 

19.^5 

1.0429 

11.10 

1.0494  1  12-79 

1 

1.0559 

14-48 

1.0624 

16.18 

1 .0689 

17.88 

1.0754 

1958 

1 .0430 

11.13 

1.049s 

12.82 

1.0560 

14-51 

i  1 .0625 

16.  21 

1 .0690 

17.90 

1.0755 

19.  60 

I. 0431 

11. IS 

1 .0496 

12.84 

1.0561 

14-54 

1  I .0626 

16.23 

I .0691 

17.93 

1.0756 

19.63 

1  .0432 

11.18 

1-0497 

12.87 

1 .0562 

14-56 

I .0027 

16.26 

I .0692 

17.9s 

1.0757 

19.65 

1  0433 

11.21 

I .0498 

12.90 

1-0563 

14-59 

1.0628 

16.28 

I .0693 

17.98 

1.0758 

19.68 

1.0434 

11.23 

1.0499 

12.92 

1.0564 

14.61 

I .0629 

16.31 

I . 0694 

18.01 

I.07S9 

19.71 

•  ^    0435 

11.26 

1 .0500 

12.95 

1.0565 

14.64 

'  1 .0630 

16.33 

1.0695 

18.03 

I .0760 

19.73 

I -0436 

11.28 

I .0501 

12.97 

1 .0566 

14.67 

I .0631 

16.36 

I .0696 

18.06 

I .0761 

19.76 

»  0437 

11  .31 

1.0502 

13.00 

1.0567 

14.69 

I .0632 

16.39 

I .0697 

18.08 

I . 0762 

19.79 

•  1.0438 

11.34 

1.0503 

13.03 

1.0568 

14.72 

1.0633 

16.41 

1 .0698 

18. n 

1.0763 

19.81 

10439 

11  .36 

1.0504 

13.05 

I .0569 

14-74 

1.0634 

16.44 

I .0699 

18.14 

1.0764 

19.84 

■  1 . 0440 

11-39 

I -050s 

13.08 

1.0570 

14-77 

1.0635 

16.47 

1 .0700 

18.16 

1.0765 

19.86 

I .0441 

11.42 

I .0506 

13-10 

1.0571 

14.80 

1.0636 

16.49 

I .0701 

18.19 

1 .0766 

10.89 

'  I .0442 

11.44 

1.0507 

13-13 

1.0572 

14.82 

1.0637 

16.52 

I .0702 

18.22 

1.0767 

19.92 

■  1.0443 

11.47 

I .0508 

13- 16 

1.0573 

14-85 

1.0638 

16.54 

1.0703 

18.24 

1.0768 

19.  94 

;  1.0444 

11.49 

1.0509 

13.18 

I.OS74 

14.87 

1 :o639 

16.57 

1 .0704 

18.27 

1.0769 

19.97 

'  i.044S 

11.52 

1 .0510 

13.  21 

1.057S 

14-90 

I .0640 

16.  60 

1.070s 

18.30; 

.1.077a. 

20.00 

1.0446 

II. SS 

1 .051 1 

13-23 

I .0576 

14-93 

1 .0641 

16.62 

1 .0706 

18.32 

1.0771 

20.02 

'  1.0447 

11.57 

1 .0513 

13.  26 

1.0S77 

14-95 

T .0642 

16.65 

1.0707 

18.35 

1.0772 

•20.05 

:  1.0448 

11  .60 

1.0S13 

13.29 

1.0578 

14.98 1 

I .0643 

16.68 

I .0708 

18.37 

1.0773 

20.07 

•^  1.0449 

11 .63 

1-0514 

13.31 

1.0579 

15-00 j 

1.0644 

16.  70 

I .0709 

18.40 

.1.0774 

20. 10 

•  1 . 0450 

11.65 

1.051s 

13-34 

1.0580 

15-03 

I . 0645 

16.73 

1 .0710 

18.45^ 

1.077s 

20.  12 

' . 04s  I 

11.68 

I. 0516  13.36 

I .0581 

15-06 

I . 0646 

i6.7S 

1 .0711 

1.0776 

20.15 

'  « .0452 

II  .70 

1.0517  1  13.39 

1 .0582 

15-08 

I .0647 

16.78 

1 .0712 

i8.-^fi 

1.0777 

20.18 

'■   1  .«453 

11.73 

1. 05 1 8  13.42 

I. 0583 

15-I1 

I . 0648 

a6.8o 

I. 0713 

18.50 

1.0778 

20.  20 

"1.0454 

11.75 

i.05i>>   13.44 

1.0584 

15-14 

I .0049 

16.83 

1 .0714 

"t 

I.07  7^i' 

120.23 

JLCOHOLIC   BEVERAGES. 


I'k. 


699 


EXTRACT  IX  WIXE— {Continued). 


1 
specific  1 

Ex- 

Specific 

Ex-  1 

Specific 

Ex- 

Specific 

Ex- 

Specific 

ix- 

Specific 

Ex- 

Gravity.! 

trarct. 
20.  26 

Gravity. 

tract.  ' 

Gravity. 

tract. 

Gravity. 

tract. 

Gravity. 
I . 1040 

tract. 

';   i 
271.09 

Gravity. 

tract. 

I .0780 

1.084s 

21 .96 

1 .0910 

23.67 

1-097S 

25-38 

I. 1105 

28.81 

I .0781 

20.28 

I .0846 

2  1.99 

I .0911 

23.70 

I -0976 

25-41 

I . 1041 

27.12 

1 . 1 106 

28.83 

1.0782 

20.31 

1.0847 

22.02  \ 

I .0912 

23.72 

1.0977 

25-43 

I . 1042 

27.15 

I. 1107 

28.86 

1.0783 

20.34 

1.0848 

22  .04 

1.0913 

23.7s 

1 .0978 

25.46 

I. 1043 

27.17 

1. 1 1 08 

28.88 

1.0784 

20.36 

I .0849 

22  .07 

1 .0914 

23.77 

1.0979 

25.49 

I. 1044 

27.20  1 

I . 1109 

28.91 

1.078s 

20.39 

I .0850 

22.09 

I. 091s 

23.80 

1.0980 

25.51 

1.104s 

27.22 ' 

1 . 1 110 

28.94 

1.0786 

20.41 

1.0851 

2  2.12 , 

I .0916 

23.83  ' 

I .0981 

25.54 

1 . 1 046 

27-25 

1 . 1 1 1 1 

28.96 

1.0787 

20.44 

1.0852 

22.15  1 

1.0917 

23.85  1 

I .0982 

25-56 

1.1047 

27.27 

1 .  1 1 1  2 

28.99 

1.0788 

20.47 

1.0853 

22.17 

I .0918 

23-88 

1.0983 

25-59 

1.J048 

27.30 

1.1113 

29 .02 

1.0789 

20.49 

I  1.0854 

22.  20 

I .0919 

23-91 

1 . 0984 

25.62 

1.1049 

27.33 

1.1114 

29.04 

I .0790 

20.52 

1.0855 

22.  22 

1 .0920 

23.93 

1.0985 

25-64 

1.1050 

27.3s 

1.1115 

29.07 

1.07QI 

20.55 

1.0856 

22.25 

I .0921 

23.96 

I .0986 

25-67 

1.1051 

27.38 

1 . 1 1 16 

29.09 

1.0792 

20.57 

1.0857 

22.28 

I .0922 

23-99 

I .0987 

25.70 

1 . 1052 

27.41 

1.1117 

29.  12 

1.0793 

20. 60 

1.0858 

22.  30 

1.0923 

24.01 

I .0988 

25-72 

I. 1053 

27-43 

1 .1118 

29. IS 

1.0794 

20.62 

j  1.0859 

22.33 

1 .0924 

24.04 

I .0989 

25.75 

I. 1054 

27.46 

1 . 1 119 

29.17 

1.079s 

20.65 

1.0860 

22.36 

1.0925 

24.07 

I . 0990 

25.78 

I. loss 

27.49 

I .1120 

29.  20' 

1 .0796 

20.68 

1  I. 0861 

22.38 

I .0926 

24.09 

1 .0991 

25-80 

1.1056 

27.51 

1 .1121 

29-23 

1.0797 

20.  70 

1.0862 

22  .41 

1.0927 

24.  12 

I .0992 

25.83 

1.1057 

27.54 

1.1123 

29.2s 

I .0798 

20.73 

1.0863 

22.43 

I .0928 

24.14 

1.0993 

25.85 

1.1058 

27.57 

1.1123 

29.28- 

1.0799 

20.75 

1.0864 

22.46 

1 .0929 

24.17 

1.0994 

25.88 

1.1059 

27.59 

1.1124 

29.31 

1 .0800 

20.78 

1.086s 

22.49 

1.0930 

24.20 

1.0995 

25.91 

I . 1060 

27.62 

1.1125 

29-33 

1 .0801 

20.81 

1.0866 

22.51 

1.0931 

24.22 

1 .0996 

25.93 

1 . 1061 

27-65 

1 . II26 

29-36 

1 .0802 

20.83 

1.0867 

22.54 

1.0932 

24.25 

1.0997 

25.96 

1 . 1062 

27-67 

I.II27 

29-39- 

1 .0803 

20.86 

1.0868 

22.57 

1.0933 

24.27 

1 .0998 

25-99 

\   1.1063 

27-70 

I. I  I  28 

29.41 

I .0804 

20.89 

1 .0869 

22.59 

1.0934 

24.30 

Z.0999 

26.01 

1.1064 

27-72 

I  . I  I  29 

29-44 

I .0805 

20.91 

\   I .0870 

22.62 

1.093S 

24.33 

1. 1000 

26.04 

1.1065 

27-75 

I  .  I  130 

29-47 

I .0S06 

20.94 

I .0871 

22.6s 

1.0936 

24.35 

1 . 1001 

26.06 

1 . 1066 

27.78 

I.II3I 

29.49 

1 .0807 

20 .  96 

I .0872 

22.67 

1.0937 

24.38 

1 . 1002 

26.09 

1 . 1067 

27.80 

1.1132 

2952 

i.o8o8 

20. 99 

1.0873 

22.  70 

1.0938 

24.41 

1.1003 

26. 12 

I. 1068 

27-83 

1.1133 

29  54 

1 .0809 

21 .02 

I .0874 

22.72 

I.0939 

24.43 

1. 1004 

26.14 

1 . 1069 

27.86 

1.1134 

29.57 

1 .0810 

21 .04 

1.0875 

22.7s 

I . 0940 

24.46 

1 . 1005 

26.17 

1 . 1070 

27.88 

1.1135 

29.60 

1 .0811 

21  .07 

1.0876 

22.78 

I .0941 

24.49 

1 . 1006 

26.  20 

1.1071 

27.96 

1.1136 

29.63 

I .0812 

21  .  10 

I  1.0877 

22.80 

r .0942 

24.51 

1 . 1007 

26.  22 

I . 1072 

27.93 

1.1137 

29.65 

1.0813 

21.12 

1.0878 

22.83 

1-0943 

24-54 

1 . 1008 

26.25 

1.1073 

27.96 

I. 1138 

29.68^ 

1 .0814 

21.15 

I .0879 

22.86 

I . 0944 

24.57 

I . 1009 

26.27 

1.1074 

27.99 

I.1139 

29.70 

1 .0815 

21.17 

1.0880 

22.88 

I . 0945 

24. 59 

1 . 1010 

26.30 

1.107s 

28.01  1 

1 . 1140 

29-73 

1.0816 

21  .  20 

1  I. 0881 

22  .91 

I .0946 

24.62 

1 . loi 1 

26.33 

1.1076 

28.04 

1 . 1141 

29.76- 

1  .oSi  7 

21  .  23 

1.0882 

22.93 

1.0947 

24.64 

I . 1012 

26.3s 

1.1077 

28.07 

1.1142 

29-73 

1.0818 

21  .  25 

1.0883 

22.96 

I .0948 

24.67 

1.1013 

26.38 

I. 1078 

28.09 

11143 

29.81 

1 .0819 

21.28 

1 . 0884 

22.99 

1.0949 

24.70 

1 . 1014 

26.41 

1.1079 

28.12 

1.1144 

29.83. 

1 .0820 

21  .31 

1.0885 

23.01 

1.0950 

24.72 

1.1015 

26.43 

1 . 1080 

28.15 

1-1145 

29.86 

I .0821 

21.33 

1.0886 

23.04 

1.0951 

24-75 

1 .  ioi6 

26.46 

1.1081 

28.17 

1 .  1146 

29.89. 

I .0822 

21  .36 

1.0887 

23.07 

1.0952 

24.78, 

1 . 1017 

26.49 

1.10S2 

28.  20 

1.1147 

29.91 

1 .0823 

21.38 

1.0888 

23.09 

1.0953 

24.80  i 

1 .  1018 

26.51 

I. 1083 

28.22 

I . 1148 

29.94 

1 .0824 

21  .41 

1.0889 

23.12 

1-0954 

24.83 

1 . 1019 

26.54 

1.1084 

28.25 

I. 1149 

29.96 

1.0823 

21  .44 

I .0890 

23.14 

1-0955 

24.8s  i 

I . 1020 

26.56 

1.1085 

28.28 

I  .1150 

29.99 

1.0826 

21  .46 

I .0891 

23.17 

1.0956 

24.88 

I . I02I 

26.59 

1.1086 

28.30 

1. 1151 

30.03 

I .0827 

21  .49 

I .0892 

23.20 

1.0957 

24.91 

1 .  1022 

26.62 

1.1087 

28.33 

1.1152 

30.04 

1 .0828 

21.52 

I .0893 

23.  22 

1.0958 

24-93 

1. 1023 

26.64 

1.1088 

28.36 

I-I153 

30.07 

I .0829 

21-54 

1 .0894 

23-25 

I -0959 

24.96 

I . 1024 

26.67 

1 . 1089 

28.38 

1.1154 

30. 10 

I .0830 

21  .  57 

1.0895 

23.28 

1 .0960 

24.99 

I.I02S 

26.  70 

1 .1090 

38.41 

i.iiSS 
1 .1156 

30.13 

I .0831 

21  .  59 

I .0896 

23-30 

;  I .0961 

25-01 

1 .  1026 

26.72 

1.1091 

28.43 
28.46 

3015 
30. i3 

I .0832 

21  .62 

I .0897 

23-33 

1 .0962 

25-04  1 

I .1027 

26.7s 

1 . 1092 

1 .1157 
1.1158 

I  -0833 

21  .65 

1.0898 

23-35 

1 .0963 

25-07 

I . 1028 

26.78 

1.1093 

28.49 
28.51 

30.  21 

1.0834 

21  .67 

I .0899 

23-38 

1 .0964 

25.09 

I . 1029 

26.80 

1.1094 

I  .1159 

30.23 

1 -0835 

21 .  70 

1 . 0900 

23-41 

1.0965 

25.12 

1 . 1030 

26.83 

1.109s 
1 . 1096 

28.54 
28.57 
28.59 
28.62  1 
28.65 

1.0836 

21  .73' 

1 .0901 

23-43 

1 .0966 

25-14 

I .1031 

26.85 

1 .0837 

21.75 

I .0902 

23.46 

1.0967 

25-17 

1 .1032 

26. 88 

1.1097 
1.1098 

1.0838 

21.78 

1.0903 

23-49 

I .0968 

25-20 

1-1033 

26.91 

1 .0839 

21.80 

I .0904 

23-51 

1.0969 

25.  22 

1.1034 

26.93 

1.1099 

1 .0840 
I .0S41 

21.83 

21.86 

1.0905 
1 .0906 

23-54 
23.57 

1 .0970 
1.0971 

25-25 
25.28 

1.1035 
1.1036 

26-96 
26.99 

1 . 1100 

1. 1101 

28.67 
28.70 
28.73 
28.75 
23.78 

1 .0842 

21.88 

I .0907 

23-59 

1.0972 

25.30 

I. 1037 

27  .OI 

1 . 1 102 

I .0843 

21 .91 

1 .0908 

23-62 

1.0673 

25  -  ir^ 

I .1038 

27-04 

I . 1103 

1.0844 

21.94 

1 .0909 

23  r6s- 

-I-:  097-4 

45-36 

1.J.039 

37^07. 

1 

-1,1 104 

^r 

;oo 


FOOD   INSPECTION  AND   ANALYSIS. 


Fig.  114. —  Apparatus  for  Determining  Volatile  Acids  in  Wine. 


fin.   115. — Hortvct's  Apparatus  for  Dctcrriiining  the  Volatile  Acids  in  Wine. 


/tLCOHOLlC  BF.l^ER/iGES.  70 1 

as  an  indicator.  Each  cubic  ccniimcter  of  icnih-normal  alkali  is  equiv- 
alent to  0.006  gram  acetic  acid. 

Hortvet  Method* — The  apparatus  (Fig.  115)  consists  of  a  300  cc. 
fiask  into  the  neck  of  which  is  fitted  a  200-cc.  cyUndrical  flask,  with  a 
steam  tube,  a  bulb-trap  leading  to  a  condenser,  and  a  stop-cock  funnel. 
The  procedure  is  as  follows:  Pour  150  cc.  of  recently  boiled  water  into 
the  larger  flask,  attach  the  smaller  flask  by  means  of  a  section  of  rubber 
tubing,  run  in  10  cc,  of  wine  (previously  freed  from  carbonic  acid), 
close  the  stop-cock  and  boil.  In  extreme  cases  add  to  the  wine  a  small 
piece  of  paraffin  to  prevent  foaming.  When  the  water  has  boiled  a 
moment,  close  the  tube  at  the  side  of  the  larger  flask  and  distil  until 
70  cc.  of  distillate  have  passed  over.  Transfer  to  a  beaker,  without 
discontinuing  the  distillation,  and  titrate,  using  phenolphthalein  as 
indicator.  Continue  the  distillation  until  the  last  10  cc.  portion  requires 
not  more  than  one  drop  of  tenth-normal  alkali  for  neutralization. 
Usually  80  or  90  cc.  of  distillate  includes  practically  all  of  the  volatile 
acids.  Cool  the  apparatus,  thus  allowing  the  wine  residue  to  be  drawn 
back  into  the  lower  flask,  rinse  with  boiled  water,  and  reserve  the  total 
liquid  for  determination  of  non-volatile  acids. 

Non-volatile  Acids. — These  may  be  determined  by  dIfTerence,  cal- 
culating the  vt)la  ile  acids  for  purposes  of  subtraction  in  terms  of  tar- 
taric or  other  acid  in  which  the  total  acidity  is  expressed.  Non-volatile 
acid  may  be  direcJy  determined  by  evaporating  to  dryness  a  measured 
portion  of  the  liquor,  boiling  the  residue  with  water,  and  titrating  the 
solution  wi'h  the  standard  alkali. 

Detection  of  Free  Tartaric  Acid. — Nessler's  Method. — Some  pow- 
dered cream  of  tartar  is  added  to  a  portion  of  the  wine  in  a  corked  flask, 
which  is  shaken  from  time  to  time,  and  the  liquid  finally  fiUered.  To 
the  filtrate  is  added  a  little  20%  potassium  acetate  solution.  If  free 
tartaric  acid  is  present,  on  stirring  and  especially  after  standing  for  some 
time,  there  wiU  be  a  precipitate  of  cream  of  tartar. 

Determination  of  Tartaric  Acid,  Total,  Free,  and  Combined. — Pro- 
visional methods  A.  O.  A.  C.f 

Total  Tartaric  Acid. — To  100  cc.  of  wine  add  2  cc.  of  glacial  acetic 
acid,  3  drops  of  a  20%  solution  of  potassium  acetate,  and  15  grams  of 
powdered  potassium  chloride,  and  stir  to  hasten  solution.  Add  15  cc. 
of  95%  alcohol  (specific  gravity  0.81)  and  rub  the  side  of  the  beaker 
vigorously  wi.h  a  glass  rod  for  about  one  minute  to  start  crystaUizalion. 

*  Jour.  Ind.  Eng.  Chein.,  i,  igog,  p.  ,^i 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chc:ii.,  Bui.  65,  p.  87. 


;c2  FOOD  INSPECTION  AND   ANALYSIS. 

Let  Stand  at  least  fifteen  hours  at  room  icmperaturc;  decant  the  Hquid 
from  ;he  separated  acid  potassium  tartrate  as  rapidly  as  possible  (using 
vacuum)  through  a  Gooch  crucible  prepared  with  a  very  thin  film  of 
asbestos,  transferring  no  more  of  the  precipitate  to  the  crucible  than 
necessars'.  Wash  the  precipitate  and  filter  three  times  with  a  small 
amount  of  a  mixture  of  15  grams  potassium  chloride,  20  cc.  of  95%  alco 
hoi  (specific  gravity  0.81),  and  100  cc.  water,  using  not  more  than  20  cc. 
of  the  wash  solution  in  all.  Transfer  the  asbestos  film  and  precipitate 
to  the  beaker  in  which  the  precipitation  took  place,  wash  out  the  Gooch 
crucible  with  hot  water,  add  about  50  cc.  of  hot  water,  heat  to  boiling, 
and  thrate  the  hot  solution  with  decinormal  sodium  hydroxide,  using 
delicate  litmus  tincture  or-  litmus  paper  as  indicator.  Increase  the 
number  of  cubic  centimeters  of  decinormal  alkali  employed  by  1.5  on 
account  of  the  solubility  of  the  precipitate.  This  figure  muUiplied  by 
0.015  gives  the  amount  of  total  tartaric  acid  in  grams  per  100  cc. 

Cream  oj  Tartar. — Ignite  the  residue  obtained  from  the  evaporation 
of  50  cc.  of  wine  as  directed  under  the  determination  of  ash.  Exhaust 
the  ash  with  hot  water,  add  to  the  filtrate  25  cc.  of  decinormal  hydro- 
chloric acid,  heat  to  incipient  boiling,  and  titrate  with  decinormal  alkali 
solution,  using  litmus  as  indicator.  Deduct  from  25  cc.  the  number 
of  cubic  centimeters  of  decinormal  alkali  employed,  and  multiply  the 
remainder  by  0.0188  for  potassium  bitartrate  exjircssed  in  grams. 

Free  Tartaric  Acid. — Add  25  cc.  of  decinormal  hydrochloric  acid  to 
the  ash  of  50  cc.  of  wine,  heat  to  incipient  boiling,  and  titrate  with  deci- 
normal sodium  hydroxide,  using  litmus  as  indicator.  Deduct  the  number 
of  cubic  centimeters  of  alkali  employed  from  25,  and  multiply  the 
remainder  by  0.0075  to  obtain  the  amount  of  tartaric  acid  necessary- 
to  combine  with  all  the  ash  (considering  it  to  consist  entirely  of  potash). 
Deduct  the  figure  so  obtained  from  the  total  tartaric  acid  for  the  free 
tartaric  acid. 

Determination  of  Free  and  Combined  Malic  Acid  in  Cider  and  Wine. 
— Evaporate  100  cc.  of  the  sample  on  the  water-bath  to  half  its  volume, 
cool,  and  treat  first  with  10  cc.  of  10%  calcium  chloride  solution,  and 
then  with  ammonia  to  strong  alkaline  reaction.  Let  stand  for  an  hour 
and  filter.  This  removes  the  tartaric  acid.  Concentrate  the  filtrate 
by  evajxjration  on  the  water-bath  to  25  cc,  add  75  cc.  of  95%  alcohol, 
heat  to  the  boiling-point,  and  filter.  Wash  the  residue  with  a  mixture  of 
3  parts  95%  alcohol  and  i  part  water,  dry,  and  burn  to  an  ash.  Add 
25  cc.  of  tenth-normal  hydrochloric  acid  to  the  ash,  dilute  with  water,, 


ALCOHOLIC    BEyERAGES.  703 

heat  to  boiling,  and  titrate  with  tenth -normal  sodium  hydroxide,  using 
phenolphthalein  as  an  indicator.  Multiply  the  difference  between  25 
and  the  number  of  cubic  centimeters  rec^uired  to  neutralize  by  0.0067 
for  the  grams  of  malic  acid. 

Polarization. — Treat  a  measured  amount  of  wine  or  cider  with  one- 
tenth  of  its  volume  of  lead  subacetate,  filter  and  polarize  the  filtrate  in 
the  200  mm.  tube.  The  reading  is  increased  by  10%  for  the  true  direct 
polarization. 

If  the  reducing  sugars  are  also  to  be  determined,  the  same  solutions 
may  be  used  for  both  the  polarization  and  the  reducing  sugars  as 
follows : 

Exactly  neutralize  with  sodium  hydroxide'  solution  200  cc.  of  the  wine, 
using  Utmus  paper  as  an  indicator,  and  evaporate  on  the  water-bath 
to  about  one-fourth  its  original  volume.  Wash  with  water  into  a  200  cc. 
flask,  add  enough  normal  lead  acetate  solution  to  clarify,  and  make  up 
with  wa-ter  to  the  mark.  Filter  and  to  the  filtrate  add  powdered  sodium 
sulphate  or  carbonate  sufficient  to  precipitate  the  lead,  again  filter  and 
polarize  before  and  after  inversion  (p.  588). 

Determination  of  Reducing  Sugars.  —  Determine  reducing  sugars 
in  portions  of  the  wine  treated  as  described  in  the  preceding  section,  after 
dilution  so  as  not  to  contain  above  0.5%  of  sugar  for  the  Defren  and  the 
Munson  and  Walker  methods  or  above  1%  of  sugar  for  the  Allihn  method. 
One  may  assume  2%  as  the  sugar-free  extract  of  wine,  the  number  of 
volumes  of  water  to  be  added  to  the  filtrate  being  determined  by  the  dif- 
ference between  2  and  the  total  extract  as  determined. 

Determination  of  Glycerin. — In  Dry  Wines.- — Evaporate  100  cc.  of 
the  wine  in  a  porcelain  dish  on  the  water-bath  to  about  10  cc,  add  about 
5  grams  of  fine  sand  and  from  3  to  4  cc.  of  milk  of  lime  (containing  about 
15%  of  calcium  oxide)  for  each  gram  of  extract  present  and  evaporate 
nearly  to  dryness.  Treat  the  moist  residue  with  50  cc.  of  95%  (by  vol.) 
alcohol,  remove  the  substance  adhering  to  the  sides  of  the  dish  with  a 
spatula,  and  rub  the  whole  mass  to  a  paste.  Heat  on  a  water-bath,  with 
constant  stirring,  to  incipient  boiling  and  decant  through  a  filter  into  a 
small  flask.  Wash  by  decantation  with  10  cc.  portions  of  hot  95%  alcohol 
until  the  filtrate  amounts  to  about  150  cc.  Evaporate  the  filtrate  to  a 
sirup  on  a  hot,  but  not  boiling,  water-bath,  transfer  to  a  small  glass- 
stoppered  graduated  cylinder  with  20  cc.  of  absolute  alcohol,  and  add  3 
portions  of  10  cc.  each  of  absolute  ether,  shaking  throughly  after  each 
addition.     Let  stand  until  clear,  then  pour  off  through  a  filter  and  wash 


704  FOOD  INSPECTION   AND  ANALYSIS. 

the  cylinder  witli  a  mixture  of  absolute  alcohol  and  absolute  ether 
(i :  1.5),  pouring  the  wash  li([uor  also  through  the  lilter.  Evaporate  the 
filtrate  to  a  sirup,  dry  for  one  hour  in  a  boiling  water  oven,  weigh,  ignite, 
and  weigh  again.     The  loss  on  ignition  gives  the  weight  of  glycerin. 

/;/  Sweet  Wines. — If  the  extract  exceeds  5%  heat  100  cc.  to  boiUng 
in  a  tlask  and  treat  with  successive  small  portions  of  milk  of  lime  until  the 
color  becomes  at  first  darker  and  then  lighter.  When  cool  add  200  cc. 
of  Q5''o  alcohol,  allow  the  precipitate  to  subside,  filter,  and  wash  with  95% 
alcohol.     With  the  filtrate  thus  obtained  proceed  as  directed  for  dry  wines 

Determination  of  Potassium  Sulphate. — Acidify  100  cc.  of  the  sample 
wilh  hydrochloric  acid,  heat  to  boiling,  and  add  an  excess  of  barium 
chloride  solution.  Filter,  wash,  dr)-,  ignite,  and  weigh  as  barium  sul- 
phate, calculating  the  equivalent  of  potassium  sulphate.  The  presence 
of  the  latter  in  excess  of  0.06  gram  per  100  cc.  indicates  plastering. 

Determination  of  Tannin. — An  approximate  method  of  determining 
tannin  is  that  of  Nessler  and  Barth.  12  cc.  of  wine  are  treated  with  30 
cc.  of  alcohol  and  filiercd.  35  cc.  of  the  filtrate,  which  corresponds  to 
10  cc.  of  the  wine,  is  evaporated  to  about  6  cc.  and  transferred  to  a  lo-cc. 
graduated  centrifuge  tube.  A  few  drops  of  40%  sodium  acetate  are 
then  added,  and  a  slight  excess  of  10%  ferric  chloride.  The  tube  is 
corked,  gently  agitated,  and  allowed  to  stand  for  twenty-four  hours.  The 
volume  of  the  precipitate  is  then  measured,  each  cubic  centimeter  being 
equivalent  to  0.033%  "^  tannin  in  the  wine. 

Foreign  Coloring  Matters  in  Wine. — -A  wide  variety  of  artificial  colors 
have  been  found  in  red  wine.  Those  most  commonly  employed  at  present 
are  cochineal,  fuchsin,  and  acid  fuchsin. 

The   Pharmacopccia  prescribes  the  following  color  tests: 

If  2  cc.  of  red  wine  be  mixed  in  a  test-tube  wilh  2  drops  of  chloroform 
and  4  cc.  of  normal  potassium  hydroxide,  and  the  mixture  carefully 
heated,  the  disagreeable  odor  of  isonitril  should  not  become  preceptible 
(absence  of  various  anilin  colors). 

If  50  cc.  of  red  wine  be  treated  with  a  slight  excess  of  ammonia  water, 
the  liquid  should  acquire  a  green  or  browTiish-green  color;  if  it  be  then 
well  shaken  with  25  cc.  of  ether,  the  greater  portion  of  the  ethereal  layer 
removed  and  cva[)oraled  in  a  [porcelain  capsule  with  an  excess  of  acetic 
acid  and  a  few  fibers  of  uncolored  silk,  the  latter  should  not  acc^uire  a 
crim.'^on  or  violet   color   (absence  of  fuchsin). 

If  25  cc.  of  rcfl  wine  heated  to  about  45°  C.  be  well  agitated  with  25 
gram-  of  manganese  dioxide,  the  liquid  filtered  off  and  acidulated  with 


ALCOHOLIC  BHytRAiJtS.  705 

hydrochloric  acid,  it  should  not  accjuire  a  red  color  (absence  of  sulpho- 
fuchsin). 

Duprfs  Method  0}  Detection* — Small  cubes  of  jelly  measuring  about 
2  cm.  in  thickness  are  prepared  as  follows:  Dissolve  i  part  of  ])ure 
gelatin  in  10  i)arts  boiling  water  and  pour  upon  a  plate  to  hanlcn.  This 
is  then  cut  into  cubes  of  the  above  size  by  a  sharp  knife.  When  a  wine 
is  suspected  of  containing  foreign  color,  one  of  the  cubes  is  immersed 
therein  and  allowed  to  remain  for  twenty-four  hours,  after  which  it  is 
removed,  washed  slightly  in  cold  water,  and  cut  through  with  a  knife.  If 
the  color  is  a  natural  one,  it  will  lightly  tinge  the  outer  surface  of  the 
cv.be,  but  will  not  permeate  far  below  the  surface,  so  that  the  inner  por- 
tion of  the  cross-section  will  be  largely  free  from  color.  Nearly  all  foreign 
coloring  matters  used  in  wine,  such  as  most  coal-tar  (h'es,  cochineal, 
Brazil  wood,  logwood,  etc.,  will  be  found  to  deej^ly  permeate  the  jelly 
cube  often  to  ihe  center.  Information  as  to  the  nature  of  the  color  may 
sometimes  be  gained  by  immersing  the  dyed  jelly  cube  in  weak  ammonia. 
If  the  color  be  rosanilin,  the  cube  is  decolorized,  if  cochineal,  a  purj)le 
coloration  will  result,  and  if  logwood,  a  brown  tinge. 

Cazeneuve's  Methods  for  Detecting  Colors  in  Wine. — While  by  no 
means  complete,  the  following  method  of  Cazeneuve  as  condensed  and 
arranged  by  Gautier  (La  Sophistication  des  Vins)  will  often  be  found 
helpful.  If  other  colors  than  these  are  evidently  present,  tests  should 
be  made  as  indicated  in  Chapter  XVII.  Cazeneuve  employs  the  fol- 
lowing reagents: 

(i)  Yellow  oxide  of  mercury,  finely  pulverized. 

(2)  Lead  hydrate,  freshly  precipitated,  well  washed,  suspended  in 
about  twice  its  volume  of  water;  to  be  kept  in  a  stoppered  bottle;  should 
be  renewed  after  several  days'  use. 

(3)  Gelatinous  ferric  hydrate,  well  washed  from  ammonia,  suspended 
in  about  twice  its  volume  of  water. 

(4)  Manganese  dioxide,  pulverized. 

(5)  Concentrated,  chemically  pure  sulphuric  acid. 

(6)  While  wool. 

(7)  Stannous  hydrate,  freshly  precipitated,  well  washed,  suspended  in 
water,  and  kept  from  exposure  to  light  and  air. 

(8)  Collodion  silk,  the  artificial  silk  produced  from  nitro-cellulosc. 
This  fiber  has  a  special  affinity  for  basic  dyes. 


*  Jour.  Chem.  Soc,  37,  p.  572. 


7o6 


FCOD    ISSPECTION   JND   ANALYSIS. 


To  lo  cc,  of  tb.e  wine  are  added  0.2  gram  finely  powdered  yellow  oxide  of  mercury. 
Boil  and  pour  upon  a  double  tilter. 


Filtrate  colored  either  before  or  after  acidifvingr. 


1  ^ 


JFiltrate  colored  yellow.  10  cc. 
of  the  wine  arc  warmed  with  2 
grams  lead  hydrate.     Filter. 

Filtrate  colored  yellow.  "^  J  §i 

.\  large  excess  of  lead  q.  ^  5  31 

hydrate  is  added  and  ^  q.'^  ? 
the  liiiuid  is  boiled. 


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cc.  of  the  wine  are  treated 
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31  Filtrate  colorless. 


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S'^.   3    2  2 


^  "1 


■^    "^  Oo    "i    ^    .^ 


5.'  s  ^  ?  ^ 


til  t?)ni     ?:"T3 
*■  S'  S"  2-  ^5  "■ 


p 


•^j ' 


33 -a  a'        ^ 
2.      6. 


•^1 


ALCOHOLIC   BRyRRAGES.  707 


MALT  LIQUORS.      BEER. 

In  its  widest  sense  beer  may  be  defined  as  the  product  of  fermentation 
of  an  infusion  of  almost  any  farinaceous  grain  with  various  bitter  extract- 
ives, but  unless  otherwise  qualified  it  should  be  strictly  applied  to  the 
beverage  resulting  from  the  fermentation  of  malted  barley  and  hops. 
In  the  manufacture  of  beer  two  distinct  processes  are  employed,  viz., 
malting  or  sprouting  the  grain,  and  brewing.  Many  brewers  do  noth- 
ing but  the  latter,  buying  their  malt  already  prepared. 

Malting. — For  the  preparation  of  malt,  the  barley  is  steeped  in  water 
for  several  days,  after  which  the  water  is  drained  off  and  the  moist  grain 
is  "couched,"  or  piled  in  hcai)s,  on  a  cement  lloor,  where  it  undergoes  a 
spontaneous  heating  process,  during  which  it  germinates,  forming  the 
ferment  diastase.  When  the  maximum  amount  of  diastase  has  been 
produced,  indicated  by  the  length  of  growth  of  the  sprout,  or  "acrospire  " 
within  the  grain,  the  germination  is  checked  by  spreading  the  grain  in 
layers  over  a  perforated  iron  floor,  and  finally  subjecting  it  to  artificial 
heat.  The  character  of  the  malt  and  of  the  beer  produced  from  it  dei)ends 
largely  on  the  heat  at  which  the  "green"  malt  is  kiln  dried.  If  dried 
between  32°  and  37°  C.  it  forms  pale  malt,  which  produces  the  lightest 
grades  of  beer.  Most  beer  is  made  from  malf  dried  at  higher  tem- 
peratures, say  from  38°  to  50°,  the  depth  of  color  of  the  liquor  varj-ing 
with  the  heat  to  which  the  malt  has  been  subjected,  while  the  color  of  the 
malt  varies  from  the  "pale"  through  the  "amber"  to  "brown,"  or  even 
black.  The  darkest  grades  are  sometimes  dried  at  temperatures  over 
100°  C,  even  to  the  point  where  the  starch  becomes  caramelized. 

A  more  modem  method  consists  in  the  so-called  pneumatic  malting, 
wherein  the  whole  operation  is  conducted  in  a  large  rotating  drum,  which 
holds  the  grain,  and  in  which  the  temperature  and  moisture  at  different 
stages  is  carefully  controlled  by  the  admission  to  the  interior  of  the  drum 
of  moisture-laden  or  dry  air,  heated  to  the  required  degree. 

The  chief  object  of  malting  is  the  production  of  diastase,  which  by 
its  subsequent  action  on  the  starch  converts  it  into  the  fermentable  sugars 
maltose  and  dextrin.  Malt  contains  much  more  diastase  than  is  necessary 
to  convert  the  starch  simply  contained  therein  to  maltose,  and  is  capable 
of  acting  on  the  starch  of  a  considerable  quantity  of  raw  grain,  such 
as  com  or  rice,  when  mixed  with  it.  This  practice  of  using  other  grains 
than  malt  is  prohibited  in  some  localities,  such  as  Bavaria. 


7oS  FOOD  INSPECTION    AND   ANALYSIS. 

Brewing. — The  malt,  or  mixture  of  malt  and  raw  grain,  is  first  crushed 
and  "mashed"  by  stirring  with  water  in  tubs  at  50°  to  60°  C.,  finally- 
heating  to  70°.  During  this  process  the  conversion  of  the  starch  to  mal- 
tose and  dextrin  takes  place.  The  resulting  liquor  is  known  as  "wort," 
containing,  besides  maltose  and  dextrin,  peptones  and  amides.  The 
clear  wort  is  then  drawn  of!  from  the  residue,  and  boiled  to  concentrate 
the  product  and  to  sterilize  it,  after  which  hops  (the  female  flower  of 
the  Ilumulus  liipulus)  are  added  and  the  boiling  continued.  Hops 
contain  resins,  bitter  principles,  tannic  acid,  and  a  pecuhar  essential  oil, 
all  of  which  arc  to  some  extent  imparted  to  the  wort.  After  cooling  and 
settling,  the  clear  wort  is  run  into  fermenting-vats,  where  selected  yeast, 
usuaUy  saccharomyccs  ccrcvisicr,  is  added,  and  the  alcoholic  fermentation 
allowed  to  proceed.  The  temperature  greatly  affects  the  character  of 
the  fermentation.  If  kept  between  5°  and  8°  C,  a  slow  fermentation 
proceeds,  known  as  bottom  fermentation,  during  which  the  yeast  settles 
out  at  the  bottom.  This  is  much  more  easily  controlled  than  the 
quick  or  top  fermentation,  which  takes  j^lacc  at  from  15°  to  18°,  much 
of  the  yeast  in  the  latter  case  being  carried  to  the  surface,  from  which  it 
is  finally  removed  by  skimming.  In  cither  case  the  yeast  feeds  upon 
the  albuminous  matter  present.  At  the  proper  stage  the  beer  is  drawn  off 
from  the  larger  portion  of  the  yeast,  and  run  into  casks,  or  tuns,  in  which, 
an  after-fermentation  proceeds.  The  beer  is  finally  clarified  by  treatment 
with  gelatin  or  beech  shavings  01  chips,  to  which  the  floating  yeast-cells 
and  other  impurities  attach  themselves.  It  is  finally  stored  in  barrels 
coated  with  brewers'  ])itch,  or  pasteurized  at  60°  C.  and  bottled. 

Varieties  of  Beer. — Formerly  the  division  of  beers  into  "lager," 
"schenk,"  and  "bock"  was  made  by  reason  of  the  fact  that  beer  had  to 
be  brewed  under  certain  climatic  conditions  and  at  certain  seasons  only. 
Now,  with  improved  means  for  artificial  refrigeration,  and  with  better 
methods  controlling  all  stages  of  the  process,  these  distinctions  are  less 
marked. 

Laf^er  Beer  (from  lager,  a  storehouse)  is  a  term  originally  applied  to 
Bavarian  beer,  but  is  now  given  to  any  beer  that  has  been  stored  several 
months.  Formerly  lager  beer  was  made  early  in  the  winter,  and  stored 
in  cool  cellars  till  the  following  spring  or  summer,  during  nearly  all  of 
which  time  a  slow  after-fermentation  took  place.  The  best  lager  beers 
contain  a  low  [proportion  of  hops,  and  are  high  in  extract  and 
alcohol. 

Schenk  Beer  is  a  quickly  fermented  beer  made  in  winter  for  immedi- 


ALCOHOLIC  BEl^ERAGES. 


70> 


ate  use.  It  is  brewed  in  from  four  to  six  weeks  and  will  not  keep  long 
without  souring. 

Bock  Beer,  according  to  older  systems  of  nomenclature,  occupied  a 
middle  place  between  lager  and  schenk,  being  an  extra  strong  beer  brewed 
for  spring  use  and  made  in  limited  quantities,  not  being  intended  for 
storage. 

Berlin  Weiss  Bier  is  prepared  by  the  quick  or  top  fcrmentati.)n  of  a 
wort  consisting  of  a  mixture  of  malted  barley  and  wheat  with  hops.  It  is 
high  in  carbon  dioxide,  being  usually  bottled  before  the  second  fermen- 
tation has  ended. 

Ale  is  virtually  the  English  name  for  beer.  It  is  usually  lighter  colored 
than  lager  beer,  being  made  from  pale  malt  by  cjuick  or  top  fermentation, 
and  containing  rather  more  hops  than  beer.  It  has  a  high  content  of 
sugar,  due  to  checking  fermentation  at  an  earlier  stage  than  in  ordinary 
beer. 

Porter  is  a  dark  ale,  the  deep  color  of  which  should  be  due  to  the  use 
of  brown  malt  dried  at  a  high  temperature,  but  which  is  sometimes  colored 
by  the  admixture  of  caramel.     It  has  a  large  extract,  chiefly  sugar. 

Stout  is  an  extra-strong  porter,  being  high  both  in  alcohol  and  extract. 

Composition  of  Beer.— Beer  is  a  somewhat  complex  liquor.  Besides 
water,  alcohol,  and  sugar,  it  contains  carbon  dioxide,  succinic  acid,  dex- 
trin, glycerin,  tannic  acid,  the  resinous  bitter  principles  of  hops,  nitrog- 
enous bodies  (chiefly  peptones  and  amides),  alkaline  and  lime  salts 
(chiefly  phosphates),  fat  (traces),  acciic  acid  and  lactic  acid.  The  latter 
acid  constitutes  the  chief  fixed  acid  of  beer. 

The  following  analyses  of  different  varicics  of  beer  are  due  to  Konig: 


Variety. 

0  -t; 

CO 

1 

"S  . 

6< 

0 

U 

Nitrogenous 
Substances. 

II 

0" 

Acid  as 
Lactic. 

Glycerin. 

< 

u 

Schenk 

Lager 

Export  beer. 

Bock 

Weiss  bier. . 

I'ortei 

Ale 

201^ 

258 
109 

84 
26 
40 
38 

1.0114 
I. 0162 
I. 0176 
1-0213 
I. 0137 
1.0191 
1.0141 

91. no. 197 
90.08  0.196 
89.01:0.209 
87. 8710.234 
91. 6310.297 
88.490.215 

80.42  0.2CI 

3-36 

3-93 
4.40 
4.69 

2-73 
4.70 
4.75 

5-34 
5-70 
6.38 
7.21 
5-34 
6.59 
5-65 

0.74 
0.71 
0.74 

0-73 
0.58 
0.65 
0.61 

0-95 
0.88 
1.20 
1.81 
1.62 
2.62 
1.07 

3-" 
3-73 
3-47 
3-97 
2.42 
3.08 
1. 81 

0.156 
0.151 
0.161 
0.165 
0.392 
0.281 
0.278 

0.12 

0.165 

0.154 

0.176 

0.092 

0.204 
0.22S 

0.247 
0.263 

0.149 

0.363 

0.51" 

0-055 
0.077 
0.074 
0.089 
0.0^4 
0.093 

D.oSo 

Fifteen  samples  of  lager  beer  and  seven  samples  of  jxile  ale,  bou~ht 
in  Massachusetts  bar-rooms,  representing  as  nearly  as  possible  the  qvalily. 


FOOD  INSPECTION  AND  ANALYSIS. 


of  liquor  sold  even"  day  to  patrons  by  the  bottle  or  glass,  were  analyzed 
bv  the  Board  of  Health  with  the  following  results: 


Per  Cent  of 

Original  Wort 

Extract. 


Per  Cent  of 

Alcohol  by 

Weight. 

7 

■07 

I 

.  lO 

4 

-45 

<; 

■37 

3 

•53 

4 

■  49 

Per  Cent  of 
Extract. 


Beer —       Maxiimim 

Miiiiiniim. 

Mean.... 
Talc  ale — Maximum 

Minimum. 

Mean 


lS.Q[ 

7  ■33 
15.04 
15.99 
10-95 
13-56 


7.76 
3-67 
5-92 
5-47 
3-38 
4-54 


Five  out  of  the  15  beer  samples  and  3  out  of  the  7  ale  samples  con- 
tained salicylic  acid. 

The  percentage  composition  of  the  ash  of  German  beer  is  thus  given 
by  Konig  as  the  mean  of  19  analyses: 


Ash  in 

100  Parts 

Beer. 

Potash. 

Soda. 

Lime. 

Magnesia. 

Iron 
Oxide. 

Phos- 
phoric 
Acid. 

sui-    ! 

phuric        Silica. 
Acid.      1 

1 

Chlorine. 

0.306         33.67 

8.94 

2.78 

6.24 

0.48 

31-35          3-47 

9.29 

2-93 

Malt  and  Hop  Substitutes. — By  reason  of  the  fluctuation  in  market 
price  of  these  two  chief  constituents  of  beer,  it  sometimes  becomes  a 
question  of  economy  to  employ  cheaper  substitutes  wholly  or  in  part 
for  one  or  the  other.  There  are  two  classes  of  malt  substitutes,  (i)  those 
■which,  like  com,  rice,  and  wheat,  are  mi.xed  directly  with  the  malt  before 
"mashing,"  and,  like  the  malt,  have  to  undergo  a  saccharous  fermenta- 
tion before  being  acted  on  by  yeast,  and  (2)  such  substances  as  cane 
sugar,  invert  sugar,  commercial  glucose,  and  dextrin,  which  are  added 
to  the  wort  at  a  later  stage  in  the  brewing,  just  before  the  addition  of  the 
yeast,  being  in  condition  to  be  readily  acted  on  by  the  latter. 

Glucose  is  by  far  the  most  common  malt  substitute,  by  reason  of  the 
fact  that  its  sugars  much  resemble  those  of  malt,  and  are  in  readily  ferment- 
able form.  Diastase  forms  from  the  malt  dextrin  and  maltose,  while 
commercial  glucose  contains  dextrin,  maltose,  and  dextrose. 

Whc-n  the  jjrice  of  malt  is  abnormally  high,  the  addition  of  glucose 
is  dccidcflly  economical,  Vjut  when  ordinary  conditions  prevail,  the  cost 
of  the  two,  figured  with  reference  to  their  yield  in  alcohol  and  extract, 
is  about  the  same.  Aside  from  the  question  of  economy,  however,  there 
are  advantages  in  the  use  of  glucose,  such  as  diminishing  the  nitrogenous 
content  of  the  wort  without  lessening  the  alcohol  or  extract  yielded. 

/ 


/1LCOHOLIC  BEVERAGES.  711 

The  nitrogenous  matter  left  after  fermentation  is  one  of  the  chief 
causes  of  cloudiness  or  turbidity  in  the  finished  product,  and  is  some- 
times difficult  to  remove.  By  the  use  of  glucose,  especially  in  brewing 
clear  bottled  ales  and  sparkling  pale  beers,  the  appearance  of  the 
product  is  much  enhanced.  The  temptation  at  times  to  add  more 
glucose  than  is  necessary  to  accomplish  this  is  great.  A  high-grade  malt 
may  have  as  much  as  40%  of  glucose  added  to  its  wort  and  still  produce 
an  acceptable  beer.  With  a  low-grade  malt,  glucose  yields  a  ver)-  poor 
quality  of  beer.  Hence  the  use  of  glucose  may  or  may  not  be  desirable, 
though  it  can  hardly  be  considered  unqualifiedly  as  an  adulterant. 

As  to  the  employment  of  hop  substitutes,  the  question  of  relative 
price  again  enters  in.  Only  when  the  price  of  hops  is  high  is  there  any 
special  inducement  to  use  substitutes.  Quassia  wood,  chiretta,  gentian, 
and  calumba,  all  of  which  yield  bitter  principles,  have  been  used  in  beer, 
and  cannot  be  considered  detrimental  to  health.  Allen  and  Chattaway 
have  found  the  first  two  in  beer  examined  by  them.*  Such  poisonous 
substances  as  cocculus  indicus,  picric  acid,  and  strychnine  are  alleged  to 
have  been  used  as  hop  substitutes,  but  there  is  no  authentic  record  of  any 
of  them  having  been  found  in  recent  years,  if  at  all. 

Adulteration  of  Malt  Liquors  and  Standards  of  Purity. — The  Joint 
Committee  on  Standards  of  the  A.  O.  A.  C.  and  the  A.  S.  N.  F.  D.  D.  has 
adopted  the  following  standards: 

Mall  Liquor  is  a  beverage  made  by  the  alcoholic  fermentation  of 
an  infusion,  in  potable  water,  of  barley  malt  and  hops,  with  or  without 
unmalted  grains  or  decorticated  and  degerminated  grains. 

Beer  is  a  malt  liquor  produced  by  bottom  fermentation,  and  contains 
in  100  cc,  at  20°  C,  not  less  than  5  grams  of  extractive  matter  and 
0.16  gram  of  ash,  chiefly  potassium  phosphate,  and  not  less  than  2.25 
grams  of  alcohol. 

Lager  Beer,  Stored  Beer,  is  beer  which  has  been  stored  in  casks  for 
a  period  of  at  least  three  months,  and  contains,  in  100  cc,  at  20°  C, 
not  less  than  5  grams  of  extractive  matters,  and  0.16  gram  of  ash,  chietly 
potassium  phosphate,  and  not  less  than  2.50  grams  of  alcohol. 

Malted  Beer  is  beer  made  of  an  infusion,  in  potable  water,  of  barley, 
malt,  and  hops,  and  contains,  in  100  cc,  at  20°  C,  not  less  than  5  grams 
of  extractive  matter,  nor  less  than  0.2  gram  of  ash,  chiefly  potassium 
phosphate,  not  less  than  2.25  grams  of  alcohol,  nor  less  than  0.4  gram 
of  crude  protein  (nitrogen  X  6.25). 

*  .\nalvst,  12,  112. 


7    2  FOOD  INSPECTION  ^ND  ANALYSIS. 

Ale  is  a  malt  liciuor  produced  by  lop  ftrmcntalion,  and  contains,  in 
loocc.  at  20°  C,  not  less  than  2.75  grams  of  alcohol,  nor  less  than 
5  grams  of  extract,  and  not  less  than  o.iO  gram  of  ash,  chiellv  ])otassium 
phosphate. 

Porter  and  Sloul  are  varieties  of  malt  licpiors  made  in  ])art  from 
highly  roasted  malt. 

Non-injurious  bitter  })rinciples  are  no  doubt  employed  in  place  of 
hops,  and  unless  the  li(iuor  is  sold  for  a  ])urc  malt  beer,  they  cannot  be 
regarded  as  adulterants. 

The  tendency  to  shorten  the  time  of  storage  of  beer,  or  to  sell  it  without 
storing  at  all,  lessens  or  does  away  with  the  after-fermentation,  resulting 
in  a  lack  of  "life"  or  effervescence  in  the  product.  This  is  sometimes 
made  up  h\  the  addition  of  sodium  bicarbonate. 

Distinction  between  Malted  and  Non-malted  Liquors.  —  In  some 
slates  where  strict  prohibitor}'  li<iuor  laws  arc  in  force,  it  is  illegal  to  sell 
"malt  licjuors,"  so  that  when  convictions  are  obtained,  it  is  necessary 
for  the  analyst  to  distinguish  between  licjuors  brewed  wholly  or  in  ])art 
from  malt  and  those  in  which  no  malt  has  been  used,  but  which  were 
brewed  entirely  from  malt  substitutes.  This  distinction  is  not  always 
easy  to  make  with  precision.  In  the.  absence  of  malt,  glucose  is  usually 
the  sole  source  of  alcohol  in  these  beverages.  Parsons  *  has  shown  that 
the  most  striking  points  of  difference  between  malted  and  non-malted 
liquors  are  in  their  per  cent  of  phosphoric  acid  and  albuminoids,  and  that 
pure  malt  beer  or  ale  should  contain  at  least  0.04%  P2O5,  and  0.25% 
albuminoids  (NX6.25).  A  low  ash  and  high  content  of  sulphates  in 
the  ash  are  also  indicative  of  glucose.  The  following  analyses  made  by 
Parsons  clearly  show  these  distinctions : 

COMPOSITION  OF  SEVENTY-SIX  SAMPLES  OF  AMERICAN  MALT  LIQUORS. 


Average 

Maximum. ... 
Minimum. 


Specific       Alcohol  Albumin-  |      Phos- 

r.T-Qvritv       by  Vol-      Extract.         oids       ■    phoric 
L-raviiy.  1      ^^^  (NX0.2s)!     Acid. 


1  .OICXJ 

I. 0210 
1.0047 


5-6i 
7-85 
0-35 


4.61 
7.64 
3-15 


0.470 
0.614 
0.290 


0.061 
0-095 
0.045 


Ash. 


Sul-  _  pree 

phates  m       Acid. 
Ash. 


0.209 
0.296 
0.147 


6.34 
12.67 

2-44 


0.26 
o.«7 


*  Jour.  Am.  Chem.  Soc,  24,  1902,  y.  1170. 


/1LCOHOLIC  BEVERAGES.  713 

TYPICAL  ANALYSES  OF  BEERS  APPARENTLY  NOT  BREWED  FROM  MALT. 


Number. 


Specific 
Gravity. 


Alcohol 
by  Vol- 
ume. 

Extract. 

Albumin- 
oids 
(NX6.2S) 

Phos- 
phoric 
Acid. 

1.68 

2.52 

0.114 

O.OIO 

2.63 

3-40 

0.215 

0.023 

2.27 

2.25 

0.150 

0.015 

2. II 

3-53 

0-133 

0.015 

1.85 

^-73 

0.031 

O.OIO 

Ash. 


Sul- 
phates. 


Free 
Acid. 


1.0074 
I .  oo(j8 
1.0062 
1.0112 
1. 0041 


0.19 

0.180 

0.124 

0.140 

0.088 


Normal 


II .  30 
10.81 
12.50 


The  ash  of  the  fifth  sample  is  thus  compared  with  that  of  the  average 
beer  as  given  by  Blyth; 

Malt  Beer  "No-malt"  Beer 

(Blyth).  (Parsons). 

K2O 37.22  12.93 

NajO 8.04  19.61 

CaO 1.93         Undetermined 

MgO 5-51 

FeA Trace 

SO-i 1.44  10.81 

P2O5 32.09  10.71 

CI 2.91  21.76 

SiO;^ 10.82  7.50 

Preservatives  in  Beer. — .\ntiseptics  are  frequently  added  to  malt 
liquors,  salicylic  acid  being  most  commonly  used.  Fluorides  of  ammo- 
nium and  sodium  have  been  found  in  American  beer.  Other  preserva- 
tives to  be  looked  for  are  benzoic  acid  and  sulphites.  Beer  casks  are 
frequently  "sulphured"  or  fumed  with  a  solution  of  calcium  bisulphite, 
so  that  the  beer  may  derive  its  content  of  sulphites  from  this  source. 

In  cases  of  police  seizure  of  beer  sold  in  bulk  or  in  opened  bottles  for 
the  purpose  of  ascertaining  whether  or  not  their  alcoholic  content  exceeds 
certain  limits  fixed  by  law,  a  little  formalin  had  best  be  added  as  soon  as 
possible  after  the  seizure  to  prevent  further  fermentation.  This  is  espe- 
cially desira])le  in  cases  where  there  is  likely  to  be  some  delay  in  making 
the  analysis,  so  as  to  forestall  any  claim  on  the  part  of  the  defendant  of 
.additional  alcohol  being  formed  after  the  seizure.  From  6  to  8  drops  of 
a  40%  solution  of  formaldehyde  to  a  quart  of  beer  is  sufficient,  and  this 
quantity  will  not  appreciably  affect   the  analysis. 

Arsenic  in  Beer. — In  1900  a  very  disastrous  epidemic  of  arsenical 
poisoning  occurred  in  ]Manchester^  England,  involving  several  thousand 
cases,  many  of  which  were  fatal.     The  arsenic  was  traced  to  sulphuric 


7-4  FOOD  INSPECTION  AND  ANALYSIS. 

acid  \vhich  entered  into  the  manufacture  of  commercial  glucose  used 
in  the  beer,  the  acid  found  so  highly  arsenical  being  made  from  a  certain 
variety  of  Swedish  pyrites,  which  was  found  to  be  abnormally  high  in 
arsenic.  There  appeared  to  be  no  doubt  whatever  that  the  beer  was  the 
sole  cause  of  the  trouble.  WHiile  the  presence  of  arsenic  was  in  this  case 
accidental,  carelessness  was  shown  on  the  part  of  those  having  to  do  with 
the  purity  of  the  materials  entering  into  the  composition  of  the  beer. 
Fortunately  no  other  instances  are  on  record  of  arsenical  poisoning  from 
malted  liquors.  A  large  number  of  samples  of  American  beer  have  been 
examined  in  the  laborator\'  of  the  Food  and  Drug  Department  of  the 
Massachusetts  State  Board  of  Health,  and  only  insignificant  traces  of 
arsenic  have  in  any  case  been  found. 

Temperance  Beers  and  Ales. — Many  varieties  of  these  so-called  tem- 
perance drinks  are  home-made,  as  well  as  sold  on  the  market.  They  are 
•usually  slightly  fermented  infusions  of  various  roots  and  herl)s,  including^ 
ginger  or  sassafras,  with  molasses  or  sugar  and  yeast,  and  more  often 
contain  less  than  i%  of  alcohol  by  volume.  Among  them  are  included 
spruce  beer,  and  the  various  root  beers,  such  as  ginger  beer  and  ginger 
ale.  The  latter  beverages  are  generally  carbonated.  Numerous  brands 
of  bottled  beer  arc  manufactured,  which  contain  virtually  the  same  body 
and  characteristic  flavor  as  lager  beer,  but  not  the  alcohol.  Indeed  the  com- 
position of  many  of  these  beverages  is  identical  with  that  of  lager  beer^ 
excepting  in  alcoholic  content,  being  made  by  substantially  the  same 
process  and  out  of  the  same  ingredients,  but  with  the  alcohol  finally 
removed  by  steaming,  so  that  the  licjuor  comes  within  the  limits  of  a 
temjK-rance  beverage.  Of  this  class  is  Uno  beer,  which  ranges  from 
o.O  to  0.9  ])er  cent  in  alcohol. 

METHODS  OF  ANALYSIS  OF  MALT  LIQUORS.* 

Preparation  of  Sample. — Transfer  the  contents  of  the  bottle  or 
bottles  to  a  large  flask  and  shake  vigorously  to  hasten  the  escape  of 
carbon  dioxide,  care  being  taken  that  the  liquor  is  not  below  15°  C, 
.smcc  below  this  temjjerature  the  carbon  dioxide  is  retained  by  the  beer 
and  is  liable  to  form  bubbles  in  the  i)ycnometer. 

Specific  Gravity. — See  page  657. 

Ash.  Determine  in  25  cc.  by  evajjoralion  and  ignition  at  dull 
redness. 

*  Bamard,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  3^.  A.  ().  A.  C.  Methods,  ibid.„ 
Bui.  107  (rev.),  p.  90. 


ALCOHOLIC  BF.yERAGES. 


ns 


Determination  of  Alcohol. — From  the  Specific  Gravity  of  (Jic  Dis- 
tillate.— Proceed  as  described  on  p.  658,  employing  100  cc.  of  ihe  liquor, 
and  determining  the  specific  gravity  at  15.5°  C.  If  the  li([uor  is 
markedly  acid,  add  o.i  to  0.2  gram  of  precipitated  calcium  carbonate 
previous  to  distillation. 

From  the  Refraction  of  the  Distillate. — Prepare  the  distillate  as 
described  on  p.  658,  except  that  it  is  made  up  to  the  mark  at  17.5°  C. 
Determine  the  refraction  at  17.5°  C.  ^y  nteans  of  the  immersion  refrac- 
tometer,  and  calculate  the  alcohol  by  the  table  of  Ackermann  and  Stein- 
mann  below. 


ACKERMANN  AND  STEINMANN'S  TABLE  FOR  OBTAINING  THE  PER- 
CENTAGE OF  ALCOHOL  IN  THE  DISTILLATE  OF  BEER  FROM  THK 
IMMERSION   REFRACTOMETER    READINGS.* 


u 

V 

V     . 

p  60 

u 
0 

ol  by 
ight, 
Cent. 

ol" 

u 

0 

(U      . 

is 

U 

h 
II 

-oi^ 

22 

%n 

It 

j:3  0)  *-• 

^1 

111 

j:  0  i- 

(^ 

< 

< 

^ 

< 

< 

Pi 

< 

< 

a 

< 

< 

15-0 

0.00 

0.00 

17.2 

1.38 

1.74 

19.4 

2.74 

3-46 

21.6 

4.02 

5.06 

15-1 

0.06 

0.08 

17-3 

1.44 

1.82 

19-5 

2.80 

3-53 

21.7 

4 

07 

5-13 

15-2 

0-13 

0.16 

17-4 

1-51 

1.90 

19.6 

2.86 

3-61 

21.8 

4 

13 

5-20 

15-3 

0.19 

0.24 

17-5 

1-57 

1.98 

19.7 

2.91 

3-68 

21.9 

4 

18 

5-26 

15-4 

0.25 

0.32 

17-6 

1.63 

2.05 

19.8 

2-97 

3-75 

22.0 

4 

22 

5-32 

15-5 

0.32 

0.40 

17.7 

1.68 

2.12 

19.9 

3-04 

3-83 

22.1 

4 

28 

5-39- 

15-6 

0.38 

0.48 

17.8 

1-74 

2.20 

20.0 

3-10 

3-90 

22.2 

4 

33 

5-46 

15-7 

0.44 

0.56 

17.9 

1. 81 

2.28 

20.1 

3-15 

3-97 

22.3 

4 

39 

5-53 

15-8 

0.50 

0.64 

18.0 

1.87 

2.36 

20.2 

3.20 

4.04 

22.4 

4 

44 

5-59 

15-9 

0-57 

0.72 

18. 1 

1-93 

2.44 

20.3 

3.26 

4-11 

22.5 

4 

49 

5-65 

16.0 

0.64 

0.80 

18.2 

2.00 

2.52 

20.4 

S-3?> 

4.19 

22.6 

4 

54 

5-72 

16. 1 

0.70 

0.88 

18.3 

2.06 

2.60 

20.5 

3-38 

4.26 

22.7 

4 

59 

5-78 

16.2 

0.77 

0.96 

18.4 

2.13 

2.68 

20.6 

3-43 

4-33 

22.8 

4 

64 

5-85 

16.3 

0.83 

1.04 

18.5 

2.19 

2.76 

20.7 

3-50 

4.41 

22.9 

4 

70 

5-92^ 

16.4 

0.88 

1. 12 

18.6 

2.25 

2.84 

20.8 

3-56 

4-48 

23.0 

4 

76 

6.00 

16.5 

0-95 

1. 19 

18.7 

2.31 

2.92 

20.9 

3-61 

4-55 

23-1 

4 

81 

6.07 

16.6 

1 .01 

1.27 

18.8 

2-37 

2-99 

21.0 

3-67 

4-63 

23.2 

4 

86 

6-13 

16.7 

1-05 

^■?,i 

18.9 

2.43 

3-07 

21. I 

3-73 

4-71 

23-3 

4 

92 

6.20 

16. 8 

1-13 

1-43 

19.0 

2.49 

3-14 

21.2 

3-78 

4-77 

23-4 

4 

97 

6.27 

16.9 

1. 19 

1-51 

19. 1 

2-55 

3.22 

21-3 

3-84 

4-84 

23-5 

5 

02 

6-33 

17.0 

1-25 

1.58 

19.2 

2.61 

3-29 

21.4 

3-90 

4-92 

17. 1 

1.32 

1.66 

19-3 

2.68 

3-37 

21-5 

3-96 

4.99 

*  Zeits.  gesamte  Brauwesen,  28,  1905,  p.  259. 

Determination  of  Extract.  — In  cases  where  extreme  accuracy  is 
desired,  the  result  obtained  by  evaporating  at  ioo°  a  weighed  amount 
of  the  beer  cannot  be  accepted,  on  account  of  the  dehydration  of  the 
maltose  at  a  temperature  exceeding  75°  C.  Unless  the  evaporaiion  is- 
conducted  at  that  temperature   (a  difficult  operation),  a  closer  appro.xi- 


7i6 


FOOD  INSPECTION  AND  ANALYSIS. 


EXTRACT  IN  BEER  WORT.* 
[According  to  Schultz  and  Ostermann.] 


Extract. 

Specific 

Extract. 

Specific 

Extract. 

Specific 

Extract. 

Specific 

Gravntv 

Per 

Grams 

Gravity 

Per 

Grams 

Gravity 

Per 

Grams 

Gravity 

Per 

Grams 

at  1 5°  C. 

Cent 

bv 

Weijjht 

per 

TOOCC. 

at  I  $°  C. 

Cent 

by 

Weight 

per 
100  cc. 

at  I s°  C. 

Cent 

by 

Weight 

per 
100  cc. 

at  15°  C. 
I.OI9S 

Cent 

by 

Weight 

per 
100  cc. 

I . oooo 

0.00 

0.00 

I .0065 

1 .69 

1.70 

I .0130 

3-35 

3-39 

S.o6 

5.16 

I .OOOI 

0.03 

0.03 

I .0066 

1.72 

1-73 

I. 0131 

3.38 

3-42 

I .0196 

5.09 

S-I9 

I .0003 

0.05 

0.05 

1 .0067 

1-74 

1-75 

1 .0132 

3.41 

3-46 

I. 0197 

5. 12 

5.22 

1.0003 

0.08 

0.08 

I .0068 

1.77 

1.78 

I.OI33 

3-43 

3.48 

I .0198 

5-15 

5-25 

I . 0004 

0. 10 

0.  to 

I .0069 

1.79 

1.80 

I. 0134 

3-46 

3-51 

I .0199 

5-17 

S.27 

1.0005 

0.13 

0.13 

1.0070 

1.82 

1.83 

I. 0135 

3.48 

3-S3 

I .0200 

S.20 

5.30 

1 .0006 

0.16 

0.  16 

1. 007 1 

r.84 

I. 8s 

I .0136 

3-51 

3.56 

I .0201 

5.23 

5-34 

1 .0007 

0.18 

0.18 

I .0072 

1.87 

1.88 

I .0137 

3-54 

3-59 

I .0202 

5-25 

5-36 

I .0008 

0.  21 

0.  2T 

1.0073 

I  .90 

1. 91 

I .0138 

3. 56 

3    61 

I .0203 

5.28 

5  •  39 

I . OOOQ 

0.24 

0.24 

1.0074 

I  .92 

1.93 

I. 01 39 

3-59 

3.64 

I .0204 

5.30 

5-41 

I .0010 

0.  26 

0.  26 

1.0075 

1-95 

1 .96 

I .0140 

3.6r 

3-66 

I .0205 

.5.33 

5-44 

I  .001  I 

0.  20 

0.  29 

I .0076 

1.97 

1.98 

I .0141 

3-64 

3   69 

I .0206 

5-35 

5.46 

t . 00 1  2 

0.31 

0.31 

1.0077 

2.00 

2.02 

I .0142 

3.66 

3.71 

1 .0207 

5.38 

5-49 

1 . 00 1  3 

0.34 

0.34 

I .0078 

2  .02 

2.04 

I. 0143 

3    69 

3-74 

I .0208 

5 -40 

5-51 

x.oot4 

0.37 

0.37 

I .0079 

2. OS 

2  .07 

1.0144 

3-72 

3.77 

I . 0209 

5-43 

5-54 

I .0015 

0.30 

0.39 

I .0080 

2.  07 

2.09 

1.014s 

3-74 

3-79 

I .0210 

5-45 

5.S6 

I .0016 

0.42 

0.42 

I .0081 

2 .  10 

2.12 

I .0146 

3-77 

3.83 

I .021 1 

5.48 

S.60 

I .0017 

0.45 

0.4S 

I .0082 

2.12 

2.14 

I. 0147 

3.79 

3-8s 

I  .0212 

5 -50 

5.62 

I .0018 

0.47 

0.47 

I .0083 

2. IS 

2.17 

I .0148 

3.82 

3 .  88 

I  .0213 

5.  S3 

5.6s 

I .0019 

0.50 

0.50 

I .0084 

2.17 

2.19 

I. 01 49 

3.8s 

3- 9  I 

I  .0214 

5-SS 

5.67 

I .0030 

o.5» 

0.52 

1.008s 

2.  20 

2.  22 

I. 0150 

3.87 

3.93 

1.021S 

5-57 

5.69 

I .0021 

O.S5 

0.5s 

I .0086 

2.23 

2.2s 

I .0151 

3.90 

3.96 

I .0216 

5.60 

5-72 

I . 00  2  2 

0.53 

0.58 

I .0087 

2.2s 

2.  27 

1.0152 

3.92 

3-98 

I .0217 

5.  62 

5-74 

1.0023 

0.60 

0.60 

1.0088 

2.28 

2.30 

I.OIS3 

3.95 

4.  01 

I .0218 

5.65 

5-77 

Z.OO24 

0.63 

0.63 

I .0089 

2.30 

2.32 

I. 0154 

3-97 

4.03 

I .0219 

S-f'T 

5.79 

I. 002s 

0.66 

0.66 

r .0090 

2.33 

2. 35 

1.015s 

4.00 

4.06 

I  .0220 

5 -70 

5.83 

1 .0026 

0.68 

0.68 

t .0091 

2.35 

2.37 

I. 0156 

4.03 

4.09 

I .022I 

5-72 

5.8s 

I .0027 

0.71 

0.71 

I .0092 

2.38 

2.40 

I.OIS7 

4.0S 

4. II 

I .0222 

5-75 

5.88 

1.0028 

0.73 

0-73 

I .0093 

2.41 

2.43 

I .0158 

4.08 

4.14 

I .0223 

5-77 

5.90 

Z.OO29 

0.76 

0.76 

I .0094 

2.43 

2.45 

I.0IS9 

4.10 

4-17 

I  .0224 

5 -80 

5.93 

1.0030 

0.79 

0.79 

1.0095 

2.46 

2.48 

I .0160 

4-13 

4.  20 

I .0225 

5. 82 

5.9s 

1.0031 

0.81 

0.81 

I .0096 

2.48 

2.50 

I .0161 

4.  10 

4-23 

I  .0226 

5.  84 

5-97 

1.0032 

0.84 

0.84 

I .0097 

2. SI 

2.53 

I .0162 

4.18 

4.25 

I .0227 

5.87 

6.00 

1.0033 

0.87 

0.87 

I . 0098 

2.53 

2.55 

I .0163 

..;.  21 

4.28 

I .0228 

5-89 

6.02 

1.0034 

0.89 

0.89 

I .0099 

2.56 

2.59 

I . 01 64 

4- 23 

4-30 

I  .0229 

5-92 

6.06 

I.003S 

0.92 

0.92 

I .oroo 

2.58 

2.61 

I .0165 

4.  26 

4-33 

I  .0230 

5.  94 

6.08 

X .0036 

0.94 

0.94 

t .0101 

2.6r 

2.64 

I .0166 

4.28 

4.3s 

1.0231 

5-97 

6.11 

1.0037 

0.97 

0.97 

I .0102 

2.64 

2.67 

I .0167 

4-31 

4.38 

1.0232 

5-99 

6.13 

1.0038 

1 .00 

1 .00 

I. 0103 

2.66 

2.69 

1.0168 

4-34 

4.41 

1.0233 

6.02 

6.16 

I .0039 

I  .02 

1.02 

I .0104 

2.69 

2.72 

I .0169 

4.36 

4-43 

I. 0234 

6.04 

6.18 

I . 0040 

I. OS 

I. OS 

i.oios 

2.71 

2.74 

1 .0170 

4-39 

4.46 

1.023s 

6.07 

6.  21 

l.004( 

1.08 

1.08 

I .0106 

2.74 

2.77 

I .0171 

4.42 

4.50 

1 .0236 

6.09 

6.23 

I .0042 

l.IO 

1 .  10 

I .0107 

2.  76 

2.79 

I .01 72 

4-44 

4.52 

1.0237 

6. II 

6.25 

1.0043 

1. 13 

1. 13 

I .0108 

2.79 

2.82 

I  .  0 1  7  3 

4-47 

4-55 

I .0238 

6.14 

6.  29 

1.0044 

«.IS 

1. 16 

I .0109 

2.»2 

2.8s 

I. 0174 

4-50 

4.58 

1.0239 

6.16 

6.31 

1.004s 

1. 18 

1. 19 

I .01 10 

2.84 

2.87 

1.0175 

4.53 

4.61 

1 .0240 

6. 19 

6.34 

1.0046 

1 .  21 

1.22 

I .01 1 1 

2.87 

2.90 

1.0176 

4-55 

4-63 

I .0241 

6.  21 

6.34 

1.0047 

«.23 

1.24 

I .01 1  2 

2.89 

2   92 

I. 0177 

4-58 

4.66 

I .0242 

6.  24 

6.39 

1.0048 

1.26 

1.27 

I  .  0 1 1 3 

2.92 

2.95 

I .0178 

4.  61 

4    69 

1.0243 

6.26 

6.41 

1.0049 

1.29 

1.30 

1 .01 14 

2.94 

2.97 

I. 0179 

4.63 

4.71 

I . 0244 

6.  29 

6.44 

I. 0050 

«.3i 

1.3a 

1 .01  IS 

2.97 

3.00 

1 .0180 

4.66 

4-74 

1.024s 

6.31 

6.46 

I.oosi 

1.34 

«.3S 

1.0116 

2.99 

3.02 

I .oi8t 

4.69 

4.77 

I  .024^' 

6.34 

6.50 

1.0052 

1.36 

1.37 

I .01 17 

3.02 

3.06 

1.0182 

4-71 

4.80 

1.024/ 

6.36 

6.52 

«-ooS3 

1.39 

1.40 

I .01 18 

3.0s 

3.09 

1 .0183 

4.74 

4.83 

1.0248 

6.39 

6.SS 

I.OOS4 

t.41 

1.42 

I .01 19 

3.07 

3. II 

1 .0184 

4.77 

4.86 

I ,0249 

6.41 

6.57 

I. 0055 

1.44 

1. 45 

I .0120 

3.10 

J. 14 

I. 0185 

4-70 

4.88 

1      I. 0250 

6.44 

6.60 

1.0056 

1.46 

1.47 

I .01 21 

3.12 

3.1O 

1.0186 

^.82 

4-&. 

I .0251 

6.47 

6.63 

1.0057 

1.49 

i.So 

I .01 23 

3-iS 

3.19 

I .0187 

4.8s 

4-94 

1 .0252 

6.50 

6.66 

1.0058 

I. SI 

1.52 

1.0123 

3.17 

3.21 

1.0188 

4.88 

4-97 

1.0253 

6.52 

6.68 

I.OOSO 

1. 54 

X.55 

I. 01 34 

3.20 

3.24 

I .0189 

4.90 

4-99 

I  .0254 

6.55 

6.72 

1.0060 

i.S6 

«.S7 

I. 0125 

S-'ii 

3.27 

I .0190 

4-93 

5.02 

1.0255 

6.58 

6.75 

1.0061 

I.  59 

1 .60 

1.0126 

3-25 

3.29 

: .0191 

4.96 

5.05 

1 .0256 

6.61 

6.78 

1.0062 

1.62 

1.63 

I .01 27 

3.28 

3.32 

1 .0192 

4.98 

5. 08 

I. 0257 

6.63 

6.80 

J. 0063 

1.64 

t.f.S 

,     I. 0128 

3.30 

3.34 

1.0I93 

5.01 

5. II 

1.0258 

6.66 

6.83 

t.0064 

1.67 

1.68 

1     I. 0129 

3.33 

3.37 

I. 0194 

S04 

S.14 

I. 0259 

6.69 

6.86 

"  Calculated  from  results  obtained  by  drying  below  75°  C. 


ALCOHOLIC   BEVERAGES. 
EXTRACT  IN  BEER  WORT— {Continued). 


717 


Extract. 

Specific 

Extract. 

Specific 

E.xtract. 

1 

Extract. 

Specific 

Specific 

' 

Gravity 

Per 

Grams 

Gravity 

Per 

Grams 

Gravity 

Per 

Grams 

Gravity 

Per 

Grams 

at  15°  C. 

Cent 

by 

Weight 

per 
too  cc. 

at  is°C. 

Cent 

by 

Weight, 

per 
100  cc. 

at  15°  C. 

Cent 

bv 

Weight 

per 
100  cc. 

at  1 5°  C. 

Cent 

by 

Weight 

per 
1 00  cc. 

1 .0260 

6.71 

6.88 

1.0325 

8.27 

8.54 

1.0390 

9.92 

10.31 

I.04S5 

II. S3 

12. OS 

X  .026'. 

6.74 

6.92 

1.0326 

8.29 

8.56 

I. 0391 

9-9S 

10.34 

1.0456 

II-5S 

12.08 

X .0262 

6.77 

6.95 

I .0327 

8.32 

8.59 

1.0392 

9-97 

10.36 

1.0457 

11.57 

12.10 

1.0263 

6.80 

6.98 

1.0328 

8.34 

8.61 

1.0393 

9.99 

10.38 

1.0458 

II  .60 

12.13 

X .0264 

6.82 

7  .00 

1.0329 

8.37 

8.65 

1.0394 

10.02 

10.41 

I.04S9 

11.62 

12.15 

1.026s 

6.8s 

7-03 

1.0330 

8.40 

8.68 

1.039s 

10.04 

10.44 

1 . 0460 

11.65 

12.19 

1.0266 

6.88 

7  .06 

1.0331 

8.43 

8.71 

1.0396 

10.06 

10.46 

I .0461 

1 1 .67 

12.21 

I .0267 

6.91 

7.09 

1.0332 

8. 45    ' 

8.73 

1.0307 

10.00 

10-49 

I .0462 

1 1  .  70 

I  2.  24 

1.0268 

6.93 

7.12 

1.0333 

8.48    1 

8.76 

1.0398 

10.11 

10.51 

I .0463 

11.72 

12.  26 

I .0269 

6.96 

7-iS 

1.0334 

8.51    1 

8.79 

1.0399 

10.  13 

10.53 

I .0464 

n-75 

12.  30 

I .0270 

6.09 

7.T8 

1.033s 

8.53    1 

8.82 

I .0400 

10.  16 

10.57 

I -0465 

11.77 

12.32 

I .0271 

7.0I 

7 .  20 

1.0336 

8.56 

8.85 

I .0401 

10.18 

10.59 

I .0466 

11.79 

12.34 

1 .0272 

7.04 

7-23 

1.0337 

8.59 

8.88 

I .0402 

10.  20 

10.  61 

I .0467 

11.82 

12-37 

1.0273 

7.07 

7.  26 

1.0338 

8.61 

8.90 

I .0403 

10.23 

1 0 .  64 

1.0468 

11.84 

12.39 

1.0274 

7.10 

7.29 

1.0339 

8.64   t 

8.93 

I .0404 

10.25 

10.  66 

1 .0469 

11.87 

12.43 

1.0275 

7.12 

7.32 

T.0340 

8.67 

8.96 

I. 0405 

10.27 

10.  69 

1.0470 

11.89 

12. 4S 

I .0276 

7.15 

7-35 

1.0341 

8.70 

9.00 

I .0406 

10.30 

10.72 

1.0471 

11.92 

12.48 

1.0277 

7.18 

7.38 

1.0342 

8.72 

9 .02 

1.0407 

10.32 

10.74 

1.0472 

11.94 

I  2.50 

1.0278 

7.21 

7-41 

1.0343 

8.75 

0.05 

I . 0408 

10. 35 

10.77 

I .0473 

11.97 

12.54 

I .0279 

7-23 

7-43 

1.0344 

8.78 

9.08 

I . 0409 

10.37 

10.79 

1.0474 

11.99 

12.56 

I .0280 

7.  26 

7.46 

I. 034s 

8 .  80 

9. 10 

I .0410 

10.40 

10.83 

I. 047s 

12.01 

12.58 

I .0281 

7.28 

7.48 

I .0346 

8.  S3 

9.14 

I .0411 

10.42 

10. 8s 

1 .0476 

12.04 

12.61 

I .0282 

7-30 

7-51 

1.0347 

8.86 

9.17 

I .041 2 

10.4s 

10.88 

1.0477 

12.06 

12.64 

1.0283 

7-33 

7-54 

I .0348 

8.88 

9.19 

I. 0413 

10.47 

10.90 

I .0478 

12.09 

12.67 

I .0284 

7-35 

7.S6 

I -0349 

8.91 

9.22 

I. 0414 

10.50 

10.93 

1.0479 

12. 1 1 

12.69 

1.028s 

7-37 

7-58 

I.03S0 

8.94 

9-25 

1.041S 

10.52 

10.96 

I .0480 

12.14 

12.72 

1.0286 

7-39 

7 .  60 

1.0351 

8.97 

9.28 

I .0416 

I0.55 

10.99 

1 .0481 

12.16 

12.74 

I .0287 

7.42 

7.63 

1.0352 

8.QQ 

9-31 

I. 0417 

10.57 

II  .01 

I .0482 

12.19 

12.78 

1.0288 

7-44 

7.6s 

1.0353 

Q  .02 

9-34 

I .0418 

10.60 

11  .04 

1 .0483 

12.21 

12.80 

I .0289 

7.46 

7.68 

1.0354 

9-05 

9-37 

I .0419 

10.62 

1 1 .06 

I .0484 

12.  23 

12. 8a 

I .0290 

7.48 

7.70 

I .0355 

9.07 

9-39 

I .0420 

10.6s 

11 .10 

1.048s 

12.  2G 

12.3s 

I .0291 

7-51 

7-73 

1.0356 

9. 10 

9.42 

I .0421 

10.67 

II  .12 

I .0486 

12.28 

12.88 

I .0292 

7  •  5  ? 

7-75 

1.0357 

9-13 

9.46 

I .0422 

10.70 

II. IS 

I .0487 

12.31 

12.91 

1.0293 

7-55 

7-77 

I    0358 

9.15 

9.48 

1.0423 

10.72 

11.17 

1 . 0488 

12.33 

12.93 

I .0294 

7-57 

7-79 

1.0359 

9.18 

9-51 

1.0424 

10.7s 

II. 21 

I . 0489 

12.36 

12.96 

1.0295 

7  .60 

7.82 

1 .0360 

9.  21 

9-54 

1.0425 

10.77 

11.23 

I . 0490 

12.38 

12.99 

1 .0296 

7.62 

7.85 

I .0361 

9.24 

9-57 

1 .0426 

10.80 

II .  26 

1 .0491 

12.41 

13-02 

1.0297 

7.64 

7.87 

1.0362 

9.  26 

9.60 

1.0427 

10.82 

11.28 

I .0492 

12.43 

13-04 

1 .0298 

7.66 

7.89 

1-0363 

9.29 

9-63 

I .0428 

10.85 

11.31 

1.0493 

12.45 

13-06 

I .0299 

7.69 

7.92 

1.0364 

9-31 

9 -65 

I .0429 

10.88 

11.35 

1.0494 

12.48 

13. 10 

1 .0300 

7.71 

7  -04 

1.0365 

9-34 

9.68 

1.0430 

10.90 

11.37 

I-049S 

12.  so 

13." 

1.0301 

7-73 

7.96 

I .0366 

9.36 

9.70 

1.0431 

10.93 

11 .40 

1 .0496 

12. S3 

13-1S 

1 .0302 

7.7s 

7.98 

1.0367 

9-38 

9.72 

1.0432 

10.9s 

1 1 .42 

1.0497 

12. SS 

13.17 

1.0303 

7-77 

8.01 

1.0368 

9.41 

9-76 

1.0433 

10.98 

II  .46 

I .0498 

12.58 

13-21 

1 .0304 

7.80 

8.04 

I .0369 

9-43 

9.78 

1.0434 

11 .00 

11.48 

1.0499 

1  2.60 

13.23 

1.0305 

7.82 

8.06 

I .0370 

9-45 

9.80 

1.043s 

II  .03 

11. SI 

I .0500 

12.63 

13.26 

1 .0306 

7.84 

8.06 

1.0371 

9.48 

9.83 

1 .0436 

11.05 

11.53 

1.0501 

12.65 

13.28 

1.0307 

7.86 

8.10 

1.0372 

9-SO 

9.85 

1.0437 

11.08 

11.56 

I .0502 

12.67 

13.31 

1.0308 

7.89 

8.13 

I-0373 

9.52 

9.88 

1.0438 

11 .  10 

11.  59 

1.0503 

12.  70 

13.34 

1 .0309 

7.91 

8. IS 

1.0374 

9-55 

9.91 

1.0439 

11.13 

1 1 .62 

I .0504 

12.72 

13.36 

I. 0310 

7-93 

8.18 

I. 037s 

957 

9-93 

1 . 0440 

11.15 

11.64 

1.0505 

12.75 

13-39 

1.03II 

7  -95 

8.20 

1.0376 

959 

9-95 

1.0441 

11.18 

11.67 

1.0506 

12.77 

13.42 

1.0312 

7.98 

8.23 

I -0377 

9.62 

9.98 

1.0444 

1 1 .  20 

II  .70 

1.0507 

I  2.80 
12.82 

I3-4S 

1-0313 

8.00 

8.25 

I .0378 

9.64 

10.00 

1.0443 

11. 23 

11-73 

1.0508 

13-47 

1.0314 

8.02 

8.27 

I.0379 

9.66 

10.03 

1.0444 

II. 25 

11 -75 

!  1.0509 

12. 8s 

13-SO 

1. 0315 

8.04 

8.29 

1 .0380 

9.69 

10.06 

1.044s 

11.28 

11.78 

I .0510 

12.87 

13-53 
13-56 
13-S8 
13-60 
13-64 

1.0316 

8.07 

8.33 

1 .0381 

9.71 

10.08 

1.0446 

II  .30 

11.80 

1.05 1 1 

12  .90 

1.0317 

8.09 

8. 35 

I .0382 

9.73 

10. 10 

1.0447 

11    ii 

11.84 

1 .051  a 

12.92 

1.0318 

8. II 

8.37 

I .0383 

9.76 

1 0 .  13 

1.0448 

11-35 

11.86 

I. 0513 

12.94 

1. 0319 

8.13 

8.39 

1.0384 

9.78 

10. 16 

1.0449 

II    ;8 

11.89 

1.0514 

12.97 

1 .0320 

8.i6 

8.42 

1.0385 

9.81 

10.19 

1.0450 

II  .40 

II  .91 

1.0515 

12.99 

13.66 
13-69 

1.0321 

8.18 

8.44 

1.0386 

983 

10.21 

1.0451 

11.43 

II.9S 

I. 0516 

13-02 

I.0322 

8.20 

8.46 

1.0387 

9-85 

10.23 

1.0452 

11.4s 

11.97 

1.0517 

13.04 

13.71 

I .0323 

8.23 

8.49 

I  .0388 

9.88 

10.  26 

1.0453 

11.48 

13.00 

1 .0518 

13.07 

13-75 

1.0324 

8.2s 

1 

8.52 

I .0389 

9.90 

10.  29 

1.0454 

II  .50 

12.02 

I. 0519 

13.09 

13-77 

7iS 


FOOD   ISSPECTION  .-IND  ANALYSIS. 


EXTRACT  IX  BEER  \\OTLT—{Cpni;iiucd). 


Extract.        1 

specific 

Extract. 

Specific 

Ext 

ract. 

Specific 

Extract. 

Specific 

1 

Gra\-ity 

Per 

Grams 

Gra\-ity 

Per 

Grams 

Gra\ntv 

Per 

Grams 

Gravity 

Per 

Grams- 

at  is" C. 

Cent 

bv 

Weight 

per 
100  cc. 

at  1 5°  C. 

Cent 

by 

Weight 

per 
100  cc. 

at  15°  C. 

Cent 

by 

Weight 

per 
100  cc. 

at  1 5°  C. 

Cent 

by 

Weight 

per 
100  cc. 

I .0520 

13-12 

13   So 

i.osSs 

14.75 

15-61 

1 .0650 

16.25 

17.31 

I. 0715 

17.81 

19.0S 

I .osai 

13.14 

13.82 

1.0586 

i.i  78 

IS. 65 

1 .0651 

16.27 

17-3.? 

I .0716 

17. 84 

19.12 

1 .0513 

13. J6 

13.85 

1.0587 

14.81 

15.68 

1 .0652 

16.30 

17.36 

I. 0717 

17.86 

19.14 

1.0S23 

13. >9 

13-88 

i.osSS 

14.83 

15.70 

1-0653 

16.32 

17.39 

I .0718 

17-88 

19.16 

I    0324 

13.21 

13.90 

1.0589 

14.86 

iS-74 

1.0654 

16.3s 

17.42 

1.0719 

17.90 

19.19 

i.osas 

13.24 

13.94 

1.0590 

14. 89 

15-77 

1-0655 

16.37 

17-44 

I .0720 

17-93 

19.22 

I .0526 

13.26 

13-96 

1.0591 

14.91 

15    79 

I .0656 

16.40 

17-4S 

I. 0721 

17.95 

19.24 

I   0527 

13-29 

13.99 

1.0592 

14.94 

15-82 

1.0657 

16.42 

17.50 

I .0722 

17-97 

19.27 

I .0528 

13.3' 

14.01 

1.0593 

14-96 

15.85 

1.0658 

16.4s 

17-5.^1 

1.0723 

17-99 

19.29 

i.osag 

13.34 

14.05 

1.0594 

14.99 

15-88 

1.0659 

16.47 

17. S6 

1.0724 

18.02 

19.32 

1.0530 

13.36 

14.07 

1.OS05 

15.02 

15-91 

I .0660 

16.50 

17.59 

1.0725 

18.04 

19-3S 

1. 0531 

13.38 

14.09 

I .0596 

15.04 

15.94 

I .0661 

16.52 

17.61 

I .0726 

18.06 

19-37 

1.0532 

13.41 

14.12 

1.0597 

15.07 

15-97 

I .0662 

16.54 

17-63 

I .0727 

18.08 

19.39 

IOS33 

13-43 

14. IS 

1.059S 

15.09 

I  5  -  99 

I .0663 

16.57 

17.67 

I .072S 

18.11 

19-43 

I.OS34 

13.46 

14.18; 

1.0599 

15.11 

16.02 

I .0664 

16.59 

17.69 

1.0729 

18.13 

19-45 

1.0S35 

13.48 

14.20 

1 .0600 

15.14 

16.05 

1.0665 

16.62 

17.73 

I .0730 

18.15 

19-47 

1.0536 

13. SI 

14-23 

I .0601 

15.16 

16.07 

1.0666 

16.64 

17.7s 

I. 0731 

18.17 

19.50 

1.0537 

13.53 

14.26 

I .0602 

15.18 

16.09 

1 .0667 

16.67 

17-78 

1.0732 

18.20 

19-53 

1.0538 

13.56 

14.29 

I .0603 

15.  20 

16.12 

1.0668 

16.69 

17.80 

1-0733 

18.22 

19. 55 

1.0539 

13. ss 

14-31 

1 .0604 

IS  23 

16    IS 

I   0669 

16.72 

17-84 

1.0734 

18.24 

19.58- 

1.0540 

13.61 

14-34 

1.0605 

IS-2S 

16.17 

I .0670 

16.74 

17.86 

I.073S 

18.26 

19 .  60 

1.0541 

13.63 

14.37 

1 .0606 

IS.27 

16.  20 

I. 0671 

16.76 

17.88 

1.0736 

18.29 

19.64 

1.0542 

13.66 

14-40 

1 .0607 

15.29 

16.22 

1 .0672 

16.79 

17.92 

1-0737 

18.31 

19 .  66- 

1.0543 

13-68 

14.42 

1.0608 

15.31 

16.  24 

1.0673 

16.81 

17-94 

1.0738 

18.33 

19.68 

1.0S44 

13.71 

14.46 

I .0609 

15.34 

16.27 

1.0674 

16.84 

17.98 

1.0739 

18.3s 

19-71 

X.054S 

13.73 

14.48 

I .0610 

IS-36 

16.30 

1.0675 

16.86 

18.00 

1.0740 

18.38 

19-74 

1.0546 

13.76 

14.51 

1 .061 1 

ls-38 

16.32 

I .0676 

16.89 

18.03 

I. 0741 

18.40 

19.76 

1.0547 

13-78 

14-53 

1 .061 2 

IS -40 

16.34 

I .0677 

16.91 

18.05 

1.0742 

18.42 

19-79 

1.0548 

13-81 

14-57 

1 -0613 

15-43 

16.38 

1.0678 

16.94 

18.09 

1.0743 

18.44 

19. 8r 

1.0549 

13.83 

14-59 

I .0614 

15.45 

16.40 

1.0679 

16.96 

18.11 

1.0744 

18.47 

19.84 

1.0550 

13-86 

14.62 

1.0615 

15.47 

16.42 

1.0680 

16.99 

18.15 

I. 074s 

18.49 

19.87 

1.0551 

13-88 

14-64 

I .0616 

15-49 

16.44 

I. 0681 

17.01 

18.17 

1 .0746 

18.51 

19.89- 

1.0552 

13-91 

14.68 

1 .0617 

15.52 

16.48 

1.0682 

17-03 

18.19 

1.0747 

18.53 

19.91 

1.0553 

13-93 

14-70 

I. 0618 

15.54 

16.50 

1.0683 

17.06 

18.23 

1.0748 

18.5s 

19.94 

I-05S4 

13.96 

14.73 

1 .0619 

15.56 

16.52 

1.0684 

17.08 

18.25 

1.0749 

18.57 

19.96 

I.OSSS 

13.98 

14.76 

I .0620 

15.58 

16. SS 

1.0685 

17. II 

18.28 

1.0750 

18.59 

19.98- 

1.0556 

14-01 

14.79 

I .0621 

15.60 

16.57 

1.0686 

17.13 

18.31 

I .0751 

18.62 

20.02 

1.0557 

J4-03 

14-81 

I .0622 

IS. 63 

16.60 

1.0687 

17-16 

18.34 

1.0752 

18.64 

20 .  04. 

1.0558 

14-06 

14-84 

1.0623 

iS-65 

16.62 

T.0688 

17.18 

18.36 

1-0753 

18.66 

20.07 

1.0SS9 

14.08 

14.87 

I .0624 

15.67 

16.64 

1.0689 

17-21 

18.40 

1.0754 

18.68 

20.09. 

1.0560 

14.11 

14.90 

1.0625 

15.69 

16.66 

I .0690 

17-23 

18.42 

1.075s 

18.70 

20.  II 

I. 0561 

14-13 

14.92 

I .0626 

15.72 

16.70 

1 .0691 

17-25 

18.44 

1.0756 

18.72 

20. 14. 

1.0562 

14-16 

14.96 

1.0627 

15.74 

16.73 

I .0692 

17-28 

18.48 

1.0757 

18.74 

20. 16 

1.0563 

14-18 

14.98 

1.0628 

15.76 

16.75 

1.0693 

17.30 

18.50 

1.0758 

18.76 

20.18. 

1.0564 

14-21 

15.01 

1 .0629 

IS. 78 

16.77 

1.0694 

17-33 

18.53 

1.0759 

18.78 

20.  21 

1-0565 

14-23 

IS. 03 

1.0630 

15.80 

16.80 

1.0695 

17-35 

18.56 

I .0760 

18.81 

20. 24. 

r.0566 

14.26 

15.07 

1 .0631 

15.83 

16.83 

I .0696 

17.38 

18. 59 

I .0761 

18.83 

20. 26- 

1.0567 

14.28 

15.09 

1.0632 

15-85 

16.85 

1.0697 

17.40 

18.61 

1 .0762 

18.85 

20.  29 

1.0568 

14.31 

15.12 

1.0633 

15.87 

16.87 

I . 0698 

17-43 

18.65 

1.0763 

18.87 

20.31 

1.0569 

14.33 

15.15 

1.0634 

15.89 

16.90 

1 .0699 

17-45 

18.67 

I .0764 

18.89 

20.33 

1.0570 

14.36 

IS. 18 

1.063s 

IS. 92 

16.93 

I .0700 

17-48 

18.70 

1.076s 

18.91 

20.36 

1.0571 

14.38 

15.20 

1.0636 

15-94 

16.9s 

1 .0701 

17 -SO 

18.73 

1.0766 

18.93 

20.38 

1.0572 

14.41 

15.23 

1.0637 

15-96 

16.98 

1 .0702 

17-52 

18.7s 

1.0767 

18. 95 

20.40 

1.0573 

14-44 

15.27 

1.0638 

15-98 

17  .00 

1.0703 

17. S4 

18.77 

1.0768 

18.97 

20.43 

1.0574 

14.40 

15.29 

1.0639 

16.01 

17.03 

1.0704 

17.57 

i8.8i 

1.0769 

19.00 

20.46 

X.OS7S 

14.49 

15.32 

I . 0640 

16.03 

17.06 

1.070s 

17.59 

18.83 

1.0770 

19.02 

20.48 

i.os-,6 

14.52 

15.36 

I .0641 

16.05 

17.08 

I .0706 

17.61 

18.8s 

1.0771 

19.04 

20.51 

1.0S77 

14.54 

IS. 38 

I .0642 

16.07 

17.10 

I .0707 

17.63 

18.88 

1.0772 

19.06 

20.53 

1.0578 

14.57 

15.41 

1  .  064  7, 

16.09 

17.12 

1 .0708 

17.66 

18.91 

1.0773 

19.08 

20.5s 

1.0579 

14-59 

15.43 

1.0644 

16.12 

17.16 

1.0709 

17-68 

18.93 

1.0774 

19. 10 

20.58 

1.0580 

14.62 

15.47 

1.0645 

16.14 

17.18 

1 .0710 

17.70 

18.96 

1.0775 

19.12 

20.60 

1.0581 

14.6s 

15.50 

1.0646 

16.16 

17.  20 

I .071 1 

17.72 

18.98 

1.0776 

19.14 

20.63 

1.0584 

14.67 

15.52 

1.0647 

16.18 

17.23 

I .0712 

17-75 

19.01 

1.0777 

19-17 

20.66- 

1.0583 

14.70 

IS. 56 

1.0648 

16.  21 

17.26 

1.0713 

17.77 

19.04 

1.0778 

19.19 

20.68 

1.0584 

14.73 

15.59 

5.0649 

16.23 

17.28 

1.0714 

17.79 

19.06 

1.0779 

19.21 

20.71 

ALCOHOLIC  BEVERAGES. 
EXTRACT  IN  BEER  WOMT  -(Continued). 


719 


Extract. 

Specific 

Extract.   1 

Specific 

Extract. 

Specific 

E.x  tract. 

Specific 

Gravity 

Per 

Grams 

Gravity 

Per 

Grams 

Gravity 

Per 

Grftms 

Gravity 

Per 

Grams 

at  15°  C. 

Cent 

by 

Weight 

per 
100  cc. 

at  15°  C. 

Cent 

by 

Weight 

per 
100  cc. 

at  15°  C. 

Cent 

by 

Weight 

per 
100  cc. 

at  is^C. 

Cent 

by 

Weight 

per 

1 00  cc. 

I .0780 

19-23 

20.73 

1.0845 

20.  70 

22.45 

1 .0910 

22 .  19 

24.  21 

1.097s 

23.  59 

25  •  89 

I .0781 

19-25 

20.7s 

I .0846 

20.73 

22.48 

I .0911 

22.21 

24-24 

I .0976 

23.61 

25.92 

I .0782 

19.27 

20.78 

I .0847 

20.7  s 

22.50 

1 .0912 

22.23 

24.  26 

1.0977 

23  63 

25.94 

I. 0783 

19.29 

20.80 

1.0848 

20.77 

22.53 

1.0913 

22.  26 

24-29 

I .0978 

23-65 

25-97 

1 .0784 

19-31 

20.82 

1 .0849 

20.79 

22.55 

I .0914 

22.28 

24-31 

1.0979 

23-67 

25-99 

1.078s 

19-33 

20.8s 

1.0850 

20.81 

22.58 

1.091S 

22.30 

24-34 

I .0980 

23.69 

26.01 

1.0786 

19-36 

20.88 

1.0851 

20.83 

22  .6i 

1 .0916 

22.32 

24-37 

I .0981 

23-71 

26.04 

t.0787 

19-38 

20.90 

1 .0852 

20.86 

22  .64 

1.0917 

22.34 

24-39 

1.0982 

23.73 

26.06 

1.0788 

19-40 

20.93 

I. 0853 

20.88 

22.66 

1 .0918 

22.37 

24-42 

1 .0983 

23.76 

26.09 

T.o78g 

19.42 

20.95 

I. 0854 

20.90 

22.68 

I .0919 

22.39 

24.44 

1.0984 

23.78 

26. 1 1 

I  .0790 

19.44 

20.98 

i.oSss 

20.93 

22.72 

I .0920 

22.41 

24-47 

1.098s 

23.80 

26.14 

1.0791 

19.46 

21 .00 

1.0856 

20.9s 

22.7s 

I .0921 

22.43 

24.49 

1 .0986 

23.82 

26.  I  7 

1  .0792 

19.49 

21 .03 

i.o8s7 

20.98 

22.78 

I .0922 

22.45 

24- SI 

1 .0987 

23.84 

26.19 

1.0793 

19-51 

21 .06 

1.0858 

21 .01 

22.81 

1.0923 

22  48 

24-54 

1.0988 

23.86 

26.  22 

1.0794 

19-53 

21. 08 

1.0859 

21 .04 

22.84 

1.0924 

22.50 

24.56 

1 .0989 

23.88 

26.  24 

1.079s 

19-56 

21  .  II 

1 .0860 

21 .06 

22.87 

1.092s 

22.52 

24.60 

I .0990 

23.90 

26.27 

I  .0796 

19-58 

21  .  14 

1.0861 

21 .09 

22.90 

1 .0926 

22.54 

24.62 

1 .0991 

23.92 

26.30 

1.0797 

19 .  60 

21.16 

1.0862 

21.11 

22.93 

1 .0927 

22.56 

24-64 

I .0992 

23-94 

26.32 

1 .0798 

19.63 

21  .  20 

1.0863 

21.13 

22.96 

I .0928 

22.59 

24.67 

I .0993 

23-97 

26.3s 

1.0799 

19.6s 

21  .  22 

I .0864 

21 .  16 

22.99 

1 .0929 

22.61 

24.70 

1.0994 

23-99 

26.37 

1 .0800 

19.67 

21  .  24 

1.086s 

21.19 

23.02 

1.0930 

22.63 

24.73 

1.0995 

24.01 

26.40 

1 .0801 

19.70 

21.28 

1.0866 

21 .  22 

23.06 

1-0931 

22.65 

24-76 

I .0996 

24-03 

26.42 

I .0802 

19.72 

21.30 

1.0867 

21  .  2S 

23-09 

1.0932 

22.67 

24-78 

1.0997 

24-05 

26.44 

1 .0803 

19-74 

21.33 

1.0868 

21.28 

23.12  I 

1.0933 

22.69 

24.81 

1 . 0998 

24.07 

26.47 

I .0804 

19-77 

21.36 

1 .0869 

21  .  30 

23-15 

1.0934 

22.71 

24-83 

1.0999 

24.09 

26.49 

1  .0805 

19.79 

21.38 

I .0870 

21.33 

23.18 

I. 093 5 

22.73 

24.86 

1 . 1000 

24.11 

26.52 

I .0806 

19.81 

21  .41 

1 .0871 

21-35 

23.21 

1.0936 

22.75 

24.89 

I . lOOI 

24.13 

26.55 

1 .0807 

19-84 

21  .43 

1.0872 

21.37 

23-23 

1.0937 

22.77 

24.91 

1 .1002 

24.1s 

26.57 

1.0808 

19.86 

21  .46 

1.0873 

21.39 

23.26 

1.0938 

22.80 

24-93 

I .1003 

24.17 

26.60 

1 .0809 

19-88 

21.49 

1.0874 

21  .41 

23.28 

1.0939 

22.82 

24.96 

1 . 1004 

24.19 

26.62 

1 .0810 

19-91 

21.52 

1.087s 

21.43 

23-31 

I .0940 

22.84 

24.99 

I. iocs 

24.21 

26.65 

1 .081 1 

19-93 

21.55 

1.0876 

21.45 

23-33 

I .0941 

22.86 

25.01 

I . 1006 

24-23 

26.68 

1 .0812 

19.96 

21. s8 

1.0877 

21.47 

23-36 

1 .0942 

22.88 

25-03 

I . 1007 

24-25 

26.  70 

1. 0813 

19-98 

21  .60 

1.0878 

21.49 

23-38 

1.0943 

22.90 

25.06 

I . 1008 

24.28 

26.73 

I .0814 

20.00 

21.63 

1.0879 

21.51 

23-40 

1.0944 

22.92 

25.08 

I .1009 

24-30 

26.7s 

1.081S 

20.03 

21.66 

1.0880 

21.54 

23-43 

1.0945 

22.94 

25. II 

I . lOIO 

24.32 

26.78 

i.o8i6 

20.0s 

21  .69 

I. 088 I 

21  .  56 

23-45 

I  .0946 

22 .  96 

25-14 

I . lOI 1 

24-34 

26.81 

1 .0817 

20  .07 

21.71 

1.0882 

21.58 

23-48 

1.0947 

22.98 

25-16 

I . 101 2 

24.36 

26.83 

1. 0818 

20. 10 

21.74 

1.0883 

21  .  60 

23-50 

1.0948 

23.00 

25.18 

1.1013 

24.39 

26.86 

1 .0819 

20. 1  2 

21.77 

1 . 0884 

21  .62 

23-52 

1.0949 

23.03 

25 .  21 

I . IOI4 

24.41 

26.88 

1 .0820 

20. 14 

21-79 

1.0885 

21  .  64 

23.55 

1 .0950 

23-05 

25.24 

I.IOI5 

24-43 

26.91 

1 .0821 

20 .  17 

21.83 

1.0886 

21  .66 

23-58 

I .0951 

23-07 

25.26 

I . IO16 

24-45 

?6.93 

1 .0822 

20.  19 

21.8s 

1.0887 

21.68 

23.60 

1.0952 

23-  10 

25-29 

I . IOI7 

24-47 

26.95 

1.0823 

20.  21 

21.87 

1.0888 

21.71 

23-63 

1-09S3 

23-12 

25-31 

I . ioi8 

24.49 

26.98 

1 .0824 

20.  24 

21  .91 

1.0889 

21.73 

23.66 

1.0954 

23-14 

25-34 

I . 1019 

24.51 

27  .00 

1 .0825 

20 .  26 

21  .93 

I .0890 

21.75 

23.69 

1-0955 

23-16 

25.37 

I . 1020 

24.53 

27-03 

1.0826 

20.28 

21  .96 

I .0891 

21.77 

23.72 

I .0956 

23.18 

25.39 

I . 1021 

24. SS 

27  .06- 

1 .0827 

20.31 

21  .99 

I .0892 

21.79 

23-74 

1.0957 

23.20 

25-42 

I . 1022 

24-57 

27.08 

1.0828 

20.33 

22.01 

1.0893 

21.82 

23.77 

1.0958 

23.23 

25-45 

I. 1023 

24.60 

27.11 

1 .0829 

20.3s 

22  .04 

I .0894 

21.84 

23.79 

I.09S9 

23.2s 

25-47 

1 . 1024 

24.62 

27-14 

1 .0830 

20.37 

22.06 

1.089s 

21.86 

23.82 

I .0960 

23.27 

25-50 

I.I02S 

24.64 

27-17 

1.0831 

20.39 

22.08 

1 .0896 

21  .89 

23-85 

I .0901 

23.29 

25-53 

I . 1026 

24.66 

27.19 

1 .0832 

20.41 

22.  11 

1.0897 

21.91 

23-87 

I .0962 

23-31 

25.55 

1 . 1027 

24.68 

27.21 

1.0833 

20.43 

22.13 

1.0898 

21.93 

23.90 

1 .0963 

23.33 

25.58 

I . 1028 

24.  70 

27.24 

1 .0834 

20.46 

22.  16 

I . 0899 

21  .96 

23-93 

1 .0964 

23.35 

2S.60 

1.1029 

24.72 

27.26 

1 .083s 

20.48 

2  2  .  I  9 

I . 0900 

21.98 

23.96 

1.0965 

23.37 

25.63 

1.1030 

24.74 

27.29 

1 .0836 

20.50 

22  .  21 

1 .0901 

22.00 

23-98 

1 .0966 

23-39 

2S.66 

I. 1031 

24.7'J 

27.32 

1.0837 

20.52 

22.  24 

I .0902 

22.02 

24.01 

1 .0967 

23-41 

25.68 

1.1032 

24-78 

27.34- 

1.0838 

20.54 

22  .  26 

1.0903 

22.04 

24.03 

I . 0968 

23-44 

25.71 

I. 1033 

24.81 

27-37 

1 .0839 

20.56 

22.  29 

1 .0904 

22.06 

24.05 

1 .0969 

23.46 

25.73 

I. 1034 

24-83 

27.39 

I .0840 

20.59 

22.32 

I .0905 

22.08 

24.08 

1 .0970 

23-48 

25.76 

1. 1035 

24-85 

27-42 

I .0841 

20.62 

22.35 

I .0906 

22 .  10 

24. 1 1 

1.0971 

83-50 

25.79 

I. 1036 

24.87 

27.45 

I .0842 

20 .  64 

22.38 

I .0907 

22.12 

24.13 

I .0972 

23-52 

25.81 

I.I037 

24.89 

27-47 

I .0843 

20 .  66 

22.40 

I .0908 

22.  IS 

24. 16 

1 -0973 

23. SS 

25-84 

1 .  1038 

24.92 

27-50 

1.0844 

20.68 

22.42 

I .0009 

22.17 

24.18 

1.0974 

23.57 

2S-86 

I. 1039 

24.94 

27-53 

FOOD  INSPECTION  JND  .4N.4LYSIS. 


EXTRACT  IX  BEER  WOKT—iCoucludei). 


E.x: 

ract. 

Specific 

E.xtract. 

Specific 

E.xtract. 

Specific 

E.xtract. 

Specific 

1 

Gravitv 

at  1 5°  C. 

Per 

Cent 

bv 

Weight 

Grams 
per 

100  cc. 

Gra\'ity 
at  15°  C. 

Per 

Cent 

bv 

Weight 

Grams 
per 

100  cc. 

Gravity 
ati5°C. 

Per      Grams 
Cent        per 

„.R>',  ^   100  cc. 
Weight 

Gravity 
at  is°C. 

i 

Per       Grams 
Cent         ripr 

K  -               pel 
^T    -i.^     100  cc. 

Weigh  t| 

I . 1040 

24-06 

27-56 

1 . 1095 

26.16     29.03 

1 .1150 

27.29 

30.43 

I  -1205 

28.38 

31-81 

I . 1041 

34.08 

27.58 

I . 1096 

26.18     29.06 

i.ilSi 

27.31 

30.45 

1 .  1 206 

28.40 

31-83 

I . 1043 

25.00 

27.60 

1.1007 

26.20     29.08 

i.iisa 

27-33 

30.47 

I . 1207 

28.42 

31.86 

J  .104.; 

15.03 

27  63 

I . 1008 

26.23     20.11 

1.1153 

27-35 

30.50 

1. 1 208 

28.44 

31.88 

I.t044 

as. OS 

27-66 

1.1099 

26.25     29.13 

1-1154 

27-37  1  30-S2 

1 . 1200 

28.46 

31.03 

1.I04S 

as. 07 

27.69 

I . I 100 

26.27     20.16 

I. 1155 

27.38  1  30.55 

I . I2tO 

28 .  48 

31-03 

I. 1046 

25.09 

27.72 

1 . IIOl 

26.20     20.19 

1  .1156 

27.43      33-57 

I  . I  21  I 

28.50 

31.95 

I . 1047 

aS-ii 

27-74 

1.H02 

26.31 

29.21 

I-IIS7 

27.42  '  30.59 

I  .  I  212 

28.52 

31.98 

1.1048 

aS.«4 

27.77 

I . 1 103 

26.33 

20.  24 

I-I15S 

27.44  '   30.62 

I.I213 

28.54 

32.00 

J.I  049 

25.16 

27.79 

I . 1104 

26.35 

29.  26 

I.IIS9 

27.46     30.64 

I . I214 

28.56     32.03 

i.ioso 

as. 18 

27.82 

I.I105 

26.37 

29.20 

I . 1160 

27.48  !  30.67 

I.I2IS 

28.58     32.05 

1.1051 

25.20 

27.8s 

I . 1106 

26.30 

20.32 

1 . 1 161 

27.50  1  30.60 

1 . I216 

28.60     32.08 

1.1052 

25.22 

27.87 

1 .  1107 

26.41 

29-34 

1 . 1 162 

27.52  1  30.72 

1.1217 

28.62     32.11 

J.IOS3 

25.24 

27.90 

1. 1 1 08 

26.44 

20.37 

I .1163 

27.54  '  30.75 

1 .1218 

28.64     32.13 

1.1054 

25.27 

27.93 

I . 1109 

26.46 

29.39 

I . 1164 

27.56 

30.77 

1 .  1219 

28.66 

32. IS 

1.105s 

25-29 

27.96 

1. 1110 

36.48 

20.42 

1    1.116^ 

27.58 

30 .  80 

I. 1220 

28.68 

32.18 

1 .  1056 

25.. ^t 

27.98 

i   I. mi 

26.  so 

20.44 

1. 1 166 

27  60 

30.82 

I . I22I 

28.70 

32.20 

1.1057 

25-33 

aS.oo 

1.1112 

26.52 

20.46 

1 . 1 167 

27.62 

30.85 

I . 1222 

28.72 

32.23 

I  .  1058 

25-35 

28.03 

1.1113 

26.54 

20-40 

i.it68 

27.64 

30.87 

r .1223 

28.74     32.25 

1.1059 

25.38 

28.06 

1.1114 

26.56 

20.51 

I . 1160 

27.66 

30.89 

I  . I  224 

28.76 

32.27 

t .1060 

25.40 

28.09 

1.1113 

26.58 

20.54 

1. 1170 

27.68 

30.93 

I.I22S 

28.78 

32.30 

1 . io6t 

25-42 

28.12 

I . 1116 

26.60 

20-57 

1.1171 

27.70 

30.04 

I. I  226 

28.80 

32.32 

1 . 1062 

25.44 

28.14 

1. 1117 

26.62 

29-59 

1.1172 

27.72 

33-97 

I . 1227 

28.82 

32.35 

I . 1063 

25.46 

28.17 

1.1118 

26.64 

20-61 

I -1173 

27-74 

31  -oo 

I. I  228 

28.84 

32.37 

1 . 1064 

25.48 

28.19 

1 .  1119 

26.66 

20.64 

1.1174 

27. 7j 

31.02 

1.1229 

28.86 

32.40 

I. 1065 

25.50 

2S.22 

t . 1120 

26.68 

29.67 

I-II7S 

27.78 

31-OS 

I. 1230 

28.88 

32.43 

I. 1066 

25.52 

28.25 

I . 1121 

26.70 

29.69 

1 .  1 176 

27.80 

31.07 

I.I231 

28.90     32.45 

I . 1067 

2S-S4 

28.27 

1.1122 

26.72 

20-71 

I. 1177 

27. 82 

3I-O0 

I. 1232 

28.92 

32.48 

1 . 1 068 

25-57 

28.30 

I. 1123 

26.75 

29.74 

1.1178 

27.84 

31.12 

I. I  233 

28.04 

32.50 

t . 1069 

as -SO 

28.32 

1.1124 

26.77 

29.77 

1.1179 

27.86 

31. IS 

I. 1234 

28.96 

32.53 

I . 1070 

25-61 

28.35 

I. 1125 

26.  79 

20.  So 

1.1180 

27.88 

31.18 

I.I233 

28.98 

32.56 

1.1071 

25-63 

28.38 

I . 1126 

26.81 

20.83 

1.1181 

27-00 

31 .  20 

I. 1236 

20.00 

32.58 

1 . 1072 

25-65 

28.40 

1.1127 

26.83 

20.85 

1.1182 

27.02 

31-23 

1. 1237 

20 .02 

32.60 

1.1073 

25-67 

28.43 

1.1128 

26.85 

20.88 

1.1183 

27-94 

31-25 

I. 1238 

20.04 

32.63 

1.1074 

25.69 

28.45 

1 . 1 1 29 

26.87 

29.90 

1.1184 

27-96 

31.27 

1. 1 239 

29.06 

32.6s 

I.T07S 

25.71 

28.48 

1.1130 

26.80 

29.93 

1.1185 

27.98 

31.30 

I . 1240 

29.08 

32.68 

1 . 1076 

25-73 

28.51 

1.1131 

26.91 

29-95 

1. 1 1 86 

28.00 

31.32 

1 . 1 241 

29. 10 

32.71 

I. 1077 

25-75 

28.53 

1.1132 

26.93 

29.97 

1.1187 

28.02 

31.3s 

I . 1242 

20. 12 

32.73 

1.1078 

25.78 

28.56 

t-1133 

26.  OS 

30.00 

1.11S8 

28.04 

31-37 

1 . 1 243 

29.14 

32.76 

1.1079 

25.80 

28.58 

1.1134 

26.97 

30.02 

1.1189 

28.07 

31.40 

1. 1 244 

29.16 

32.78 

1.1080 

25.82 

28.61 

r.ii3S 

26.99 

30.06 

1.1190 

28.00 

31.43 

1-1245 

20.18 

32.81 

1 .1081 

25-84 

28.64 

1.1136 

27  .01 

30.08 

I . I lOI 

28.11 

31.45 

I . 1246 

29.  20 

32.83 

1 .1082 

25-86 

28.66 

1.1137 

27.03 

30.10 

I . 1102 

28.13 

31.48 

1.1247 

20.  22 

32.86 

1 . 1083 

25.89 

28.69 

1.1138 

27.05 

30 . 1 3 

1.1103 

28.1^ 

31.51 

1.1248 

20.24 

32.89 

1 .1084 

25.91 

28.72 

I. 11 39 

27.07 

30.15 

I. I 194 

28.17 

3t.53 

1. 1  249 

29.26 

32.91 

I  .  1085 

25- 03 

28.7s 

t . I 140 

27.09 

.30.18 

1.1195 

28.10 

31.56 

1.1250 

29.28 

32.94 

1 . 1086 

25-06 

a8.78 

I. 114" 

27.11 

30.20 

I . 1 106 

28.21 

31.59 

1.1251 

29.30 

32.96 

1,1-^7 

25-98 

28.80 

I.II42 

27.13 

30.22 

1.1197 

28.23 

31-61 

1.1252 

29.32 

32.90 

II     ..■( 

26.01 

28.83 

1. 1 143 

27. IS 

30.25 

1. 1 108 

28.2s 

31.63 

I. 1253 

29-34 

33-02 

I.I-  -ii) 

26.03 

28.86 

1.1144 

27.17 

30.27 

I. 1199 

28.27 

31.65 

I.I2S4 

29.36 

33.04 

I.fOOO 

a6.o5 

28.89 

X.I14S 

27.19 

30.31 

1 . 1 200 

28.  28 

31.68 

i.iass 

29.38 

33.  ■37 

1 . 1 09 1 

a6.o7 

28.92 

1 . 1 146 

27.21 

30.33 

I . 1201 

28.30 

31.70 

I . 1256 

29.40 

33.09 

I.I092 

26.09 

28.94 

1.1147 

27.23 

30.3s 

I . 1202 

28.32 

31.73 

1. 1257 

29-42 

33-12 

I. 1003 

26.  12 

28. Q7 

t.1148 

27.2s 

30.37 

1. 1 203 

28.34 

31.75 

1.1258 

29-45 

33-14 

1. 1094 

26. 14 

31)  .  00 

1. 1 149 

27-  27   ■   .3^.40  1 

I . I  204 

23.36 

31-78 

1.1*59 

29.47 

33-17 

ALCOHOLIC   BEyFRAGFS. 


721 


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"• 

7JJ  FOOD  INSPECTION  AND  /IN. 4 LYSIS. 

mation  to  the  truth  is  obtained,  especially  with  beer  high  in  sugar,  by 
calculation  as  follows: 

From  fJi:'  Specific  Gravity. — Evaporate  a  measured  (juantity  of  the 
beer  to  one-fourth  its  volume  on  the  water-bath,  make  up  with  water 
to  its  original  measure,  and  determine  the  specific  gravity  of  the  dcal- 
coholized  beer.  Then  by  means  of  Schultz  and  Ostermann's  table,  pp. 
716-20,  calculate  the  extract  corresponding. 

From  the  Refraction. — Method  of  Ackermann  and  Foggcnhurg. 
— Determine  the  refraction  of  the  li([Uor  at  17.5°  C.  by  means  of  the 
immersion  refractometer.  Determine  also  the  refraction  of  the  dis- 
tillate from  100  cc.  of  ih.'  licjuorat  17.5°  C.  after  making  up  to  its  original 
volume.  In  order  to  secure  accurate  results,  care  should  be  taken 
to  cool  the  prism  of  the  instrument  to  exactly  17.5°  C.  by  immersing 
for  five  minutes  in  the  water-bath  previous  to  taking  the  refraction  of 
the  liquids.  If  determinations  are  made  on  a  number  of  samples,  this 
cooling  is  not  necessary  except  before  taking  the  reading  of  the  first  of 
the  series. 

Calculate  the  grams  of  extract  {E)  from  the  refraction  of  the  liquor 
{R)  and  of  the  distillate  {R')  by  the  following  formula: 

E  =  o.2sios{R-R'). 

The  extract  is  more  conveniently  obtained  from  Ackermann's  table 
given  on  j).  721. 

Original  Gravity  of  Beer  Wort  and  its  Determination. — Following  a 
long-establi>hed  custom  of  the  English  excise,  tlie  duty  on  beer  has  been 
based  on  the  specific  gravity  of  the  original  wort,  by  which  is  meant  the 
wort  of  the  beer  before  any  of  its  sugar  has  been  lost  by  fermentation. 

From  the  content  of  alcohol  in  the  beer  the  sugar  originally  present 
in  the  wort  may  be  calculated,  assuming  that  the  alcohol  amounts  to 
about  half  the  sugar  used  up  in  fermentation. 

Obtain  the  specific  gravity  of  the  beer,  dealcoholized  and  made  up 
to  its  original  volume,  as  in  the  calculation  of  the  extract.  This 
Is  called  the  "extract  gravity."  Note  the  specific  gravity  correspond- 
ing to  the  alcohol  found,  i.e.,  the  specific  gravity  of  the  distillate  in  the 
alcohol  determination,  when  made  up  to  the  original  volume,  and  subtract 
this  from  i.  The  difference  is  known  arVjitrarily  as  the  "degree  of  spirit 
indication." 

From  the  table  of  Graham,  Hofmann,  and  Redwood,*  p.  723, 
the  "degrees  of  gravity  lost"  corresponding  to  the  "spirit  indication"' 

•  Report  on  Original  Gravities,  1852;  Allen's  Com.  Org    Anal.,  4  Ed.,  Vol.  I,  p.  151. 


/iLCOHOLIC  BEyEllAGES. 

«-are  ascertained.     This  figure  is  added  lo  the  " 
the  "original  gravity  of  the  wort." 


723 

extract  gravity"  to  find 


SUGAR  USED  UP  IN  FERMENTATION. 


0^: 

2:5-2 

1 

(1.0000   c 

.0001 

0 . 0002 

0 .0003 

0.0004 

0.000s 

0.0006 

0.0007 

o.oooS 

0.0009 

Q-  - 

0.000 

0 

0003 

0.0006 

0.0009 

0.0012 

0.0015 

0.0018 

0.0021 

0.0024 

0.0027 

.001 

.  0030 

0033 

.0037 

.0041 

-0044 

.0048 

.0051 

■0055 

.0059 

.0062 

.002 

.  0066 

0070 

.0074 

.0078 

.0082 

.0086 

.0090 

.0094 

.  9098 

.0102 

.003 

.0107 

OIII 

.0115 

.0120 

.0124 

.0129 

■0133 

.0138 

.0142 

.0147 

.004 

.0151 

0155 

.0160 

.0164 

.0168 

-0173 

.0177 

.0182 

.0186 

.0191 

,005 

-0195 

0199 

.0204 

.0209 

.0213 

.0218 

.0222 

.0227 

.0231 

.0236 

,006 

.0241 

0245 

.0250 

-.0255 

.0260 

.0264 

.0269 

.0274 

.0278 

.0283 

.007 

.0288 

0292 

.0297 

.0302 

.0307 

.0312 

•0317 

.0322 

.0327 

-0332 

-008 

-0337 

0343 

.0348 

•0354 

-0359 

■0365 

.0370 

-0375 

.0380 

.0386 

.009 

•0391 

0397 

.0402 

.0407 

.0412 

.0417 

.0422 

.0427 

•0432 

■0437 

.010 

.0442 

0447 

.0451 

■0456 

.0460 

.0465 

.0476 

•0475 

.04S0 

.0485 

-Oil 

.0490 

0496 

.0501 

.0506 

.0512 

-0517 

.0522 

.0527 

■0533 

-0558 

.012 

■0543 

0549 

-OS54 

.0559 

.0564 

.0569 

•0574 

-0579 

.0^84 

.0589 

.013 

-0594 

0600 

.  0605 

.0611 

.0616 

.0622 

.0627 

•0633 

.0638 

.0643 

.014 

.0648 

0654 

.0659 

.0665 

.0471 

.0676 

.0682 

.0687 

.0693 

.0699 

.015 

.0705 

07II 

.0717 

■0723 

.0729 

•0735 

.0741 

•0747 

■0753 

•0759 

Example. — Suppose  the  "extract  gravity"  is  1.0389  and  the  specific 
gravitv  of  the  alcoholic  distillate  is  0.9902,  both  at  15.6.  Then  i  —0.9902  = 
0.0098,  the  "degree  of  spirit  indication."  From  the  above  table  the  cor- 
Tesponding  "degree  of  gravity  lost"  is  found  lo  be  0.0432. 

0.0432+1.0389  =  1.0821,  the  original  gravity  of  the  wort. 

The  calculation  in  the  above  simplified  form  is  accurate  for  normal 
beer  wherein  the  free  acid  present,  expressed  as  acetic,  does  not  exceed 
0.1%.  In  case  of  beer  that  has  developed  free  acid  much  in  excess  of 
the  above  limit,  a  correction  should  be  added  to  the  degrees  of  spirit 
indication.  This  correction,  which  in  practice  it  is  rarely  necessar\'  to 
apply  except  in  extreme  cases  of  old  or  sour  beer,  is  calculated  as  follows: 

If  a  represents  the  grams  of  free  acid  (as  acetic)  in  100  cc,  then  the 
correction  to  be  added  to  the  spirit  indication  =o.ooi3a  — 0.00014. 

Example. — Supposing  the  "extract  gravity"  to  be  1.0413,  the  specific 
gravity  of  the  alcoholic  distillate  to  be  0.9890,  and  the  free  acid  as  acetic 
to  be  0.35%.     Then  1—0.989=0.0110,  the  degree  of  spirit  indication. 

0.35X0.0013—0.00014=0.0003,  correction  to  be  added  to  the  spirit 
indication. 

0.0110+0.0003=0.0113,  corrected  spirit  indication. 


724  FOOD    INSPECTION    ^ND   yINALYSlS. 

From  the  above  table  the  corresponding  degrees  of  gravity  lost  are 

o.o5o(v 

0.050(1  -  1.0413=  T.OQio.  the  original  gravity  of  the  \vort. 

Determination  of    Degree    of    Fermentation. — This  is  calculated  by 

200.1 
the  t\>rmula  D-=     1^^,  in  which  /)  =  (legree  of  fermentation,  J=per  cent 

of  alcohol  by  weight,  and  /^  =  the  original  extract. 

Determination  of  Reducing  Sugars. — Dealcoholize  25  cc.  of  the  beer 
and  make  uj)  to  100  cc.  Determine  reducing  sugars  by  the  Defren- 
O'SuUivan  or  Munson-Walker  method,  and  calculate  as  maltose. 

Determination  of  Dextrin. — Dilute  50  cc.  of  the  beer  to  200  cc, 
hydrolize  by  heating  in  a  boiling  water-bath  for  2\  hours  with  20  cc. 
of  hydrochloric  acid  (specific  gravity  1.125),  nearly  neutralize  the  free 
acid  with  sodium  hydroxide,  make  uj)  to  300  cc,  filter,  and  determine 
the  dextrose  by  copper  reduction.  Multiply  the  amount  of  reducing 
sugars  as  maltose  by  0.95,  .subtract  tliis  from  the  dextro.'-e,  and  multiply 
the  difference  by  o.(),  thus  obtaining  tlie  dextrin  in  the  b 'cr 

Determination  of  Glycerin. —  Proceed  as  directed  on  jjagc  703  under 
wine.  The  milk  of  lime  is  added  during  evaporation  after  the  carbon 
dioxide  has  been  expelled.  It  is  advisable  that  the  filtrate,  after  being 
evaporated  to  a  syrupy  consistency,  be  treated  again  with  5  cc.  of 
absolute  alcohol  and  two  portions  of  7.5  cc.  each  of  absolute  ether. 
If  clear,  continue  as  directed.  If  not  clear,  it  is  necessary  to  repeat 
the  treatment  with  lime. 

Determination  of  Total,  Fixed,  and  Volatile  Acids.  —  A  measured 
volume  of  the  beer,  say  10  cc,  is  freed  from  car]jon  dioxide  by  bringing 
to  boiling.  It  is  then  cooled  and  titrated  with  tenth-normal  sodium 
hydroxide,  using  neutral  litmus  solution  as  an  indicator.  Each  cubic 
centimeter  of  tenth-normal  alkali  is  equivalent  to  0.009  gram  of  lactic 
acid,  in  which  the  total  acidity  is  usually  expressed. 

Fixed  acid,  also  expressed  as  lactic,  though  small  quantities  of  suc- 
cinic, tannic,  and  malic  acids  are  usually  also  present,  is  determined  as 
follows:  Dealcoholize  a  measured  amount  of  the  beer,  say  10  cc,  by 
evaporation  to  one- fourth  its  volume,  dilute  with  v/ater  to  the  original 
volume,  and  titrate  with  tenth-normal  alkali,  as  before. 

Volatile  acid  is  exjjressed  as  acetic,  and  is  usually  calculated  by  dif- 
ference between  total  and  fixed  acid.  Each  cubic  centimeter  of  tenth- 
normal alkali  is  the  equivalent  of  0.006  gram  acetic  acid. 


ALCOHOLIC  BF.yRRAGES.  725 

Determination  of  Proteins.  -Fifty  cc.  of  the  beer  arc  first  trealcfl 
with  5  cc.  of  dilute  sulphuric  acid,  and  concentrated  by  boiling  to  syrupy 
consistency.  Then  proceed  by  the  Gunning  method,  \).  69.  Nx6.25  = 
j)roteins. 

Determination  of  Phosphoric  Acid.— Unless  the  samjjle  is  ver\-  dark- 
colored,  sufficiently  close  results  can  usually  be  obtained  by  direct  titra- 
tion of  the  beer  itself  with  uranium  acetate  solution.  For  ver}'  accurate 
results  the  ash  should  be  used.  Prepare  a  solution  of  uranium  acetate  of 
such  strength  that  20  cc.  will  corres])ond  to  o.i  gram  P-.O^.  This  solution 
is  best  standardized  against  pure,  crystallized,  unefiloresced,  powdered 
hydrogen  sodium  phosphate,  10.085  grams  of  which  are  dissolved  in 
water  and  made  up  to  a  liter.  50  cc.  of  this  solution  contains  o.i  gram 
phosphoric  anhydride,  if  the  salt  is  pure.  If  the  solution  is  of  proper 
strength,  50  cc.  evaporated  to  dr>-ness  and  ignited  in  a  tared  jjlatinum 
dish  should  have  an  ash  weighing  0.1874  gram.  For  preliminary  trial 
about  35  grams  of  uranium  acetate  are  dissolved  in  water,  25  cc.  of  glacial 
acetic  acid,  or  its  equivalent  in  weaker  acid  added,  and  the  solution  made 
up  to  a  liter  with  water. 

To  standardize,  50  cc.  of  the  standard  phosphate  solution  prepared 
as  above  are  heated  to  90°  or  100°  C,  and  the  uranium  solution  run  in 
from  a  burette  till  the  resulting  })recipitate  of  hydrogen  uranium  ])hos- 
phate  is  complete.  The  end-point  is  determined  by  transferring  a  few 
drops  of  the  solution  to  a  porcelain  plate,  and  touching  with  a  drop  of 
freshly  prepared  potassium  ferrocyanide  solution.  When  the  slightest 
excess  of  uranium  acetate  has  been  added,  a  reddish-brown  color  is  pro- 
duced by  the  ferrocyanide.  The  uranium  acetate  solution  is  purposely 
made  rather  stronger  than  necessary  at  first,  and  by  repeated  trials  is 
brought  by  dilution  with  water  to  the  required  strength  (20  cc.  equivalent 
to  50  cc.  of  the  phosphate  solution). 

Fifty  cc.  of  the  beer  are  heated  to  90°  or  100°  C.  and  titrated  widi 
the  uranium  acetate  solution  under  the  same  conditions  and  in  ])recisely 
the  same  manner  as  when  standardizing  that  solution.  Each  cubic  centi- 
meter of  the  uranium  acetate  corresponds  to  0.01%  of  P2O5. 

For  the  phosphoric  acid  determination  in  the  ash,  50  cc.  of  the  beer 
are  incinerated  in  the  regular  manner,  and  the  ash  moistened  with  con- 
centrated hydrochloric  acid.  The  acid  is  then  evaporated  off  on  the 
water-bath,  after  which  the  ash  is  Ijoiled  with  50  cc.  of  distilled  watc",  and 
titrated  with  the  standard  uranium  s(>luti()n. 


7^ J  FOOD  INSPECTION    AND   ANALYSIS. 

Determination  of  Carbon  Dioxide.* — In  the  case  of  beer  and  other 
carbonated  drinks  put  up  in  corked  bottles,  the  carbon  dioxide  may  be 
readily  determined  by  piercing  the  cork  with  a  metal  champagne  tap, 
which  is  connected  by  a  flexible  tube,  first  with  a  safety  flask  and  then 
with  an  absorption  apparatus  somewhat  after  the  style  of  that  used  in 
the  determination  of  carbon  dioxide  in  baking  powder,  the  liberated 
carbon  dioxide  being  absorbed  for  weighing  in  a  concentrated  solution 
of  potassium  hydroxide  contained  in  a  tared  Liebig  bulb.  The  beer- 
bottle  thus  connected  is  immersed  in  a  vessel  of  water,  which  is  heated 
over  a  gas- flame,  after  all  the  carbon  dioxide  that  will  escape  spontaneously 
has  been  allowed  to  do  so.  Before  weighing  the  absorbed  carbon  dioxide, 
the  beer-bollle  is  replaced  by  a  soda-lime  tube,  and  a  current  of  air  drawn 
through  the  tubes. 

Beer  and  ale  put  up  in  bottles  having  patent  metallic  or  rubber  stoppers 
cannot  thus  be  treated.  In  this  case  a  measured  quantity,  say  200  cc, 
of  the  sample  is  transferred  as  quickly  as  possible  to  a  large  flask  pro- 
vided with  an  outlet-tube  having  a  glass  stopper,  this  being  connected 
up  with  the  safety-flask  and  absorption-tubes.  In  this  case  heat  may  be 
directly,  though  cautiously,  applied  to  the  flask  containing  the  beer  by 
means  of  a  gas-flame,  after  all  the  carbon  dioxide  has  gone  over  that  will 
<io  so  spontaneously.  Exactly  the  same  apparatus  as  that  shown  in  Fig. 
71  may  be  used  to  advantage  for  determination  of  carbon  dioxide  in  beer, 
except  that  a  larger  distilling-flask  should  be  used  in  the  case  of  beer. 

Detection  of  Bitter  Principles. — Elaborate  schemes  have  been  worked 
out  for  the  systematic  treatment  of  beer  and  ale  for  bitter  principles.  Nearly 
all  of  these  are  complicated  and  somewhat  unsatisfactory.  The  presence 
of  alkaloids  in  malt  liquors,  deliberately  introduced  during  the  process 
of  manufacture,  is  now  so  rare  that  the  analyst  need  seldom  look  for  them, 
except  in  cases  of  suspected  poisoning,  when  the  scheme  of  Dragendorff 
or  of  Olto-Stas  should  be  employed.  While  it  is  somewhat  difficult  to 
positively  identify  the  various  alkaloids,  it  is  usually  easy  to  prove  their 
absence  in  clear  solutions,  if  on  treatment  with  either  of  the  general 
alkaloidal  reagents,  Mayer's  solution  (Reagent  No.  170),  or  iodine  in  potas- 
sium iodide  (Reagent  No.  143),  no  precipitate  is  formed. 

It  is  comparatively  easy  to  prove  the  mere  presence  or  absence  of  hop 
substitutes.  The  bitter  principle  of  hops  is  readily  soluble  in  ether, 
when  a  sample  of  the  beer  evaporated  to  syrupy  consistency  is  extracted 

•  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  95;   Bui.  107  (rev.),  p.  92. 
t  Gcrichtlich-Chemisthe  F>mittclung  von  Giften,  St.  Petersburg,  1876. 


/tLCQHOLlC  BEyERAGES.  727 

therewith,  while  the  bitters  of  quassia  and  aloes,  common  hop  substitutes, 
are  insoluble  in  ether.  Though  many  varieties  of  bitters  might  be  em- 
ployed that  are  soluble  in  ether,  the  absence  of  a  bitter  taslc  from  the 
■ether  extract  is  evidence  of  the  absence  of  hops. 

The  most  marked  dilTcrence  analytically  between  hops  and  their 
substitutes  in  malt  liquors  lies  in  the  fact  that  the  Ijilter  j)rinciple  of  hops 
is  completely  precipitated  therefrom  by  treatment  of  the  l^eer  with  lead 
acetate  (either  basic  or  neutral),  leaving  no  bitter  taste  in  the  filtrate 
after  concentration,  while  if  any  of  the  hop  substitutes  are  present,  the 
concentrated  filtrate  from  the  lead  acetate  treatment  will  have  a  bitter 
taste.  The  excess  of  lead  should  be  removed  from  the  filtrate,  before 
concentration  and  tasting,  by  treatment  with  hydrogen  sulphide.  If  the 
residue  from  the  ether  or  chloroform  extraction  of  the  concentrated  filtrate 
from  a  beer  after  treatment  with  lead  acetate  be  found  to  be  bitter,  there 
is  positive  evidence  that  a  foreign  substitute  has  been  employed. 

The  following  are  characteristic  reactions  that  may  help  to  identify 
some  of  the  common  hop  substitutes.* 

Qiiassiin  is  readily  soluble  by  chloroform  from  acid  solution.  If  a 
residue  containing  quassiin  be  moistened  with  a  weak  alcoholic  solution 
of  ferric  chloride  and  gently  heated,  a  marked  mahogany-brown  color- 
•ation  is  produced. 

On  treatment  of  quassiin  with  bromine  and  sodium  hydroxide  or 
.ammonia,  a  bright-yellow  color  is  shown. 

Chiretta  is  readily  dissolved  by  ether  from  its  aqueous  solution.  Its 
«ther  residue,  when  treated  with  bromine  and  ammonia,  gives  a  straw 
■color,  slowly  changing  to  a  dull  purple-brown.  This  is  not  true  of 
its  chloroform  residue,  so  that  it  is  not  to  be  mistaken  for  quassia 
.(Allen). 

Gentian  Bitter  may  be  extracted  by  treatment  of  the  acid  lic^uor  with 
•chloroform.  When  the  residue  containing  gentian  bitter  is  treated  with 
concentrated  sulphuric  acid  in  the  cold,  no  color  is  produced,  but  on 
■warming  gently  a  carmine-red  color  is  shown;  if  further  treated  with 
ferric  chloride  solution,  a  green-brown  color  is  formed. 

Aloes. — ^This  substance  is  separated  from  ]:»eer  by  treating  the  dried 
residue  from  200  cc.  of  the  beer  with  warm  ammonia,  fihering,  cooling, 
and  treating  the  fiUrate  with  hydrochloric  acid.  The  resin  of  aloes  is 
precipitated  and  collecte:!  on  a  filter.     It  is  insoluble  in  cold  water,  ether, 


*  Allen,  Analyst,  12,  1887,  p.  107. 


yaS  FOOD  INSPECTION  ^ND   ANALYSIS. 

chloroform,  or  petroleum  ether,  but  i^  soluble  in  alcohol.  It  has  a  very- 
characteristic  odor,  which  serv'es  to  identify  it.  The  hot- water  solution 
gives  a  curdv  precipitate  on  treatment  with  lead  acetate. 

Capsicin  is  extracted  by  treatment  of  the  acid  liquor  with  chloroform. 
It  is  recognizable  by  its  sharp,  pungent  taste. 

Detection  of  Arsenic. — By  ihe  Marsh  Method. — Measure  loo  cc.  of 
the  beer  (^frced  from  carbon  dioxide  by  agitation)  into  a  seven-inch  porce- 
lain evaporating-dish,  add  20  cc.  pure  concentrated  nitric  acid,  and  3  cc. 
pure  concentrated  sulphuric  acid,  and  cautiously  heat  till  vigorous  chemi- 
cal action  sets  in,  accompanied  by  frothing  and  swelling  of  the  beer.  Turn 
the  flame  low  or  remove  it  altogether,  and  stir  vigorously  till  the  frothing 
ceases,  after  which  the  liquid  may  be  boiled  freely.  At  this  stage 
transfer  to  a  large  casserole,  and  continue  the  boihng  till  nearly  all 
the  nitric  acid  is  driven  oii.  Then,  holding  the  casserole  by  the  handle^ 
continue  the  heating  till  the  mass  chars  and  the  fumes  of  sulphuric  acid 
are  given  off,  giving  the  casserole  a  rotary  motion  to  i)revent  sputtering. 
The  residue  should  be  reduced  to  a  dry,  black,  pulverulent  char  soon  after 
the  sulphuric  acid  fumes  begin  to  come  off  freely.  If  still  liquid,  pieces  of 
filter-paper  should  be  stirred  in  while  still  heating,  till  the  residue  is  drj', 
avoiding  an  excess  of  paper. 

Cool,  add  50  cc.  of  water,  and  remove  the  masses  of  char  from  the  sides 
of  the  dish  by  the  stirring-rod.  Heat  to  boiling  and  filter.  Use  the 
filtrate  for  the  Marsh  apparatus,  adding  it  gradually. 

The  arsenic  mirror  may  be  weighed  in  the  usual  manner,  if  of  suffi- 
cient size. 

Keinsch^s  Test.* — Two  hundred  cc.  of  the  beer  arc  acidified  with  i  cc. 
of  pure,  concentrated,  arsenic-free  hydrochloric  acid,  and  evaporated  to 
half  its  volume.  15  cc.  more  of  hydrochloric  acid  are  then  added,  and 
a  jjiece  of  pure  burnished  copper  foil  half  an  inch  long  and  a  quarter  of 
an  inch  wide  is  immersed  in  the  liquid  and  kept  in  it  for  an  hour  while 
simmering,  replacing  from  time  to  time  the  water  lost  by  evaporation.  If 
after  the  lapse  of  an  hour  the  c()])i)er  still  remains  bright,  no  arsenic  is 
present. 

If  the  copper  shows  a  deposit,  remove,  wash  with  water,  alcohol,  and 
ether,  and  diy.  Then  place  the  copper  in  a  subliming-tube,  and  heat 
over  a  low  flame.  Tetrahedral  crystals,  aj^parent  under  the  microscope^ 
show  the  presence  of  arsenic.  Blackening  of  the  copper  does  not  in  itself 
prove  arsenic. 

*  Jour.  Soc.,  Chem  Ind.,  20,  p.  646. 


ALCOHOLIC  REl^ERAGES. 


72; 


Detection  and  Determination  of  Preservatives.  —See  Chapter  XVI T I. 
Sulphurous  acid  may  be  determined  by  direct  titration,  as  in  the  case  of 
wine. 

MALT    EXTRACT. 

True  malt  extract  is  a  syrupy  tluid  having  a  specific  gravity  of  from 
1.3  to  1.6,  and  made  up  in  accordance  with  the  following  directions  of 
the  1880  Pharmacopoeia:  U[)on  100  parts  of  coarsely  powdered  malt 
contained  in  a  suitable  vessel,  pour  100  parts  of  water,  and  macerate 
for  six  hours.  Then  add  400  [)arts  of  water,  heated  to  about  30°  C. 
and  digest  for  an  hour  at  a  temperature  not  exceeding  55°  C.  Strain 
the  mixture  with  strong  pressure.  Finally,  by  means  of  a  water-bath  or 
vacuum  apparatus,  at  a  temperature  not  exceeding  55°  C,  evaporate 
the  strained  liquid  rapidly  to  the  consistence  of  thick  honey. 

Keep  the  product  in  well- closed  vessels  in  a  cool  place. 

Such  an  extract  has  a  residue  of  at  least  70%,  consisting  chieflv  of 
maltose,  and  contains  about  2%  of  diastase.  It  should  furthermore  he 
capable  of  converting  its  own  weight  of  starch  at  55°  C.  in  less  than  ten 
minutes. 

The  following  are  analyses  of  three  samples  of  pure  malt  extract:* 


•a.H 

i 

tC  > 

•r;  js 

0 
< 

0 
2 

•A 

ii  9 

Volatile 
Acids. 

'C 
X 

Q 

< 

Phosph 
Acid. 

Diastatic  Action. 

A 

r-.^87 

0 

72.31 

0.231 

0-033 

3-329 

62.52 

5-25 

1. 21 0.483 

Complete  in  less  than    ,  min. 

B 

1.421 

0 

76.65  0.275 

0.021 

3.116(65.41 

6.94 

1. 190. 556 

"          "    "       "     10    " 

C 

1.498 

0 

79.81  0.386 

1 

0.0534.872I61.32 

12.39 

r. 23  0.428 

5 

There  are  on  the  market  man\'  so-called  malt  extracts  widely  advertised 
for  their  tonic  and  medicinal  virtues,  having  the  taste  and  consistency 
of  beer  or  ale.  In  fact  they  are  virtually  beer,  differing  therefrom  mainly 
in  respect  to  price.  Such  "malt  extracts"  have  no  diastase,  and  their 
value  as  nutrients  depends  almost  entirely  on  their  sugar  content. 

Harrington t  has  analyzed  twenty-one  of  the  best  known  of  these 
alleged  malt  extracts,  the  maximum,  minimum,  and  mean  results  of  his 
analyses  being  as  follows: 


*  Penn.  Dept.  of  Agric.  An.  Rep.,  1898,  p.  85. 

t  Boston  Medical  and  Surgical  Journal,  Dec.  31,  1896. 


750 


FOOD  INSPECTION  /IND  ANALYSIS. 


Specific  Alcohol. 

Cjravitv. 


Total 
R  sidue. 


Ash. 


Maximum i-0555  7- 13 

Minimum 1.0149       [         0.74 

Mean I        I         3.94 


13-63         j         0.53 
5.13  0.20 

8.78 


Xonc  of  them  contained  any  diastase,  and  several  were  preserved 
with  salicylic  acid. 

DISTILLED   LIQUORS. 

These  beverages  differ  from  those  hitherto  considered,  by  reason  of 
their  high  alcoholic  content  and  low  extract  or  residue.  Indeed,  when 
first  distilled  they  are  entirely  without  residue,  but  from  long  storage  in 
casks,  they  absorb  certain  extractives  from  the  wood,  that  impart  more 
or  less  flavor  as  well  as  color. 

When  any  fermented  alcoholic  infusion  is  subjected  to  distillation 
under  ordinarv  circumstances,  a  distillate  results  which  consists  of  a 
mixture  with  water  of  a  large  number  of  alcohols,  chief  among  which 
is  ethyl  alcohol.  The  high  boiling  alcohols — amyl,  butyl,  propyl,  etc.,. 
with  their  esters — exist  in  the  distillate  in  small  amount,  constituting 
what  is  known  as  fusel  oil.  The  various  distilled  liquors  of  commerce 
are  made  by  just  such  a  process  of  distillation,  the  product  var^'ing  widely 
in  flavor  and  character  with  the  basis  from  which  it  was  distilled. 

The  so-called  pot-still  (the  old-fa.shioned  copper  still  and  worm) 
is  well  adapted  for  the  production  of  ] rotable  spirits  such  as  whiskey, 
brandy,  gin,  and  rum,  as  these  products  .should  contain  the  congeneric 
substances  which  give  the  liquors  their  special  character;  it  is  not,, 
however,  suited  for  the  manufacture  of  pure  alcohol,  because  repeated 
distillation  would  be  required  for  purification. 

Xow,  however,  by  the  use  of  improved  ajjjjaratus,  such  as  the  Coffey 
still,  involving  the  principle  of  fractional  condensation,  it  is  possible  to 
obtain  what  is  known  as  "  silent  spirit,"  or  ethyl  alcohol,  free  from 
fusel  oil.  With  proper  appurtenances  for  rectifying,  one  can  now  obtain 
95%  alcohol  by  two  di.stillations. 

Standards  for  Spirits.— The  following  are  the  .standards  adopted 
by  the  Joint  Committee  of  the  Association  of  Official  Agricuhural 
Chemi.sts  and  the  Association  of  State  and  National  Food  and  Dairy 
Departments: 

Distilled  Spirit  is  the  di.stillate  obtained  f-om  a  fermented  ma.sh  of 
cereals,   mola.sses,   sugars,   fruits,   or  other   fermentable   substance,   and 


ALCOHOLIC  BEVERAGES. 


731 


contains  all  the  volatile  flavors,  essential  oils,  and  other  substances 
derived  directly  from  the  material  used,  and  the  hij^her  alcohols,  ethers, 
acids,  and  other  volatile  Ijodies  congeneric  with  ethyl  alcohol  produced 
during  fermentation,  which  are  carried  over  at  the  ordinary  temjjera- 
ture  of  distillation,  and  the  princijial  part  of  which  are  higher  alcohols 
estimated  as  amylic. 

Alcohol,  Cologne  Spirit,  Neutral  Spirit,  Velvet  Spirit,  or  Silent  Spirit, 
is  distilled  spirit  from  which  all,  or  practically  all,  of  its  constituents 
except  ethyl  alcohol  and  water,  are  separated,  and  contains  not  less  than 
94.9%  (189.8  proof)  by  volume  of  ethyl  alcohol. 

Composition  of  Fusel  Oil. — Fusel  oil  varies  considerably  in  compo- 
sition with  the  source  from  which  it  is  derived.  Amyl  alcohol,  being 
ir.  all  cases  its  chief  constituent,  is  frequently  known  commercially  as 
fusel  oil.  The  alcohols  found  in  fusel  oil  with  their  formulas,  specific 
gravity,  and  boiling-points  are  as  follows: 


Formula. 

Specific 
Gravity. 

Boiling-point. 

Ethvl    alcohol QH^OH 

Propyl       "      C.,H-OH 

•794 
.820 
.803 
.811 

78.4° c. 

97°  C. 
iiS°C. 
130°  c. 

Butvl         "      CJI/)H 

Amvl         "      C\H,,OH 

Hexvl        "      CeHijOH 

The  following  acids  have  been  found  in  fusel  oil,  usually  combined 
with  the  alcohols  to  form  compound  ethers: 


Acetic HC^HjO, 

Propionic HC3H5O2 

Butyric HC.H.O, 

Valerianic HC.HoO, 


Caproic HCgHnO, 

(Enanthylic HCjHjaO, 

Capr}lic HC^H.^O, 

Pelargonic HC.jHj^O, 


Aging. — Freshly  distilled  liquors  all  contain  notable  quantities  of" 
fusel  oil,  wliich  renders  them  harsh  and  unfit  for  use,  but  by  the  process- 
of  aging,  they  become  in  several  years  mellow  and  palatable.  The  chemi- 
cal changes  which  take  place  during  aging  are  discussed  under  whiskey. 


WHISKEY. 


Process  of  Manufacture. — Whiskey  is  the  liquor  resulting  from  the 
distillation  of  a  fermented  infusion  of  grain,  the  process  being  carried 
out  in  a  pot-still,  or  some  other  form  of  still,  constructed  so  that  the 
resulting  liquor  contains  not  only  the  alcohol,  but  also  the  greater  part 


732  FOOD    INSPECTION  /1ND   ANALYSIS. 

of  the  congeneric  substances  which  are  vaporized  with  the  alcohol.  The 
fermented  infusion  known  as  the  "mash"  is  obtained  by  steeping  in 
water  the  starch-containing  material,  usually  barley,  rye,  corn  (maize), 
or  oats  mixed  with  malt,  and  subjecting  the  mixture  to  the  action  of 
tht  diastase  contained  in  the  mall,  in  much  the  same  manner  as  the 
mashing  process  in  the  brewing  of  beer,  excei)t  that  for  whiskey  the 
process  of  saccharous  fermentation  is  carried  further,  with  a  view  to 
obtaining  a  maximum  yield  of  maltose  and  a  minimum  of  dextrin. 
Yeast  is  afterwards  added,  an^l  alcoholic  fermentation  allowed  to  proceed 
Avith  pro])er  precautions. 

The  fermented  wort  from  whatever  source  obtained  is  subjected  to 
distillation,  purposely  avoiding  rectification  or  separation  of  the  fusel 
oil  and  other  congeneric  substances  which  are  valuable  as  flavors.  The 
product  of  the  first  distillation  is  called  "low  wines,"  and  is  redistilled; 
the  product  of  the  second  distillation  is  commonly  divided  into  three 
fractions,  of  which  the  middle  portion,  or  "  clean  si)irit  "  is  retained 
for  the  whiskey,  while  the  first  ("  foreshots  ")  and  the  last  fraction 
("faints")  are  mixed  with  the  next  portion  of  low  wine  to  be  redistilled. 
If  the  whiskey  is  too  high  in  alcohol,  it  is  diluted  to  the  proper  strength. 

As  new  whiskey  is  crude  and  harsh  in  taste,  it  is  subjected  to  "  aging," 
or  storing  in  casks  for  a  number  of  years.  The  aging  process  softens 
and  refines  the  flavor,  but  recent  investigations  have  proved  that  this 
Is  not  due,  as  formerly  believed,  to  transformation  of  fusel  oil  into  esters, 
although  the  esters  increase  in  amount  during  aging,  as  do  also  the  acids 
— esjjecially  the  volatile  acids — the  aldehydes,  and  the  furfural.  As  a 
matter  of  fact,  the  jK-rcentage  of  fusel  oil  increases  instead  of  diminishes 
on  aging,  due  to  the  evaporation  of  water  and,  in  a  lesser  degree,  of 
alcohol  through  the  wood;  the  actual  amount,  however,  remains  f)rac- 
tically  the  same  as  at  the  start  (see  table,  p.  737).  When  first  distilled, 
whiskey  is  perfectly  colorless,  but  during  the  aging  it  extracts  more  or 
less  color  and  some  flavor  from  the  casks  in  which  it  is  stored.  This 
color  is  especially  pronounced  in  American  whiskies,  owing  to  the  pre- 
vailing custom  of  charring  the  inside  of  the  cask.  Its  flavor  varies 
considerably  with  the  nature  of  the  grain  used  in  its  preparation. 

U.  S.  Rulings. — The  following  decision  of  President  Roosevelt,  based 
on  an  opini(;n  of  Attorney-General  Bona[)arte,  was  promulgated  by  Sec- 
retary Wilscjn,  April  11,  1907:* 

♦  Thus  dct ision  has  Ixren  overruled  by  President  Taft,  whose  (^pinion  is  the  basis  of  Food 
laspcrtirjn  Det  Ision  \o.  113  (Feb.  i6,  igio),  sif^nefl  by  the  secretaries  of  the  Treasury,  Agri- 
culture, and  Commerce  and  LafK)r.     The  (  hief  points  of  thus  decision  foll<jw: 


ALCOHOLIC  BRyERAGHS.  733 

"  Straight  whiskey  will  be  labeled  as  such. 

"  A  mixture  of  two  or  more  straight  whiskies  will  be  labeled  '  blended 
whiskey,'  or  '  whiskies.' 

"  A  mixture  of  straight  whiskey  and  ethyl  alcohol,  provided  that 
there  is  a  sufficient  amount  of  straight  whiskey  to  make  it  genuinely  a 
*  mixture,'  will  be  labeled  as  compound  of,  or  compounded  with,  pure 
grain  distillate. 

"  Imitation  whiskey  will  be  labeled  as  such." 

Joint  Standards. — The  following  are  the  standards  of  the  Joint  Com- 
mittee of  the  A.  O.  A.  C.  and  the  A.  S.  N.  F.  D.  D. : 

New  Whiskey  is  the  properly  distilled  spirit  from  the  properly  pre- 
pared and  properly  fermented  mash  of  malted  grain,  or  of  grain  the  starch 
of  which  has  been  hydrolyzed  by  malt;  it  has  an  alcoholic  strength 
corresponding  to  the  excise  laws  of  the  various  countries  in  which  it  is 
produced,  and  contains  in  100  liters  of  proof  spirit  not  less  than  100  grams 
of  the  various  substances  other  than  ethyl  alcohol  derived  from  the  grain 
from  which  it  is  made,  and  of  those  produced  during  fermentation, 
the  principal  part  of  which  consists  of  higher  alcohols  estimated  as 
amylic. 

Whiskey  {Potable  Whiskey)  is  new  whiskey  which  has  been  stored 
in  wood  not  less  than  four  years  without  any  artificial  heat  save  that 
which  may  be  imparted  by  warming  the  storehouse  to  the  usual  tem- 
perature, and  contains  in  100  liters  of  proof  spirit  not  less  than  200  grams 
of  the  substances  found  in  new  whiskey,  save  as  they  ar2  changed  or 
eliminated  by  storage,  and  of  those  produced  as  secondary  bodies  during 
aging;  and,  in  addition  thereto,  the  substances  extracted  from  the  casks 
in  which  it  has  been  stored.     It  contains,  when  prepared  for  consumption 

All  unmixed  distilled  spirits  from  grain,  colored  and  flavored  with  harmless  color  and 
flavor,  in  the  customary  w^ays,  either  by  the  charred  barrel  process,  or  by  the  addition  of 
caramel  and  harmless  flavor,  if  of  potable  strength  and  not  less  than  80°  proof,  are  entitled 
to  the  name  whiskey  without  qualification. 

Whiskies  of  the  same  or  different  kinds  (i.e.,  straight,  rectified,  redistilled,  and  neutral 
spirits  whiskies)  are  like  substances  and  mixtures  of  such,  with  or  without  harmless  color 
or  flavor  used  for  purposes  of  coloring  and  flavoring  only,  are  blends. 

Potable  alcoholic  distillates  from  sources  other  than  grain  (e.g.,  cane,  fruit,  or  vegetables), 
colored  and  flavored,  are  imitations  and  mixtures  of  such  with  grain  distillate  are  com- 
pounds. 

A  distillate  of  grain  (e.g.,  corn)  flavored  to  simulate  a  whiskey  of  another  kind  (e.g., 
rye)  is  an  imitation  of  that  whiskey. 

Attorney-General  Wickersham  (F.  I.  D.  No.  127)  has  further  decided  that  the  name 
"Canadian  Club  whiskey"  is  distinctive  and  it  is  therefore  unnecessar)-  to  place  the  word 
"blend"  on  the  label. 


734  FOOD   INSPECTION   AND   ANALYSIS. 

as  permitted  by  the  regulations  of  the  Bureau  of  Internal  Revenue,  not 
less  than  45^^  by  volume  of  ethyl  alcohol,  and,  if  no  statement  is  made 
concerning  its  alcoholic  strength,  it  contains  not  less  than  50*^  of  ethyl 
alcohol  by  volume,  as  prescribed  by  law. 

Rye  Whiskey  is  a  whiskey  in  the  manufacture  of  which  rye,  cither 
in  a  malted  condition  or  with  sufticicnt  barley  or  rye  malt  to  hydrolyze 
the  starch,  is  the  only  grain  used. 

Bourbon  Whiskey  is  a  whiskey  made  in  Kentucky  from  a  mash  of 
Indian  corn  and  rye,  and  barley  malt,  of  which  Indian  corn  forms  more 
than  5o9c. 

Coru  Whiskey  is  whiskey  made  from  malted  Indian  com  or  of 
Indian  com  the  starch  of  which  has  been  hydrolyzcd  by  barley  malt. 

Blended  Whiskey  is  a  mixture  of  two  or  more  whiskies. 

Scotch  Whiskey  is  whiskey  made  in  Scotland  solely  from  barley  malt, 
in  the  dr}-ing  of  which  peat  has  been  used.  It  contains  in  100  liters  of 
proof  spirit  not  less  than  150  grams  of  the  various  substances  prescribed 
for  whiskey  exclusive  of  those  extracted  from  the  cask. 

Irish  Whiskey  is  whiskey  made  in  Ireland,  and  conforms  in  the 
proportions  of  its  various  ingredients  to  Scotch  whiskey,  save  that  it  may 
be  made  of  the  same  materials  as  prescribed  for  whiskey,  and  the  malt 
used  is  not  dried  over  peat. 

U.  S.  P.  Standards. — The  requirements  for  whiskey  are  as  follows: 
It  should  be  at  least  two  years  old;  in  specific  gravity  it  should  lie 
between  the  limits  of  0.945  and  0.924;  its  alcoholic  content  should  be 
not  less  than  y,%  nor  more  than  47.5%  by  weight;  the  residue  from 
100  cc.  should  be  not  more  than  0.5  gram,  which  should  be  neither  sweet 
nor  spicy,  should  dissolve  in  10  cc.  of  cold  water,  and  this  solution  should 
be  colored  only  a  pale  green  when  treated  with  a  drop  of  very  dilute 
ferric  chloride  solution  (a  deeper  color  would  indicate  more  than  traces 
of  tannin).  In  evaporating  the  liquor  on  the  water-bath  for  the  residue, 
the  last  traces  volatilized  should  have  an  agreeable  odor  free  from  harsh- 
ness, indicative  of  the  absence  of  fusel  oil.  Its  reaction  should  be  slightly 
acid,  but  not  more  than  1.2  cc.  of  normal  alkali  .should  be  required  to 
neutralize  100  cc.  of  the  liquor,  using  litmus  as  an  indicator.  If  50  cc. 
are  shaken  vigorou.sly  with  25  grams  of  kaolin,  allowed  to  stand  an  hour 
and  filtered,  the  color  of  the  filtrate  should  not  be  much  lighter  than 
before  treatment. 

Composition.^ — Whi.skey  consi.sts  chiefly  of  alcohol  and  water,  with 
relatively  small  amounts  of  fusel  oil,  acids,  esters,  aldehydes,  and  fur- 


ALCOHOLIC  RRyER/IGES. 


735 


fural.  Its  extract,  derived  mainly  from  the  casks  in  which  it  is  stored, 
should  consist  only  of  small  amounts  of  tannin,  sugar,  and  coloring 
matter. 

British  Whiskies. — Scotch  and  Irish  whiskies  are  aged  in  uncharred 
barrels,  hence  they  are  of  a  lighter  color  than  the  American  ])roduct. 
Scotch  whiskey  is  further  characterized  by  its  smoky  taste,  due  to  the 
peat  over  which  it  is  dried.  The  following  analyses  by  Vasey  *  illustrate 
the  composition  of  Scotch  and  Irish  whiskey  of  dilTerent  ages,  of  neutral 
spirits  used  in  compounding  ("  blending ")  and  adulterating,  and  of 
the  compounded  liquors: 


Grams  per  lOO  Liters  of  Absolute  Alcohol. 


Volatile 
Acids. 


Esters. 


Alde- 
hydes. 


Furfural. 


Fusel  Oil. 


Pot-still  Scotch  whiskey,  8  years  old  . 
Pot-still  Scotch  whiskey,  25  years  old 

Irish  whiskey,  new 

Irish  whiskey,  7  years  old 

Neutral  spirit  for  "blending" 

"  Blended  "  Scotch 

"Scotch,"  probably  all  neutral  spirits 


64.8 
20.9 
41.8 
8.4 
39-1 
16.8 


125. 1 

7-7 
20.9 

23.8 
106.8 


14.2 
66.1 

6.5 
II  .2 

4-9 
14-3 


4.0 

5-4 
0.4 

3-4 
0.4 

3-5 
none 


200.0 
180.0 
174.0 
204.0 
trace 
108.5 
none 


It  will  be  noted  that  the  congeneric  substances  in  whiskey  increase 
on  aging,  although  in  the  ca.se  of  fusel  oil  this  apparent  increase  is 
doubtless  due  merely  to  concentration  dependent  on  evaporation.  The 
sample  of  neutral  spirits  contained  only  small  amounts  of  the  congeneric 
substances,  while  the  "  blended  "  whiskies  were  deficient  in  most  of 
these  substances. 

American  Whiskies. — These  have  a  deeper  color  than  the  British 
whiskies  (due  to  the  charred  barrel)  and  a  rich  fruity  flavor  without 
the  suggestion  of  smoke. 

In  the  table  on  p.  736  are  given  analyses  by  Shepard  f  of  fourteen 
leading  brands,  including  both  rye  and  bourbon,  varying  in  age  from 
four  to  eight  years;  also  of  two  samples  of  neutral  spirits  used  for  com- 
pounding and  adulterating. 

A  summary  of  the  resuks  obtained  by  Crampton  and  Tolman  %  in 
the  analysis  of  fourteen  brands  of  rye  and  seventeen  brands  of  bourbon 
whiskey  at  differing  stages  of  aging  appear  in  the  table  on  page  737.  The 
barrels  were  kept  in  U.  S.  bonded  warehouses  during  aging,  and  samples 

*  Potable  Spirits,  pp.  82,  83,  and  87. 

fThe  Constants  of  Whiskey,  S.  Dak.  Food  and  Dairy  Commission,  March,   1906. 

X  Jour.  Am.  Chem.  Soc,  30,  190S,  p.  98. 


736 


FOOD  INSPECTION  AND  ANALYSIS. 


Grams  per  lOO  Liters  of  the  Liquor. 


Acids. 


(L, 


W 


Rye 

Bourbon  

Standard  

Hand-made  sour  mash. 

Hand-made  sour  mash. 

Hand-made  sour  mash. 

Bourbon  

Special  reserve 

Sour  mash 


Neutral  spirits. 


5 

4i 

4 

4 

6 

6 

7 

5* 

7 

=; 

7i 

4 


5°- 1 
50-1 
50.0 

49-8 

50-- 

49-9 

50-4 

50 

50 

49-9 

49.8 

50-1 
49-8 
50.1 
95-6 
94-4 


160 
162 
148 
132 
138 

153 
180 
129 
212 
124 
177 
139 
10 

3 


-3 


92.0 
68.4 
66.8 
67.1 
62.4 
49-2 
74.8 
58.8 
74-4 
60.9 

93 -o 

58.2 

66.5 

50-3 

7-5 

6-3 


12.8 

9-3 
10.2 
10.2 
7-5 
7-5 
8.6 

9-9 
9-9 

7-2 
13-5 

7-2 

9.0 

6.3 

1.2 

1-4 


81.8 
60.7 

55-9 
74-8 
55-9 
39-6 
61.6 
69.6 
70.8 

49-3 
94.0 
64.0 
76.6 
54-6 
15-4 
64.2 


17-5 
17-5 
10.0 
12.0 

15-0 
8.0 
10.5 
14.0 
12.5 
9-5 
22.5 

9-5 
10. o 

7-5 

2-5 

II  .0 


3-0 

3-2 
2-4 
2.6 
2.6 
I.O 

1-3 
0.7 

2.5 
0.8 

5-0 
0.5 
1.7 
1-5 


84.9 
102.6 
160.4 

130-9 
152.0 
107.4 
192.7 

137. 1 
117. o 

141. 7 

II9-5 

95-3 

193.6 

152.0 

30.0 

39-6 


were  withdrawn  at  intervals  of  a  year  for  eight  years.  As  the  minimum 
figures  for  certain  constituents  are  abnormal,  the  next  to  the  minimum 
figures  are  also  given.  It  will  be  noted  that  during  the  first  few  years 
there  was  a  marked  increase  in  actual  amounts  of  all  the  constituents 
determined,  except  fusel  oil,  over  and  above  that  due  to  concentration, 
but  after  three  or  four  years  the  acids  and  esters  do  not  materially 
change.  The  r}'e  whiskies  contained  larger  amounts  of  solids,  acids, 
esters,  etc.,  than  the  bourbons,  but  this  was  attributed  to  the  fact  that 
heated  warehou.ses  are  used  for  r)'e,  and  unhcated  for  bourbon  whiskey. 
The  authors  state  that  the  characteristic  aroma  of  American  whiskey, 
also  the  oily  appearance  and  the  "  body  "  (solids),  are  due  to  the  charred 
barrels. 

Thirty-.seven  samples  of  whiskey,  purchased  by  the  glass  from  various 
Mas.sachu.setts  saloons,  were  examined  by  the  Massachusetts  State 
Board  of  Health  in  1894,  with  the  following  results: 


Per  Cent 

Alcohol  by 

Weight. 

Per  Cent 
Extract. 

Maximum 

45-96 
30.70 

36-51 

1.68 
0.08 
0.50 

Minimum 

Mean 

/tLCOHOLlC  BEVERAGES.  737 

SUMMARY  OF  ANALYSES  OF  AMERICAN  WHISKIES  OF  DIFFERENT  AGES 


One  year  old: 


Two  years  old: 


Rye  Whiskey. 
New:  Average  .  .. 

Maximum  . 

Minimum  * 

Average  .  .. 
Maximum  . 

Minimum  * 

Average  .  .. 
Maximum  . 

Minimum  * 

Three  years  old:  Average  .  .. 
Maximum  . 

Minimum  * 

Four  years  old:    Average  .  .. 
Maximum  . 

Minimum  * 

Eight  years  old :   Average... 
Maximum  . 

Minimum  * 

Bourbon  Whiskey. 
New:  Average  .  .. 

Maximum  . 

Minimum  * 

Average  .  . 
Maximum 

Minimum  * 

Two  years  old:     Average  . 

Maximum  . 

Minimum  * 

Three  years  old :  Average  .  . . 
Maximum  . 

Minimum.* 

Four  years  old:    Average  .  . 
Maximum 

Minimum  * 

it  years  old:  Average  .  .. 
Maximum  . 

Minimum  * 


One  year  old: 


Eight 


Proof. 


101.2 
102,0 

100. o 

102.5 
104.0 

lOI.O 

104.9 
109.0 

100. o 

107.7 
112.0 

104.0 

111.2 
118. o 

105.0 

123.8 
132.0 

112. o 


101.0 
104.0 

100. o 

101.8 
103.0 

1 00.0 

102.2 
104.0 

100.  o 

103.0 
106.0 

1 00.0 

104.3 
108.0 

100. o 

111.1 
124.0 

102.0 


Grams  per  100  Liters  of  100  Proof  Spirits. 


Color 


0.0 
0.0 

0.0 

8.8 

13.8 

7-2 

6.6 

11.6 

16.7 

8.8 

8.6 

13.2 

18.3 

/  11-4 

\  10. 1 

14.0 

18.9 

11.6 

18.6 

24.2 

/13-8 

\13-7 


0.0 


7.1 
10.9 


6 

5 
10.0 
13.8 

8.9 

7- 
10.8 
14.8 

8.6 

7-4 
14.2 
20.9 

12-3 

10.5 


Extract. 


13.3 

30.0 

5-0 
119.7 
171. o 

93-0 
92.0 
144.7 
199.0 
121 .0 
94.0 
171.4 
224.0 
145-0 
119. o 
185.0 
238.0 
156.0 

153-0 
256.0 

339-0 
214.0 
200.0 


26.5 
i6[  .0 

4.0 

99.6 

193-0 

61.0 

54-0 

126.8 

214.0 

81.0 

78.0 

149.3 

245.0 

95-0 

90.0 

151.9 

249.0 

101. o 

92.0 

210.3 

326.0 

152.0 

141-0 


Acids. 


4.4 
72.0 


46.6 
60.5 

31-1 

5-8 

51.9 

75-6 

44-3 
11.0 
62.7 
81.8 

52-3 
16.4 
65.9 

83.8 
58.6 

17-3 
82.9 


10.0 
29.1 


41.1 

55-3 
24.7 

7-2 
45.6 
61.7 
25-5 
23-3 
54.3 
64.8 
38-4 
32 
58 

73 

40 

40 

76 

91.4 

64.1 

S3-7 


Esters 


16.3 

21.8 

4.3 
37.0 
64.8 
6.8  1 
6.8/ 
54.0 
75-1 
41-5 
31-2 
61.5 
79-8 
47-6 

34-3 
69.3 
89.1 

57-7 

89.1 

126.6 

68.4 

40.9 


18. 4 
53-2 
13.0 
28.6 

55-9 
17.2 
10.4 
40.0 
59-8 
24-4 
II. 2 
48.1 
73-0 
27.2 


53.5 
80.6 
28.2 
13-8 
65.6 
93-6 
37-7 


Alde- 
hydes. 


5.4 
15-0 

0-7 

7.0 

15-5 

2.8 

10.5 
18.7 

5-4 

12.5 
20.8 

6.5 
13.9 
22.1 

6.4 
16.0 
26.5 

7-9 


3.2 
7-9 


Fur- 
fural. 


1.0 
1.9 

trace 

1.8 
Z-i 
0.4 
2.2 
5-7 
0-7 
1.5 
6.1 

0.7 
2.8 
6-7 

0.7 

3.4 
9-2 

0.8 


1.0 

trace 

5.8 

1.6 

8.6 

7-9 

2-7 

trace 

8.4 

1.6 

12.0 

9-1 

5-9 

0.4 

10.5 

1.7 

22.1 

9-5 

5-9 

0.6 

11.0 

1.9 

22.0 

9.6 

6-9 

0.8 

12.9 

2.1 

28.8 

10.0 

Fusel 
Oil. 


90.4 

161.8 

/    61.8 

I    43-7 

111.5 

194.0 

/    80.4 

I    66.4 

112.4 

214.0 

/    83.4 

\    82.2 

112.7 

202.0 

/    79-0 

\    60.0 

125.1 

203 -5 
/  83.8 
I  67.8 
154.2 
280.3 
f  109.0 
1  107.1 


100.9 

171-3 

'    71.3 

I    42.0 

110.1 

173-4 

r    58.0 

L    42-8 

108.9 

197. 1 

r    86.2 

I    42.8 

112.4 

221.8 

f    88.0 

I    43-5 
123.9 

237-1 
f    9S-0 

I    43-5 

143.5 

241.8 

f  110. o 

I    47-6 


*  Minimum  and  next  to  the  minimum. 


738  FOOD  INSPECTION  AND  ANALYSIS. 

Seven  of  these  samples  had  an  excess  of  tannic  acid,  three  had  no 
tannic  acid  at  all,  and  two  or  three  had  insoluble  residues. 

Adulteration  of  Whiskey. — Imitation  whiskey  is  often  concocted  by 
diluting  alcohol  or  neutral  spirit  to  the  proper  strength,  coloring  with 
caramel,  sometimes  adding  for  body  prune  juice,  and  adding  for  flavor 
certain  essential  oils,  such  as  oil  of  winlcrgreen,  and  artificial  fruit 
essences,  such  as  a'nanthic  and  jK-largonic  ethers.  As  a  rule,  a  small 
amount  of  pure  whiskey  is  mixed  with  the  artilkial  to  give  it  flavor. 

What  has  long  been  known  as  "  blended  whiskey  "  is  either  an 
imitation  pure  and  simple,  or  a  compound  of  whiskey  and  neutral  spirits, 
artificially  colored  and  flavored.  According  to  the  U.  S.  decisions, 
the  term  "  blended  whiskey  "  is  restricted  to  a  mixture  of  different 
kinds  of  genuine  whiskey,  colored  and  flavored. 

Among  Fleischman's  recipes  for  "  blended  "  whiskey  is  the  following, 
which  he  claims  to  be  the  very  lowest  grade: 

Spirits 32  gallons 

Water 16 

Caramel 4  ounces 

Beading  oil i  ounce 

"Beading  oil"  is  prepared  by  mixing  48  ounces  oil  of  sweet  almonds 
with  12  ounces  C.  P.  sulphuric  acid,  neutralizing  with  ammonia,  adding 
double  the  volume  of  proof  spirits,  and  distilling.  This  i)reparation  is 
so  called  because  it  is  largely  used  for  putting  an  artificial  bead  on  cheap 
liquors. 

A  little  creosote  is  sometimes  added  to  give  a  burnt  taste  in  sem- 
blance of  Scotch  whiskey.  Pungent  materials  such  as  cayenne  pepper 
are  said  to  be  used  as  adulterants,  but  no  record  is  known  of  any  substance 
being  used  more  injurious  than  the  alcohols.  Sugar  is  a  frequent  adul- 
terant. 

Some  doubt  exists  as  to  the  injurious  effects  of  fusel  oil  on  the  system. 

The  following  analyses  by  Ladd  *  show  the  composition  of  neutral 
spirits,  and  imitation  whiskey  consisting  of  neutral  spirits  diluted  with 
water,  colored  with  caramel  and  flavored : 

*  N.  Dak.  Agric.  Exp.  Sta.  Rep.,  1906,  Part  II,  p.  145. 


/tLCOHOLIC   BEl^ER/IGES. 


739 


0 
O 

h 

< 

Grams  per  100  Liters  of  the  Liquor. 

X 

< 

Acids. 

0) 

•p 

v 

•0 

< 

■3 
1 

•0 

K 

pi 
<« 
I 

0 

1 

3 
111 

Neutral  spirits 

94.0 

40. 1 
45-8 
45-0 

2.4 

.^66. 4t 
854-ot 
456. of 

0.0 

4-4 
2.0 

5-5 

7.2 
43-2 
20.4 

9.6 

0.0 
9.0 
3-0 

3-0 

7-2 

34.2 

17-4 
6.6 

26.4 

3-5 
14.0 

5-2 

6.0 

trace 
trace 
trace 

trace 
0.4 

I.O 

0.8 

28.0 

37.0 
42-3 

Imitation  whiskey,  rye 

"               "         malt  .  .  .  . 
"               "         rye 

t   Includes  caramel  color. 


BRANDY  AND  COGNAC. 


Brandy  is  the  product  of  the  distillation  of  fermented  grape  Juice  or 
wine.  In  a  broader  sense  the  term  brandy  is  sometimes  applied  to  liquor 
distilled  from  the  juices  of  other  fruits,  such  as  apples,  peaches,  cherrieS; 
etc.  The  finest  grades  of  brandy,  such  as  pure  cognac  and  armagnac 
(named  from  towns  in  France  in  which  they  were  originally  distilled), 
are  made  from  choice  white  wine  by  the  use  of  pot  stills,  and  naturally 
command  a  high  price.  Brandy  of  a  lower  grade  is  distilled  from  the 
cheaper  wines,  and  sometimes  from  the  fermented  marc,  or  refuse,  of  the 
grape,  as  well  as  from  the  lees  and  "scrapings"  of  the  casks.  The  best 
brandies  are  sometimes  rectified  by  a  second  distillation.  Like  whiskey, 
the  fresh  brandy  is  colorless,  and  would  so  remain  if  stored  in  glass  or 
stone.  The  color  is  due  to  the  wooden  casks  in  which  it  is  stored.  Brandy 
consists  of  nearly  pure  alcohol  and  water,  having  a  characteristic  flavor, 
differing  somewhat  according  to  the  nature  and  quality  of  the  wine  from 
which  it  was  prepared.  The  chief  flavor  of  pure  cognac  is  due  to  ccnan- 
thic  ether. 

Composition. — Vasey    gives    the    following    analyses    of    cognac    and 

of  brandy  adulterated  with  neutral  spirits: 

Ten  Year^'^OId.  Brandy  Mixed  with  Neutral  Spirits. 

Volatile  acids 74.5  79.4  grams  per  100  liters  of  absolute  alcohol 

Esters 109.3  3--4 

Aldehydes 16.6  7.4 

Furfural 1.7  0.6 

Fusel  oil 124.2  490 


Analysis  of  Potable  Spirits,  p.  20. 


740 


FOOD  INSPECTION  AND  AN  A  LYSIS. 


Thirty-seven  samples  of  brandy,  collected  from  Massachusetts  bar-, 
rooms  in  1S04  and  examined  by  the  State  Board  of  Health,  showed  the 
followint:  results: 


Per  Cent 

Alcohol  by 

Weight. 

Per  Cent 
Extract. 

50.70 
21.30 
40-54 

3.00 

O.IO 

0-93 

Minimum 

Mean 

Three  of  these  samples  were  artificially  prepared  mixtures  of  alcohol 
and  water,  one  showed  the  presence  of  cloves,  live  contained  tannin  in 
e.xcess.  nine  were  excessively  acid,  and  two  had  insoluble  residues. 

Joint  Standards. — The  following  are  the  standards  of  the  A.  O.  A.  C. 
and  the  A.  S.  N.  F.  D.  D.: 

New  Brandy  is  a  properly  distilled  spirit  made  from  wine,  and 
contains  in  100  liters  of  proof  spirit  not  less  than  100  grams  of  the 
volatile  flavors,  oils,  and  other  substances,  derived  from  the  material 
from  which  it  is  made,  and  of  the  substances  congeneric  with  ethyl  alcohol 
produced  during  fermentation  and  carried  over  at  the  ordinary  tem- 
peratures of  distillation,  the  principal  part  of  which  consists  of  the 
higher  alcohols  estimated  as  amylic. 

Brandy  {Potable  Brandy)  is  new  brandy  stored  in  wood  for  not  less 
than  four  years  without  any  artificial  heat  save  that  which  may  be 
imparted  by  warming  the  storehouse  to  the  usual  temperature,  and 
contains  in  100  liters  of  proof  spirit  not  less  than  150  grams  of  the  sub- 
stances found  in  new  brandy,  save  as  they  are  changed  or  eliminated 
by  storage,  and  of  those  [produced  as  secondary  bodies  during  aging; 
and,  in  addition  thereto,  the  substances  extracted  from  the  casks  in 
which  it  has  been  stored.  It  contains,  when  prepared  for  consumption, 
as  permitted  by  the  regulations  of  the  Bureau  of  Internal  Revenue,  not 
less  than  45%  by  volume  of  ethyl  alcohol,  and,  if  no  .statement  is  made 
concerning  its  alcoholic  strength,  it  contains  not  less  than  50%  by 
volume  of  ethyl  alcohol  as  pre.scribed  by  law. 

Cognac,  Cognac  Brandy,  is  brandy  produced  in  the  departments  of 
the  Charente  and  Charente  Inferieure,  France,  from  wine  produced  in 
tho.se  departments. 

U.  S.  Pharmacopoeia  Standards. — According  to  the  U.  S.  Pharmacopoeia, 
brandy  should  be  at  least  four  years  old;    its  specific  gravity  should  be 


ALCOHOLIC  BEyERAGES.  741 

not  more  than  0.941  nor  less  than  0.925;  its  alcoholic  content  should 
be  from  39  to  47  per  cent  by  weight;  the  residue  from  100  cc.  .should 
not  exceed  0.5  gram,  and  should  dissolve  readily  in  10  cc.  of  cold  water, 
and  this  solution  should  not  be  colored  deeper  than  a  pale  green  by  the 
addition  of  dilute  ferric  chloride  solution  (absence  of  more  than  traces 
of  tannin);  the  residue  should  not  be  sweet  nor  spicy  in  taste;  a  marked 
disagreeable  pungent  odor  of  fu.scl  oil  should  not  manifest  itself  on  the 
volatilization  of  the  last  traces  of  alcohol  in  evaporating  for  the  residue; 
in  acidity,  not  more  than  i  cc.  of  tenth-normal  alkali  should  be  required 
to  neutralize  100  cc.  of  the  brandy,  using  litmus  as  an  indicator. 

Adulteration  of  Brandy. — Much  of  the  brandy  sold  on  the  market 
is  a  compound  or  imitation,  having  for  its  basis  alcohol  reduced  to  the 
requisite  strength,  flavored  either  by  the  admixture  of  real  brandy,  or  by 
various  preparations  such,  for  example,  as  .syrup  of  raisins,  prune  juice, 
rum,  acetic  ether,  oenanthic  ether,  infusion  of  green  walnut-hulls,  infusion 
of  bitter  almond  shells,  catechu,  balsam  of  Tolu,  etc. 

Fleischmann  gives  the  following  recipe  for  artificial  brandy  of  the 
cheapest  grade: 

Spirits 45  gallons 

Coloring  (caramel) 6  ounces 

Cognac  oil ^  ounce 

"  Cognac  oil  "  is  made  up  of  melted  cocoanut  oil  16  ounces,  sulphuric 
acid  8  ounces,  alcohol  16  ounces,  mixed  and  distilled. 

While  commercial  brandy  often  fails  to  meet  the  pharmacopoeial 
requirements,  and  may  contain  any  of  the  above  flavoring  materials, 
not  one  sample  has  been  found  among  the  many  examined  by  the  Massa- 
chusetts Board  of  Health  during  upwards  of  twenty  years  containing  a 
more  injurious  ingredient  than  alcohol. 

Genuine  new  brandy  may  be  "aged"  or  "improved"  for  immediate 
use,  according  to  Duplais,  by  adding  to  100  liters  the  following: 

Old  rum 2 .  00  liters 

Oldkirsch* 1-75     " 

Infusion  of  walnut-hulls 75  liter 

Syrup  of  raisins 2.00  liters 

The  addition  of  sugar  and  caramel  to  brandy  is  very  common.     The 


*  Brandy  distilled  from  cherry  wine. 


742 


FOOD  INSPECT IO\'  AND  ANALYSIS. 


lack  of  flavor  resulting  from  the  employment  of  "silent  spirit,"  or  from 
watering  the  product,  may  be  compensated  for  by  the  employment  of 
so-called  cognac  essences  sold  for  the  purpose,  containing  mixtures  of 
the  aromatic  compounds  named  above. 

RUM. 

Rum  is  the  liquor  distilled  from  fermented  molasses  or  cane  jtrice, 
or  from  the  scum  and  other  waste  juices  from  the  manufacture  of  raw 
sugar.  The  molasses  wort  is  mixed  with  the  residue  from  a  previous 
fermentation  and  allowed  to  ferment  for  a  number  of  days,  after  which 
it  is  distilled  twice  and  stored  in  wood  for  a  long  time,  to  remove  the  dis- 
agreeable odor,  which  in  the  new  product  is  especially  marked.  The 
characteristic  flavor  of  old  rum  is  due  to  a  mixture  of  butyric  and  acetic 
ether,  principally  the  former.  Pineapples  and  guavas  are  often  put 
in  the  still  to  impart  a  fruity  flavor.  The  best  varieties  of  rum  come 
from  Jamaica  and  Vera  Cruz. 

Composition. — The  following  analysis  of  rum  is  by  Vasey:* 

\'olatile  acids. . . . . , 28.0  grams  per  100  liters  of  absolute  alcohol 

Esters 399-o           "               "                     " 

Aldehydes 8.4           "              "                      '' 

Furfural 2.8            "               ''                      '' 

Fusel  oil 90.6 

Thirty-nine  samples  of  rum,  sold  at  retail  in  Massachusetts  in  1894, 
were  examined  by  the  State  Board  of  Health  with  the  following  results: 


Per  Cent 

Alcohol  by 

Weight. 

Per  Cent 
Extract. 

Maximum 

42.9 
24.7 
37-1 

3-93 
0.04 
0.51 

Mean 

Of  these,  two  samples  were  new  rum,  and  several  were  entirely  arti- 
ficial. 

Joint  Standards.— The  following  are  the  joint  standards  of  the 
A.  O.  A.  C.  and  the  A.  S.  X.  F.  D.  D.: 


*  Analysis  of  Potable  Spirits,  p.  85. 


ALCOHOLIC   BEVERAoES.  743 

New  Rum  is  properly  distilled  spirit  made  from  the  properly  fer- 
mented clean,  sound  juice  of  the  sugar  cane,  the  clean,  sound  massacuite 
made  therefrom,  clean,  sound  molasses  from  the  massecuite,  or  any  sound 
clean  intermediate  i)roduct  save  sugar,  and  contains  in  100  liters  of 
proof  spirit  not  Lss  than  loo  grams  of  the  volatile  -lavors,  oils,  and 
other  substances  derived  from  the  materials  of  which  it  is  made,  and 
of  the  substances  congeneric  with  the  ethyl  alcohol  produced  during 
fermentation,  which  are  carried  over  at  the  ordinary  temperatures  of 
distillation,  the  principal  part  of  which  is  higher  alcohols  estimated  as 
amylic. 

Rum  {Potable  Rum)  is  new  rum  stored  not  less  than  four  years  in 
wood  without  any  artificial  heat  save  that  which  may  be  imparted  by 
warming  the  storehouse  to  the  usual  temperature,  and  contains  in  100 
liters  of  proof  spirit  not  less  than  175  grams  of  the  substances  found  in 
new  rum,  save  as  they  are  changed  or  eliminated  by  storage,  and  of  those 
produced  as  secondary  bodies,  during  aging;  and,  in  addition  thereto, 
the  substances  extracted  from  the  casks.  It  contains,  when  prepared 
for  consumption  as  permitted  by  the  regulations  of  the  Bureau  of  Inter- 
nal Revenue,  not  less  than  45%  by  volume  of  ethyl  alcohol,  and  if  no 
statement  is  made  concerning  its  alcoholic  strength,  it  contains  not  less 
than  50%  by  volume  of  ethyl  alcohol  as  prescribed  by  law. 

More  or  less  factitious  rum  is  sold  on  the  market,  made  up  of  alcohol 
diluted  to  the  right  strength,  colored  with  caramel,  and  flavored  by  the 
addition  of  "  rum  essence."     Prune  juice  is  sometimes  added. 

Fleischman  gives  the  following  recipe  for  low-grade  artificial  rum: 

Spirits 40  gallons 

New  England  rum 5       " 

Prune  juice ^  gallon 

Caramel 12  ounces 

Rum  essence 8 

The  "rum  essence"  is  made  up  by  distilling  32  ounces  of  a  mixture 
of  2  ounces  black  oxide  of  manganese,  4  ounces  pyroligneous  acid,  32 
ounces  alcohol,  and  4  ounces  sulphuric  acid.  To  this  is  added  32  punces 
of  acetic  ether,  8  ounces  of  butyric  ether,  16  ounces  saflfron  extract,  and 
^  ounce  oil  of  birch. 


744  FOOD   INSPECTION   /fND   AN. 4 LYSIS. 


GIN. 


Gin  is  an  alcoholic  liquor,  flavored  with  the  volatile  oil  of  juniper  and 
sometimes  with  other  aromatic  substances,  such  as  coriander,  grains  of 
paradise,  anise,  cardamom,  orange-peel,  and  fennel.  The  choicest  variety 
is  known  as  Schiedam  schnapps,  named  from  the  town  of  Schiedam  in 
Holland,  where  there  are  upwards  of  200  distilleries  devoted  to  the  manu- 
facture of  gin.  The  mash  used  for  this  variety  is  fermented  by  yeast 
from  malted  barley  and  rye,  after  w-hich  it  is  distilled  and  redistilled 
in  pot  stills  with  juniper  berries  and  sometimes  hops. 

Juniper  berries,  to  which  the  most  characteristic  flavor  of  gin  is  due, 
are  dark  blue  in  color,  and  possess  a  pungent  taste.  They  grow  on  the 
slender  evergreen  shrub  Juniperus  communis.  Gin  differs  from  the 
other  distilled  liquors  by  being  water-white.  To  this  end  it  is  kept  in 
glass  and  not  in  wood. 

Much  of  the  gin  of  commerce  is  made  by  redistilling  com  or  grain 
whiskey  wiih  oil  of  juniper,  and  frequently  one  or  several  of  the  above- 
named  flavoring  materials.  Sugar  is  often  added,  and  sometimes  in  the 
cheaper  productions  oil  of  turpentine  is  substituted  for  juniper  oil. 

Composition. — The  following  analysis  of  unsweetened  gin  is  by  Vascy :  * 

Volatile  acids 0.0  grams  per  100  liters  of  absolute  alcohol 

Esters 37.3 

Aldehydes 1.8 

Furfural o.o 

Fuseloil 44-6  "  "  " 

Thirty-three  samples  of  gin,  purchased  in  Massachusetts  saloons  and 
analyzed  by  the  State  Board  of  Health  in  1894,  gave  the  following 
results  in  per  cent  of  alcohol  by  weight:  Maximum  42.5,  minimum  29.5, 
mean  38.2. 

♦  Analysis  of  Potable  Spirits,  p.  85. 


ALCOHOLIC  BEVERAGES.  745 


METHODS  OF  ANALYSIS  OF  DISTILLED  LIQUORS. 

Specific  gravity  and  alcohol  arc  determined  as  described  on  pp.  657- 
677.  The  following  methods  with  the  exception  of  the  qualitative  test 
for  fusel  oil,  Mitchell's  method,  and  McGill's  opalescence  test  are 
those  of  the  A.  O.  A.  C* 

Determination  of  Extract. — Weigh  or  measure  (at  15.6°  C.)  100  cc. 
of  the  sample,  evaporate  nearly  to  dryness  on  the  water-bath,  then 
transfer  to  a  water-oven,  and  dry  at  the  temperature  of  boiling  water 
for  2^  hours. 

Determination  of  Acids. — Titrate  100  cc.  (or  50  cc.  diluted  to  100  cc. 
if  the  sample  is  dark  in  color)  with  tenth-normal  alkali,  using  phenol- 
phthalein  as  indicator,  i  cc.  of  tenth-normal  alkali  is  equal  to  0.006  of 
acetic  acid. 

Determination  of  Esters. — Dilute  200  cc.  of  the  sample  with  25  cc, 
of  water  and  distil  slowly  into  a  graduated  200-cc.  flask  until  nearly 
filled  to  the  mark.  Complete  the  volume,  shake,  and  use  aliquot 
portions  for  the  determination  of  esters,  aldehydes,  and  furfural. 

Exactly  neutralize  50  cc.  of  the  distillate  with  tenth-normal  alkali, 
using  phenolphthalein  as  indicator,  and  add  from  25  to  50  cc.  of  the 
tenth-normal  alkali  in  excess  of  that  required  for  neutralization.  Either 
boil  for  one  hour  with  a  reflux  condenser,  or  allow  to  stand  overnight 
in  a  stoppered  flask,  and  heat  with  a  tube  condenser  for  one-half  hour 
below  the  boiling-point.  Cool,  and  titrate  with  tenth-normal  acid,  using 
phenolphthalein  as  indicator.  Multiply  the  number  of  cc.  of  tenth- 
normal alkali  used  in  the  saponification  by  0.0088,  thus  obtaining  the 
grams  of  esters  calculated  as  ethyl  acetate. 

Determination  of  Aldehydes. — i.  Reagents. — (a)  Alcohol  Free  from 
Aldehydes. — Prepare  by  first  redistilling  the  ordinary  95%  alcohol  over 
caustic  soda  or  potash,  then  add  from  2  to  3  grams  per  liter  of  w-phenyl- 
enediamine  hydrochloride,  digest  at  ordinary  temperature  for  several 
days  (or  reflux  on  the  steam-bath  for  several  hours),  and  then  distil 
slowly,  rejecting  the  first  100  cc.  and  the  last  200  cc. 

{h)  Sulphite-fiichsin  Solution. — Dissolve  0.50  gram  of  pure  fuchsin 
in  500  cc.  of  water,  then  add  5  grams  of  SO2  dissolved  in  water,  make 
up  to  a  liter,  and  allow  to  stand  until  colorless.  Prepare  this  solution 
in  small  quantities,  as  it  retains  its  strength  for  only  a  very  few  days. 

*U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107  (rev.),  pp.  95  to  loi;    Circular  43. 


746  FOOD   INSPECTION   /iND  ANALYSIS. 

(c)  Standard  Acetic  Aldehyde  Solution. — Prepare  according  to  the 
directions  of  \'asey  *  as  follows :  Grind  aldehyde  ammonia  in  a  mortar 
with  ether,  and  decant  the  ether.  Repeat  this  operation  several  times, 
then  dry  the  purified  salt  in  a  current  of  air  and  linally  in  a  vacuum 
over  sulphuric  acid.  Dissolve  1.386  grams  of  this  purified  ammonium 
aldehyde  in  50  cc.  of  95%  alcohol,  to  this  add  22.7  cc.  of  normal  alco- 
hohc  sulphuric  acid,  then  make  up  to  100  cc.  and  add  0.8  cc.  to  com- 
pensate for  the  volume  of  the  ammonium  sulphate  precipitate.  Allow 
this  to  stand  over  night  and  filter.  This  solution  contains  i  gram  of 
acftic  aldehyde  in   100  cc.  and  will  retain  its  strength. 

The  standard  found  most  convenient  for  use  is  2  cc.  of  this  strong 
aldehyde  solution  diluted  to  100  cc.  with  50%  alcohol  by  volume.  One 
cc.  of  this  solution  is  equal  to  0.0002  gram  of  acetic  aldehyde.  This  solu- 
tion should  be  made  up  fresh  every  day  or  so,  as  it  loses  its  strength. 

2.  Process. — Determine  the  aldehyde  in  the  distillate  prepared  for 
esters.  Dilute  from  5  to  10  cc.  of  the  distillate  to  50  cc.  with  aldehyde- 
free  alcohol  (50%  by  volume),  add  25  cc.  of  the  fuchsin  solution,  and 
allow  to  stand  for  fifteen  minutes  at  15°  C.  The  solutions  and  the 
reagents  should  be  at  15°  C.  before  they  are  mixed.  Prepare  standards 
of  known  strength  in  the  same  way. 

Determination  of  Furfural. — Standard  Furfural  Solution. — Dissolve 
I  gram  of  redistilled  furfural  in  loc  cc.  of  95%  alcohol.  This  strong 
solution  will  keep.  Standards  are  made  by  diluting  i  cc.  of  this  solution 
to  100  cc.  with  50%  by  volume  alcohol.  One  cc.  of  this  solution  con- 
tains 0.000 1  gram  furfural. 

Process. — Dilute  from  10  to  20  cc.  of  the  distillate,  prepared  as 
described  under  esters,  to  50  cc.  with  furfural-free  alcohol  (50%  by 
volume).  To  this  add  2  cc.  of  colorless  anilin  and  0.5  cc.  of  hydro- 
chloric acid  (specific  gravity  1.125),  and  keep  for  fifteen  minutes  in  a 
water-bath  at  about  15°  C.  Prepare  standards  of  known  strength  in 
the  same  way. 

Detection  of  Fusel  Oil. — In  the  process  of  dealcoholizing  a  licjuor  by 
eva[xjration  in  an  open  dish  over  the  water-bath,  one  may  readily  detect 
fusel  oil,  if  present,  by  its  harsh  and  nauseating  odor,  if  the  nose  is 
applied  just  at  the  moment  when  the  last  traces  of  alcohol  are  going 
off.  At  this  stage  any  considerable  trace  of  fusel  oil  will  be  especially 
apparent  by  the  elTect  on  the  throat  of  the  one  who  smells  it,  causing 

*  Analysis  of  Potable  Spirits,  p.  30. 


ALCOHOLIC  BEl^ERAGES.  747 

an  uncontrollable  desire  to  cough.  Other  ways  of  applying  the  odor 
test  consist  in  pouring  a  small  portion  of  the  sjjirit  into  the  hand,  and 
allowing  it  to  evaporate  slowly  therefrom,  or  in  rinsing  out  a  warm  glass 
with  the  liquor,  observing  the  odor  in  each  case. 

Goebel  suggests  the  following  test,  based  on  the  detection  of  the 
volatile  acids:  Agitate  about  30  cc.  of  the  hcpior  with  2  or  3  cc.  of 
a  dilute  solution  of  potassium  hydroxide;  evaporate  over  the  water- 
bath  to  the  volume  of  2  or  3  cc,  cool,  and  to  the  residue  add  5  or  6  cc. 
of  concentrated  sulphuric  acid.  If  fusel  oil  be  present,  the  character- 
istic odors  of  valerianic  and  butyric  acids  will  be  apparent. 

Determination  of  Fusel  Oil. — AUen-Marqiiardt  Method. — Add  to 
100  cc.  of  whiskey  20  cc.  of  half-normal  sodium  hydroxide,  and  saponify 
the  mixture  by  boiling  for  one  hour  under  a  reflux  condenser.*  Connect 
the  flasks  with  a  distilling  apparatus,  distil  90  cc,  add  25  cc.  of  water, 
and  continue  the  distillation  until  an  additional  25  cc.  is  collected. 

Approximately  saturate  the  distillate  with  finely  ground  sodium 
chloride,  and  add  a  saturated  solution  of  sodium  chloride  until  the  specific 
gravity  is  i.io. 

Extract  this  salt  solution  four  times  with  carbon  tetrachloride,!  using 
40,  30,  20,  and  10  cc.  respectively,  and  wash  the  carbon  tetrachloride 
three  times  with  50-cc.  portions  of  a  saturated  solution  of  sodium  chloride, 
and  twice  with  saturated  solution  of  sodium  sulphate.  Then  transfer 
the  carbon  tetrachloride  to  a  flask  containing  5  cc.  of  concentrated 
sulphuric  acid,  45  cc.  of  water,  and  5  grams  of  potassium  bichromate, 
and  boil  for  eight  hours  under  a  reflux  condenser. 

Add  30  cc,  of  water,  and  distil  until  only  about  20  cc.  remain;  add 
80  cc  of  water,  and  distil  until  but  5  cc.  are  left.  Neutralize  the  distillate 
to  methyl  orange,  and  titrate  with  sodium  hydroxide,  using  phenol- 
phthalein  as  indicator.  One  cc.  of  tenth-normal  sodium  hydroxide  is 
equivalent  to  0.0088  gram  of  amyl  alcohol. 

Rubber  stoppers  can  be  used  in  the  saponification  and  first  distilla- 
tion, but  corks  covered  with  tinfoil  must  be  used  in  the  oxidation  and 
second  distillation.     Corks  and  tinfoil  must  be  renewed  frequently. 


*  Or  100  cc.  of  the  liquor  may  be  mixed  with  20  cc.  of  half-normal  sodium  hydroxide, 
allowed  to  stand  overnight  at  room  temperature,  and  distilled  directly. 

t  Purify  5  liters  of  carbon  tetrachloride  by  boiling  for  several  hours  under  a  reflux  con- 
denser with  200  cc.  of  sulphuric  acid  and  25  grams  of  potassium  bichromate  in  200  cc.  of 
water;  separate  from  the  oxidizing  mixture  by  distillation,  and  redistil  over  barium  car- 
bonate. 


74^  FOOD  INSPECTION  AND  ANALYSIS. 

Tolman  and  Hillye/s  Modijicatiofi  of  the  Alkfi-M arquardt  Method. — 
Proceed  with  the  Allcn-Marquardt  method  to  the  point  where  the 
carbon  tetrachloride  solution  of  the  higher  alcohols  is  ready  to  be 
oxidized.  Add  50  cc.  of  a  solution  of  200  grams  of  pulverized  potassium 
bichromate  in  iSoo  cc.  of  water  and  200  cc.  of  concentrated  sulphuric 
acid,  very  carefully  measured  with  pij)ette  or  burette,  and  start  the 
eight-hour  oxidation.  Take  great  care  to  prevent  any  isolation  of  spots 
of  bichromate  on  the  flask  during  the  oxidation.  Decomposition  of 
the  bichromate  from  overheating  can  best  be  prevented  by  slow  boiling 
over  several  thicknesses  of  asbestos  board.  After  the  oxidation  is 
complete,  separate  the  bichromate  solution  froni  the  carbon  tetrachloride 
in  a  separatory  funnel,  care  being  taken  to  wash  the  carbon  tetrachloride 
free  from  bichromate.  IMake  up  the  bichromate  solution  to  500  cc. 
Place  200  cc.  of  this  solution  in  a  liter  flask,  add  20  cc.  of  concentrated 
hydrochloric  acid,  100  cc.  of  potassium  iodide  solution  (1:1),  and  50  cc. 
of  approximately  three-fourths  normal  thiosulphate  not  standardized. 
Make  this  last  addition  by  means  of  a  burette.  (If  a  high  content  of 
fusel  oil  is  present,  50  cc.  of  thiosulphate  may  be  excessive  and  a  smaller 
amount  should  be  used,  the  same  quantity  being  added  to  the  sample 
and  to  the  blank.)  Run  blanks  containing  exactly  the  same  amount 
of  reagents  with  each  series,  and  treat  them  in  the  same  way,  starting 
them  at  the  point  where  the  carbon  tetrachloride  is  washed  with  sodium 
chloride.  The  titration  of  this  blank,  to  which  has  been  added  exactly 
the  same  amount  of  three-fourths  normal  thiosulphate,  gives  the  value 
of  the  bichromate  solution.  The  difference  in  cubic  centimeters  of  tenth- 
normal thiosulj)hate  used  in  titrating  the  blank  and  the  samples  gives 
the  amount  of  bichromate  reduced  by  the  higher  alcohols.  This  differ- 
ence in  cubic  centimeters  of  tenth-normal  thiosulphate  multiplied  by 
the  factor  0.001773  gives  grams  of  higher  alcohols  present. 

Mitchell  and  Smith  Method* — This  is  more  rapid  than  the  Allen- 
Marciuardt  method  and  gives  more  nearly  the  true  amount  of  fusel  oil. 

Saponify,  distil,  shake  with  sodium  chk^ride,  and  extract  with  carbon 
tetrachloride,  as  in  the  Allen-Marquardt  method.  To  the  carbon  tetra- 
chloride extract,  contained  in  the  separatory  funnel,  add  10  cc.  of 
potassium  hydroxide  solution  (1:1).  Cool  the  mixture  in  ice- water  to 
approximately  o'^  C.  Similarly  cool  100  cc.  of  a  solution  of  potassium 
permanganate  solution   (20  grams  to  the  liter),  accurately  measured  in 

*  \.  O.  A.  C.  Pfot.  iyo8,  U.  S.  IXpt.  of  Agric,  Bur.  oi  Chcm.,  I5ul.  122,  j).  199. 


ALCOHOLIC  BEyERAGES.  749 

a  flask.  To  the  contents  of  the  separator}-  funnel  add  the  bulk  of  the 
permanganate  solution,  but  without  rinsing,  retaining  the  residue  to  be 
added  at  a  later  stage.  Remove  the  mixture  from  the  bath,  and  shake 
vigorously  for  five  minutes;  set  aside  for  thirty  minutes,  with  occasional 
shaking,  permitting  the  liquid  to  warm  to  room  temperature  (20  to  25°  C.) 

Accurately  measure  into  a  liter  Erlenmeyer  flask  100  cc.  of  a  solution 
of  hydrogen  j)eroxide  slightly  (about  2%)  stronger  than  the  perman- 
ganate solution,  acidulate  with  100  cc.  of  an  approximately  25%  sul- 
jjhuric  acid  solution,  and  slowly  add  the  contents  of  the  separatory 
funnel  with  constant  shaking,  keeping  the  acid  solution  constantly  in 
excess.  Rinse  the  separatory  funnel  and  the  flask  containing  the  residue 
of  permanganate  with  water  and  add  to  the  peroxide  solution.  Finally 
titrate  the  excess  of  hydrogen  peroxide  with  standard  potassium  per- 
manganate solution  (10  grams  to  the  liter). 

Run  a  blank  determination,  using  the  same  amounts  of  the  stronger 
permanganate,  potassium  hydroxide,  hydrogen  peroxide,  and  sulphuric 
acid  solutions,  and  titrating  the  residual  peroxide  with  the  standard 
potassium  permanganate  as  before. 

The  difference  in  the  amounts  of  permanganate  consumed,  in  grams, 
times  0.696,  gives  the  amount  of  amyl  alcohol. 

Detection  of  Methyl  Alcohol. — Leach  and  Lythgoe  Immersion  Refrac- 
tometer  Me/hod  * — Determine  at  20°  C.  the  refraction  of  the  distillate 
obtained  in  the  determination  of  alcohol  by  the  immersion  refractometer. 
If  on  reference  to  the  table  the  refraction  shows  the  percentage  of  alcohol 
agreeing  with  that  obtained  from  the  specific  gravity,  it  may  be  safely 
assumed  that  no  methyl  alcohol  is  present.  If,  however,  there  is  an 
appreciable  amount  of  methyl  alcohol,  the  low  refractometer  reading  will 
at  once  indicate  the  fact.  If  the  absence  from  the  solution  of  other 
refractive  substances  than  water  and  the  alcohols  is  assured,  this  quali- 
tative test  by  difference  in  refraction  is  conclusive. 

The  addition  of  methyl  to  ethyl  alcohol  decreases  the  refraction  in 
direct  proportion  to  the  amount  present;  hence  the  quantitative  calcu- 
lation is  readily  made  by  interpolation  in  the  table,  using  the  figures 
for  pure  ethyl  and  methyl  alcohol  of  the  same  alcoholic  strength  as  the 
sample. 

Example. — Suppose  the  distillate  made  up  to  the  original  volum.e 
of   the   measured    portion    taken    for    the    alcohol   determination    has   a 

*  Jour.  Am.  Chem.  Soc,  27,  1905,  p.  964. 


'50 


FOOD  INSPECTION   AND   ANALYSIS. 


specific  gravity  of  0.9736,  corresponding  to  18.38%  alcohol  by  weight, 
?nd  has  a  refraction  of  35.8  at  20°  C.  by  the  immersion  refractometcr; 
by  interpolation  in  the  refractometer  table  the  readings  of  ethyl  and 
methyl  alcohol  corresponding  to  18.38%  alcohol  are  47.2  and  25.4, 
respectively,  the  dilTerence  being  21.8;  47.2-35.8=11.4;  (i  1.4 -- 21.8) 
100=^2.3,  showing  that  52.3  of  the  alcohol  present  is  methyl  alcohol. 

SC.\LE  READINGS  OX  ZEISS  IMMERSION  REFRACTOMETER  AT  20°  C, 
CORRESPONDING  TO  EACH  PER  CENT  BY  WEIGHT  OF  METHYL  AND 
ETHYL   ALCOHOLS. 


Scale 

Scale 

Scale 

Scale 

Readings. 

Readings. 

Readings. 

Readings. 

Per  Cent 

\ 

Per  Cent 
Alcohol 

Per  Cent 
Alcohol 

Per  Cent 
Alcohol 

Alcohol 

bv 

Wcifiht. 

Methyl 

Al- 

Ethyl' 
Al- 

by 
Weight. 

Methyl 
Al- 

Ethyl 
Al- 

by 
Weight. 

Methyl 
Al- 

Ethyl 
Al- 

by 
Weight. 

Methyl 
Al- 

Ethyl 
Al- 

cohol. 

cohol. 

cohol. 

cohol. 

cohol. 

cohol. 

cohol 

cohol. 

0 

14.5 

14.5 

26 

30-3 

61.9 

51 

39-7 

91.1 

76 

29.0 

lOI.O 

I 

14.8 

16.0 

27 

30-9 

63-7 

52 

39-6 

91.8 

77 

28.3 

1 00 . 9 

3 

15-4 

17.6 

28 

31.6 

65.5 

53 

39-6 

92.4 

78 

27.6 

100.9 

3 

16.0 

19. 1 

29 

32-2 

67.2 

54 

39-5 

93 -o 

79 

26.8 

100.8 

4 

16.6 

20.7 

30 

32.8 

69.0 

55 

39-4 

93-6 

80 

26.0 

100.7 

5 

17.2 

22.3 

31 

33-5 

70.4 

56 

39-2 

94-1 

81 

25-1 

100.6 

6 

17.8 

24.1 

32 

34-1 

71.7 

57 

39-0 

94-7 

82 

24-3 

100.5 

7 

18.4 

25-9 

33 

34-7 

73-1 

58 

38.6 

95-2 

83 

23-6 

100.4 

8 

19.0 

27.8 

34 

35-2 

74-4 

59 

38-3 

95-7 

84 

22.8 

100.3 

9 

19.6 

29.6 

35 

35-8 

75-8 

60 

37-9 

96.2 

85 

21.8 

100. 1 

10 

30. 2 

31-4 

36 

36.3 

76.9 

61 

37-5 

96.7 

86 

20.8 

99.8 

11 

20.8 

33-2 

37 

36.8 

78.0 

62 

37-0 

97-1 

87 

19.7 

99-5 

12 

21.4 

35-0 

38 

37-3 

79-1 

63 

36.5 

97-5 

88 

18.6 

99.2 

13 

22.0 

36.91 

39 

37-7 

80.2 

64 

36.0 

98.0 

89 

17-3 

98.9 

14 

22.6 

38.7I 

40 

38-1 

81.3 

65 

35-5 

98.3 

90 

16.1 

98.6 

IS 

33.2 

40.51 

41 

38-4 

82.3 

66 

35-0 

98.7 

91 

14-9 

98-3 

16 

23-9 

42-5! 

42 

38.8 

83-3 

67 

34-5 

99.1 

92 

13-7 

97-8 

17 

24-5 

44.5 

43 

39-2 

84.2 

68 

34-0 

99.4 

93 

12.4 

97-2 

18 

25.2 

46.5 

44 

39-3 

85-2 

69 

33-5 

99-7 

94 

II  .0 

96-4 

»9 

25-8 

48.5 

45 

39-4 

86.2 

70 

33-0 

1 00.0 

95 

9.6 

95.7 

20 

36.5 

50-5 

46 

39-5 

87.0 

71 

32-3 

100.2 

g6 

8.2 

94-9 

31 

27.1 

52.4 

47 

39-6 

87.8 

72 

31-7 

100.4 

97 

6.7 

94.0 

33 

27.8 

54.3 

48 

39-7 

88.7 

73 

3I-I 

100.6 

98 

5-  ' 

93.0 

23 

28.4 

56.3 

49 

39-8 

89-5 

74 

30-4 

100.8 

99 

3-5 

g2.o 

24 

29.1 

.S8.2 

50 

39-8 

90-3 

75 

29.7 

lOI  .0 

100 

2.0 

91 .0 

25 

1^]      " 

'■'  .  I 

TriJlal  Method  * — To  50  cc.  add  50  cc.  of  water  and  8  grams  of  lime, 
and   fractionally  distil   by  the   aid  of   Glinksy  bulb  tubes.     Dilute   the 


♦A.  TrilJat,  Analyst,  24,  1899,  pp.  13,  211-212. 


ALCOHOLIC  BEVERAGES.  751 

first  15  cc.  of  the  distillate  to  150  cc,  mix  with  1 5  grams  of  potassium 
bichromate  and  70  cc.  of  sulphuric  acid  (1:5),  and  allow  to  stand  for 
one  hour  with  occasional  shaking. 

Distil,  reject  the  first  25  cc,  and  collect  100  cc.  Mix  50  cc.  of  the 
distillate  with  i  cc  of  rectified  dimethyl-anilin,  transfer  to  a  stout, 
tightly-stoppered  flask,  and  keep  on  bath  at  70  to  80°  C.  for  three  hours 
with  occasional  shaking.  Make  distinctly  alkaline  with  sodium  liydrox- 
ide,  and  distil  the  excess  of  dimethyl-anilin,  stopping  the  distillation 
when  25  cc.  have  passed  over. 

Acidify  the  residue  in  the  flask  with  acetic  acid,  shake,  and  test  a 
few  cc.  by  adding  four  or  five  drops  of  water  with  lead  dioxide  in 
suspension  (i  gram  in  100  cc).  If  methyl  alcohol  be  present,  a  blue 
coloration  occurs  which  is  increased  by  boiling. 

Note. — Ethyl  alcohol  thus  treated  yields  a  blue  coloration,  changing 
immediately  to  green,  afterwards  to  yellow,  and  becoming  colorless  when 
boiled. 

Riche  and  Bardy  Methoa.^ — The  following  method  for  the  detection 
of  methyl  alcohol  in  commercial  spirit  of  wine  depends  on  the  formation 
of  methyl-anilin  violet: 

Place  10  cc.  of  the  sample,  previously  rectified  over  potassium  car- 
bonate if  necessary,  in  a  small  flask  with  15  grams  of  iodine  and  2  grams 
of  red  phosphorus.  Keep  in  ice-water  for  from  ten  to  fifteen  minutes 
until  action  has  ceased.  Distil  on  a  water-bath  the  methyl  and  ethyl  iodides 
formed  into  about  30  cc.  of  water.  Wash  with  dilute  alkali  to  eliminate 
free  iodine.  Separate  the  heavy  oily  liquid  which  settles,  and  transfer 
to  a  flask  containing  5  cc  of  anilin.  The  flask  should  be  placed  in  cold 
water,  in  case  the  action  shouki  be  violent,  or,  if  necessary,  the  reaction 
may  be  stimulated  by  gently  warming  the  flask.  After  one  hour  boil 
the  product  with  water,  and  add  about  20  cc.  of  a  15%  solution  of  soda; 
when  the  bases  rise  to  the  top  as  an  oily  layer,  fill  the  flask  up  to  the 
neck  with  water,  and  draw  them  off  with  a  pipette.  Oxidize  i  cc.  of 
the  oily  liquid  by  adding  10  grams  of  a  mixture  of  100  parts  of  clean 
sand,  2  of  common  salt,  and  3  of  cupric  nitrate;  mix  thoroughly,  intro- 
duce into  a  glass  tube,  and  heat  to  90°  C.  for  eight  or  ten  hours.  Exhaust 
the  product  with  warm  alcohol,  filter,  and  make  up  with  alcohol  to  100  cc. 
If  the  sample  of  spirits  be  pure,  the  liquid  is  of  a  red  tint,  but  in  the 
presence  of  1%  of  methyl  alcohol,  it  has  a  distinct  violet  shade;    with 

*  Allen's  Commercial  Organic  Analysis,  3d  ed.,  I,  p.  So. 


75-' 


FOOD   INSPECT/ON    AND  ANALYSIS. 


2.5%  the  shade  is  very  distinct,  and  still  more  so  with  5%.  To  detect 
more  minute  quantities  of  methyl  alcohol,  dilute  5  cc.  of  the  colored 
liquid  to  100  cc.  with  water,  and  dilute  5  cc.  of  this  again  to  400  cc.  Heat 
the  liquid  thus  obtained  in  porcelain,  and  immerse  a  fragment  of  white 
merino  (free  from  sulj)hur)  in  it  for  half  an  hour.  If  the  alcohol  be 
pure,  the  wool  will  remain  white,  but  if  methylated,  the  fiber  will  become 
violet,  the  depth  of  tint  giving  a  fair  approximate  in- 
dication of  the   proportion  of  methyl  alcohol  present. 

Detection  of  Caramel.  —  Crampton  and  Simon^s 
Method* — Evaporate  50  cc.  of  the  licjuor  nearly  but  not 
quite  to  dryness  in  an  evaporating-dish  on  the  water-bath. 
\Va.sh  with  water  into  a  50-cc.  graduated  glass-stoppered 
flask,  add  25  cc.  of  absolute  alcohol,  and  fill  to  the  mark 
with  water.  Shake,  and  transfer  25  cc.  of  the  solution 
to  a  separatory  funnel  of  the  type  presented  in  Fig.  116, 
the  stem  of  which  terminates  in  a  25-cc.  graduated 
bulb  j)ipette,  provided  with  a  stop-cock  as  shown. 

Add  50  cc.  of  ether,  and  .shake  carefully  at  intervals 
during  half  an  hour.  After  complete  separation,  make 
up  the  lower  aqueous  layer  with  water  to  the  25-cc. 
mark,  which  may  be  done  by  siphoning  it  in  through 
a  rubber  tube  from  an  elevated  flask,  controlling  the 
supply  by  the  .stoj)-cock.  Shake  the  separatory  funnel, 
and  again  allow  the  layers  to  sej)arale,  draw  off  the 
Fig.  116. — Separa-  aqueous  layer,  and  compare  with  the  color  of  the  orig- 
tory  Funnel  for  j^^^j   liquor.     Express   the  amount  of  color  removed  as 

Delecton  of  r        ■,  ^  t-    ^  -n  iM  1- 

Caramel  P^''  ^•"""^^  ^'   ^"^  ^^^^^  amount.     Ether  will    readily  dis- 

-solve   the   natural    color  due  to  oakwood    (mainly   flave- 

scin),  while  caramel   is  in.soluble   in   ether;  hence   uncolored   liquors  are 

partially  decolorized  by  this  treatment,  while  tho.se  colored  with  caramel 

show  little  change. 

Amihor  Test,  Modified  by  Lasche.'\ — Add  10  cc.  of  paraldehyde  to 
5  cc.  (}f  the  sample  contained  in  a  test  tube  and  shake.  Add  ab.solute 
alcohol,  a  few  drops  at  a  time,  .shaking  after  each  addition  until  the 
mixture  becomes  clear.  Allow  to  .stand.  Turbidity  after  ten  minutes 
is  an  indication  of  caramel. 


*  Jour.  Am.  Chem.  Soc.,  22  1900,  p.  810. 
t  The  Brtwer  Distiller,  May,  1903. 


ALCOHOLIC   RF.yF.RACF.S.  VSS 

Determination    of    Water-insoluble    Color    in   Whiskies. — Evaporate 

5c  cc.  of  the  sample  just  to  dryness.  Take  w\)  with  cold  water,  using 
approximately  15  cc,  filter,  anfl  wash  until  the  liUrale  amounts  to  nearly 
25  cc.  To  this  filtrate  add  25  cc.  of  absolute  alcohol  or  26.3  cc.  of  95% 
by  volume  alcohol,  and  make  up  to  50  cc.  by  the  addition  of  water. 
Mix  thoroughly  and  compare  in  a  colorimeter  with  the  original  material. 
Calculate  the  per  cent  of  color  insoluble  in  water  from  these  readings. 

Determination  of  Color  Insoluble  in  Amyl  Alcohol. — Modified  Marsh 
Test. — Evaporate  50  cc.  of  the  whiskey  just  to  dryness  on  the  steam- 
bath.  Add  26.3  cc.  of  95%  alcohol  to  dissolve  the  residue.  Transfer 
to  a  50-cc,  flask  and  make  up  to  volume  with  water  to  obtain  a  uniform 
alcohol  concentration.  Place  25  cc.  of  this  solution  in  a  separatory 
funnel,  and  add  20  cc.  of  the  Marsh  reagent,  shaking  lightly  so  as  not 
to  form  an  emulsion.  (This  reagent  consists  of  100  cc.  of  pure  amyl 
alcohol,  3  cc.  of  syrupy  phosphoric  acid,  and  3  cc.  of  water;  shake 
before  using.)  Allow  the  layers  to  separate,  and  repeat  this  shaking 
and  standing  twice  again.  After  the  layers  have  clearly  separated,  draw 
off  the  lower  or  watery  layer  which  contains  the  caramel  into  a  25-cc. 
cylinder,  and  make  up  to  volume  with  50%  by  volume  alcohol.  Com- 
pare this  solution  in  a  colorimeter  with  the  untreated  25  cc.  Calculate 
the  result  of  this  reading  to  the  per  cent  of  color  insoluble  in  amyl 
alcohol. 

Opalescence  in  Diluted  Alcohol  Distillate. — McGill  *  has  shown  that 
in  the  case  of  liquors  made  from  thoroughly  rectified  grain  spirit,  there 
is  little  or  no  opalescence  produced  when  the  alcoholic  distillate  (i.e., 
that  used  in  determining  the  alcohol)  is  diluted  with  an  equal  volume 
of  water,  while  in  the  case  of  liquors  distilled  from  alcoholic  infusions 
without  rectification,  the  opalescence  is  marked.  He  ascribes  the  opales- 
cence to  the  presence  of  minute  amounts  of  volatile  oils  present  in  wine 
maic,  grains,  and  other  sources  of  these  liquors,  soluble  in  strong,  but 
insoluble  in  dilute  alcohol.  Whether  due  to  this  or  to  the  separation 
of  minute  traces  of  fusel  oil  on  dilution,  the  presence  or  absence  of  tur- 
bidity certainly  furnishes  a  rough  distinguishing  test,  indicating  in  some 
cases  the  exclusive   use  of  rectified  spirit. 


*  Bui.  27,  Canadian  Inland  Rev.  Dept. 


754  FOOD   INSPECTION  AND  ANALYSIS. 


LIQUEURS  AND   CORDIALS. 

These  are  manufactured  beverages,  usually  high  in  alcohol  and  sugar, 
flavored  with  a  wide  \'ariety  of  aromatic  herbs  or  essences,  and  often 
strongly  colored.  Red  colors  most  frequently  used  for  this  purpose 
are  cochineal,  cudbear,  and  red  sandal  and  Brazil  woods;  for  yellow 
colors,  caramel  and  safifron-yellow  are  employed;  for  blue,  indigo;  and 
for  green,  chlorophyll  and  malachite  green. 

Some  of  the  oldest  of  the  liqueurs,  such  as  chartreuse  and  benedictine, 
derive  their  names  from  certain  monasteries  of  Europe,  in  which  they 
have  been  made  for  many  years. 

Absinthe  is  one  of  the  best-known  cordials,  made  by  redistilling  40% 
alcohol  in  which  wormwood,  anise,  sweet  flag,  and  marjoram  leaves 
have  been  macerated.  Sometimes  coriander  and  fennel  are  also  used. 
It  is  highly  intoxicating. 

Curacao  is  made  by  distilling  dilute  spirits  in  which  Curasao  orange- 
peel,*  cinnamon  and  often  other  spices  have  been  soaked,  and  by  adding 
sugar  to  the  resulting  li(iucur. 

De  Brevans  gives  the  following  recipe  for  curafoa: 

Rasped  skins  of 18  or  20  oranges 

Cinnamon 4  grams 

Mace 2      " 

Alcohol  (85%) 5  liters 

White  sugar 1750  grams 

Macerate  for  fourteen  days,  distill  without  rectification,  and  color  with 
caramel. 

Angostura  owes  its  flavor  to  Angostura  bark  and  various  spices. 

Maraschino  had  originally  for  its  basis  the  fermented  juice  of  the 
sour  Italian  cherr\',  to  which  honey  was  added.  It  is  more  commonly 
made  by  distilling  a  mixture  in  alcohol  of  ripe  wild  cherries,  raspberries, 
cherry  leaves,  peach  nuts,  and  orris.     Finally  sugar  is  added. 

Cfiartreuse  and  Benedictine  contain  much  sugar,  and  are  flavored 
with  the  volatile  oils  of  angelica,  hyssop,  nutmeg,  and  peppermint. 

Noyau,  or  Crime  de  Noyau,  is  a  i)re[)aration  distilled  from  brandy, 
bitter  almonds,  mace  anrl  nutmeg.  Sugar  and  coloring  matter,  usually 
pink,  are  added  to  the  final  product. 

*  This  is  a  very  rare  and  highly  prized  orange,  growing  in  the  island  of  Curasao. 


ALCOHOLIC  RRl^F.RAGES. 


755 


I 


Creme  de  Menthe,  according  to  De  Brevans,  is  made  by  distilling  a 
jnixture  of 

Peppermint 600  grams 

Balm 40      " 

Sage 10      " 

Cinnamon 20       " 

Orris  root 10       " 

Ginger 15       " 

Alcohol  (80%) 5030  cc. 

producing  finally  10  liters  of  the  liquor,  after  3750  grams  of  white  sugar 
have  been  introduced. 

The  better  grades  of  creme  de  menthe  were  formerly  colored  with 
an  alcoholic  solution  of  chlorojjhyll,  derived  by  macerating  bruised  green 
leaves  of  various  plants  with  alcohol,  but  at  present,  coal-tar  dyes  are 
used.  Frequently  the  desired  shade  is  secured  by  mixing  a  green  (e.g., 
Light  Green  S.F.),  a  blue-green  (e.g..  Malachite  Green),  or  a  blue  (e.g., 
Indigo  Carmine)  with  a  yellow  color. 

The  following  analyses,  due  to  Konig,  show  the  chemical  composition 
!of  the  best-known  cordials: 


Specific 
Gravity. 


Alcoliol 
by  Vol- 
ume. 


Alcohol 

by 
Weight. 


Extract. 


Cane 
Sugar. 


Other 
Extrac- 
tives. 


Ash. 


Absinthe 

Benedictine 

Ginger 

Creme  de  menthe.  . . . 
Anisette  de  Bordeaux 

CuraijOa 

Kiimmel 

Angostura 

Chartreuse 


o.gi 16 
i.oyog 
I .0481 
1.0447 
1.0847 
I . 0300 
I .0830 
0.9540 
1.0799 


58.93 
52 

47-5 
48.0 
42.0 
55-0 
33-9 
49-7 
43-18 


38.5 
36.0 

36-5 
30-7 
42.5 
24.8 


0.18 
36.00 
27.79 
28.28 
34.82 
28.60 
32.02 

5-85 
36.11 


32-57 
25.92 
27.63 
37-44 
28.50 
31.18 
4. 16 
34-35 


0.32 

3-43 
1.87 
0.65 
0.38 
o.io 
0.84 
1 .69 
1.76 


0.043 
0.141 
0.068 
0.040 
0.040 
0.058 


Analysis  of  Cordials  and  Liqueurs. — The  character  of  the  essences 
and  flavoring  principles  used  in  these  beverages  is  so  widely  varied  that 
no  regular  systematic  plan  for  identifying  them  can  be  made  applicable 
to  all  cases.  The  senses  of  smell  and  taste  arc  most  useful,  both  when 
■applied  directly  to  the  liqueur  itself  and  to  the  dry  extract,  for  suggestions 
as  to  the  main  ingredients  employed.  Coloring-matters,  sugars,  acids, 
and  alcohol  are  determined  as  with  other  liquors,  except  that  in  the  case 
.of  alcohol  all  volatile  oils  must  first  be  sej)arated  out  by  treatment  with 
.■magnesia,  as  directed  for  alcohol  in  lemon  extract.     Presence  of  volatile 


;56  FOOD  IKSPBCTION  AND   ANALYSIS. 

oils  is  shown,  if  on  treatment  of  a  few  cubic  centimeters  of  the  sample 
in  a  test-tube  with  water  a  precipitate  is  formed. 

GENERAL  REFERENCES  ON  ALCOHOLIC  BEVERAGES. 
(See  also  References  on  Leavening  Materials,  page  364.) 

Bersch,  J.     Gahrungs-Chemic  fiir  Praktikcr.     Berlin.    Vol.  I,  Die  Hefe  und  die  Gahr- 

ungs  Erscheinungen,  1879.     Vol.  II,  Fabrikation  von  Malz,  Malz  Extract  und 

Dextrin,   1880.     Vol.  Ill,  Die  Bierbrauerei,   188 1. 
BiGELOW,  W.  D.     Fermented  and  Distilled  Liquors.     U.  S.  Dept.  of  Agric,  Bur.  of 

Chem.,  Bui.  65,  p.  81.     1902. 
BouRGUELOT,  E.     Des  Fermentations.     Paris,  1889. 

Brev'.\ns,  J.  DE.     The  Manufacture  of  Liquors  and  Preserves.     Nevir  York,  1893. 
Cramptox,  C.  a.     Fermented  .\lcoholic  Beverages.     U.  S.  Dept.  of  Agric,  Div.  of 

Chem.,  Bui.  13,  part  3.     1887. 
DuPLAis,  P.     (Translated  by  McKennie,  M.)     A  Treatise  on  the  Manufacture  and 

Distillation  of  Alcoholic  Liquors.     Philadelphia. 
Fleischmax,  J.     The  .\rt  of  Blending  and  Compounding  Liquors  and  Wines.     New 

York,  1885. 
GlR.\RD,  C.     La  Fai)rication  des  Liqueurs  ct  des  Conserves.     Paris,  1890. 
Hansen,  E.  Ch.     Untersuchungen  aus  der  Praxis  der  GahrungsTndustrie.     Miinchen, 

1889. 
Leach,  A.  E.,  and  Lythgoe,  H.  C.     The  Detection  and  Determination  of  Ethyl  and 

Methyl  .\lcohols   in    Mi.xtures  by  the   Immersion    Refractometer.     Jour.   Am. 

Chem.  Soc,  27,  1905,  p.  964. 
Mew,  J.,  and  Ashton,  J.     Drinks  of  the  World.     London,  1892. 
Pasteur,  M.     Studies  in  Fermentation.     London,  1879. 

Prescott,  \.  B.     Critical  F.xamination  of  Alcoholic    Liquors.     New  York,  1880. 
Spencer,  E.     The  Flowing  Bowl.     A  Treatise  on  Drinks  of  all  Kinds  and  of  all  Periods. 

London,  1899. 
Stevenson,  T.     A  Treatise  on  Alcohol  with  Tables  of  Spirit  Gravities.     London,  1888. 
A  Treatise  on  the  Manufacture,  Imitation,  .Adulteration  and  Reduction  of  Foreign 

Wines,   Brandies,   Rums  and  Gins,  ba.sed  uf)on  the  "  French  System,"  by  a 

Practical  Chemist  and  Experienced  Liquor  Dealer. 

REFERENCES   ON    BEER. 

Allen,  A.  11.,  and  Chattaway,  W.     Detection  of  Hoj)  Suljslitutes  in  Beer.     Analyst, 

12,  1887,  p.  107;  also  Analyst  15,  1890,  p.  181. 
Barnard,  H.  E.     RcjKirt  on  Beer.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  90, 

p.  64. 
Brevans,  J.  UK.     Analyse  des  Matieres  .Alimentaircs  (Girard  el  Dupro),  p.  183.     Paris, 

1894. 
Elion,  H.     Detection  of  Antiseptics  in   Fk-er.     Analy.st,   16,   1891,  jj.   116. 
Fai:i.knkr,  F.     Theory  and  Practice  of  Modern  Brewing.     London,  1888. 
Hefelmann,  k.,  and  .Mann,  P.     Detection  (A  Fluorine  in  Beer.     Pharm.  Centralh.^ 

16,  1895,  p.  249;   ,Abs.  Analyst,  20,  >S95,  p.  185. 


ALCOHOLIC  BEyERAGES.  7S7 

Kelynack,  T.  N.,  and  Kirby,  W.     Arsenical  Poisoning  in  Beer  Drinkers.     London, 

1901. 
LiNDET,  L.     La  Bierre.    Pans,  1892. 

Lindner,  C.     Lehrbuch  der  Bierbrauerei.    Braunschweig,  1878. 
Macfarlane,  T.     Malt  Liquors.     Canada  Inl.  Rev.  Dept.,  Bui.,  52. 
Parsons,  C.  L.     The  Identification  and  Comj)osition  of  Malt  Liquors.     Jour.  Am. 

Cham.  Soc,  24,  1902,  p.  11 70. 
Pasteur,  M.     Etudes  sur  la  Bierre.    Paris,  1876. 
PiESSE,  C.  H.     Chemistry  in  the  Brewing  Room.     London,  1891. 
Prior,  E.     Chemie  und  Physiologie  des  Maizes  und  des  Bieres.     Leipzig,  1896. 
Stierlein,  R.      Das  Bier  und  seine  Yerfalschungen.     Berlin,  1878. 

REFERENCES   ON   CIDER   AND   WINE. 

Alwood,  W.  B.     a  Study  of  Cider  Making.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem., 

Bui.  71. 
Alwood,  W.  B.,  Davidson,  R.  J.,  and  Moncure,  W.  A.  P.     The  Chemical  Com- 
position of  Apples  and  Cider.     U.  S.  Dept.  of  Agric,  Bur.  Chem.,  Bui.  88. 
Arauner,  p.     Der  Wein  und  seine  Chemie.  Kitzingen,  a.  M.,  1906. 
Barillot,  E.     Manuel  de  I'Analyse  des  Vins.     Paris,  1889. 
Barth,  M.     Die  Weinanalyse.     Leipzig,  1884. 
Bastide,  E.     Les  Vins  Sophistiques.     Paris,   1889. 

Browne,  C.  A.     The  Chemical  Analysis  of  the  Apple,  and  some  of  Its  Products.     Jour. 
Am.  Chem.  Soc,  23,  1901,  p.  869. 

The  Effects  of  Fermentation  upon  the  Composition  of  Cider  and  Vinegar.     Jour. 

Am.   Chem.   Soc,   25,   1903,  p.    16. 
Borgmann,  E.     Anleitung  zur  chemischen  .\nalyse  des  Weines.     Wiesbaden,  1898. 
Cazeneuve,  P.     La  Coloration  des  Vins  par  les  Couleurs  de  la  Houille.     Paris,  1886. 
Chace,  E.   M.     Qualitative  Detection   of  Saccharine   in  Wine.     Jour.   Am.   Chem. 

Soc,  26,  1904,  p.  1627. 
Embrey,  G.     a  Comparison  of  English  and  .American  Cider^  ^.-ith  Suggestions  for 

Estimating  the  Amount  of  Added  Water.     Analyst,  16,  1891,  p.  41. 
Gautier,  a.     La  Sophistication  des  Vins.     Paris,  1884. 
Macfarlane,  T.     Wines.     Canada  Inl.  Rev.  Dept.,  Bui.  38. 
Nessler,  J.     Die  Bereitung,  Pflege  und  L^ntersuchung  des  Weins.     Stuttgart,  1889. 
Niviere,  G.,  and  Hubert,  A.     Detection   of  Fluorine   in  Wine.     Monit.  Scient.,  9, 

1895,  p.  324;   Abs.  Analyst,  20,  1895,  p.  185. 
Pasteur,  M.     Etudes  sur  le  Vin.     Paris,  1873. 
Robinet,  E.     Manuel  Pratique  d'Analyse  des  Vins.     Paris,  1888. 
Ross,  S.  H.     Determination  of  Glycerine  in  Wine.     \.  O.  \.  C.  Proc  1909.     U.  S. 

Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  132,  p.  85. 
Sangle-Ferriere.      Analyse    des  Matieres  Alimentaires   (Girard  et   Dupre),   Paris, 

1894.     Vin.,  p.  65.     Cidre,  p.  217. 
Smith,  A.  W.,  and  Parks,  N.     Composition  of  Ohio  Wines.     Jour.  .\m.  Chem.  Soc, 

20,  1908,  p.  878. 
Windisch,  K.     Die  chemische  Untersuchung  und  Beurtheilung  des  Weines.     Berlin, 
1806. 


75S  FOOD    INSPECTION   AND   ANALYSIS. 

REFERENCES  OX   DISTILLED   LIQUORS. 

Adams,  A.  B.     The  Detection  of  Substitution  of  Spirits  for  Aged  Whiskey.     Jour. 

Ind.  Eng.  Chem.,  3,  191 1,  p.  647. 
Allen,  .-\.  IT    The  Chemistry  of  Whiskey  and  Allied  Products.     Jour.  Soc.  Chem.  Ind., 

10,  1S91,  p.  312. 
Brannt,  W.  T.     Practical  Treatise  on  the  Distillation  of  Alcohol.     Phila.,  1885. 
Cr.\m?ton,  C.  a.    Detection  of  Foreign  Coloring  Matter  in  Spirits.    Jour.  Am.  Chem. 

Soc,  22,  1900,  p.  810. 
Cr-AMPTON,  C.  .\.,  and  Tolm.\n,  L.  "M.     A  Study  of  the  Changes  Taking  Place  in 

Whiskey  Stored  in  Wood.     Jour.  Am.  Chem.  Soc,  30,  1908,  p.  98. 
G.-VBF.R,  A.  'Die  Fabrikation  von  Rum,  Arrak,  Cognac,  etc.     Leipzig,  1886. 
M.\rF.\RL.\NE,  T.,  and  MrGiLL,  A.     Distilled  Liquors.     Canada  Inl.  Rev  Dept.,  Bui. 

27- 

Mitchell,  A.  S.,  and  Smith,  C.  R.     The  Determination  of  Fusel  Oil  by  Alakaline 

Permanganate.     A.  O.  A.  C.  Proc  1908.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem., 

Bui.  122,  p.  199. 
MorzERT.     The  Practical  Distiller.     1890. 
Ladd,  E.  F.     Whiskey.     X.  Dak.  Agric.  E.xp.  Sta.  Bulletins  57,  63  and  69.     Reports 

1906  and  1907. 
RirHTER,  Yl.     .\nalyse  des  Rums.     Zeits.  landw.  Gerwerbe,  9,  1889,  p.  11. 
S.A.NGLIER,  A.     Alcohols  et  Spiritueu.\-.     Analyse  des  Matieres  Alimentaires  (Girard  et 

Dupre),  p.  253.     Paris,   1894. 
Sc.ALA,  A.     Rum  and  Its  Adulteration.     Gazetta  Chem.  Ital.,  1891,  396;   Abs.  Ana- 
lyst, 17,  1892,  p.  79. 
Sell,  E.     Ueber  Cognac,  Rum,  Arrak,  etc.     Berlin,  1890. 
Shtpard,  J.  H.     The  Constants  of  Whiskey.     Report  of  the  Chemist  of  the  South 

Dakota  Food  and  Dairy  Commission,  March,  1906. 
Stallings,  R.  E.     An  Examination  of  Whiskeys.     X.  Dak.  Agric.  Exp.  Sta.  Rep.  1906, 

p.  138. 
ToLMAN,   L.   M.,   and  Hillyer,  W.  E.     Methods  of  Analysis  of  Distilled  Spirits. 

A.  O.  A.  C.  Proc.  1908.     U.  S.  Dept.  Agric.  Bur.  of  Chem.,  Bui.  122,  p.  206. 
Tolman,  L.  M.,  and  Trescot,  T.  C.     A  Study  of  the  Methods  for  the  Determination 

of  Esters,  Aldehydes  and  Furfural  in  Whi.skey.     Jour.  Am.  Chem.  Soc,  28, 

1906,  p.  1619. 
Vasey,  S.    A.     Guide  to  the  Analysis  of  Potable  Spirits.     London,  1904. 
U.  S.  Dept.  of  Agric,  Food  Insjx;ction  Decisions,  45,  65,  95,  98,  113,  and  127. 


CHAPTER  XVI. 
VINEGAR. 

Vinegar  is  the  product  formed  by  the  acetic  fermentation  of  an  alco 
lioh'c  liquid  under  the  influence  of  the  organism  mycoderma  aceti,  existing 
in  the  "  mother-of- vinegar. "  While  vinegar  may  be  made  directly  from 
a  dilute  solution  of  pure  alcohol,  it  is  more  often  obtained  from  fruit  juice, 
wine,  or  other  saccharine  liquid  that  has  first  undergone  alcoholic  fer- 
mentation. 

Of  the  following  equations,  (i)  and  (2)  illustrate  the  processes  of 
inversion  and  alcoholic  fermentation  respectively,  while  (3)  and  (4)  show 
the  double  process  of  acetic  fermentation,  wherein  the  alcohol  is  oxidized, 
first  to  acetaldehyde  and  finally  to  acetic  acid: 

Cx2H230u+H20  =  2C«H,A5 (^) 

Cane  sugar  Invert  sugar 

QH,306  =  2C,H,0+2C02; (2) 

Invert  sugar,        Alcohol 
dextrose,  or 
maltose 

QH^O  +  O^QH.O  +  H^O; (3) 

Alcohol  Aldehyde 

C2H,0  +  0  =  C2HA.     .    , (4) 

Aldehyde  Acetic  acid 

In  addition  to  the  acetic  acid,  its  chief  active  principle,  \dnegar  usually 
contains  traces  of  other  organic  acids  free  or  combined,  small  amounts 
of  alcohol,  aldehyde,  sugar,  glycerin,  coloring  matter,  aromatic  ethers, 
and  mineral  salts,  its  extract  varying  considerably  with  the  source  from 
which  the  vinegar  was  obtained. 

Varieties. — The  principal  varieties  of  vinegar  are  the  following :  Cider 
vinegar,  wine  vinegar,  malt  or  beer  vinegar,  spirit  vinegar,  glucose  vinegar, 
molasses  vinegar,  and  wood  vinegar,  the  three  last  being  more  frequently 
used  as  adulterants  of  the  others. 

759 


7^D  FOOD   INSPECTION  /IND  ^N.^ LYSIS. 

Manufacture  of  Vinegar. — Cider  vinegar,  the  principal  variety  used  in 
the  United  States  and  Canada,  was  formerly  made  almost  entirely  by  the 
slow  process  of  cask  fermentation,  the  fresh  cider  being  allowed  to  undergo' 
both  alcoholic  and  acetic  fermentation  in  barrels  with  open  bung-holes  in 
a  warm  cellar,  or  exposed  to  the  sun.  Two  or  three  years  are  required 
for  this  process.  Sometimes  fresh  cider  is  added  to  the  barrels  at  regular 
intervals  of  two  or  three  weeks,  thus  causing  a  series  of  ])rogressive  fer- 
mentations. The  acetic  fermentation  is  hastened  by  adding  old  vinegar,, 
or  mother-of-vinegar  to  the  cider.  While  farmers  and  some  manufac- 
turers still  ctintinue  to  make  cider  vinegar  by  tlie  slow  process,  the  quick 
or  "generator"  vinegar  process  is  now  much  used  for  cider  vinegar, 
though  originall}-  intended  and  almost  exclusively  used  in  the  manufacture 
of  malt,  beer,  and  sj)irit  vinegar.  This  process  requires  only  two  or 
three  days  for  complete  acetification.  In  the  quick  process,  the  cider 
or  other  alcoholic  liquor  is  allowed  to  percolate  slowly  through  beech- 
wood  shavings  or  birch  twigs,  held  in  a  cask  known  as  a  generator, 
provided  with  a  ])erforated,  false  ])ottom,  the  shavings  or  twigs  being 
previouslv  saturated  with  old  vinegar,  and  a  current  of  air  being  passed 
up  through  them. 

The  alcoholic  li(|uid  from  which  genuine  malt  vinegar  is  made  is 
deri\e(l  from  the  wort  obtained  by  mashing  malt,  or  a  mixture  of  malt 
and  barley.  Si)irit  vinegar  is  derived  from  diluted  whiskey,  brandy,  or 
grain  alcohol.  Wine  vinegar  is  made  by  allowing  the  wine  to  stand  over 
wine  lees  for  a  time,  after  which  it  is  clarified  bypassing  through  beech 
shavings,  and  subjected  to  progressive  acetification  in  large  open  oak 
casks,  to  which  the  wine  is  added,  the  vinegar  being  drawn  off  in  much 
the  same  manner  as  the  slow-process  cider  vinegar. 

Characteristics  and  Composition  of  the  Various  Vinegars. 
—  Cider  Vinegar  is  Ijrownish  yellow  in  color,  and  possesses  an  odor  of 
ai)i»k>.  It  i.-  cliielly  distinguished  from  other  vinegar  by  the  large  amornt 
of  malic  acid  normally  jjrcsent,  by  the  character  of  its  sugars,  and  by  the 
predominance  of  jiotash  in  the  ash.  Its  specilic  gravity  varies  from 
I. CI 3  to  1. 015.  Its  acidity  varies  from  3  to  6  per  cent,  and  its  solids 
from  i^  to  3  per  cent.  Cider  vinegar  under  polarized  light  is  always 
Ucvo-rotar}-. 

The  following  are  summarized  data  of  analyses  made  by  H.  C.  Lyth- 
goe  in  the  writer's  laboratory  of  twenty-two  samples  of  cider  vinegar  of 
known  purity: 


yiNEGAR. 


761 


Acetic 
Acid. 

Tbtal 
Solids. 

Ash. 

Alkalin- 
ity of 
Ash.i 

PzOj  in  Ash  of  100 
Grams  Vinegar. 

Soluble 
(mgr.). 

Insoluble 
(mgr.). 

Maximum 

5.86 
3-92 
4.84 

3.20 
1.84 
2.49 

0.42 
0.20 
0.34 

36-1 

22.2 
29.7 

31-7 
12. 1 

19-2 

31-5 

6.5 

15-6 

Minimum 

Average 

Reducing  Sugars. 

Polariza- 
tion, 
Degrees 
Ventzke 

200-nrim. 
Tube. 

Malic 
Acid. 

Per  Cent 
Ash  in 
Total 

StjUds. 

Per  Cent 

Reducing 

Sugars 

in  Total 

Solids. 

Ratio  of 

Soluble 

to  Total 

P^Os. 

AlkaUn- 

Before 
Inversion. 

After 
Inversion. 

I  Gram  of 
Ash,  cc. 

—  Acid. 
10 

Maximum 

Minimum.  — 
Average 

0-51 
0-15 
0.25 

0-53 
0.15 
0.25 

-3-6 
-0-3 
-1-3 

0.  t6 
0.08 
o.ir 

19.0 
10. 0 
13-8 

16.6 

7-3 
10.7 

66.9 
50.0 
56.3 

125.0 
69.0 
90.0 

■  Number  of  cubic  centimeters  of  tenth-normal  acid  to  neutralize  the  ash  of  100  grams  of  vinegar. 

Twenty-two  samples  of  pure  cider  vinegar  were  analyzed  by  A.  W. 
Smith  *  with  the  following  results : 


Acetic 
Acid. 

Total 
Solids. 

.   ,         'Alkalinity 
^'^-       1   of  Ash.i 

Soluble 
P2OS. 

Insoluble      Total 
P2O5.           P2O5. 

Maximum 

7-6r 
3-24 
4.46 

4-45 
2.00 
2.83 

0-51     i     55-2 
0.31     i     28.4 
0.39     1     38.8 

22.7 
13.6 
19. 1 

19.4 

4-2 

10. 1 

39-0 
19.8 
28  6 

Minimum 

Average 

'  Number  of  cubic  centimeters  of  tenth-normal  acid  required  to  neutralize  the  ash  from  1 00  grama 
of  vinegar. 

The  composition  of  cider  vinegar  ash  is  found  by  Doolittle  and  Hess  f 
to  be  as  follows: 


Calcium  oxide CaO. 


.4    to    8.21 


Magnesium  oxide ^%0-  •  • i-88  ''    3.44 

Potassium  oxide K2O 46.33  ''65.64 

Sodium  oxide NajO None 

Sulphuric  anhydride.  .  . .    SO3 4.66  to  16.29 

Phosphoric  anhydride  .  .   P2O5 3-29  "    6.66 

Iron  oxide FczO,   None  "  trace 

CO,  and  loss 0.00  '*  40.44 

Wine  Vinegar  is  light  yellow  if  made  from  white  wine,  and  red  if  from 
red  wine.    The  former  is  the  highest  prized.     Wine  vinegar  varies  in  specific 

*  Jour.  Am.  Chem.  Soc,  20  (1898),  p.  6. 
t  Ibid.,  22  (1900),  p.  220. 


76: 


POOD   INSPECTION   AND   ANALYSIS. 


graviiy  from  1.0129  lo  1.0213,  ^"^  contains  from  6  to  9  per  cent  of  acetic 
acid.  It  is  characteri/.ed  chictlv  by  the  bitartrate  of  j)otassium  (creami 
of  tartar)  which  true  wine  vinegar  always  possesses.  Free  tartaric  acid 
is  also  usually  present.  Wine  vinegar  is  the  principal  vinegar  of  France 
and  Germany.  In  the  United  States  the  term  wliiie  wine  vinegar  is 
usually  applied  to  distilled  or  spirit  vinegar,  which  is  much  chca})er  than 
the  real  wine  vinegar  and  altogether  inferior  to  it. 

Wine  vinegar  is  slightly  laivo-rotary  with  polarized  light. 

The  composition  of  genuine  white  wine  ^•inegar  is  shown  by  the  follow- 
ing summar}'  of  the  analyses  of  twenty-two  samples,  made  in  the  Municipal 
Laboratorv  of  Paris: 


Specific 
Gravity. 


Total 
Solids. 


Sugar. 


Bitartrate 
of  Potash. 


Ash. 


Acidity 
(as  Acetic). 


Maximum I-0213     I        3.19 

Minimum 1.0129  1.38 

Mean i-oi75  i-93 


0.46 
0.06 

0.22 


0.36 
0.07 
0.17 


0.69 
o.  16 
0.32 


7-38 
4-44 
7-38 


Weigmann  gives  the  following  average  of  analyses  of  red  wine  \inegar: 


Specific    j    Acetic 
Crravity.       Acid. 

Tl;;Lnc     Tamric     Cream  of 
Acid.           Acid.          ^^'^^'^• 

Alcohol.  ; Extract.,     ^^T^           Ash. 

Phos- 
phoric 
Acid. 

I. 0143   1     7-79 

0.216    i    0.006    1    0.057 

1. 19        0.863 

0.141        0.118 

0.012 

Malt  or  Beer  Vinegar  is  of  a  brown  color,  and  its  odor  is  suggestive 
of  sour  Ix-er.  It  varies  in  specific  gravity  from  1.015  to  1.025;  its  acidity- 
is  aVjout  the  same  as  cider  vinegar,  but  the  extract  is  much  larger,  varying 
from  4  to  6  jx-r  cent.  Malt  vjnegar  contains  considerable  nitrogenous 
matter,  and  notable  quantities  of  jjhosjjhates,  dextrin,  and  maltose.  It 
contains  no  cream  of  tartar.     Malt  vinegar  is  largely  used  in  Great  Britian. 

Hehner  gives  the  following  data  of  the  analyses  of  seven  samples 
of  vinegar  undoubtedly  made  from  malt  only.* 


Maximum 
Minimum. 
Mean 


♦  Analyst,  16,  p.  82.     See  ai.^o  .\naly.sl,  18,  p.  240. 


yiNEGAR. 


763 


Allen  gives  the  results  of  the  analyses  of  three  samples  of  genuine 
vinegar  brewed  from  a  mixture  of  malted  and  unmalted  barley  as  follows :  * 


specific 
Gravity. 

Acetic 
Acid. 

Total 
Solids. 

K,         :  Alkalinity 
^^^-          as  K2O. 

Phos- 
phoric 
Acid. 

Nitrogen. 

Albumin- 
oids. 

I 

1.0170 
1.0228 
I. 0160 

6-39 
5.26 
4.86 

2.67 
3-96 
2.31 

0.34          0.091 
0.40          O.I18 
0-47        

0.077 
0.093 
0.057 

.099 

.095 
.099 

.624 
-598 
.624 

2 

■5 

Distilled,  Spirit,  or  Alcohol  Vinegar. — This  vinegar,  being  made  from 
diluted  alcohol,  is  nearly  colorless,  unless  artificially  colored,  as  it  often 
is,  with  caramel.  As  stated  on  page  762,  the  "white  wine"  vinegar  (incor- 
rectly so-called)  commonly  sold  in  the  United  States  is  of  this  class.  Its 
specific  gravity  ranges  from  1.008  to  1.013.  Spirit  vinegar  contains 
from  3  to  10  per  cent  of  acetic  acid.  Its  content  of  total  solids  is  insig- 
nificant, and  it  contains  only  traces  of  ash.  It  always  contains  non- 
acetified  alcohol  and  aldehyde.  It  has  no  optical  activity  with  polarized 
light. 

Twelve  samples  of  alcohol  vinegar  analyzed  in  the  Municipal  Labora- 
tory of  Paris  gave  the  following  results: 


Specific 
Gravity. 


Total 
Solids. 


Sugar. 


Ash. 


Acidity. 


Maximum i  .0131 

Minimum '     i .  0082 

Mean i  .0100 


o.  16 
0.07 
0-35 


Trace 


.09 

7.98 

.04 

4.98 

Trace 

6.34 

Glucose  Vinegar  is  made  from  the  acetification  of  alcohol,  obtained 
from  the  fermentation  of  commercial  glucose.  This  vinegar  usually 
possesses  the  odor  and  taste  of  fermented  starch.  It  is  low  in  total  solids, 
the  extract  consisting  almost  entirely  of  untransformed  glucose,  and  the 
vinegar  therefrom  contains  all  the  ingredients  of  the  product  from  which 
it  was  made,  viz.,  dextrin,  maltose,  and  dextrose,  as  well  as  chloride  of 
sodium.  It  is  decidedly  dextro-rotatory  with  polarized  light  bo  en  before 
and  after  inversion. 

Molasses  Vinegar. — This  is  largely  the  product  of  the  acetic  fermen- 
tation of  sugar-house  wastes,  and  sometimes  of  the  accidental  acetic 
fermentation  of  molasses  itself,  after  it  has  undergone  alcoholic  fermenta- 
tion for  the  manufacture  of  rum.     This  variety  of  vinegar  is  sometimes 


*  ,\naly.st,   19,  p.  15. 


764  FOOD  INSPECTION   AND   ANALYSIS. 

used  as  an  adulterant  of  cider  vinegar.  With  polarized  light  molasses 
vinegar  is  dextro-rotary  before,  and  laevo-rotary  after  inversion. 

Wood  Vinegar  is  prepared  by  the  purification  of  pyroligneous  acid, 
which  may  be  accomplished  by  saturating  the  crude  acid  with  lime  or  soda, 
adding  hydrochloric  or  sulphuric  acid,  and  distilling.  It  is  further  purified 
by  redistillation  with  potassium  bichromate,  and  filtration  through  bone- 
black.     Acetic  acid  is  sometimes  added  to  impart  flavor. 

The  extract  and  ash  of  wood  vinegar  are  ver)'  small.  Its  specific 
gravity  averages  1.007  according  to  Blyth.  Empyreumatic  or  tarry 
products  are  nearly  always  present  in  vinegar  of  this  class. 

AN.\LYSIS   OF   VINEGAR. 

Specific  Gravity. — This  is  obtained  either  with  the  hydrometer,  pyC' 
nometer,  or  Wcstphal  balance. 

Determination  of  Total  Solids. ^Weigh  10  grams  of  the  sample  in  a 
tared  platinum  dish  50  mm.  in  diameter,  evaporate  to  dryness  on  a  boiling- 
water  bath  and  dry  for  two  and  one-half  hours  in  a  water  oven  at  the  tem- 
perature of  boiling  water.      Cool  in  a  desiccator  and  weigh. 

Determination  of  Ash. — Transfer  the  dish  containing  the  last  residue 
or  extract  to  a  muflle,  and  burn  at  a  low  red  heat  to  an  ash,  or  the  ignition 
may  be  accomplished  with  care  over  a  direct  flame  turned  low.  Cool 
ihc  dish  and  weigh. 

Determination  of  Solubility  and  Alkalinity  of  the  Ash. — SmilKs 
Method.''^ — Twenty-five  cc.  of  the  vinegar  are  evaporated  to  dryness  in 
a  tared  platinum  dish,  ignited,  cooled,  and  the  ash  weighed.  The  ash  is 
then  repeatedly  extracted  with  hot  water  by  washing  into  a  Gooch  crucible 
provided  with  a  layer  of  asbestos  (previously  igniled  in  the  crucible,  cooled, 
and  weighed)  or  ujjon  an  ash-free  filter.  Dr\-  the  Gooch  or  filter,  ignite, 
cool,  and  weigh  the  insoluble  ash.  The  aqueous  extract  is  titrated  directly 
with  tenth-normal  acid,  using  methyl  orange  as  an  indicator,  or  treated 
by  adding  an  excess  of  tenth-normal  hydrochloric  acid,  boiling  and  titrat- 
ing back  with  tenth-normal  sodium  hydroxide,  using  phenolphthalein. 
Express  the  alkalinity  in  terms  of  100  grams  of  the  vinegar,  by  multiplying 
"by  4  the  numVjcr  of  cubic  centimeters  of  acid  required  to  neutralize. 

Determination  of  Phosphoric  Acid.f — Extract  repeatedly  the  insoluble 
ash  as  obtained  in  the  j>receding  section  with  hot  water  acidulated  with 
nitric  acid,  and  acidify  with  nitric  acid  the  neutralized  solution  of  the 

*  Jour.  Am.  Chem.  Soc.,  20,  p.  5. 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  46,  p.  12. 


yihlEGAR.  765 

soluble  ash.  Add  to  each  solution  15  grams  of  ammonium  nitrate,  heat 
to  boiling,  and  precipitate  the  phosphoric  acid  with  50  cc.  of  ammonium 
molybdate  (reagent  No.  53).  Digest  for  an  hour  at  a  temperature  of 
about  65°,  filter,  and  wash  with  cold  water.  Dissolve  the  precipitate  on 
the  filter  with  ammonia  and  hot  water,  and  wash  into  a  beaker  to  a 
bulk  of  not  more  than  100  cc.  Nearly  neutralize  with  hydrochloric 
acid,  cool,  and  add  slowly  magnesia  mixture  (reagent  No.  164)  drop 
by  drop  while  stirring  vigorously.  After  fifteen  minutes  add  30  cc.  of 
ammonia  (specific  gravity  0.96),  let  stand  for  at  least  two  hours,  filter 
on  a  Gooch  crucible,  wash  with  2.5%  ammonia  till  practically  free  from 
chlorides,  ignite,  and  weigh  as  ]Mg2P207.  Express  results  in  terms  of 
milligrams  of  phosphoric  anhydride  in  the  soluble  and  insoluble  vinegar 
ash  from  100  grams  of  vinegar. 

Phosphoric  acid  in  the  soluble  and  insoluble  ash  may  be  conveniently 
determined  also  by  the  uranium  acetate  method,  page  725. 

Determination  of  Nitrogen. — Concentrate  from  50  to  100  cc.  of 
vinegar  to  a  syrupy  consistency,  and  proceed  as  directed  under  the 
Kjeldahl  or  Gunning  method,  page  69. 

Determination  of  Total  Acidity. — Six  cc,  of  vinegar  are  carefully 
measured  from  a  pipette  into  a  white  porcelain  dish  and  diluted  with 
water.  Using  phenolphthalein  as  an  indicator,  titrate  with  tenth-normal 
sodium  hydroxide.  The  number  of  cubic  centimeters  of  the  latter  required 
to  neutralize,  divided  by  10,  expresses  the  acidity  in  terms  of  percentage 
of  acetic  acid. 

A  pproximate  Determination  0}  Vinegar  A  cidity  by  Lime  Water.  —  It 
has  generally  been  considered  difficult  for  vinegar  dealers  and  others 
who  desire  to  estimate  the  acidity  of  their  vinegar  to  do  this  themselves, 
in  that  it  has  been  necessary  to  obtain  for  the  purpose  a  carefully  standard- 
ized alkaline  solution,  the  exact  strength  of  which  it  is  impossible  for 
them  to  determine. 

It  has  been  found  that  very  satisfactor}',  though  of  course  not  abso- 
lutelv  accurate,  results  may  be  obtained  by  the  use  of  ordinar)-  lime 
water,  which  any  one  may  easily  prepare  by  making  a  saturated  solution 
of  ordinary  air-slaked  lime.  The  strength  of  such  a  solution  is  very  nearly 
constant,  and  has  been  found  to  be  about  ^t.t  of  the  normal.  If,  there- 
fore, it  is  not  easy  to  obtain  exactly  normal  or  tenth-ncfrmal  alkali,  approx- 
imate figures  may  be  obtained  by  employing  such  a  saturated  lime  water. 
If  2.75  cc.  of  vinegar  are  titrated  with  lime  water  contained  in  a  burette, 
■using  phenolphthalein  as  an  indicator,  the  number  of  cubic  centimeters 


766  FOOD  INSPECTION  AND  ANALYSIS. 

of  the  lime  water  necessan-  to  neutralize  the  vinegar,  divided  by  lo, 
gives  the  percentage  of  acetic  acid  in  the  vinegar.  To  make  sure  that 
the  lime  water  is  saturated,  an  excess  of  lime  should  always  be  present 
in  the  rca^ient  bottle. 

Determination  of  Volatile  and  Fixed  Acids. — Thirty  cc.  of  the  vine- 
gar are  transferred  to  a  distilling-fiask  and  subjected  to  distillation,  using 
a  current  of  steam.  Receive  the  distillate  in  a  25-cc.  graduated  cylinder. 
After  15  cc.  have  passed  over,  test  from  time  to  time  the  drops  of 
distillate  as  they  fall  into  the  receiving  vessel  with  litmus-paper,  and  when 
free  from  acid  discontinue  the  distillation.  Note  the  volume  of  the 
distillate,  mix  by  shaking,  and  transfer  one-fifth  to  a  white  porcelain  dish. 
Titrate  as  in  the  case  of  total  acidity,  expressing  the  volatile  acids  as 
acetic. 

Calculate  the  fixed  acid,  expressed  in  the  case  of  cider  vinegar  as 
malic,  by  subtracting  the  percentage  of  volatile  acid  from  the  percentage 
of  total  acid,  and  multiplying  the  result  by  the  factor  1.117.  In  the  case 
of  wine  vinegar,  express  as  tartaric  acid  by  using  the  factor  1.25.  To 
express  acidity  in  terms  of  sulphuric  acid,  multiply  the  percentage  of 
acetic  acid  by  0.817. 

Determination  of  Alcohol. — Alcohol  is  present  in  very  small  amounts 
in  fruit  vinegar  that  has  not  been  completely  acetified.  Frear  recom- 
mends concentrating  the  distillates  as  follows:  Neutralize  100  cc.  of 
the  sample  and  distill  off  40  cc.  Then  redistill  the  distillate  till  20  cc. 
have  gone  over.  Cool  to  15.6°  C.  and  make  up  to  20  cc.  with  distilled 
water.  Determine  the  specific  gravity  with  a  lo-cc.  pycnometer,  and 
ascertain  from  the  table  on  page  661  the  per  cent  by  weight  of  alcohol 
corresponding  to  the  specific  gravity.  The  percentage  in  the  last  distil- 
late, divided  \)\  5,  expresses  the  amount  of  alcohol  in  the  vinegar. 

Detection  of  Free  Mineral  Acids. — The  ash  of  genuine  cider  vinegar 
is  always  alkaline.  If  the  a^h  is  neutral,  free  mineral  acids  are  doubtless 
present.  For  their  detection  the  following  is  a  modification  of  Brannt's 
method  of  procedure: 

Add  to  50  cc.  of  the  vinegar  in  an  Erlenmeyer  flask  a  small  bit  of 
starch  the  size  of  a  wheat-grain,  and  shake  to  disseminate  it  through  the 
fluid.  Boil  for  some  minutes,  cool,  and  add  a  drojj  of  iodine  solution. 
If  a  blue  ccjloration  occurs,  no  mineral  acid  is  present.  In  the  presence 
of  an  appreciable  amount  of  mineral  acid,  the  starch  will  be  converted 
to  dextrin  and  sugar,  and  no  coloration  will  be  produced  by  the  iodine.. 

Frear'' s  Metliod. — .Add  5  or  10  cc.  of  water  to  5  cc.  of  the  vinegar,  and 


yiNHGAR.  767 

to  the  mLxture  add  a  few  drops  of  a  solution  of  methyl  violet  (one  part 
of  methyl  violet  2B  in  100,000  parts  of  water).  In  the  presence  of  mineral 
acids,  a  blue  or  green  coloration  will  be  produced. 

Ditermination  of  Free  Mineral  Acids. — Hehner^s  Melhod*— To  a 
weighed  quantity  of  the  sample  add  an  excess  of  decinormal  alkali,  evap- 
orate to  dryness,  incinerate,  and  titrate  the  ash  with  decinormal  acid. 
The  difference  between  the  number  of  cubic  centimeters  of  alkali  added 
in  the  first  place,  and  the  number  of  cubic  centimeters  needed  to  titrate 
the  ash,  represents  the  equivalent  of  the  free  acid  present. 

Detection  and  Determination  of  Sulphuric  Acid. — This  is  determined 
as  Imrium  sulphate  by  the  addition  of  barium  chloride  solution.  A  slight 
cloudiness  on  the  addition  of  the  reagent  indicates  the  presence  of 
small  quantities  of  sulphate  as  an  impurity,  rather  than  free  sulphuric 
acid.  If  a  minute  quantity  of  free  sulphuric  acid  be  present,  a  rather 
heavy  white  cloud  on  the  addition  of  the  barium  chloride  will  be  formed, 
which  slowly  settles  out.  According  to  Brannt,  if  the  quantity  of  sul- 
phuric acid  is  more  than  one  part  in  a  thousand,  the  svdphate  of  barium 
formed  by  addition  of  the  reagent  produces  a  copious  precipitate  that 
rapidly  falls  to  the  bottom  of  the  receptacle.  This  may  be  filtered, 
washed,  ignited,  and  weighed  in  the  usual  manner. 

Detection  of  Free  Hydrochloric  Acid. — Distill  off  half  of  a  measured 
volume  of  vinegar  into  the  receiving-flask  of  a  distillation  apparatus, 
and  to  the  distillate  add  a  few  drops  of  nitrate  of  silver  reagent.  A  pre- 
cipitate indicates  hydrochloric  acid. 

Detection  of  Malic  Acid  (Free  or  Combined). — Absence  of  malic  acid 
may  be  assured,  if  no  precipitate  occurs  with  neutral  acetate  of  lead, 
when  a  few  drops  of  a  solution  of  this  reagent  are  added  to  the  vincgai". 
In  the  presence  of  malic  acid,  as  in  the  case  of  a  pure  cider  vinegar,  the 
precipitate  which  is  formed  with  lead  acetate  is  flocculent,  forms  at  once, 
and  is  of  considerable  amount.  In  pure  cider  vinegar  the  precipitate 
will  settle  to  the  bottom  of  the  test-tube,  leaving  a  clear  supernatant 
licjuid  within  ten  minutes.  Unfortunately  the  acetate  of  lead  test  is 
a  negative  one,  in  that  several  organic  acids  other  than  malic  will  cause 
a  precipitate,  as,  for  instance,  tartaric  and  saccharic  acids,  the  former 
being  found  in  wine  and  the  latter  in  molasses  vinegar.  Malt  vinegar 
also  gives  a  copious  precipitate  with  lead  acetate,  due  to  phosphoric  acid. 

The  writer  employs  the  following  test  f  for  detecting  malic  acid   in 

*  Analyst,  i,  1877,  p.  105. 

t  An.  Rep.  Mass.  State  Board  of  Health,  1902,  p.  485.     Food  and  Drug  Reprint,  p.  33. 


768  FOOD  JNSFECTION  AND  ANALYSIS. 

vinegar:  Aeid  a  few  drops  of  a  10%  solution  of  calcium  chloride  to  some 
of  the  vinegar  in  a  test-tube,  and  make  the  mixture  slightly  alkaline  with 
ammonia.  Filter  olT  the  prcciphate  that  occurs  at  this  point,  to  the 
filtrate  add  two  or  three  \oli.mes  of  95^^  alcohol,  and  heat  to  boiling. 
A  copious,  floccv-lent  preci[)i.ate  of  calcium  malate  will  form,  if  malic 
acid  be  present,  settling  to  the  l)ottom  of  the  tube  in  a  few  minutes. 
A  precipitate  will  occur  in  malt  and  glucose  vinegar,  due  to  dextrin. 

To  confirm  the  presence  of  malic  acid,  fdtcr,  wash  the  precipitate 
with  a  little  alcohol,  dry,  dissolve  it  in  strong  nitric  acid  in  a  porcelain 
evaporating-dish,  and  e\-a])oratc  to  diyness  over  the  water-bath,  forming 
•calcium  oxalate.  Boil  \.\\^  residue  with  sodium  carbonate,  filter,  acidify 
the  filtrate  with  ace'ac  acid,  boil  to  expel  the  carbon  dioxide,  and  add  a 
solution  of  calcium  sulphate.  A  precipitate  of  calci-im  oxalate  confirms 
the  presence  of  malic  aci  1. 

For  the  determination  of  malic  acid  proceed  as  directed  on  page  702. 

Lead  Precipitate. — Ilortvct  Number. — The  quantitative  measurement 
of  the  precijjitate  formed  with  lead  acetate,  or  subacctate,  is  of  con- 
siderable importance.  Even  though  the  precipitate  formed  may  not  be 
due  as  was  long  thought  to  malic  acid,  but  may  be  due  to  j)hosphoric 
acid  (though  this  has  not  been  fully  proved),  it  nevertheless  remains  a 
fact  that  the  (pialitative  lead  acetate  test  is  one  of  the  most  important 
of  all  in  judging  the  purity  of  cider  vinegar. 

The  lead  precipitate  is  best  measured  as  follows:  To  25  cc.  of  the 
vinegar  add  2.5  cc.  of  U.  S.  P.  subacetate  of  lead  solution.  Shake  and 
whirl  in  a  graduated  Hortvet  tube  in  the  centrifugal  machine,  and  read 
the  volume  of  the  precipitate  in  the  bottom  of  the  tube.  The  results 
expressed  in  cc.  on  thirty  samples  of  pure  cider  vinegar  are  summarized 
as  follows:  Highest,  1.4;  lowest,  0.5;  average,  0.84.  The  lead  number 
of  adulterated  cider  \inegar  runs  from  a  mere  trace  to  0.5  and  some- 
times higher. 

Winlon's  Lead  Number. — This  is  determined  by  the  method  de- 
scribed for  maple  products,  page  628, 

Bailey*  obtainerl  b\'  this  method  the  following  results: 

Cider  vinegar  (8  samples) 0.075  to  o.  290 

Malt  vinegar  (3  samples) o.  158  to  o. 548 

Distilled  vinegar  (1  sample) 0.018 


*A.  O.  A.  C.  Pnx.,   1908.     U.  S.  Dept.  of  AkhV  .,   Bur.  of  Chem.,  Bui.   122,  p.  27. 


l/IJ^EGAR.  769 

Hickcy  *  follows  the  same  method,  except  that  he  employs  only  5  cc, 
of  standard  lead  subacetate  solution  and  determines  the  lead  in  50  cc. 
of  the  fillrate.  The  lead  number  found  by  him  in  twenty  samples  of 
cider  vinegar  varied  from  0.076  to  0.166. 

Determination  of  Acid  Tartrate  of  Potassium. — Berlhelot  and  Fleu- 
rien's  Method.^ — Twenty-hvc  cc.  of  the  vinegar  are  evaporated  on  the 
water-bath  to  syrupy  consistency,  and  the  residue  is  dissolved  in  water 
and  made  up  to  its  original  volume.  It  is  then  transferred  to  a  250-cc. 
Erlenmeyer  flask,  and  100  cc.  of  a  mixture  of  equal  parts  of  strong  alcohol 
and  ether  are  added,  the  flask  is  corked,  shaken,  and  set  on  ice  or  in  a 
cold  place  for  forty-eight  hours.  At  the  end  of  this  time,  if  a  crystalline 
precipitate  has  gathered,  the  supernatant  liquid  is  decanted  upon  a  filter, 
and  finally  the  precipitate  is  washed  upon  it  by  a  fresh  quantity  of  the 
ether-alcohol  mixture,  and  the  washing  continued  with  this  reagent  till 
practically  free  from  acid.  The  filter  and  its  contents  are  then  trans- 
ferred to  the  original  fiask,  and  the  tartrate  is  dissolved  in  boiling  water, 
after  which  the  solution  is  titrated  in  the  same  flask  with  tenth-normal 
sodium  hydroxide,  using  phenolphthalein  as  an  indicator.  Multiply 
the  number  of  cubic  centimeters  of  alkali  required  to  neutralize  by  the 
factor  0.0188,  and  the  quotient  expresses  the  grams  of  bitartrate  of  potash 
in  the  sample.     Multiply  this  by  4  to  obtain  the  percentage  present. 

Polarization  and  Determination  of  Sugar. — If  the  vinegar  is  light- 
colored  and  quite  free  from  turbidity,  it  may  sometimes  be  polarized  undi- 
luted in  the  loo-mm.  tube.  Vinegar  may  often  be  sufficiently  clarified 
for  polarization  by  filtering  twice  through  the  same  filter.  It  is,  how- 
ever, best  to  add  10%  of  basic  lead  acetate  solution,  and  to  filter  before 
polarizing,  thus  removing  the  malic  or  tartaric  acids  which  may  have  a 
slight  effect  on  the  polarization.  In  case  of  dark-colored  or  turbid 
samples,  add  to  50  cc.  of  the  sample  5  cc.  of  about  equal  quantities  of 
lead  subacetate  and  alumina  cream,  shake,  filter,  and  polarize  in  a  200- 
mm.  tube,  adding  10%  to  the  reading  on  account  of  the  dilution. 
The  polarization  value  of  the  vinegar  is  conveniently  expressed  in  terms 
of  actual  direct  reading  obtained  by  the  undiluted  sample  in  a  200-  or 
400-mm.  tube. 

If  the  invert  reading  is  desired  for  calculation  of  sucrose  or  com- 
mercial glucose,  subject  the  sample  to  inversion  with  hydrochloric  acid 
and  heat,  as  in  the  case  of  sugars. 

*  Ibid. 

t  Girard  et  Duprc,  Analyse  des  Matiercs  Alimentaires,  p.  12& 


770  FOOD   INSPECTION    AND  ANALYSIS. 

For  the  determination  of  sucrose,  use  Clerget's  formula  (p.  588), 
calculating  the  true  direct  and  invert  readings  from  the  direct  and  invert 
readings  of  the  undiluted  vinegar  on  the  basis  of  the  normal  weight  of 
the  sample,  by  multiplying  the  obtained  readings  by  0.26  in  the  case  of  the 
Soleil  \'ent/ke  instnmient. 

Determination  of  Reducing  Matter  before  and  after  Inversion. — 
Measure  two  portions  of  25  cc.  each  into  100  cc.  llasks.  Dilute  one  por- 
tion with  25  cc.  of  water,  add  5  cc.  of  concentrated  hydrochloric  acid  and 
invert  in  the  usual  manner.  Neutralize  both  portions  with  sodium 
hydroxide,  clear  with  normal  lead  acetate,  remove  the  excess  of  lead  with 
potassium  sulphate  or  carbonate,  and  make  up  to  the  mark.  Determine 
reducing  sugars  in  each  portion  by  the  Munson  and  Walker  method 
(p.  598)  and  calculate  as  invert  sugar. 

Determination  of  Pentosans. — Place  100  cc.  of  the  vinegar  in  a  flask, 
add  43  cc.  of  concentrated  hydrochloric  acid  (sp.gr.  1.19)  and  proceed  as 
described  on  page  286. 

Determination  of  Glycerin. — The  glycerin  is  extracted  by  essentially 
the  same  process  as  is  used  for  dry  wines  (p.  703)  and  determined  by 
the  Hehner  method  modified  by  Richardson  and  Jaffe  *  and  Low.  These 
processes  have  been  adapted  to  vinegar  analysis  by  Ross  f  as  follows : 

Standard  Solutions. — i.  Strong  Bichromate. — Dissolve  74.56  grams 
of  dry,  recrystalli/ed  potassium  bichromate  in  water,  add  150  cc.  concen- 
trated sulphuric  acid,  cool,  make  up  to  1000  cc.  at  20°  C,  and  determine 
the  specific  gravity  at  20°/20°C.;  i  cc.  =0.01  gram  glycerin.  Accurate 
measurements  being  difficult  owing  to  changes  in  room-temperature 
it  is  well  to  use  weighed  amounts  of  the  solution  from  a  weight  burette, 
dividing  by  the  specific  gravity  to  obtain  the  volume  used.  The  solution 
has  an  apparent  expansion  in  glass  of  0.0005  (^oro.o5^Y)  for  each  degree 
centigrade.     The  solution  may  be  measured  if  this  correction  is  made. 

2.  Dilute  Bichromate. — Introduce  a  weighed  amount  (12.5  times  the 
specific  gravity)  of  the  strong  bichromate  from  a  weight  burette  into  a 
250  cc.  glass-stoppered  volumetric  flask,  make  up  to  the  mark  with  water 
at  room  temperature;  20  cc.  =  i  cc.  of  the  strong  solution.  If  slightly 
more  than  12.5  cc.  equivalent  is  used,  make  up  to  the  mark  and  then 
add  the  required  amount  of  water  to  make  one-twentieth  dilution. 

3.  Ferrous  Ammonium  Sulphate. — Dissolve  30  grams  of  the  crystallized 
salt  in  water,  add  50  cc.  of  concentrated  sulphuric  acid,  cool,  and  dilute 

•Jour.  Soc.  Chem.  Ind.  17,  i8g8,  p.  330. 

t  Proc.  A.O.A.C.  1910.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  137,  p.  61. 


yiNEGAR.  771 

to  1000  cc.  at  room  temperature;  i  cc.  =  approximately  i  cc.  of  the  dilute 
bichromate.  Owing  to  daily  changes  in  strength  it  should  be  standardized 
against  the  bichromate  whenever  used. 

Extraction  of  Glycerin. — Make  all  evaporations  on  a  water-bath  kept 
at  85°  to  90°  C.  Evaporate  100  cc.  of  the  vinegar  to  about  5  cc,  add  20  cc. 
of  water  and  again  evaporate  to  about  5  cc.  to  expel  acetic  acid.  kd<\ 
about  5  grams  of  fine  sand  and  15  cc.  of  milk  of  lime  (freshly  prepared 
and  containing  about  15%  of  calcium  oxide),  and  evaporate  nearly, 
but  not  quite,  to  dryness,  with  frec^uent  stirring,  avoiding  formation  of 
dry  crust.  Rub  into  a  homogeneous  paste  with  5  cc.  of  hot  water,  add  45 
cc.  of  absolute  alcohol,  washing  down  paste  adhering  to  the  sides  of  the 
dish,  and  stir  thoroughly.  Heat  the  mixture  on  a  water-bath  with  con- 
stant stirring  to  incipient  boiling,  decant  onto  a  12.5  cm.  fluted  filter, 
wash  twice  by  decantation  and  finally  on  the  filter  with  90%  alcohol 
up  to  about  150  cc,  or,  instead  of  filtering,  centrifuge  and  wash  three 
times.  Evaporate  to  a  sirup,  dissolve  in  10  cc  of  absolute  alcohol,  and 
wash  into  a  50  cc.  glass-stoppered  cylinder  with  two  5  cc.  portions  of  abso- 
lute alcohol.  Add  three  portions  of  10  cc.  each  of  absolute  ether,  thor- 
oughly shaking  after  each  addition.  Let  stand  until  clear,  then  pour  off 
through  a  filter,  and  wash  the  cylinder  and  filter  with  mixed  absolute 
alcohol  and  absolute  ether  (1:1.5).  If  a  heavy  precipitate  is  observed 
in  the  cylinder,  it  is  well  to  centrifuge  at  low  speed  and  decant  the  clear 
liquid  through  a  filter.  Add  20  cc  of  the  mixture  of  absolute  alcohol 
and  absolute  ether  to  the  precipitate  in  the  cylinder,  shake  thoroughly, 
centrifuge  and  decant,  repeating  three  times.  Evaporate  filtrate  and 
washings  at  85^-90°  C,  to  about  5  cc;  dilute  and  evaporate  to  5  cc. 
three  times,  using  respectively  20,  20  and  10  cc.  of  water.  Wash  residue 
with  hot  water  into  a  50  cc  volumetric  flask,  cool,  add  silver  carbonate 
freshly  precipitated  from  o.i  gram  of  silver  sulphate,  shake  occasionally, 
and  allow  to  stand  10  minutes;  then  add  0.5  cc  of  lead  subacetate  solu- 
tion, shake  occasionally,  and  allow  to  stand  10  minutes.  Make  up  to 
the  mark,  shake  well,  filter,  rejecting  the  first  portion  of  the  filtrate,  and 
pipette  off  25  cc.  of  the  clear  filtrate  into  a  250  cc.  glass-stoppered  volumetric 
flask.  Precipitate  the  excess  of  lead  with  i  cc.  of  concentrated  sulphuric 
acid,  and  determine  the  glycerin  by  the  following  method: 

Determination. — From  a  weight  burette  introduce  into  the  250  cc 
flask,  containing  the  25  cc.  of  purified  glycerin  solution,  a  weighed  amount 
of  the  strong  bichromate  solution  (with  ordinary  vinegar  30-35  cc.)  suf- 
ficient to  leave  about  12.5  cc.  in  excess,  carefully  add  24  cc.  of  concentrated 


77^  FOOD   INSPECTION    ^ND  ANALYSIS. 

sulphuric  acid,  rotating  gently  to  mix  and  avoid  ebullition,  then  heat  in 
boiling-water  bath  for  exactly  20  minutes.  Dilute  at  once,  cool,  and  make 
up  to  mark  at  room  temperature.  The  oxidation  is  a  trifle  more  complete 
if  only  15  cc.  of  concentrated  sulphuric  acid  are  added  and  the  digestion 
is  continued  for  at  least  2  hours. 

Standardize  the  ferrous  ammonium  sulphate  solution  against  the 
dilute  bichromate  by  introducing  from  burettes  approximately  20  cc.  of 
each  into  a  beaker  containing  100  cc.  of  water.  Complete  the  titration, 
using  potassium  ferricyanide  solution  (0.5  to  i''()  as  indicator  on  a 
porcelain  spot  plate.  Calculate  the  volume  {F)  of  ferrous  ammonium 
sulphate  ecjuivalcnt  to  20  cc.  of  the  dilute  and,  consequently,  to  i  cc.  of 
the  strong  bichromate  solution. 

Substitute  for  the  dilute  bichromate  a  burette  containing  the  oxidized 
glycerin  with  excess  of  bichromate  solution,  and  ascertain  how  many  cubic 
centimeters  of  it  are  equivalent  to  F  cc.  of  the  ferrous  ammonium  sulphate 
solution,  and  therefore  to  i  cc.  of  the  strong  bichromate.  Then  250  divided 
by  this  last  equivalent  equals  the  number  of  cubic  centimeters  excess  of  the 
strong  bichromate  present  in  the  250  cc.  flask  after  oxidation  of  the  glycerin. 

The  number  of  cubic  centimeters  of  strong  bichromate  added,  minus 
the  excess  found  after  oxidation,  multi])lied  by  o.oi  equals  the  weight  of 
glycerin  in  the  25  cc.  of  pjurified  solution  used  in  the  determination;  this 
result,  multiplied  by  2,  gives  the  weight  of  glycerin  in  grams  per  100  cc. 
of  the  vinegar. 

ADULTERATION  OF  VINEGAR. 

Standards  of  Purity. — In  England,  where  the  principal  vinegar  is 
malt  vinegar,  the  legal  standards  are  considerably  different  from  those  in 
force  in  France  and  Germany,  where  wine  vinegar  is  prevalent.  These 
difler  again  from  the  recjuirements  found  in  the  United  States  and  Can- 
ada, where  cider  vinegar  is  the  chief  product. 

Most  of  the  state  food  laws  flx  a  standard  for  the  acidity  of  cider 
vinegar  varying  from  3.5  to  4.5  per  cent  of  acetic  acid,  and  in  most  cases 
also  a  minimum  standard  for  total  solids  or  residue  of  from  1.5  to  2  per 
cent.  Special  laws  stij;ulate  furthermore  in  some  states  that  cider  vine- 
gar, sold  as  such,  must  be  exclusively  the  product  of  pure  apple  cider. 
In  such  cases  cider  vinegar  may  be  adulterated  by  non-conformance 
to  the  standard  in  either  acidity  or  solids  or  both,  while  yet  it  may  be 
exclusively  made  from  pure  apple  cider.  This  may  be  due  either  to 
actual   watering   or    to    incomplete   acetification.      On    the   other   hand. 


yiNEGAR.  773 

so-called  cider  vinegar  may  be  of  legal  standard  as  to  solids  and  acidity, 
and  yet  be  entirely  spurious. 

Following  arc  the  U.  S.  standards  for  the  various  vinegars: 

Vinegar,  Cider  Vinegar,  Apple  Vinegar,  is  the  product  made  by  the 
alcoholic  and  subsequent  acetous  fermentations  of  the  juice  of  apples, 
is  la3vo-rotatory,  and  contains  not  less  than  4  grams  of  acetic  acid,  not 
less  than  1.6  grams  of  apple  solids,  of  which  not  more  than  50%  are 
reducing  sugars,  and  not  less  than  0.25  gram  of  apple  ash  in 
100  cc.  (20°  C);  and  the  water-soluble  ash  from  100  cc.  (20°  C.)  of 
the  vinegar  contains  not  less  than  10  milligrams  of  phosphoric  acid 
(r*205),  and  requires  not  less  than  30  cc,  of  decinormal  acid  to  neutralize 
its  alkalinity. 

Wine  Vinegar,  Grape  Vinegar,  is  the  product  made  by  the  alcoholic 
and  subsequent  acetous  fermentations  of  the  juice  of  grapes,  and  con- 
tains in  100  cc.  (20°  C),  not  less  than  4  grams  of  acetic  acid,  not  less 
than  i.o  gram  of  grape  solids,  and  not  less  than  0.13  gram  ot  graps  ash. 

Malt  Vinegar  is  the  jjroduct  made  by  the  alcoholic  and  subsequent 
acetous  fermentations,  without  distillation,  of  an  infusion  of  barley  malt, 
or  cereals  whose  starch  has  been  converted  by  malt,  is  dextro-rotatory, 
and  contains,  in  100  cc.  (20°  C),  not  less  than  4  grams  of  acetic  acid, 
not  less  than  2  grams  of  solids,  and  not  less  than  0.2  gram  of  ash;  and 
the  water-soluble  ash  from  100  cc.  (20°  C),  of  the  vinegar  contains  not 
less  than  9  milligrams  of  phosphoric  acid  (P2O5),  and  requires  not  less 
than  4  cc.  of  decinormal  acid  to  neutralize  its  alkalinity. 

Sugar  Vinegar  is  the  product  made  by  the  alcoholic  and  subsequent 
acetous  fermentations  of  solutions  of  sugar,  syrup,  molasses,  or  refiners' 
syrup,  and  contains,  in  100  cc.  (20°  C),  not  less  than  4  grams  of  acetic 
acid. 

Glucose  Vinegar  is  the  product  made  by  the  alcoholic  and  subsequent 
acetous  fermentations  of  solutions  of  starch  sugar  or  glucose,  is  dextro- 
rotatory, and  contains,  in  100  cc  (20°  C),  not  less  than  4  grams  of  acetic 
acid. 

Spirit  Vinegar,  Distilled  Vinegar,  Grain  Vinegar,  is  the  product  made 
by  the  acetous  fermentation  of  dilute  distilled  alcohol,  and  contains,  in 
100  cc.  (20°  C),  not  less  than  4  grams  of  acetic  acid. 

Accidental  Adulteration  of  vinegar  may  result  in  the  presence  of  injuri- 
ous metallic  salts,  such  as  of  copper,  lead,  or  zinc,  derived  from  vessels  or 
utensils  used  in  the  manufacture  of  vinegar,  or  even  minute  traces  of 
arsenic  may  be  found,  when  glucose  has  been  employed  as  an  ingredient 


77+  FCOD   INSPECTION    AND    ANALYSIS. 

or  source  of  the  vinegar,  the  arsenic  being  in  this  case  probably  due  to 
impure  sulphuric  acid  used  in  the  manufacture  of  the  glucose. 

Willful  or  Fraudulent  Adulteration  is,  however,  common,  in  w^hich 
misbranded  vinegar  is  sold  under  names  suggesting  a  class  other  than 
that  to  which  it  really  belongs,  or  wherein  entirely  artificial  substitutes 
are  made  up  for  pure  cider,  malt,  or  wine  vinegar,  in  which  the  color, 
residue,  and  acid  princi]de  may  1)e  either  or  all  of  spurious  origin. 

Artificial  Cider  Vinegar  i>  in  most  cases  readily  detected,  though 
ven-  ingenious  imitations  are  on  the  market,  involving  not  a  little  skill 
and  chemical  knowledge  in  their  manufacture. 

Entirely  artificial  substitutes  for  cider  vinegar  are  frequently  made 
up  of  spirit  vinegar,  colored  with  caramel,  and  having  the  solids  rein- 
forced by  ap'ple  jelly,  made  for  the-  most  part  out  of  exhausted  apple 
pomace,  which  is  the  residue  left  after  the  apple-stock  has  been  sub- 
jected to  one  and  sometimes  two  pressings.  The  jelly  used  for  this 
purpose  is  not  infrequently  made  up  with  commercial  glucose.  All 
grades  of  adulterated  vinegar  are  to  be  found,  from  the  wholly 
spurious  substitute  above  described,  to  the  varieties  in  which  cider 
vinegar  is  itself  present,  but  is  pieced  out  or  reinforced  by  the  admixture 
of  coloring  matter,  mineral  acid,  wood  vinegar,  or  of  molasses  or  glucose 
vinegar.  Acetic  ether  is  sometimes  ?mploye(l  to  impart  flavor  to  the 
product.  All  the  characteristics  of  a  pure  cider  vinegar  are  difficult  to 
duplicate  artificially,  though  some  of  them  may  be. 

Character  of  the  Residue. — The  residue  of  pure  cider  vinegar  should 
be  thick,  light  brown  in  color,  of  a  viscid  or  mucilaginous  consistency, 
somewhat  foamy,  having  an  astringent  acid  though  pleasant  taste  very 
suggestive  of  baked  apples,  which  it  also  resembles  in  odor.  The  odor 
of  molasses  is  very  apparent  in  the  residue  of  vinegar  having  sugar-house 
wastes,  and  the  smell  of  a  malt-vinegar  residue  is  also  very  characteristic. 
If  i>yroligneous  or  wood  vinegar  has  been  introduced,  the  dried  residue 
will  have  a  tarry  or  smoky  taste  and  smell. 

The  residue  of  cider  vinegar  is  very  soluble  in  alcohol,  while  that  of  malt 
vinegar  is  only  slightly  soluble.  Wine  vinegar  residues  dissolve  readily 
in  alcohol,  except  for  the  granular  residue  of  cream  of  tartar.  If  the 
loop  of  a  clean  jdatinum  wire  be  rubbed  in  the  vinegar  residue  and  ignited 
in  a  colorless  Buasen  flame,  the  color  imparted  will,  if  the  vinegar  has 
been  made  from  pure  cider  exclusively,  consist  altogether  of  the  pale- 
lilac  color  of  a  potash  salt  withfjut  any  of  the  yellow  sodium  flame  being 


yiNEG/iR.  775 

visible.  In  all  vinegars  other  than  of  pure  cider,  the  sodium  flame  will 
predominate,  when  the  residue  is  burnt  as  above.  Again,  the  ignited 
residue  left  in  the  loop  of  wire  in  the  case  of  a  pure  cider  vinegar  will 
form  a  fusible  bead,  having  a  strong  alkaline  reaction  upon  moistened 
test-paper,  and  effervescing  briskly  when  immersed  in  acid.  The  pres- 
ence in  vinegar  of  even  a  slight  trace  of  added  mineral  acid  will  prevent 
the  ignited  residue  from  having  the  alkaline  reaction,  or  effervescing  with 
acid.* 

The  residue  of  malt  or  beer  vinegar  is  brown  and  gummy,  containing 
a  considerable  quantity  of  dextrin.  Not  only  are  the  appearance  and 
odor  of  the  dried  vinegar  residue  to  be  particularly  noted,  but  also  the 
odor  given  off  in  the  first  stages  of  burning  this  residue  to  an  ash.  With 
cider  vinegar  the  apple  odor  is  very  marked  while  burning.  In  vinegar 
wherein  molasses  products  have  been  employed,  the  smell  of  charred 
sugar  is  usually  apparent,  while  with  glucose  vinegar  the  smell  of  burnt 
corn  predominates. 

On  burning  the  residue  of  malt  vinegar,  the  odor  produced  at  first 
is  not  unlike  that  of  toasted  bread.  At  a  later  stage  in  the  burning  the 
vapors  evolved  are  ver)'  pungent. 

The  Character  of  the  Ash  is  of  considerable  importance  in  determin- 
ing the  source  of  a  sample  of  vinegar.  The  ash  of  pure  cider  and  malt 
vinegar  is  quite  strongly  alkaline,  while  that  of  distilled  and  wood  vinegar 
is  only  slightly  alkaline.  The  ash  of  cider  vinegar  is  high  in  alkaline 
carbonates. 

In  cider  and  malt  vinegar  the  quantity  of  phosphoric  acid  present 
in  the  ash  is  considerable,  while  only  traces  are  present  in  distilled  or 
spirit  vinegar.  Considerably  more  than  half  the  phosphoric  acid  in 
the  ash  of  cider  vinegar  is  soluble,  while  no  soluble  phosphoric  acid  is 
present  in  the  ash  of  spirit  vinegar. 

The  percentage  of  ash  in  total  solids  is  of  some  value  in  judging  the 
purity  of  cider  vinegar.  According  to  Frear.f  if  the  ash  of  the  vinegar 
is  less  than  io%  of  the  total  solids,  the  vinegar  may  be  suspected  of 
having  added  unfermented  material,  while  a  percentage  of  ash  less  than 
6  is  absolute  evidence  that  the  vinegar  is  not  genuine  cider  vinegar. 

The  alkalinity  of  i  gram  of  the  ash  of  pure  cider  vinegar  should  be 

*  Davenport,  i8th  An.  Rep.,  Mass.  Board  of  Health,  1887,  p.  159. 
t  Report  of  Penn.  Dept.  of  Agric,  1898,  p    t,'6. 


-■jb  FOOD   l\SPECTJON  /IKD  .^N. 4 LYSIS 

eqifvalcnt    to  at  loast   65  cc.   of  tenth-normal  add.      At  least   50%  oi 
the  phosphates  in  the  ash  should  be  soluble  in  water. 

Character  of  the  Sugars. — One  of  the  most  important  steps  in  es- 
tablishing the  source  of  a  vinegar  consists  in  subjecting  it  to  ])olariza- 
tion  (]■).  7O0).  From  the  nature  of  the  sugar-content  of  the  apple  juice, 
not  only  when  freshly  expressed,  but  also  when  allowed  to  undergo 
alcoholic  fermentation,  and,  furthermore,  after  it  has  gone  over  into 
vinegar,  the  polarization  through  all  three  stages  is  always  left-handed. 

Browne*  has  shown  that  the  optical  rotation  of  the  freshly  expressed 
juice  of  eleven  varieties  of  apple  varies  from  19.24°  to  49°  to  the  left  on 
the  \'entzke  scale,  in  a  400- mm.  tulje.  Also  that  in  the  case  of  five 
samples  of  completely  fermented  cider,  examined  five  or  six  months 
after  pressing,  the  left  handed  rotation  in  a  400-mm.  tube  varied  from 
1.76°  to  5.28°.  He  showed,  furthermore,  that  a  sample  of  pure  cider 
jelly  made  up  of  concentrated  apple  juice  had  a  left-handed  rotation 
amounting  to  21.35°  "''  '-^  200-mm.  tube  (20  grams  made  up  100  cc),  and 
finally  that  four  cider  vinegar  samples  of  known  purity  showed  left- 
handed  readings  of  from  0.96°  to  2.94°  Vcntzke  in  a  400-mm.  tube. 

The  left-handed  rotation  of  pure  cider  vinegar  is  a  characteristic  so 
fixed  and  unalterable  that  a  right-handed  polarization  of  more  than  0.5° 
may  safely  be  assumed  as  evidence  of  adulteration.  The  polarization  of 
cider  vinegar,  expressed  in  terms  of  200  mm.  of  the  undiluted  sample 
should  lie  between  —0.1°  and  —4.0°  Ventzke.  If  the  direct  ])olarization 
of  a  samj)lc  of  vinegar  is  right-handed,  wliile  the  invert  is  left-handed, 
sugar-house  wastes  or  molasses  may  be  suspected  as  an  adulterant. 

If  both  direct  and  invert  readings  are  right-handed,  commercial 
glucose  is  undoubtedly  present.  If  the  polarization  of  the  vinegar  is 
far  to  the  left,  unfermented  cider  jelly  has  j^robably  been  used  to  rein- 
iorce  the  solids. 

Frear  regards  the  ratio  of  reducing  sugars  after  inversion  to  total 
solids  as  a  useful  factor  in  discriminating  between  i)ure  cider  vinegar 
and  the  common  artificial  substitutes  in  which  the  solids  of  distilled  vinegar 
arc  reinforced  by  aj^plc  jelly,  or  in  which  commercial  glucose  or  molasi:es 
vinegars  are  used.  When  the  reducing  sugars  after  inversion  form  more 
than  2^^  t    of  the  entire  solids,  the  alleged  cider  vinegar  is  undouluedly 


•Bull.  58,  Penn.  Dcpt.    of    Agric,  "A  Chemical  Stufly  of    the    Ai>p]e    and    Its    Pro- 
ducts." 


l^INEGAR. 


777 


spurious.  In  pure  cider  vinegar  the  [>er  cent  of  reducing  sugar  is 
the  same  after  inversion  as  before.  The  same  is  true  of  glucose 
vinegar 

Vinegar  containing  added  molasses  or  cane  sugar  will,  however, 
naturally  show  an  increase  in  reducing  sugar  after  inversion. 

A  large  content  of  alcohol  in  cider  vinegar,  otherwise  showing  the 
constants  of  pure  vinegar  except  for  the  low  acidity,  would  indicate  incom- 
plete acetification.  A  high  content  of  nitrogen  is  characteristic  of  malt 
vinegar. 

Data  of  analyses  of  samples  of  vinegar  examined  in  the  Food  and 
Drug  Department  of  the  Massachusetts  State  Board  of  Health  are  given 
in  the  tables  on  this  page  and  the  next.  The  table  below  shows  in  sum- 
■marized  form  the  results  obtained  from  the  examination  of  eighty-four 
samples  of  undoubtedly  pure  cider  vinegar  examined  in  1901.* 

CIDER  VINEGAR  FOUND  PURE. 


Acid 
(Per  Cent). 

Solids 
(Per  Cent). 

Ash 
(Percent). 

Polarization. 

Maximum 

6.36 
4-50 
4.84 

4.00 
2.01 
2-43 

0.58 

O.IQ 

0.38 

-5-4 
—  0.4 

Minimum 

Mean 

—  2.0 

The  second  table  includes  samples  of  adulterated  vinegar,  sold  for 
cider  vinegar,  none  of  which  were  probably  made  from  cider.  It  will 
"be  noticed  that  in  several  of  the  samples  the  amount  of  glucose  was 
abnormally  large,  as  is  showm  by  the  very  high  right-handed  polarization, 
in  one  case  amounting  to  over  12°. 

Direct  Tests  Made  on  the  Vinegar. — The  genuine  or  spurious  natur-^ 
of  cider  vinegar  may  usually  be  established  by  direct  tests  with  reagents 
on  the  vinegar  itself.  The  appearance,  taste,  and  odor  of  the  vinegar 
should  be  noted.  Brannt  f  applies  the  test  of  odor  in  vinegar  as  deter- 
mining its  character,  by  rising  out  a  large  beaker  with  the  sample,  and' 


*  32d  An.  Rep.  (1900),  p.  661,  Food  and  Drug  Reprint,  p.  44;    33d  An.  Rep.  (1901),  p. 
467,  Food  and  Drug  Reprint,  p.  47;   34th  An.  Rep.  (1902),  p.  483,  Food  and  Drug  Reprint, 

P-  31- 

t  A  Practical  Treatise  on  the  Manufacture  of  Vinegar,  p.  219. 


7/8 


FOOD  INSPECTION  AND  ANALYSIS. 


VINEGAR  NOT  THE  EXCLUSIVE  PRODUCT  OF  PURE  APPLE  CIDER. 


Per  Cent 

Per  Cent 

Per  Cent 

Per  Cent 

Polarization 

Acetic  Acid. 

Total  Solids. 

Ash. 

Ash  in  Total 
Solids. 

in  200-min. 
Tube. 

Lead  Acetate. 

5.QO 

-40 

.... 

+  1-4 

No  precipitate 

5-M 

■36 

.... 

.... 

.0 

"           " 

5.12 

-53 

.... 

.... 

+    .6 

"           " 

4-83 

3-70 

-  ^2 

8.65 

+  8.ot 

"           " 

4.82 

2.71 

-13 

4.80 

+  9-6t 

Heavy  precipitate*" 

4.80 

I-Q7 

.20 

10.15 

+    -Q 

Precipitate 

4.80 

1.03 

.27 

M-75 

+  I-1 

' ' 

4.66 

2.92 

.20 

6-49 

-f  2.2 

No  precipitate 

4.60 

2-57 

.... 

.... 

+  2.6 

"          " 

4.56 

2.60 

.... 

.... 

+  7-ot 

t 

4-54 

3-97 

.19 

4.78 

+  5-6 

No  precipitate 

4.54 

3-90 

•2,2 

9.72 

+  5-0 

t  t                n 

4-54 

2-94 

•23 

7.82 

+  5-0 

"             " 

4-54 

2.70 

-23 

8.52 

+    -4 

Precipitate 

4.50 

3-05 



+  2.2 

No  precipitate 

4-50 

2.92 

.22 

7-52 

+    -9 

t  (          I  i 

4.50 

2.69 

.... 

.... 

-f2.8 

<(          << 

4-48 

3-80 

.... 

.... 

+  12.0+ 

<  <          << 

4.46 

2.80 

.... 

.... 

+  2.6 

11          ti 

4.42 

2.75 



.... 

+  3-2 

Slight  precipitate 

4-42 

2.10 

+  9-2 

Precipitate 

4-40 

2.51 

.20 

II. 15 

+  I.I 

* ' 

4.40 

-97 



+    -4 

No  precipitate 

4-38 

.29 



+  1.6 

<  (          ( ( 

4-32 

-70 

.09 

12.86 

.... 

<  (          1 1 

4.08 

3-35 

.... 

.... 

+  1.2 

Precipitate 

3-98 

.55 





+  1.8 

Slight  precipitate 

*  Cider  vinegar  to  which  apple  jelly  containing  glucose  had  been  added  for  the  purpose  of  increas- 
ing the  Sfjlids  after  watering. 

t  This  sample  contained  a  large  amount  of  phosphate,  and  consequently  the  test  for  malatcs  is 
obficured. 

J  These  samples  polarized  practically  the  same  after  as  before  inversion,  indicating  much  glucose. 


after  allowing  it  to  stand  for  some  hours,  examining  the  few  drops  remain- 
ing in  the  beaker.  The  acetic  acid  having  for  the  most  part  become 
volatilized,  the  characteristic  vinous  odor  of  pure  wine  vinegar  would 
at  this  stage  be  very  y^rominent,  while  that  of  cider  vinegar  would  be 
entirely  dilTercnt.  The  odor  of  the  two  vinegars  is  very  similar  in  their 
ordinan.'  state.  The  peculiar  fruity  flavor  of  pure  cider  vinegar  is  very 
characteristic  and  not  readily  imitated  by  cheaper  substitutes.  Only 
a  very  slight  turbidity  should  be  ])roduccd  in  pure  cider  vinegar  l^y  the 
addition  of  either  ammonium  oxalate  (absence  of  lime),  barium  chloride 
(absence  of  sulphuric  acid  or  sulphate),  and  nitrate  of  silver  (absence 
of  hydrochloric  acid  or  chlorides). 


yiNEG/IR.  779. 

The  character  of  ihc  precipitate  produced  by  neutral  lead  acetate 
should  be  particularly  noted.  Unless  it  is  flocculent  and  copious,  set- 
tling out  after  a  few  minutes,  cider  vinegar  is  not  pure,  even  if  a  marked 
turbidity  is  produced.  Added  apple  jelly  from  exhausted  apple  pomace 
gives  such  a  turbidity,  and  is  to  be  suspected  when  not  more  than  a  cloudi- 
ness is  produced  on  addition  of  the  lead  acetate  reagent.  Pure  cider 
vinegar  should  respond  in  a  perfectly  normal  manner  to  both  the  lead 
acetate  and  the  calcium  chloride  tests  for  malic  acid. 

Wood  Vinegar  or  Pyroligneous  Acid  is  sometimes  rendered  apparent 
by  the  empyreumatic  or  tarry  taste  and  odor  imparted  to  the  product. 
When,  however,  the  added  acetic  acid  has  been  so  purified  that  the  tarry 
taste  and  odor  are  lacking,  its  presence  may  often  be  proved  by  the  traces 
of  furfurol  which  always  accompany  it. 

Test  for  Furfural. — A  little  of  the  vinegar  is  subjected  to  distillation, 
and  to  the  first  few  drops  of  the  distillate  is  added  a  little  colorless  anilin 
solution.  A  fading  crimson  color  will  be  produced  in  presence  of  furfurol. 
This  reaction  may  sometimes  be  obtained  upon  the  vinegar  itself  without 
distillation,  if  sufficient  added  wood  vinegar  be  present. 

The  first  portion  of  the  distillate  of  wood  vinegar  reduces  permanga- 
nate of  potassium  to  a  marked  degree. 

The  Addition  of  Spices  to  vinegar  in  order  to  increase  the  pungency 
is  best  detected  by  first  neutralizing  the  vinegar  with  sodium  carbonate 
and  then  tasting.  Under  these  conditions,  the  admixture  of  spices  is 
rendered  very  apparent. 

Detection  of  Caramel. — Considerable  added  caramel  in  vinegar  is 
apparent  from  the  unnaturally  dark  color  and  extremely  bitter  taste  of 
the  residue  after  evaporation. 

Tests  for  caramel  made  on  the  vinegar  residue,  if  long  dried  at  the 
temperature  of  the  water-bath,  are  not  to  be  depended  on  as  establishing 
the  presence  of  added  caramel,  since  at  that  temperature  the  decomposi- 
tion of  the  sugar  may  in  any  event  cause  a  positive  test. 

Caramel  is  detected  by  Crampton  and  Simon's  and  Amthor's  tests  (p. 
752).  A  further  indication  of  caramel  is  the  reducing  power  of  the  water 
solution  of  the  precipitate  obtained  in  Amthor's  test. 

Examination  for  Metallic  Impurities. — Lead  and  Zinc  are  best  looked 
for  in  the  ash  of  the  vinegar  in  cases  where,  like  cider  vinegar,  the  percent- 
age of  extract  is. high.  A  large  volume  of  the  vinegar  is  evaporated  to 
substantial  dryness  over  the  water-bath.  This  may  most  readily  be 
done  in  a  loo-cc.  platinum  wine-shell,  adding  the  vinegar  in  successive 


7 So  FOOD   INSPECTION  AND  /iN. 4 LYSIS. 

ponions.  To  the  residue  add  a  small  amount  of  sodium  hydroxide,  and 
burn  to  an  ash  in  a  muffle,  or  over  a  low  flame,  using  potassium  nitrate 
if  nccessar}-,  a  little  at  a  time.  Take  up  the  ash  in  dilute  hydrochloric 
acid,  and  examine  for  lead  and  zinc  as  in  the  case  of  canned  goods. 

In  the  case  of  vinegar  low  in  extract,  as  in  spirit  vinegar,  the  sample 
may  be  evaporated  to  dryness,  the  residue  dissolved  directly  in  dilute 
hvdrochloric  acid  without  ignition,  and  the  acid  solution  subjected  to 
direct  examination  for  lead  and  zinc. 

Copper  is  best  determined  by  electrolysis.  loo  cc.  of  the  vinegar 
are  evaporated  to  a  volume  of  about  lo  cc.  with  a  little  sulphuric  acid, 
filtered  into  a  platinum  dish,  and  subjected  to  electrolysis,  using  con- 
veniently the  apparatus  described  on  page  608. 

Arsenic. — Boil  down  a  portion  of  the  vinegar,  to  which  concentrated 
nitric  acid  has  been  added,  to  a  small  volume,  then  add  a  few  cubic  centi- 
meters of  concentrated  sulphuric  acid,  and  continue  the  heating  till  fumes 
of  sulphuric  acid  show  the  nitric  to  have  been  driven  ofif.  Cool,  dilute 
with  water,  and  test  in  the  Marsh  apparatus. 

REFERENXES  ON  VINEGAR. 

Allent,  a.  H.     \Vhite  Wine  Vinegar.     Analyst,  21,  1896,  p.  253. 

Allen,  A.  H.,  and  Moor,  C.  G.     Vinegar.     Analyst,  18,  1893,  pp.  180  and  240. 

Bersch,  J.     Die  Essigfabrikation.     Vienna,  1895. 

Bran'kt,    W.     Vinegar,    Acetates,    Cider,  Fruit  Wines   and   Preservation   of   Fruits. 

London,  1900. 
Brow.ne,  C.  a.     a  Chemical  Study  of  the  Apple  and  Its  Products.     Penn.  Dept.  of 

Agric.  Bui.  58,  1899. 
The  EfTects  of  Fermentation  upon  the  Composition  of  Cider  and  Vinegar.     Jour. 

Am.  Chem.  Soc,  25,  1903,  p.  16. 
Crampton,  C.  a.,  and  Simons,  F.  D.     Detection  of  Caramel  in  Spirits  and  Vinegar. 

Jour.  Am.  Chem.  Soc,  21,  1899,  p.  355. 
Davenport,  B.  F.     Analysis  of  Vinegar.     Chem.  News,  1887,  3  and  66. 
DooLlTTLK,  R.  E.,  and  Hp:ss,  W.  H.     Cider  Vinegar,  Its  Solids  and  Ash.     Jour.  Am. 

Chem.  Soc,  22,  1900,  p.  218. 
Dubois,  W.  L.     The  Fuller's  Earth  Test  for  Caramel  in  Vinegar.     Jour.  Am.  Chem. 

Soc,  29,  1907,  p.  75. 
Frear,   W.     Apple  Juice,   Fermented   Cider  and  Vinegar.     Penn.   Dept.   of  Agric. 

Rcf).,  1H98,  p.  138. 

Cider  Vinegars  of  Pennsylvania.     Venn.  Dept.  of  Agric,  Bui.  22,  1897. 

V'inegar.     U.  S.  Dept.  of  .Agric,  Bur.  of  Chem.,  Bui.  65,  p.  62.     Washington, 

1902. 
Gardner,  J.     Acetic  .\cid  and  Vinegar.     I'hiladclfjhia.,  1885. 
I^EACH,   .\    v..,  and   LvTHfioK,   H.  C.     Cider  Vinegar  and  Suggested  Standards  of 

Purity.     Jour.  Am.  Chem.  Soc,  26,  1904,  p.  375. 


VINEGAR.  781 

Leeds,  A.  R.     Acetic  Acid  in  Vinegar.     Jour.  Am.  Chem.  Soc,   17,   1895,  p.   741. 
Macfarlane,  T.     Vinegar.     Canada  Inl.  Rev.  Dept.,  Bui.  35.     Ottawa,  1893. 
Pasteitr,  M.     Etudes  sur  la  Vinaigre.     Paris,  1868. 

Sangl^-Ferriere.     Vinaigre.     Analyse  des  Matibres  Alimentaires  (Girard),  p.  263. 
Smith,  A.  W.    Vinegar  Analysis  and  Characteristics  of  Pure  Cider  Vinegar.     Jour.  Am. 

Chem.  Soc,  20,  1898,  p.  3. 
Sykes,  W.  J.     Detection  of  Adulteration  in  Vinegar.     Analyst,  16,  1891,  p.  83. 

Connecticut  Exp.  Sta.  An.  Reports,  1897,  1898,  1899. 

Massachusetts  State  Board  of  Health,  An.  Reports,  1900,  1901,  1902,  and  1903. 

North  Carolina  Exp.  Station  Bui.  153. 


CHAPTER  XVII. 
ARTIFICIAL  FOOD  COLORS. 

The  use  of  artificial  dyestuffs  in  food  products  has  greatly  increased 
during  recent  years,  both  in  degree  and  in  variety  of  colors  employed. 
Where  formerly  but  a  few  well-known  coloring  matters,  chiefly  so-called 
vegetable  colors  and  occasionally  mineral  ])igments  were  used  for  this 
purpose,  a  vast  array  of  dyes,  chosen  largely  from  the  coal-tar  colors, 
are  now  found  in  food,  so  that  at  present  the  exact  identification  of  the 
particular  dvestuff  employed  in  all  cases  presents  a  somewhat  formidable 
problem  to  the  analyst.  The  problem  may  consist  in  determining  the 
class  to  which  a  commercial  food  color  or  combination  of  colors  belongs,. 
or  it  may  consist  in  isolating  the  color  itself,  and  afterwards  identifying 
it  as  far  as  possible,  for  the  purpose  of  determining  whether  or  not  it  is 
harmless  within  the  meaning  of  the  law. 

The  effect  of  imparting  to  the  cheaper  varieties  of  jellies,  jams,  and 
ketchups  which  flood  the  market  such  intense  and  striking  colors  that 
these  products  in  no  wise  resemble  their  pure  uncolored  prototypes,  has 
a  tendency  in  many  cases  to  mislead  the  public  into  the  idea  that  the 
genuine  products  are  inferior  by  contrast,  and  to  create  a  craving  for 
unnaturally  colored  varieties.  Indeed,  the  adherents  to  the  free  use  of 
coloring  matters  in  food  assert  that  these  brilliant  hues  please  the  eye  and 
are  hence  legitimate. 

Objectionable  Features. — With  the  exception  of  confectionery  and 
certain  des>ert  prej^aralions,  in  which  dyes  may  be  employed  y)urely  for 
jesthetic  considerations  only  (a  fact  which  is  well  understood  l)y  the 
consumer),  the  use  of  coloring  matters  in  food  is  mainly  for  the  purpose 
of  deceiving  as  to  their  true  character.  The  use  of  dyestuffs  in  food 
is  objectionable  on  two  accounts,  first  as  introducing  in  some  cases 
materials  injurious  to  health,  and  second,  in  nearly  all  cases  as  deceiv- 
ing  the   purchaser  by   concealing   inferiority,   or  by   making   the  goods 

782 


ARTIFICIAL   FOOD   COLORS.  783 

appear  of  greater  value  than  they  really  are.  In  most  states  the  food 
laws  regarding  employment  of  colors  are  so  framed,  that  the  presence 
of  such  colors  constitutes  an  offense  under  one  or  the  other  of  the  above 
heads,  mainly,  however,  because,  by  reason  of  their  use,  cheaper  or 
inferior  materials  arc  made  to  masquerade  for  the  higher  or  genuine 
grades,  as,  for  instance,  when  alleged  currant  jelly  is  found  to  consist 
chiefly  of  apple-stock  and  commercial  glucose,  colored  with  an  artilicial 
red  dye. 

In  such  cases  the  analyst  has  merely  to  prove  conclusively  that  an 
artificial  color  is  present,  even  if  he  does  not  identify  the  dye  itself.  It 
is  of  course  more  satisfactory  to  at  least  show  in  addition  whether  the 
dye  present  is  of  vegetable  origin,  or  is  of  the  coal-tar  variety,  and  in  most 
cases  this  can  readily  be  done,  even  if  it  is  not  easy  to  identify  the  exact 
color. 

In  localities  where  laws  prevail  stipulating  that  what  are  commonly 
known  as  "mixtures"  or  "compounds"  to  be  legally  sold,  must  be 
labeled  with  the  names  and  percentages  of  ingredients,  the  law  applies  to 
coloring  matters  as  well  as  other  ingredients,  and  the  exact  dye  or  dyes 
employed  should  appear  on  the  label.  Otherwise  the  product  must  be 
classed  as  adulterated. 

Toxic  Effects  of  Colors. — Formerly  the  use  of  such  pigments  as 
chromate  of  lead  was  common  in  coloring  confectioner}-,  but  lead 
chromate  is  rarely  used  at  present.  Other  mineral  pigments  obviously 
unfit  for  use  in  food  by  reason  of  their  well-known  poisonous  effects  are 
those  which  contain  salts  of  arsenic,  mercury,  lead,  and  copper.  While 
most  of  the  coal-tar  colors  are  considered  harmless  in  themselves,  some 
are  decidedly  objectionable,  and  should  not  be  used  in  foods.  Under 
the  latter  class  are  included,  first,  those  in  connection  with  the  manu- 
facture of  which  arsenic,  mercury,  or  other  poisonous  mineral  ingredients 
have  been  used,  such  for  example  as  arsenical  fuchsin,  and,  second,  those 
which  are  themselves  inherently  poisonous,  as  for  instance  picric  acid. 
Fuchsin  is  now  largely  made  without  the  aid  of  arsenic  acid,  and  this 
variety  is,  perhaps,  harmless.  The  toxic  eft'ects  of  many  of  the  coal-tar 
colors  have  not  been  thoroughly  established  excepting  in  a  negative  way, 
Weyl  has  made  many  experiments  on  dogs  and  rabbits  in  which  these 
animals  have  been  fed  with  varying  amounts  of  coloring  material.  In 
nearly  all  cases  the  doses  far  exceeded  the  amounts  ordinarily  taken  in 
food,  and  the  experiments  are  of  value  mainly  in  so  far  as  they  show 
harmless  results  of  certain  colors  on  the  animal.     It  is  to  be  regretted 


784  FOOD  INSPECTION  AND  ANALYSIS. 

that  physiological  experiments  cannot  more  readily  be  tried  on  human 
beings,  so  as  to  study  the  effects  of  administering  to  them  such  amounts 
as  are  used  in  food. 

More  conclusive  results  (though  still  of  a  negative  character)  tending 
to  establish  the  harmlcssness  of  most  of  the  coal-tar  colors  are  given  by 
Grandhomme  *  in  statistics  showing  the  condition  of  health  of  laborers 
in  factories  where  these  dyestuffs  are  made,  in  comparison  with  those 
engaged  in  other  industries  where  poisonous  materials  are  handled. 
From  these  it  appears  that  the  proportion  of  illness  among  the  anilin- 
makers  is  remarkably  small. 

In  the  case  of  coloring  confectionery  by  the  use  of  mineral  pigments, 
a  considerable  amount  of  the  coloring  material  must  be  used,  forming 
without  doubt  a  source  of  danger  in  some  cases.  With  coal-tar  dyes,  on 
the  contrar}',  the  case  is  different.  One  ounce  of  auramine,  for  instance, 
has  been  found  suflScient  to  give  a  deep-yellow  color  to  2,000  pounds 
of  confectioner}',  so  that  almost  an  infinitesimal  amount  of  the  actual 
dyestuff  is  taken  into  the  system.  Hence  it  is  that  ver)^  little  danger 
need  be  apprehended  from  the  use  of  most  coal-tar  colors  in  food,  objec- 
tionable as  they  certainly  arc  as  a  commercial  fraud. 

Injurious  and  Non-injurious  Colors. — Various  countries  have  enacted 
specific  laws  regulating  the  use  of  coloring  matters  in  foods,  especially 
England,  France,  Germany,  Austria,  and  Italy.  In  some  cases  attempts 
have  been  made  to  specify  harmful  and  harmless  colors.  The  National 
Confectioners'  Association  of  the  United  States  has  compiled  a  useful 
classified  list  of  injurious  and  harmless  colors, f  the  classification  being 
based  largely  on  the  results  of  experiments  by  Weyl  and  Konig,  as  well 
as  upon  the  Resolutions  of  the  Association  of  Swiss  Chemists,  and  on 
the  French  Ordinances  regarding  food  colors.     The  list  is  as  follows: 

HARMFUL   MINERAL   COLORS. 

Compounds  oj  Copper. — Blue  ashes,  mountain  blue,  etc. 

Compounds  oj  Lead. — Massicot,  red  lead,  white  lead,  Cassel  yellow, 
Paris  yellow,  Turner  yellow,  Naples  yellow,  sulphates  of  lead,  chrome 
yellow,  Cologne  yellow,  etc. 

Compounds  oj  Barium. — Ultramarine  yellow,  etc. 

♦  Weyl,  Sanitary  Relations  of  the  Coal-tar  Colors,  pp.  28-30. 

t  Colors  in  Confectionery.  An  OfTicial  Circular  from  the  Executive  Committee  of  th» 
Nmtional  Confectioners'  Association  of  the  U.  S.,  1899. 


ARTIFICML   FOOD   COLORS.  785 

Compounds  oj  Mercury. — Vermilion,  etc. 

Compounds  0}  Arsenic. — Schecle's  green,  Schweinfurth  green,  etc. 
In  Other  Words  colors  in  whose  preparation  mercury,  lead,  copper, 
arsenic,  antimony,  tin,  zinc,  chromium,  and  barium  compounds  are  used. 

HARMFUL  ORGANIC  COLORS. 

Red  Colors. — Ponceau  3/?^. — Ponceau  B  extra,  fast  ponceau  B, 
new  led  L,  scarlet  EC,  imperial  scarlet,  old  scarlet,  Biebrich  scarlet. 

Crocein  Scarlet  ^B. — Ponceau  4RB. 

Cochenille  Red  A. — Crocein  scarlet  4B  and  G,  brilliant  scarlet, 
brilliant  ponceau  4R,  ponceau  4R,  ponceau  brilliant  4R,  new  coccin, 
scarlet. 

Crocein  Scarlet  'jB. — Crocein  scarlet  8B,  ponceau  6RB. 

Crocein  scarlet  O  extra. 

Sajranin. — Safranin  T,  safranin  extra  G,  safranin  G  extra  GGSS, 
safranin  GOOO,  safranin  FF  extra  No.  O,  safranin  cone,  safranin  AG 
extra,  safranin  AGT  extra,  anilin  pink. 

Yellow  Colors. — Gum  gutta. 

Picric  acid. 

Martins  Yellow. — Naphthylamin  yellow,  jaune  d'or,  Manchester  yel- 
low, naphthalin  yellow,  naphthol  yellow,  jaune  naphthol. 

Acme  Yellow. — Chr}'soin,  chryseolin  yellow  T,  gold  yellow,  resorcin 
yellow,  acid  yellow  RS,  tropasolin  O,  jaune  II. 

Victoria  Yellow. — Victoria  orange,  anilin  orange,  dinitrocresol,  saf- 
fron substitute,  golden  yellow. 

Orange  II. — Orange  No.  2,  orange  P,  orange  extra,  orange  A,  orange 
G,  acid  orange,  gold  orange,  mandarin  G  extra,  beta-naphtholorange, 
tropceolin  OOO  No.  2,  mandarin,  chrysaurin. 

Metanil  Yellow. — Orange  MN,  tropaeolin  G,  Victoria  yellow  (O  double 
cone),  jaune  G  (metanil  extra). 

Sudan  I. — Carminaph. 

Orange  IV. — Orange  No.  4,  orange  N,  orange  GS,  new  yellow,  acid 
yellow  D,  tropasolin  OO,  fast  yellow,  diphenylorange,  diphenylamine 
orange,  jaune  d'anilin,  anilin  yellow. 

Green  Colors. — Naphthol  green  B. 

Blue  Colors. — Methylene  blue  BBG. — Methylene  blue  BB,  in  powder 
extra,  methylene  blue  DBB  extra,  methylene  blue  BB  (crystalline) 
ethylene  blue. 


7S6  FOOD  INSPECTION  AND  ANALYSIS. 

Brown  Colors. — Bismarck  Brown. — Bismarck  brown  G,  Manchester 
brown,  phcnylcn  brown,  vesuvin,  anilin  brown,  leather  brown,  cinnamon 
brown,  canelle,  English  brown,  gold  brown. 

Vesuvin  B. — Manchester  brown  EE,  Manchester  brown  PS,  Bis- 
marck brown,  Bismarck  brown  T,  brun  Bismarck  EE. 

Fast  Brown  G. — Acid  brown. 

Chrysoidin. — Chrj'soidin  G,  chrysoidin  R,  chrysoidin  J,  chrysoidin  Y. 

HARMLESS   MINERAL   COLORS. 

Blue  Colors. — Ultramarine  blue. 

Violet  Colors. — Ultramarine  violet. 

Brown  Colors. — Manganese  brown. 

Chocolate-brown  and  colors  of  a  similar  nature  have  as  their  basis 
natural  or  precipitated  oxide  of  iron,  which  in  an  impure  condition  may 
have  small  quantities  of  arsenic  in  its  composition.  It  is  possible  with 
proper  care  to  secure  a  raw  material  entirely  free  from  this  objectionable 
element,  and  no  oxide  of  iron  containing  any  traces  of  arsenic  should 
be  used  in  the  preparation  of  color. 

Green  Colors. — Ultramarine  green. 

HARMLESS   ORGANIC   COLORS. 

Red  Colors. — Cochineal  carmine. 

Carthamic  acid  (from  saffron). 

Redwood. 

Artificial  alizarin  and  purpurin. 

Cherry  and  heel  juices. 

Eosin. — Eosin  A,  eosin  G  extra,  eosin  GGF,  eosin  water  soluble,  eosin 
3 J,  eosin  4J  extra,  eosin  extra,  eosin  KS  ord.,  eosin  DH,  eosin  JJF. 

Erythrosin. — Erythrosin  D,  erythrosin  B,  pyrosin  B,  primrose  solu- 
ble, eosin  bluish,  eosin  J,  dianthin  B. 

Rose  Bengale. — Rose  bengale  N,  Rose  bengale  AT,  rose  bengale  G, 
bengalrosa. 

Phloxin. — Phloxin  TA,  eosin  blue,  cyanosin,  eosin  loB. 

Bordeaux  and  Ponceau  reds,  resulting  from  the  action  of  naphthol- 
sulphonic  acids  on  diazoxylenc : 

Ponceau  2R. — Ponceau  G,  ponceau  GR. 
Ponceau  R. — Brilliant  ponceau  G,  ponceau  J. 


ARTIFICIAL   FOOD  COLORS.  787 

Bordeaux  B. — Fast  red  B,  Bordeaux  R  extra. 

Ccrasin. — Rouge  B. 

Ponceau  2G. — Brilliant  ponceau  GG,  ponceau  JJ. 

Fuchsin  S. — Acid  magenta,  rubin  S,  fuchsin  acide  (free  from  arsenic). 

Archil  Substitute. — Naphthion  red. 

Orange  I. — Orange  No.  i,  naphtholorange,  alpha-naphtholorange, 
tropaeolin  000  No.  i. 

Congo  red. 

Azorubin  S. — iVzorubin,  azorubin  A,  azoacidrubin,  fast  red  C,  car- 
moisin,   brilliant  carmoisin   O,   rouge  rubin  A. 

Fast  Red  D. — Fast  red  EB,  fast  red  NS,  amaranth,  azoacidrubin  2B, 
Bordeaux  DH,  Bordeaux  S,  naphthol  red  S,  naphthol  red  O,  Victoria 
ruby,  wool  red  (extra),  oenanthinin. 

Fast  Red. — Fast  red  E,  fast  red  S,  acid  carmoisin  S. 

Ponceau  4GB. — Crocein  orange,  brilliant  orange  G,  orange  GRX, 
pyrotin  orange,  orange  ENL. 

Fuchsin. 

Metanitrazotin. 

Yellow  and  Orange  Colors. — Annatto. 

Saffron. 

Sajjlower. 

Turmeric. 

Naphthol  Yellow  S. — Citronin  A,  sulphur  yellow  S,  jaune  acide, 
jaune  acide  C,  anilin  yellow,  succinine,  saffron-yellow,  solid  yellow, 
acid  yellow  S. 

Brilliant  Yellow. — (Sch.) 

Ponceau  4G5.  — Crocein  orange,  brilliant  orange  G,  orange  GRX, 
pyrotin  orange,  orange  ENL. 

Fast  Yellow. — Fast  yellow  G,  fast  yellow  (greenish),  fast  yellow  S, 
acid  yellow,  new  yellow  L. 

Fast  Yellow  R. — Fast  yellow,  yellow  W. 

Azarin  S. 

Orange  I. — Orange  No.  i,  naphtholorange,  alpha-naphtholorange^ 
tropaeolin  OOO  No.  i. 

Orange. — Orange  GT,  orange  RN,  brilliant  orange  O,  orange  N. 

Mixtures  of  harmless  red  and  yellow  colors. 

Green  Colors.— S pinach  green. 

Chinese  green. 

Malachite  Green. — Malachite  green  B,  benzaldehyde  green,  new  Vic- 


788  FOOD  INSPECTION  /tND  ANALYSIS. 

toria  green,  new  green,  solid  green  crystals,  solid  green  O,  diamond  green, 
bitter  amond  oil  green,  fast  green. 

Dinltrosoresorcin. — Solid  green  O  in  paste,  dark  green,  chlorine  green, 
Russia  green,  Alsace  green,  fast  green,   resorcinol  green. 

Mixtures  of  harmless  blue  and  yellow  colors. 

Blue  Colors. — Indigo. 

Litmus. 

Archil  blue. 

Gentian  Blue  6B. — Spirit  blue,  spirit  blue  FCS,  opal  blue,  blue 
lumierc,  Hessian  blue,  light  blue. 

Couplers  Blue. — Fast  blue  R  and  B,  solid  blue  RR  and  B,  indigin  DF, 
indulin  (soluble  in  alcohol),  indophenin  extra,  blue  CB  (soluble  in  alcohol), 
nigrosin  (soluble  in  alcohol),  noir  CNN. 

In  General  such  blues  as  are  derived  from  triphenylrosanilin  or  from 
diphenylamin. 

Violet  Colors.  —  Paris  Violet.  —  Methyl  violet  B  and  2B,  methyl 
\iolet  V3,  pyoktanin  coeruleum,  malbery  blue. 

Wool  black. 

Naphlhol  black  P. 

Azoblue. 

Mauvein. — Rosolan,  violet  paste,  chrome  violet,  anilin  violet,  anilin 
purj)le,  Perkins  violet,  indisin,  phenamin,  purpurin,  tyralin,  tyrian  purple, 
lydin. 

Brown  Colors. — Caramel. 

Licorice. 

Chrysamin  R. 

Use  of  Colors  in  Confectionery. — Regarding  the  choice  of  colors  for 
use  in  confectionery  and  precautions  to  be  observed  in  their  use,  the 
Confectioners'  Association  has  offered  the  following  considerations: 

First.  That  coal-tar  colors  arc  specially  adapted  to  the  wants  of 
confectioners  on  account  of  their  Ijrilliancy,  j)ermanency,  and  high  color- 
ing j)ower,  by  reason  of  which  last-named  quality  only  infinitesimal 
amounts  of  color  need  be  or  can  be  used  to  give  the  desired  effects. 

Second.  That  there  is  no  evidence  to  show  that  any  poisonous  or 
hurtful  colorings  have  in  recent  years  been  found  in  confectionery. 
Reports  of  deaths  from  jK)isoned  candy  are  only  too  frequently  made, 
but  no  autopsy  has  ever  been  published  confirming  them. 

Third.  That  while  the  exceedingly  small  proportions  of  color  used 
in  confectionery  constitute  a  practical  safeguard  to  the  public  health,  con- 


ARTIFlCl/tL  FOOD  COLORS.  789 

fectioncrs  are  in  duty  bound  to  provide  against  all  possible  contingencies 
of  harm,  by  using  the  utmost  care  in  obtaining  absolutely  non-poisonous 
colors,  buying  only  from  color-dealers  of  established  reputation  and 
unquestioned  responsibility,  whose  colors  arc  tested  at  frequent  intervals, 
and  are  vouched  for  by  competent  chemists. 

Confectioners  should  require  that  a  guarantee  be  put  upon  each 
package  of  color,  stating  not  only  that  the  contents  are  non-poisonous, 
but  also  that  they  will  not  in  any  way  interfere  with  digestion  or  injure 
health. 

Fourth.  Any  illegitimate  use  of  coloring  matter  in  comtctionery  as 
a  substitute  for  chocolate  or  any  other  material  or  ingredient,  or  for  the 
purpose  of  adding  bulk  or  increasing  the  weight  of  the  confectionery 
in  which  it  is  incorporated,  should  not  be  permitted  or  countenanced. 
Both  the  letter  and  the  spirit  of  these  laws  should  clearly  prevent  the 
illegitimate  use  of  coal-tar  colors  or  of  earth  colors,  such,  for  example,  as 
chocolate-brown,  coconole  brown,  or  chocolatina. 

Fi]th.  That  color-dealers  furnishing  colors  to  confectioners  should 
publish  printed  lists  of  their  colors  under  the  various  names  and  titles 
by  which  they  are  known  and  offered  for  sale,  accompanying  such  lists 
with  ample  certifications  by  competent  chemists  to  their  purity  and  suit- 
ableness for  coloring  confectionery  and  other  articles  of  food.  They 
should  also  attach  to  each  package  or  other  container  of  color  a  guar- 
antee that  it  does  not  contain  anything  injurious  to  health. 

VEGETABLE   COLORS. 

These  with  a  few  mineral  pigments  and  cochineal  were  formerly 
almost  exclusively  used  for  coloring  food  products,  and  are  stUl  used 
to  some  extent. 

Most  of  the  vegetable  colors,  according  to  L.  Robin,*  react  ■^^^th 
ammonia  to  form  a  coloration,  usually  passing  from  violet  to  blue,  then 
to  a  brownish  green,  when  the  ammonia  is  added  little  by  little  in  excess 
to  the  color  in  solution.  If  by  the  addition  of  ammonia  to  a  solution 
of  an  unknown  color  the  green  coloration  does  not  result,  the  presence 
may  be  suspected  of  orchil  or  cudbear,  logwood,  cochineal,  or  a  coal-tar 
dye. 

The  following  vegetable  colors  are  occasionally  found  in  food,  with 
some  of  the  reactions  in  aqueous  solution,  as  given  by  Robin: 

*  Girard,  Anah'se  des  Matieres  Alimcntaires,  pp.  678,  679. 


790 


FOOD  INSPECTION  AND  ANALYSIS. 
RED  COLORS. 


Nature  of  Color. 

Ammonia. 

Alum  and  Sodium  Carbonate 
20%  Solution. 

Mixture  of 
Aluminum 
Acetate  and 

Lake.               1        Filtrate  from 

Sodium 
Carbonate. 

Bill^erry     (whor- 

lleberr\-) Dull  <'reenish 

Greenish    blue, 

Beet 

Muddy      yellow, 
brown,  or  rose- 
red 
Deep  green 
Red   tinged  with 
violet 

Currant-red 
Bluish  green 

Yellow-brown  to 
greenish 
Yellowish  green 

Lilac 
Light  green 

rose-colored  on 
edges 
Dull  green  or  rose 

Greenish  blue 
Blue  tinged  with 
violet 

Rose 
Rose  tinged 

Gray  to  lilac 

White  or  rose  vio- 
let 

Violet 

Blue  tinged  with 
violet 

Black  currant.  . . 
Logwood 

Brazil  wood 

Raspberry 

Currant 

Blackberry 

Phytolacca 

Bottle-green 

Violet-blue 
Tinged  with  violet 

Lilac  to  wine  color 
Lilac  tinged  with 
violet 
Red-maroon 

Dull  violet 

Clear  violet,  pass- 
ing to  yellow 
with  ammonia 

Violet,  quickly 
passing  to  blue 
with  acetate  of 
copper 

Rose  tinged 
Bluish  green 

Dull    maroon    to 
bottle-green 
Bluish 

Elderberry 

YELLOW  COLORS. 


Nature  of  Color. 

Ammonia. 

Hydrochloric  Acid. 

Alum  and  Carbonate 

of  Soda  20% 

Solution. 

Lake. 

Persian  berries 

Old  fustic 

Yellow-red 

Very  bright  yellow 
Becomes  clearer 

Yellowish  red 
Brown-red 

Precijjitate  yellow- 
brown 
Yellow-orange 
Bright  yellow  pre- 
cipitate 
Becomes  yellower 
Crimson  precipitate 

Orange 

Orange 

Yellow-red  tending  to 

green 

Bright  yellow 

Bright  yellow 

Quercitron  bark 

Young  fustic 

Turmeric 

Additional  yellow  vegetable  colors  sometimes  used  in  foods  are  the 
following,  taken  from  a  table  of  Leed's,*  showing  reactions  given  by 
treating  a  few  drops  of  an  alcoholic  solution  of  the  color  with  an  equal 
volume  of  the  reagent. 

Most  of  these  vegetable  colors  do  not  directly  dye  wool  or  silk  a  fast 
color,  but  as  a  rule  require  the  use  of  a  mordant.  Many  of  these  colors 
may  be  fixed  on  cotton  (previously  mordanted  by  boiling  in  a  solution 

*  Analyst,  12,  150. 


/IRTIFiaAL  FOOD   COLORS. 


791 


REACTIONS  OF  COLORING    MATTERS. 


Coloring 

Concentrated 

Concentrated 

H2S04-(-HN03. 

Concentrated 

Matter. 

H2SO4. 

HNO3. 

HCl. 

Annatto 

Indigo-blue,  chang- 

Blue,      becoming 

Same 

No  change,  or  only 

ing  to  violet 

colorless     on 
standing 

shght  dirty  yel- 
low and  brown 

Turmeric. . . 

Pure  violet 

Violet 

Violet 

\'iolet,  changing  to 
original  color  on 
evaporation  ol 
HCl 

Saffron 

Violet     to     cobalt 

Light  blue,  chang- 

Same 

Yellow,     changing 

blue,  changing  to 

ing  to  light  red- 

to dirty  yellow 

reddish  brown 

dish  brown 

Carrot 

Umber  brown 

Decolorized 

Same    with     NO2 
fumes    and  odor 
of  burnt  sugar 

No  change 

Marigold. . . 

Dark    olive -green, 

Blue,  changing  in- 

Green 

Green  to  yellowish 

permanent 

stantly    to    dirty 
yellow-green 

green 

SafBower.  . . 

Light  brown 

Partially    decolor- 
ized 

Decolorized 

No  change 

of  aluminum  acetate  or  potassium  bichromate)  by  boiling  the  mordanted 
fibers  in  a  bath  of  the  colored  solution,  rendered  acid  by  acetic  acid.  The 
dyed  fibers  are  then  examined  by  reagents,  as  in  tables  given  on  pages 
806-13. 

Special  Tests  for  Vegetable  Colors. — Orchil  and  Cudbear,  both 
derived  from  lichens,  dye  wool  red  in  acid  bath.  The  colored  fiber, 
in  the  case  of  cudbear,  is  turned  blue  by  treatment  with  ammonia.  For 
reactions  of  orchil  on  the  fiber  see  table,  page  809.  Robin's  test  for  orchil 
in  aqueous  solution  consists  in  shaking  it  with  ether,  which,  if  orchil  is 
present,  is  colored  yellow.  On  treatment  of  the  ether  with  ammonia, 
the  yellow  color  is  changed  to  blue,  and,  by  adding  acetic  acid,  goes  over 
to  a  reddish  violet. 

Logwood,  according  to  Robin,  in  aqueous  solution  colors  ether  yellow, 
and  on  treating  the  ether  with  ammonia  the  color  becomes  red  or  faintly 
violet.  Potassium  bichromate  gives  a  violet  coloration,  mingled  with 
greenish  yellow.  If  cotton  is  first  mordanted  by  boiling  with  aluminum 
acetate,  it  is  dyed  violet  when  boiled  in  a  solution  of  logwood. 

Turmeric  is  best  extracted  from  a  dry  residue  with  alcohol,  which  it 
colors  }ellow.  The  color  is  transferred  to  a  piece  of  filter-paper  by  soak- 
ing the  paper  in  the  alcoholic  tincture,  the  paper  is  dried  and  dipped 
in  a  dilute  solution  of  boric  acid  or  borax  slightly  acidulated  with  hydro- 
chloric acid.  On  again  drying  the  paper,  it  will  be  of  a  cherr\^-red  color 
if  turmeric  is  present,  and  when  touched  with  a  drop  of  dilute  alkali  will 
turn  dark  olive. 


79*  FOOD  INSPECTION  AND  ANALYSIS. 

Caramel. — Care  should  be  taken  in  testing  for  caramel  not  to  subject 
the  sample  to  long-continued  heating,  even  on  the  water-bath.  Indeed 
caramel  is  sometimes  developed  spontaneously  in  saccharine  food  prod- 
ucts during  their  process  of  manufacture  when  heat  is  used,  by  the  charring 
cf  the  sugar.  If  solutions  are  to  be  concentrated  or  brought  to  dryness 
before  testing  for  caramel,  this  should  be  done  in  a  vacuum  desiccator 
over  sulphuric  acid,  or  at  a  temperature  not  exceeding  70°.  For  detection 
of  caramel  in  milk,  vinegar,  and  liquors,  special  tests  are  given  elsewhere.. 

Fradiss  Test* — The  dried  residue  of  the  sample  to  be  tested  is 
extracted  wi.h  warm,  pure  methyl  alcohol,  which,  if  caramel  be  present,. 
is  colored  brown.  Filter,  and  to  the  filtrate  add  amyl  alcohol  or  chloro- 
form. In  presence  of  caramel,  a  brown  flocculent  precipitate  is  formed^ 
which  slowly  settles  to  the  bottom  of  the  tube. 

Indigo  in  aqueous  solution  turns  green  with  ammonia.  On  boiling, 
the  solution  becomes  bright  blue.  Indigo  in  neutral  or  acid  solution, 
dyes  wool  or  silk. 

ANIMAL  COLORS. 

Cochineal. — This  dyestulT  is  used  in  ketchujjs,  cordials,  confections, 
and  other  food  products.  Robin's  test  for  cochineal  is  as  follows:  The 
aqueous  solution  is  acidulated  with  hydrochloric  acid,  and  shaken  out 
in  a  separatory  funnel  with  amyl  alcohol.  Cochineal  im})arts  to  this 
solvent  a  yellowish  color,  the  depth  depending  on  the  amount  j^resent. 
The  separated  amyl  alcohol  is  washed  with  water  till  neutral,  and 
divided  into  two  portions.  To  one  of  these  a  little  water  is  added, 
and  then  drop  by  drop  a  solution  of  uranium  acetate,  shaking  each  time 
a  drop  is  added.  In  presence  of  cochineal  the  water  is  colored  a  very 
characteristic  emerald-green  color.  To  the  other  j)ortion  ammonia  is 
added.     If  cochineal  has  been  used,  a  violet  coloration  is  produced. 

MINERAL  PIGMENTS. 

Evidence  of  the  jjresence  of  these  ])igments  is  usually  best  looked  for 
in  the  ash  of  the  suspected  samj)le.  In  .some  cases  the  color  may  be 
cxlractcrl  frf)m  the  dried  residue  by  water,  alkali,  or  alcohol. 

Prussian  Blue.  -This  pigment  is  insoluble  in  water.  It  is  decom- 
posed  and  decolori/cd   by  treatment    with   jjotassium   hydroxide.     If  the 

*  Oestr.  ungar.  Zeits.  Zucker.  Ind.,  1899,  28,  229-231;  Abs.  Zeits.  f.  Unlers.  Nahr.  u- 
Genuss.,  2,  1899,  p.  881. 


ARTIFICML   FOOD   COLORS.  793 

filtered  alkaline  solution  of  the  coloring  matter  be  treated  with  hydro- 
chloric acid  and  ferric  chloride,  a  precipitate  of  the  original  Prussian 
blue  will  be  produced.     For  reactions  on  the  fiber  see  table,  page  812. 

Ultramarine  Blue  is  decolorized  by  hydrochloric  acid  with  evolution 
of  hydrogen  sulphide,  which  blackens  filter-paper  moistened  with  lead 
acetate.  For  the  recognition  of  ultramarine  in  sugar  see  page  590.  For 
its  detection  on  the  fiber  see  table,  page  813. 

Chromate  of  Lead  has  never  been  used  to  any  extent  in  food  products 
with  the  exception  of  confectionery.     For  its  detection,  see  page  647. 

COAL-TAR  COLORS. 

So  many  of  the  coal-tar  dyes  are  adapted  for  use  in  food  that  it  would 
be  impossible  to  even  name  them  all,  especially  in  view  of  the  fact  that 
new  coiors  are  from  time  to  time  being  added  to  the  list.  No  attempt 
will  be  made  in  the  present  work  to  give  the  nature  and  composition  of 
the  dyes  named,  as  such  descriptions  would  lead  beyond  its  scope.  For 
detailed  information  along  this  line  the  reader  is  directed  to  the  references 
on  pp.  819  and  820,  especially  to  the  works  of  Schultz  and  Julius,  Bene- 
dict and  Knecht,  Weyl,  etc. 

About  2000  separate  coal-tar  dyes  are  at  present  on  the  market. 
Various  classifications  of  these  colors  are  attempted,  based  on  (i),  their 
origin,  as  anilin  dyes,  naphthalin  dyes,  anthracene  dyes,  etc.;  (2),  their 
chemical  composition,  as  nitro,  nitroso,  azo,  diazo,  and  other  compounds; 
(3),  their  solubility  in  water  and  other  solvents;  and  (4),  their  mode 
of  application  to  the  fiber,  as  basic  dyes,  acid  dyes,  direct  cotton  dyes,  mor- 
dant dyes,  etc. 

These  dyes  are  sold  in  the  form  of  powder,  and  are  readily  made 
into  solutions  for  food  colors  in  the  case  of  the  water-soluble  varieties, 
and  into  pastes  in  the  case  of  the  insoluble  forms.  Most  of  the  coal-tar 
colors  employed  in  foods  are  naturally  of  the  soluble  variety,  especially 
such  as  are  found  in  jellies,  jams,  fruit  products,  canned  foods,  ketchups, 
beverages,  and  milk.  Pastes  made  from  insoluble  dyes  are  adapted 
mainly  for  exterior  coatings  of  hard  substances  such  as  candies.  Colors 
in  the  dry  form  are  to  be  looked  for  in  such  spices  as  cayenne,  mustard, 
and  mace,  but  a  commoner  method  of  coloring  these  spices  high  in  oil 
is  to  mix  with  them  a  solution  of  the  color  in  oil  (usually  cottonseed). 
Oil  solutions  of  coal-tar  dyes  are  also  employed  for  coloring  butter  and 
oleomargarine. 

The  chief  concern  of  the  food  analyst,  as  regards  artilicial  color    is 


;94  FOOD  INSPECTION  AND   ANALYSIS. 

its  recognition  in  food  products.  Coal-tar  dyes  may  usually  be  iden- 
tified as  such,  but  it  is  not  always  possible  to  name  the  particular 
individual  dye  or  combination  of  dyes  employed,  even  though  the  class 
to  which  they  belong  may  be  determined.  One  reason  for  this  is  that 
not  infrequently  mixtures  of  two  or  more  colors  are  employed. 

Coal-tar  Colors  Allowed  under  the  Federal  Law. — The  use  of 
any  dye,  harmless  or  otherwise,  to  color  food  in  a  manner  whereby 
damage  or  inferiority  is  concealed  is  in  violation  of  Sec.  7  of  the  Food 
and  Drugs  Act  of  June  30,  1906.  The  addition  of  all  mineral  or  metallic 
dyes,  and  of  all  coal-tar  dyes,  other  than  those  specially  provided  for, 
is  also  prohibited.  Pending  further  investigation  the  following  coal-tar 
colors  are  permitted  in  foods,  provided  they  are  certified  to  be  true  to 
name  and  to  be  free  from  mineral  and  metallic  poisons,  harmful  organic 
constituents,  and  contaminations  due  to  improper  or  incomplete  manu- 
facture: * 

Red  Shades. — 107.  Amaranth  [ilf.]  [C].  Synonyms:  Fast  red  D.  [5.] 
Bordeaux  S.  [A.],  azoacidrubine  2B.  [D,],  fast  red  EB.  [B.]. 

56.  Ponceau  3R.  [.4.]  [5.]  [M.].  Synonyms:  Ponceau  4R.  [A.]y 
cumidin  red,  cumidin  jjonceau. 

517.  Erythrosin  [5.]  [M.]  [^.5.5.].  Synonyms:  Erythrosin  D.  [C], 
erythrosin  B.  [.4.],  pyrosin  B.  [il/o.],  iodeosin  B.,  eosin  bluish,  eosin  J.  {B.\. 

Orange  Shade. — 85.  Orange  I.  Synonyms:  Alphanaphthol  orange, 
naphthol  orange  [.4.],  tropa;olin  000  No.  i,  orange  B,  [Z,.]. 

Yellow  Shade. — 4.  Naphthol  yellow.  S.  [B.\.  Synonyms:  Naphthol 
yellow,  acid  yellow  S.,  citronin  A.  [/,.]. 

Green  Shade. — 435.  Light  green  S.  F.  yellowish  [B.].  Synonyms: 
Acid  green  [By.]  [M.]  [T.M.]  [O.],  acid  green  extra  cone.  [C.]. 

Blue  Shade. — 692.  Indigo  disulphoacid.  Synonyms:  Indigo  car- 
mine, indigo  extract,  indigotine  [B.],  sulphonated  indigo. 

None  of  these  seven  colors  is  patented,  hence  their  manufacture  is 
not  likely  to  become  a  monopoly.  They  may  be  used  in  combinations, 
thus  securing  any  desired  shade.  For  example,  violet  may  be  obtained 
by  mixing  indigo  disulphoacid  and  one  of  the  red  colors,  a  blue-green  by 
mixing  indigo-disulphoacid  with  naphthol  yellow  S.  or  light-green  S.F. 
and  so  on. 


•The  numljcrs  preceding  the  dyes  are  those  given  in  Green:  A  Systematic  Survey  of 
the  Organic  Colouring  Matters  founded  on  the  German  of  Schultz  and  Julius,  London* 
1904;    the  letters  in  brackets  represent  the  manufacturers  who  originated  the  names. 


ARTIFICIAL    FOOD  COLORS.  795 

Detection  of  Coal-tar  Colors  in  Foods. — There  are  various 
methods  for  the  separation  of  coloring  matters  from  food  products,  and 
these  may  be  divided  into  three  general  classes:  First,  dying  silk  or  wool 
with  the  color  by  boiling  the  fiber  in  a  solution  of  the  sample  to  be 
examined;  second,  extracting  the  color  from  a  solution  of  the  sample 
by  the  use  of  an  immiscible  solvent;  and  third,  extracting  the  color  from 
the  dried  residue  of  the  sam])le  by  means  of  a  suitable  solvent.  Of  these 
the  method  of  dying  wool  lends  itself  most  readily  to  the  analyst's  use, 
by  reason  of  its  simplicity,  and  from  the  fact  that  almost  without  excej)- 
tion  coal-tar  dyes  adaptable  for  food  colors  are  substantive  dyes,  being 
readily  taken  up  by  wool. 

Basic  and  Acid  Dyes. — The  soluble  coal-tar  dyes  arc  either  basic 
or  acid.  Basic  dyes  are  precipitated  from  their  aqueous  solution  l:)y 
tannin.  Acid  dyes  are  not  so  precipitated.  Theoretically,  all  the  basic 
colors  are  taken  up  by  wool  from  a  faintly  alkaline  or  neutral  bath,  while 
the  acid  colors  are  left  in  solution.  Thus  if  a  dilute  solution  of  the  color 
be  made  faintly  alkaline  with  ammonia  and  boiled  with  the  wool,  only 
basic  colors  will  be  taken  up.  If  both  acid  and  basic  dyes  are  present 
in  the  same  solution,  the  basic  color  should  first  be  exhausted  by  the 
use  of  fresh  pieces  of  wool  in  the  ammoniacal  solution,  till  they  no  longer 
take  out  color,  after  which  the  solution  should  be  made  slightly  acid 
with  hydrochloric  acid  and  again  boiled  with  wool,  which  under  these 
conditions  takes  out  any  acid  colors.  Comparatively  few  basic  colors 
are  employed  in  foods.  Basic  colors  can  be  removed  from  the  liber 
by  boiling  with  5%  acetic  acid.  Acid  colors  are  removed  therefrom  by 
boiling  with  5%  ammonia.  Having  dissolved  the  dye  from  the  fiber 
by  the  appropriate  solvent  as  above,  the  decolorized  fiber  may  be  removed, 
and  the  solution  evaporated  to  dryness  on  the  water-bath.  The  residue 
consists  chiefly  of  the  dyestuff,  and  may  be  put  through  various  reactions 
for  identification  according  to  Rota's  scheme,  page  799. 

Methods  of  Dyeing  Wool  from  Food  Products. — The  wool  employed 
should  be  white  worsted,  or  strips  of  white  cloth,  such  as  nun's  veiling 
or  albatross  cloth.  Care  should  be  taken  that  the  color  is  pure  white 
and  not  the  more  common  cream  white.  The  woolen  material  should 
be  freed  from  grease  by  boiling  first  in  very  dilute  soda  solution  and 
finally  in  water.  Strips  of  the  woolen  cloth,  or  pieces  of  the  worsted  thus 
previously  cleansed,  are  boiled  in  diluted  filtered  solutions  of  jams,  jellies, 
ketchup,  fruit  and  vegetable  products,  and  similar  food  preparations,  or 


796  FOOD    INSPECTION   AND   ANALYSIS. 

in  solutions  of  candy  colors,  or  in  wines,  the  clear  solution  of  the  sample 
to  be  tested  being  slightly  acidified  with  hydrochloric  acid. 

Arata  *  recommends  boiling  the  wool  in  a  dilute  solution  of  the  food 
material  to  which  potassium  bisul[)hate  has  been  added,  using  lo  cc. 
of  a  lo'^T  solution  of  the  bisulphate  to  loo  cc.  of  the  solution  to  be  tested. 
If  the  color  solution  is  neutral,  the  wool  should  first  be  boiled  in  this 
before  acidifying,  to  separate  out  any  basic  dyes.  The  dyed  wool,  after 
removal  from  the  solution,  is  boiled  first  in  water,  and  afterwards  prefer- 
ably in  an  alkali-free  soap  solution.  It  is  then  washed  and  dried.  The 
dried  fiber  may  then  be  subjected  to  the  various  reactions  given  in  the 
table,  pp.  806-813;  for  recognition  of  the  dye,  this  method  of  identifying 
colors  by  means  of  reactions  on  the  dyed  fiber  being  one  of  the  most  con- 
venient. 

Some  of  the  vegetable  dyes  (including  lichen  colors),  also  cochineal,  dye 
wool  directly,  and  these  may  be  identified  by  reactions  given  in  the  table 
with  the  coal-tar  dyes.  Other  vegetable  colors,  and  the  natural  colors 
of  fruits  nearly  always  give  a  slight  dull  coloration  or  stain  to  the  wool, 
but  this  is  not,  as  a  rule,  to  be  mistaken  for  the  vivid  hues  of  the  coal- 
tar  dyes.  Moreover  most  of  the  vegetable  colors  on  the  fiber  turn  green 
when  treated  with  ammonia.  Care  should  be  taken  to  thoroughly  wash 
the  wool  after  the  dyeing,  so  that  colored  particles  simply  held  thereon 
mechanically  may  be  removed. 

Sostegni  and  Carpentieri'\  recommend  a  method  of  double  dyeing, 
applicable  when  acid  dyes  are  employed.  The  method  consists  in 
first  boiling  the  wool  in  a  dilute  acid  solution  of  the  food  sample  as 
above  described,  after  which  the  fiber  is  removed  and  boiled,  first  in 
very  dilute  hydrochloric  acid  solution,  and  then  in  water,  till  free  from 
acid.  The  color  is  then  dissolved  from  the  fiber  by  boiling  the  latter 
in  a  weak  ammoniacal  solution,  some  of  the  colors  being  more  readily 
dissolved  than  others.  The  fiber  is  then  removed  from  the  solution, 
the  latter  is  acidified  with  hydrochloric  acid,  and  the  color  fixed  on  a 
fresh  piece  of  wool  by  boiling  therein.  The  second  dyeing  fixes  coal- 
tar  and  lichen  colors  on  the  fiber,  but  fruit  colors  and  most  others  of 
vegetable  origin  remain  in  solution  after  this  treatment.  Any  color  left 
on  the  first  fiber,  after  treatment  with  ammonia,  is  probably  due  to  the 


*  Ztsch.  anal.  Chem.,  28  (1889),  639. 
t  Ibid.,  35  (1896),  397. 


ylRTIFCML    FOOD   COLORS.  797 

natural  vegetable  color  of  the  sample,  and  is  usually  no  more  than  a 
dull  stain. 

Vegetable  Colors  on  Wool. — In  case  no  color  is  directly  fixed  on  the 
fiber  by  boiling  wool  in  a  solution  of  the  sample,  either  neutral  or  acid, 
absence  of  coal-tar  colors  may  be  assumed.  In  this  case  it  is  sometimes 
advisable  to  boil  strips  of  previously  mordanted  white  cotton  in  an  acid 
solution  of  the  sample,  to  remove  certain  vegetable  colors  for  purposes 
of  testing  on  the  fiber.  The  cotton  is  mordanted  by  boiling  in  a  dilute 
(5%)  solution  of  potassium  bichromate. 

Extraction  of  Colors  from  their  Solution  by  Immiscible  Solvents. — 
Methods  based  on  this  principle  are  in  use  in  the  municipal  laboratory 
at  Paris.*  Sangle-Ferriere  uses  the  following  method:  50  cc.  of  the 
wine  or  solution  to  be  tested  for  color  are  rendered  slightly  alkaline  by 
ammonia,  and  cautiously  shaken  with  about  15  cc.  of  amyl  alcohol.  If 
acid  dyes  are  present,  they  will  be  dissolved,  and  will  impart  to  the  amyl 
alcohol  a  distinct  color.f  Basic  dyes  also  are  dissolved,  but  when  they 
are  present  the  amyl  alcohol  solution  is  colorless.  Remove  the  amyl 
alcohol  by  means  of  a  separatory  funnel,  wash  with  water,  and  finally, 
if  the  alcohol  is  colored,  dilute  with  about  an  equal  volume  of  distilled 
water  and  evaporate  on  the  water-bath  with  a  piece  of  white  wool.  The 
wool  should  be  kept  in  the  solution  till  the  odor  of  the  amyl  alcohol  has 
disappeared,  and,  if  not  then  colored,  for  a  short  time  longer,  as  with 
some  colors  the  wool  will  dye  more  readily  in  the  aqueous  solution  than 
in  the  amyl  alcohol.  Remove  the  wool,  and  evaporate  the  solution  to 
dr}mess.     Test  for  color  in  the  dried  residue,  and  on  the  fiber  also. 

Orchil,  like  the  acid  colors,  is  extracted  by,  and  imparts  a  coloration 
to  the  amyl  alcohol  under  the  above  conditions,  the  color  being  a  light 

violet. 

If  the  amyl  alcohol  extract  after  separation,  washing,  and  fihcring 
is  colorless,  acidify  with  acetic  acid;  if  a  basic  color  is  present,  it  will 
be  indicated  by  a  coloration  at  this  stage;  if  there  is  no  coloration  on 
the  addition  of  acetic  acid,  no  basic  color  is  present  excepting  fuchsin, 
which  is  separately  tested  for.  In  case  a  basic  dye  is  indicated,  add  dis- 
tilled water  and  evaporate  with  wool  as  before.  Test  the  dried  residue 
with  pure  concentrated  sulphuric  acid. 

*  Girard,  Analyse  des  Matieres  Alimentaires,  pp.  183,  681. 

t  Acid  fuchsin  forms  an  exception  to  this  rule  by  dissolving  colorless  like  basic  dyes. 
A  special  test  is,  however,  given  for  it,  p.  799. 


798  FOOD  INSPECTION  AND   ANALYSIS. 

Fuchsin  is  indicated  by  a  yellow-brown  color  with  sulphuric  acid, 
which  by  dilution  with  water  becomes  rose;  sajranin,  by  a  green  color 
becoming  first  blue,  then  red,  when  diluted  with  water,  and  magdala 
red  by  a  dark  blue  color,  turning  red  on  the  addition  of  water. 

Basic  colors  are  also  extracted  readily,  according  to  Robin,  by  making 
the  solution  to  be  tested  alkaline  with  sodium  hydroxide,  and  shaking 
with  acetic  ether.  The  solvent  is  removed,  washed,  and  evaporated 
with  wool  (on  which  the  tests  are  to  be  made),  or  the  evaporation  is 
carried  to  dryness  and  the  tests  made  on  the  residue. 

Many  coal-tar  colors  are  extracted  by  amyl  alcohol  in  acid  solution, 
but  some  of  the  natural  fruit  colors  arc  also  dissolved  under  these  con- 
ditions. The  coal-tar  dyes  thus  dissolved  will,  however,  dye  wool  and 
tlie  fruit  colors  will  not.  Fruit  colors  are  not  extracted  from  acid  or 
alkaline  solution  by  ether,  nor  from  alkaline  solution  by  amyl  alcohol. 

Robin's  method  for  ascertaining  whether  acid  colors  are  present 
consists  in  adding  to  the  liquid  to  be  tested  an  excess  of  calcined  magnesia, 
and  a  httle  20'^c  mercuric  acetate  solution,  the  mixture  being  boiled  and 
fihercd.  If  the  fihrate  is  colored,  or  if  by  the  addition  of  acetic  acid 
to  the  colorless  fihrate  a  color  is  developed,  a  coal-tar  dye  is  indicated. 

Separation  of  Acid  and  Basic  Colors  with  Ether.* — Acid  and  basic 
colors  may  be  separated  from  their  dilute  aqueous  solution,  according 
to  Rota,  by  means  of  ether  as  follows:  To  100  cc.  of  the  solution  add 
I  cc.  of  20%  potassium  hydroxide  and  shake  in  a  separator)^  funnel  with 
several  portions  of  ether.  Basic  dyes  are  dissolved  by  the  ether,  leaving 
behind  as  a  rule  the  acid. colors. f  Wash  the  ether  extract  with  faintly 
alkaline  water,  and  shake  out  with  5%  acetic  acid.  Some  colors  remain 
in  the  ether,  others  are  dissolved  in  the  acid.  Separate  the  two  solvents, 
and  evaporate  each  to  dr\'ness  on  the  water-bath. 

The  acid  colors  left  in  the  slightly  alkaline,  aqueous  solution  after 
removal  of  the  basic  colors  by  ether  as  above,  may,  if  desired,  be  separated 
into  several  groups  by  successive  extraction,  as  follows:  first  slightly 
acidulate  with  acetic  acid  and  extract  with  ether,  then  acidify  with  hydro- 
chloric acid  and  again  extract,  and  finally  examine  the  residual  solution 
for  colors  that  are  insoluble  in  ether.  Thus  erythrosin  and  eosin  are 
sfjluble  in  ether  when  shaken  with  their  afjueous  solution  made  acid  with 
hydrfx:hloric  acid,  while  acid  fuchsin  is  insoluble. 

*  Analyst,  24,  p.  45. 

t  A  few  acid  dyes  are  exceptional  in  being  soluVjle  in  ether  with  alkali,  as  for  example, 
quinolin  yellow  and  the  sudans. 


ARTIFICIAL    FOOD    COLORS.  799 

Separation  of  Colors  from  Dried  Food  Residues  by  Solvents.— This 
melhod  is  rarely  emi)loyed,  excepting  in  the  case  of  colors  insoluble  in 
water,  but  soluble  in  e.her  or  alcohol.  The  dried  pulp  of  canned  veget- 
ables, ketchups,  etc.,  may  be  acidified  \vi  h  hydrochloric  acid,  and  the 
color  extracted  therefrom  direcJy  wih  alcohol.  In  this  case  however, 
there  is  no  obvious  advantage  over  the  previous  methods  of  dyeing  the 
fiber  directly  in  the  acid  solution  of  the  sample. 

Girard's  Tests  for  Acid  Fuchsin.*  —  Add  2  cc.  of  5%  potassium 
hydroxide  to  10  cc.  of  the  wine  or  Oiher  solution  to  be  tested,  or  enough 
of  the  alkali  to  neutralize  the  acid.  Then  add  4  cc.  of  10%  acetate  of 
mercury  and  filter.  The  fihrate  should  be  alkaline  and  colorless.  If 
the  solution  remains  uncolored  after  acidifying  with  dilute  sulphuric 
acid,  no  acid  fuchsin  is  present.  If,  however,  there  is  produced  a  red 
to  violet  coloration,  and  no  other  coal-tar  colors  have  been  found  by  the 
amyl  alcohol  extraction,  the   presence   of  acid   fuchsin   is  shown. 

Bellier's  Test  for  Acid  Fuchsin. — Presence  of  acid  fuchsin  is  indicated 
by  adding  to  20  cc.  of  wine  or  other  solution  to  be  tes  ed  aboui  4  grams 
of  freshly  precipitated  yellow  oxide  of  mercury,  boiling  and  filtering. 
The  filtrate,  if  acid  fuchsin  is  present,  is  colored  red,  tinged  with 
violet. 

According  to  Blarez,  all  red  coal-tar  colors,  with  the  exception  of 
acid  fuchsin,  and  all  red  vegetable  colors  arc  completely  decolorized 
by  acidulating  their  aqueous  solution  with  tartaric  acid,  and  digesting 
with  dioxide  of  lead.f 

Schemes  for  Identification. — These  serve  for  identifying  unknown 
colors  by  their  characteristic  reactions,  first  grouping  them  into  classes, 
and  finally  ascertaining  the  particular  color  itself.  Of  these  may  be 
mentioned  the  tabular  schemes  of  Witt,t  Weingartner,§  Green, H  Mar- 
tinon,^  and  Rota.** 

Rota's  Scheme  is  one  of  the  latest,  and  on  some  accounts  the  best, 
being  based  on  the  relation  between  the  color  and  the  composition  of 

*  Analyse  der  Substances  Alimentaires.  p.  185.  ! 

t  Allen,  Commercial  Org.  Analysis,  4  Ed.,  Vol.  V,  p.  250. 

%  Zeits.  anal.  Chem.,  1887,  26,  p.  100;   Analyst,  11,  p.  in. 

§  Jour.  Soc.  Dyers,  etc.,  Ill,  p.  67. 

II  Jour.  Soc.  Chem.  Ind.,  12,  No.  i. 

^  Jour.  Soc.  Dyers,  3,  p.  124. 

**  Chem.  Zeit.,  1898,  pp.  437-442;   Anal.,  24,  p.  41. 


8oo 


FOOD   INSPECTION   AND   yINyl LYSIS. 


the  dyc>.  The  colors  arc  divided  into  two  main  groups,  according  to 
whether  or  not  they  are  reducible  by  stannous  chloride.  These  two 
groups  are  each  further  subdivided  into  two  classes,  the  reducible  colors 
being  classed  according  to  whedier  the  color  remains  unchanged,  or  is 
restored  by  treatment  with  ferric  chloride,  and  the  non-reducible  colors 
according  to  their  action  with  potassium  hydroxide. 

The  tests  are  carried  out  on  a  dilute  aqueous  or  alcoholic  solution 
of  the  coloring  matter,  the  strength  being  about  i  in  10,000.  Treat 
about  5  cc.  of  this  solution  with  4  or  5  drops  of  concentrated  hydrochloric 
acid  and  about  as  much  stannous  chloride  in  a  test-tube,  shake  the  mix- 
ture, and  heat  if  necessary  to  boiling.  With  some  colors  the  process  of 
decolorization  is  a  slow  one,  especially  if  the  solution  is  too  concentrated, 
and  it  is  well  to  repeat  the  experiment,  if  in  doubt,  diluting  the  original 
sample  still  further  with  water.  Tin  in  solution  in  concentrated  hydro- 
chloric acid  may  be  employed  instead  of  stannous  chloride,  if  desired. 

Here,  as  in  all  cases  of  color  testing,  it  is  well  to  make  comparative 
tests  with  known  colors. 

CLASSIFICATION  OF  ORGANIC  COLORING  MATTERS. 
[A  portion  of  the  aqueous  or  alcoholic  solution  is  treated  with  HCl  and  SnClj.] 


Complete  decolorization.  Reducible  coloring 
matters.  Coloriess  solution  is  treated  with 
Fe^Cl«,  or  shaken  with  exposure  to  air. 


The  color  changed  no  further  than  with  IICl 
alone.  Nonreducible  colors.  A  part  of 
original  solution  is  mi.xed  with  20%  KOH 
and  warmed. 


The  liquid  remains 
unchanged.  Color- 
ing matters  not  re- 
o.xidizablc. 


Class  I. 

Nitro,  nitroso,  and  azo 
colors,  including 
oxyazo  and  hydrazo 
colors. 

Picric  acid,  naphthol 
yellow,  ponteau, 
Bordeaux,  and 
Congo  red. 


The  original  color  re- 
stored. Reoxidiz- 
able  coloring  mat- 
ters. 


Cl.vss  II. 

Indogenide  and  imido- 
quinone  coloring 
matters,  methylene 
blue,  safranin,  in- 
digo carmine. 


Decolorization,  or  a 
precipitate.  Imido- 
carbo-quinone  color- 
ing matters. 


Class  III. 

Amido-derivatives  of 
di  and  triphenyl 
methane,  aura- 
mins,  acridins, 
q  u  i  n  (}  1  i  n  s,  and 
color  derivatives  of 
thio  benzenil. 

Fuchsin,  rosanilin, 
auramin. 


No  preci  p  i  t  a  I  i  o  n. 
Litjuid  becomes 
more  colored.  Oxy- 
carbo-quinone  col- 
oring matters. 

Class  IV. 

Nonamide  diphenyl 
methane,  oxy-ke- 
tone,  and  most  of 
natural  organic  col- 
oring matters. 

Eosins,  aurin,  aUz- 
arin. 


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ARTIFICIAL   FOOD   COLORS.  805 

Direct  Identification  of  Colors, — In  identifying  the  colors  commonly 
used  in  food,  it  is  rarely  necessary  to  carry  out  such  involved  processes 
of  analyses  as  are  rendered  necessary  by  Rota's  scheme.  It  is  frequently 
possible  to  ascertain  the  color  or  group  of  colors  present  by  making  direct 
tests  with  various  reagents,  cither  on  the  dyed  fiber  as  described  on  p.  814, 
or  on  the  dry  coloring  matter,  or  in  a  solution  containing  it. 

Many  tables  for  this  purpose  are  prepared,  but  they  are  never  com- 
plete by  reason  of  the  many  new  dyestuffs  constantly  introduced.  Such 
tables  are  to  be  found  in  Allen's  "Commercial  Organic  Analysis,"  and 
in  Schiiltz  and  Julius's  "Systematic  Survey  of  the  Coal  Tar  Colors." 
While  it  is  true  that  the  limitation  of  the  dyes  suitable  for  purposes  of 
food  coloring  imposes  a  somewhat  lighter  task  on  the  food  analyst  than 
that  of  the  chemist  who  has  to  deal  with  alL  varieties  of  commercial  colors, 
yet  it  is  obviously  impossible  to  make  a  complete  list  covering  even  the 
restricted  field  of  food  colors.  Doubtless  there  are  colors  long  well 
known  that  would  serve  admirably  for  this  purpose,  but  have  never  yet 
been  tried. 

Mainly  from  such  sources  as  the  above  comprehensive  tables  of  colors 
and  their  reactions,  the  writer  has  compiled  the  table  on  pp.  806-13, 
taking  as  a  basis  the  scheme  of  Allen.*  This  table  includes  over  fifty 
selected  coloring  matters,  which  are  adapted  for,  and  have  been 
found  in,  foods  by  various  analysts,  as  listed  in  state  and  government 
reporli,  as  well  as  in  laws  of  various  countries  dealing  with  food 
colors.  This  table  will  at  least  contain  the  colors  most  commonly  met 
with,  and  will  nearly  always  serve,  if  not  to  identify  the  exact  dye,  to 
aid  in  classifying  it.  In  case  the  analyst  wishes  to  identify  the  color, 
he  should  be  provided,  for  standards,  with  as  complete  a  collection  of 
known  purity  dyestuffs  as  possible  covering  the  colors  he  is  likely  to 
meet  with  in  foods,  and  should  make  comparative  tests,  if  the  slightest 
doubt  exists.  If  the  unknovm  color  is  apparently  not  found  in  the  following 
table,  and  the  more  exhaustive  tables  are  unavailable,  it  is  still  possible 
to  locate  the  dye,  by  making  similar  tests  on  other  standard  colors  sug- 
gested by  the  behavior  of  the  unknown  color,  and  carefully  comparing 
them. 

Most  difficulty  is  encountered  when  the  coloring  matters  are  mixtures 
instead  of  simple  dyes.  In  this  case  it  may  be  necessary  to  resort  to  frac- 
tional extraction  by  ether,  as  suggested  by  Rota  (p.  799),  in  order  to 
separate  the  colors. 

*  Commercial  Organic  Analysis,  4  Ed.,  Vol.  V,  p.  540  et  seq. 


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Sl4  FOOD   IXSPCCTION   AND   ANALYSIS. 

Reagents. — In  applying  tests  on  the  fiber,  the  reagents  commonly  used 
arc  as  follows:  Concentrated  hydrocliloric  acid,  concentrated  sulphuric 
acid,  sodium  hydroxide  (io%  solution),  strong  ammonia  (28%),  a  hydro- 
chloric acid  solution  of  stannous  chloride,  and  concentrated  nitric  acid.. 
The  tests  should  be  made  on  pieces  of  the  fiber  in  small  p'orcelain  evapo- 
rating-dishes,  which  more  readily  than  test-tubes  show  exact  shades  of 
color.  In  cases  of  suspected  fluorescence,  test-tubes  should  be  used. 
Nitric  acid  is  conveniently  applied  by  a  glass  rod  to  the  fiber.  The 
stannous  chloride  should  first  be  allowed  to  act  in  the  cold.  If  no  change 
occurs.  <jjentle  heat  should  then  be  a{)])Hcd,  and  finally  boiling. 

Separation  and  Identification  of  Allowed  Colors. — Price  Method.'^ — 
The  procedure  is  according  to  the  analytical  scheme  given  on  page  815. 
As  a  preliminary  test  the  powdered  material  is  scattered  upon  water, 
alcohol,  and  sulphuric  acid,  noting  whether  one  or  more  colors  are 
present. 

Quantitative  Separation  of  Acid  Coal-tar  Colors.  —  Mathcwson 
Mclliod.1[ — This  process,  like  the  preceding,  is  for  the  colors  themselves, 
but  may  be  adapted  for  the  detection  of  the  colors  in  food  products  after 
separation  by  means  of  solvents  or  less  satisfactorily  by  dyeing.  Mathew- 
son's  table  is  given  on  pages  816  and  817. 

In  applying  the  data  given  in  the  table  proceed  essentially  as  follows: 
Treat  the  solution  containing  0.2  to  0.4  gram  of  color  (depending  on  the 
nature  of  the  dyes)  with  sufficient  water  and  hydrochloric  acid  to  bring 
its  volume  to  about  50  cc.  and  its  acid  concentration  to  that  point  for 
which  the  difference  in  percentage  of  color  extracted  for  the  two  dyes  is 
near  its  maximum.  Shake  the  solution  with  the  immiscible  solvent, 
passing  it  in  succession  through  three  or  four  separatory  funnels  each 
containing  50  cc.  of  the  latter.  Wash  the  portions  of  the  solvent  with  50 
cc.  of  hydrochloric  acid  of  the  same  normality  as  the  solution,  passing  it 
successively  through  the  separatory  funnels  in  the  same  order  as  was 
the  original  solution,  and  repeat  this  operation  with  one  or  two  fresh 
amounts  of  the  hydrochloric  acid.  The  dye  relatively  more  soluble 
in  water  is  determined  in  the  combined  washings  and  extracted  solution. 
Remove  the  second  dye  frf)m  the  solvent  by  shaking  with  water,  very 
dilute  caustic  soda,  or,  more  ((uickly,  with  dilute  caustic  soda  after  the 
addition  of  some  gasoline,  or  similar  substance  in  which  the  color  is 
insoluble. 

•  U.  S.  Dept.  of  Agric;,  Bi^.  of  An.  Ind.,  Circ.  180. 
t  U.  S.  Dept.  of  Agr^c.j'Bv^.  of  Chcm.,  Circ.  89. 


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8i6 


FOOD   INSPECTION  AND   ANALYSIS. 


The  following  table  by  Mathewson  *  shows  the  percentage  of  color 
in  the  water  solution  after  shaking  with  an  equal  volume  of  immiscible 
solvent. 

MATHEWSOXS  TABLE  SHOWING  PERCEXTAGE  OF  COLOR  IX  THE  WATER 
SOLITIOX  AITER  SHAKIXG  WITH  AX  EQU.\L  VOLUME  OF  IMMISCIBLE 
SOLNEXT. 

solvent:  amvl  alcohol. 


Colors. 


Normality  of  Hydrochloric  Acid  in  Water  Layer  before  Shaking 


Percentage  of  Color  in  Water  Solution  after  Shaking. 


X'aphthol  Yellow  S  Xo.  4 

Orange  I  Xo.  85 

Ponceau  3  R  Xo.  56 

.Amaranth  Xo.  107 

Light  Green  S  F  Xo.  435 I     90 

Er>'throsin  Xo.  517 ! .  . .  . 

Indigo  Carmin  Xo.  692 34 

Fast  Yellow  Xo.  8 36 

Crocein  Orange  G  X'o.  13 

Orange  G  Xo.  14 ' .  . . . 

Ponceau  2  R  Xo.  55 ! . . . . 

Cnstal  Ponceau  Xo.  64 

Fast  Red  B  Xo.  65 

Resorcin  Yellow  Xo.  84 

Orange  II  Xo.  86 

Brilliant  Yellow  S  No.  89 ....  . 

Tartrazin  Xo.  94 

Mctanil  Yellow  Xo.  95 

Fast  Red  .\  Xo.  102 

Fast  Red  C  Xo.  103 

Fast  Red  E)  Xo.  105 

Xew  Coccin  Xo.  106 

Scarlet  6  R  Xo.  108 

Resorcin  Brown  X'o.  137 

Cotton  Scarlet  3  B  Xo.  146.  .  . 

Congo  Red  No.  240  * 

■\70  Blue  No.  287  t 

Chr>'sf>phenin  X'o.  329 

Guinea  Green  B  No.  433 

Acid  Magenta  No.  462 


I 
IS 
95 


51 


41 


80 


75 


3 
52 
97 


7 
82 

99 


89 
61 


73 

47 


95 


48 
93 


96 


14 


II 

o. 


93 
99 


99 


16 

5 


90 


4 
17 
75 

8 
2 


32 


17 


43 


27 

2 

64 


39 
62 


68 


20 
10 


43 

4 

78 


17 
3 


♦  Color  acid  nearly  insoluble  in  both  layers. 

t  Similar  to  Congo  Red  but  color  acid  more  soluble  in  alcohol. 


*  U.  S.  Dept.  of  .\gric.,  Bur.  of  Chem.,  Circ. 


/IRTlhia/lL  FOOD  COLORS. 


hj 


MATHEWSON'S  TABLE  SHOWING  PERCENTAGE  OF  COLOR  IN  THE  WATER 
SOLUTION  AFTER  SHAKING  WITH  AN  EQUAL  VOLUME  OF  IMMISCIBLE 

SOLVENT— (Continued). 


SOLVENT:   DICHLORHYDRIN. 


Colors. 


Normality  of  Hydrochloric  Acid  in  Water  Layer  before 

^Shaking. 


Percentage  of  Color  in  Water  Solution  after  Shaking. 


Naphthol  Yellow  S  No.  4 . 

Ponceau  3  R  No.  56 

Orange  I  No.  85 

Amaranth  No.  107 

Light  Green  S  F  No.  435 . 
Indigo  Carmin  No.  692. .  . 
Acid  Magenta  No.  462 .  .  . 


15 
37 
4 
95 
15 
01 
86 


17 


Naphthol  Yellow  S  No.  4 . 
Ponceau  3  R  No.  56  .  .  .  . 


solvent:  amyl  acetate. 


95 


33 
96 


48 
97 


Naphthol  Yellow  S  No.  4 . 
Orange  I  No.  86.  .  ; 


solvent:  ether. 


94 
97 


07 
97 


Assuming  the  distribution  ratios  to  remain  constant,  this  procedure 
using  four  funnels  and  making  three  washings  gives  for  a  pair  of  colors 
whose  "  distribution  numbers  "  (as  the  percentage  numbers  given  in  the 
table  may  be  called)  are  80  and  20,  respectively,  a  separation  of  98.30 
per  cent  for  each  color.  With  distribution  numbers  90  and  10  four  funnels 
and  three  washings  give  a  calculated  separation  of  99.73%,  and  the  same 
is  obtained  with  distribution  numbers  81. S  and  5.3  if  the  solvent  in  which 
the  dyes  are  relatively  more  soluble  be  taken  in  portions  one-half  the 
volume  of  those  of  the  other  liquid.  If  the  second,  third,  and  fourth 
funnels  be  given  a  fifth  washing,  the  third  and  fourth  funnels  a  sixth, 
and  the  last  funnel  a  seventh  washing,  the  calculated  loss  for  the  color  more 
soluble  in  the  solvent  layer  is  0.76%,  while  the  percentage  of  the  other 
dye  removed  is  relatively  much  increased  (to  99.99  per  cent).  In  most 
mixtures  the  progress  of  the  separation  is  always  apparent. 


SlS  FOOD  INS PECTIOhi   /IND   ANALYSIS. 

In  practice,  because  of  incomplete  extraction  and  separation,  and 
especially  on  account  of  uncertainty  due  to  small  amounts  of  subsidiary 
dyes  always  present,  it  is  necessary  to  increase  the  number  of  successive 
extractions.  The  formation  of  esters  of  the  color  acids  is  a  possible 
source  of  difficulty,  but  is  not  believed  to  take  place.  With  amyl  alcohol 
as  solvent  it  is  usually  desirable  to  make  the  original  solution  more  strongly 
acid  than  is  indicated  by  the  distribution  data  and  use  relatively  more 
portiohs  of  the  washing  liquid. 

Of  the  permitted  colors,  Naphthol  Yellow  S  is  best  separated  from 
Orange  I  by  washing  the  amyl  alcohol  solution  of  the  color  acids  with 
strong  salt  solution,  care  being  taken  that  not  too  much  color  is  present. 
With  a  solution  containing  20  grams  of  salt  and  0.04  gram  Naphthol 
Yellow  S  per  100  cc.  and  shaken  with  an  equal  volume  amyl  alcohol,  97% 
of  the  color  is  retained  by  the  water.  With  a  similar  solution  contain- 
ing 0.07  gram  Orange  I,  the  water  layer  contains  1.5%  of  the  total  color. 
With  higher  concentrations  some  color  may  be  salted  out  in  solid  form, 
but  this  does  not  interfere  if  the  amount  is  small.  Erythrosin  being 
quantitatively  removed  from  slightly  acid  solutions  by  amyl  acetate,  ether, 
or  amyl  alcohol,  its  separation  from  sulphonated  colors  presents  no 
difficulty. 

Analysis  of  Food  Colors. — Seeker  and  his  co-workers  have  devised 
methods]  tor  the  analysis  of  the  seven  coal-tar  colors  allowed  by  federal 
decision  in  the  United  States.  The  methods  are  for  the  detemination  of 
the  ultimate  constituents  and  for  impurities,  including  arsenic  and  other 
heavy  metals.  The  reader  is  referred  to  Hesse's  report  (see  reference, 
page  8191  for  details  of  these  processes. 

Solubility  Tables. — Robin*  has  pubHshed  tables  showing  the  reactions 
of  the  coal-tar  dyes  used  in  confectionery,  classified  as  basic,  acid,  and 
water-insoluble  colors,  the  distinction  of  basic  and  acid  colors  being  based 
on  their  extraction  by  amyl  alcohol  or  ethyl  acetate  from  alkaline  and  acid 
solutions.  Rota  (page  798)  employs  ether  for  the  separation  of  basic 
colors, 

Loomis  (see  reference,  page  819)  has  prepared  a  table  giving  the 
solubility  of  food  colors  in  various  solvents,  including  those  named  above, 
and  another  table  showing  the  relative  amounts  extracted  from  neutral, 
alkaline,  and  acid  solutions,  shaking  with  amyl  alcohol,  ethyl  acetate  and 
acetone,  the  aqueous  solution  in  the  latter  case  being  saturated  with  salt. 

•  Girard:  .Vnalyse  des  Mati^res  alimentaires,  2  Ed.,  pp.  679-691. 


/JRTlhlCML   FOOD    COLORS.  819 

REFERENCES  ON   COLORS. 

.Arata,  p.  N.     (Spccielle  analytische  Methoden.)     Zcits.  anal.  Chcm.,  28,  p. 639. 
Bellip:r,  J.     Detection  of  Artificial  Coloring  Matters  in  Wine.     Ann.  de  Chim.  Anal., 

5,  1900,  p.  407;   Abs.  Analyst,  26,  1901,  p.  42. 
Benedikt,  R.,  and  Knecht,  E.    The  Chemistry  of  the  Coal-tar  Colours.   London,  1889. 
Berry,  W.  G.     Coloring  Matters  for  Foodstuffs  and  Methods  for  their  Detection. 

U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circular  No.  25. 
DOMMERGUE,  G.     Detection   of  Colors   on    Dyed  Wool.      Monit.    Scient.,  2)2),  P-  25; 

Abs.  lour.  Soc.  Chem.  Ind.,  8,  p.  216. 
FoL,  F.     Testing  of  Dyestuffs.     Jour.  Chem.  Soc,  28,  1875,  p.  193. 
Green,  A.  G.     On  the  Qualitative  Analysis  of  Coal  Tar  Coloring  Matters.    Jour, 

Soc.  Chem.  Ind.,  12,  1893,  P-  3- 
Hesse,  B.  C.      Coal  Tar  Colors  Used  in  Food  Products.     U.   S.    Dept.  of  Agric, 

Bur.  of  Chem.,  Bui.  1.37,  1912. 
Leeds,  .\.  R.     Tabellarische    Uebersicht    dcr    kiinsllichen  organischen  FarbstofTe. 

Berlin,  1894. 
Looms,  H.  M.     Report  on  Colors:    The  Solubility  and  Extraction   of  Colors  and 

the  Color  Reactions  of  Dyed  Fiber  and  of  Aqueous  and  Sulphuric-Acid  So- 
lutions.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circulars  Nos.  35  and  63. 
Martinon,  B.      Jour.  Soc.  Dyers,  3,  p.  174. 

Milliken,  S.  p.     Identification  of    Pure  Organic    Compounds.      Vol.  III.  Com- 
mercial Dyestuffs.      New  York,  1910. 
NiETZKi,  R.     Chemie  der  organischen  Farbstoffe.     Berlin,  1901. 
PosETTO,  G.     Composition  of  Vegetable  Coloring  Matters  for  Use  in  Confectionery. 

Zeits.  Nahr.  Unters,  u.  Hygiene,  9,  1895,  p.  150. 
Rawson,  C,  Knecht,  E.,  and  Lowenthal,  R.     A  Manual  of  Dyeing.     London,  1893. 
Rawson,  Gardner,  and  Laycock.     A  Dictionary  of  Dyes,  ^lordants,  etc.     1890. 
Reichelmann  and  Leuscher.     Detection  of  Coal  Tar  Colors  in  Pastry,  Cakes,  Fruit 

Products,  etc.     Zeit.  fiir  offentl.  Chem.,  8.  1902,  p,  204;   Abs.  Analyst,  27,  1902, 

p.  276. 
Rota,  A.  R.     A  Method  of  Analyzing  Natural  and  Artificial  Organic  Coloring  Matters 

Analyst,  24,  1899,  p.  41.     From  Chem.  Zeit.,  1898,  p.  437. 
ScHULTz,   G.,  u.  Julius,  P.     Taballarische  Uebersicht  der  kiinstlichen  organischen 

Farbstoffe.     1897. 
Translated  by  Green,   A.   G.     A  Systematic  Survey  of  the  Organic  Coloring 

Matters,     ist  ed.,  1894;    2d  ed.,  1904. 
Seeker,  A.  F.    Coloring  Matters  in  Foods.    Allen's  Commercial  Organic  Analysis. 

4th  Ed.,  Vol.  V,  p.  625. 
Sostegni,  L.,    and    Carpentieri,  F.      (Specielle  analytische  Methoden.)      Zeits. 

anal.  Chem.,  35,  1896,  p.  397. 
Spaeth,  E.      Foreign    Coloring    Matters   in    Fruit    Juices.      Zeits.  Unters.  Nahr. 

Genuss.,  2,  189Q,  p.  633. 
Tolman.  L.  ]\L     Coloring  Matter  in  Food.     V.  S.  Dept.  of  .A.gric.,  Bur.  of  Chem., 

Bui.  65,  p.   III. 
vU.  S.  Food  Inspection  Decisions:    No.  76.    Dyes,  Chemicals   and  Preservatives  in 


820  FOOD   INSPECTION  ^ND  /ANALYSIS. 

Foods.    No.  77.   Certificate  and  Control  of  Dyes  Permissible  for  Use  in  Color- 
ing Foods  and  Foodstuffs.     No.  106.   Amendment  to  No.  77.     No.  117.  The 
Use  of  Certified  Colors.      No.  120.    Amendment  to  No.  77. 
Weber,  H.  A.     Effect  of  Coal  Tar  Colors  on  Digestion.     Am.  Chem.  Jour.,  8,  1896, 

p.   1092. 
Weingartner.     Eine  Anleitung  zur  Untersuchung  der   im  Handel  vorkommenden 

kiinstlichen  Farbstoffe.     Zeits.  anal.  Chem.,  27,  1888,  p.  232. 
Weyl,  T.     Translated  by  LefTmann,  H.     The  Sanitary  Relations  of  the  Coal  Tar 

Colors.     Philadelphia,  1892. 
WiNTON,  A.  L.     The  Use  of  Coal  Tar  Dyes  in  Food.     Conn.  Agric.  Exp.  Sta.  Rep., 

T901,  p.  179. 
Witt,   O.   N.     Versuch.   ciner  qualitativen  Analyse  der  im   Handel  vorkommenden 
Farbstoflfe.     Zeits.  anal.  Chem.,  26,  1887,  p.  100. 


CHAPTER  XVIII. 
FOOD    PRESERVATIVES. 

Preservation  of  Food. — Various  processes  have  from  ancient  times 
been  known  and  used  for  arresting  the  fermentative  changes  which  food 
products  in  their  natural  state  undergo  on  long  standing.  These  proc- 
esses include  pickling  with  vinegar,  drying,  smoking,  salting,  preserving 
with  sugar,  and  finally  in  the  employment  of  heat  in  sterilizing  and  pas- 
teurizing, and  of  low  temperature  as  in  cold  storage.  All  of  them  are 
still  in  use,  and  are  universally  regarded  as  unobjectionable.  In  addi- 
tion to  these  old  and  well-known  methods  of  food  preservation  is  the 
comparatively  modern  practice  of  arresting  fermentation  by  the  use  of 
such  antiseptic  chemical  agents  as  formaldehyde,  beta-naphthol,  boric, 
salicylic,  benzoic,  and  sulphurous  acids  or  saUs  of  these  acids,  etc.,  in 
regard  to  the  wholesomeness  of  which  there  is  considerable  difference 
of  opinion.  These  substances  depend  for  their  efficiency  on  the  more 
or  less  complete  inhibition  of  bacterial  gro^vth.  Nearly  all  exert  a  power- 
ful antiseptic  influence,  to  such  an  extent  that  to  accomplish  their  object 
only  small  quantities  need  be  used  in  food. 

Apart  from  their  toxic  effects,  a  marked  difference  naturally  exists 
between  the  employment  of  such  substances  as  salt,  sugar,  and  vinegar 
for  food  preservation,  all  of  which  are  in  themselves  foods,  and  in  the 
use  of  chemical  agents  that  have  no  food  value.  The  advocates  of 
the  use  of  chemical  antiseptics  claim  that  there  are  no  authentic  instances 
on  record  of  injury  from  the  use  of  such  small  quantities  of  these  sub- 
stances as  are  necessary  to  arrest  decay,  while  there  are  many  cases  of 
injury  arising  from  the  use  of  foods  which,  while  apparently  wholesome, 
have  undergone  such  fermentation  as  to  develop  ptomaines  or  other 
harmful  toxins,  and  that  because  antiseptics  prevent  such  spoiling  of  the 
food,  their  use  is  decidedly  beneficial;  that  there  is,  besides,  no  more 
reason  why  a  prejudice  should  exist  against  the  employment  of  these 

821 


S22  FOOD  INSPECTION  AND  ANALYSIS. 

newer  chemicals  than  against  saltpeter,  which  has  long  been  used  in  the 
coming  of  meat,  or  against  the  cresols  and  phenols  left  as  a  product  of 
smoking. 

The  opponents  to  their  use  assert,  that  the  addition  to  food  of 
such  antiseptic  substances  as  prevent  its  decay  also  serves  to  retard 
the  digestive  processes  when  the  food  is  eaten;  that  many  of  these 
substances  are  dmgs,  and  as  such  cannot  fail  even  in  small  quantities 
to  exercise  a  toxic  effect  of  some  sort  on  the  system;  that  finally  their 
use  is  objectionable,  as  allowing  the  employment  in  certain  foods  of 
old  materials  llial  ha\c  in  some  cases  already  imdergonc  incipient 
decomposition  before  the  addition  of  the  antiseptic,  and  are  thus  un- 
wholesome. 

Regulation  of  Antiseptics  in  Food. — ^In  the  absence  of  legislation 
directly  prohibiting  the  use  of  any  of  the  above-named  antiseptics,  and 
in  view  of  the  difference  of  opinion  regarding  their  toxic  effects  when 
present  in  small  quantities,  it  is  difficult  to  maintain  a  complaint  under 
tlie  general  food  laws  as  they  exist  in  most  slates,  basing  the  complaint 
solely  on  their  harmfulness.  In  some  localities  certain  antiseptics  are 
specifically  allowed  and  others  are  prohibited.  Some  of  the  states,  as, 
for  example,  Massachusetts,  have  special  laws  under  which  it  is  required 
that  in  the  case  of  all  foods  thus  treated,  the  name  and  percentage  of  such 
antiseptics  as  are  used  must  appear  plainly  on  labels  of  the  packages 
or  containers  thereof,  such  a  provision  being  based  on  the  assumption. 
that  the  general  public  should  be  informed  of  what  they  are  buying,  where 
anv  doubt  exists  as  to  the  wholesomeness  o£  any  ingredient  present. 
Where  such  laws  as  these  are  in  force,  the  chemist's  task  is  compara- 
livelv  easy,  in  that  conviction  in  court  is  not  dependent  on  his  individual 
opinion  regarding  the  toxic  effects  of  the  antiseptic  employed. 

Physiological  experiments  for  testing  the  toxicity  of  these  chemical 
preservatives  were  formerly  confmed  to  the  lower  animals,  but  no 
satisfactory  results  could  be  thus  obtained.  Later,  metabolism  exjx-ri- 
ments  were  made  on  human  beings  treated  with  varying  amounts  of  the 
preservatives  under  carefully  controlled  conditions,  but  the  resuhs  of 
these,  though  made  by  experts  of  unciuestioned  ability,  do  not  agree. 
Even  if  any  of  these  substances  as  used  in  food  appear  to  have  little  or 
no  effect  on  i>eople  in  good  health,  they  cannot  be  assumed  to  be  equally 
harmless  to  those  who  are  inclined  to  be  delicate  or  sickly.  Even  though 
pronounced  harmless  in  themselves,  there  is  .still  the  objection  thai  the 
chemical  preservatives  may  readily  conceal  unclean  methods  or  materials. 
If    perishable    fcxxls    are    free    from    preservatives    and    are    sweet   and 


FOOD    PRESERl^ATiyFS.  823 

untainted,  the  consumer  has  reason  to  believe  that  clean  and  whole- 
some materials  and  sanitary  i)rocesses  were  employed  throughout  in 
their  manufacture. 

Commercial  Food  Preservatives. — A  large  number  of  commercial 
preparations  are  sold  for  ])urposes  of  preserving  specific  articles  of  food 
and  are  put  out  under  trade  names  that  usually  convey  no  suggestion 
of  their  true  character.  Some  of  these  consist  of  a  single  antiseptic  sub- 
stance, such  as  salicylic  acid,  ammonium  fluoride,  calcium  sulphate, 
"borax,  or  benzoic  acid,  while  others  are  mixtures  of  several  antiseptics, 
of  which  the  following  are  typical  examples,  showing  their  composition 
as  found,  together  with  the  amount  of  the  mixture  to  be  employed. 

A.  For  preserving  sausage  meat,  using  8  ounces  ])cr  10c  pounds 
cf  meat: 

Borax 36% 

Sah 467o 

Saltpeter 18% 

(Colored  with  an  anilin  dye.) 

B.  For  preserving  cider  and  ketchup, 

A  34%  solution  of  beta-naphthol  in  alcohol,  using  2  fluid  ounces  to 
45  gallons  of  cider,  or  i^  ounces  to  10  gallons  of  ketchup. 

C.  For  preserving  beer,  using  i^  ounces  per  barrel  of  beer: 

Salt 45% 

Salicylic  acid 27% 

Sodium  carbonate  and  salicylate 28% 

D.  Fcr  preserving  chopped  meats,  using  i  ounce  to  50  pounds  of 
meat* 

Sodium  sulphite 65% 

Borax 35% 

E.  Effective  for  curing  beef,  hams,  tongues,  bacon,  pig's  feet, 
etc.: 

Borax 28% 

Boric  acid 1 2% 

Sodium  chloride 35% 

Potassium  nitrate 25% 

F.  For  preserving  milk  and  cream: 

Boric  acid 75% 

Borax 25% 


S24  FOOD  INSPECTION  ^ND  ANALYSIS. 

G.   For  preserving  jellies,  jams,  presen-es,    mince-meat,    and   syrups, 
using  from  i  to  2  ounces  of  preservative  to  100  pounds  of  product: 


Sodium  bcnzoate 5o\ 


(7 

/o 


Boric  acid 40% 

Sodium  chloride 5% 

Sodium  bicarbonate 5% 

H.  For    preserving    ketchup    and    tomato    pulp,    using  from  6  to 
8  ounces  to  43  gallons  of  the  product : 

Sodium  benzoate 50% 

Sodium  chloride 40% 


Sodium  sulphite 10  / 


ct 


J.  Effective  for  keeping  butter  from  becoming  tainted  or  rancid, 
also  for  salt  codfish,  using  8  to  12  ounces  per  100  pounds  butter: 

Boric  acid 25% 

Borax 50% 

Sodium  chloride 25% 

J.  For  preserving  eggs  (surface  appl'.caiion ).  A  saturated  solu- 
tion of  salicylic  acid  in  3  quarts  of  water,  i  quart  strong  alcohol  and  7 
ounces  of  glycerin. 

FORMALDEHYDE. 

Formaldehyde  (HCHO)  is  a  gas  formed  by  the  action  of  a  red-hot 
spiral  of  jjlatinum  wire  on  vaporized  methyl  alcohol.  It  is  also  pro- 
duced by  the  dry  distillation  of  calcium  formate.  In  the  market  it  com- 
monly appears  in  the  form  of  a  40%  solution  of  the  gas  in  water  under 
the  name  of  formalin,  and  for  use  as  a  food  preservative  dilute  solutions 
of  from  2  to  5  per  cent  strength  are  usually  employed.  Its  use  as  a  food 
preservative  is  comparatively  modern.  Formaldehyde,  while  not  con- 
fined exclusively  to  milk  products,  is,  as  a  matter  of  fact,  more  com- 
monly used  in  these  than  in  other  foods.  Its  prompt  and  direct  action 
in  checking  or  preventing  the  growth  of  lactic  acid  bacteria  renders  it 
especially  desirable  for  use  as  a  milk  and  cream  preservative,  from  the 
standpoint  of  the  dair}'  man  who  does  not  concern  himself  as  to  whether 
or  not  its  use  is  injurious  or  illegal. 

When  present  in  milk  to  the  extent  of  i  ])art  formaldehyde  to  20,000 
parts  milk  (a  pro])ortion  c^uitc  comnjonly  employed;,  the  sample  is  kept 


FOOD  PRESERyATiyES.  825 

sweet  for  four  days  in  summer  weather,  when  under  ordinary  conditions, 
the  milk  untreated  would  curdle  in  less  than  forty-eight  hours. 

Determination  of  Formaldehyde  in  the  Commercial  Preservative. — 

(i)  lodomdric  Method* — Mix  10  cc.  of  the  aldehyde  solution  (diluted 
if  necessary  to  a  strength  not  exceeding  3%  of  formaldehyde)  with  25  cc. 
of  tenth-normal  iodine  solution,  and  add  drop  by  drop  a  solution  of  sodium 
hydroxide,  till  the  color  of  the  licjuid  becomes  clear  yellow.  The  solution 
is  set  aside  for  at  least  ten  minutes,  after  which  hydrochloric  acid  is  added 
to  set  free  the  uncombined  iodine,  and  the  latter  is  titrated  back  whh 
tenth-normal  thiosulphate.  Two  atoms  of  iodine  are  equivalent  to 
one  molecule  of  formaldehyde,  in  accordance  with  the  following  reactions: 

6Na(3H+6I  =NaI03+5NaI+3H,0. 

3CH,0  -f  NalOj  =  3CH,02-f  NaT 

SNal  4- NaIO:,-f  6HC1  =  6NaCl-f- le-t- 3H2O. 

(2)  Method  oj  Blank  and  Finkenbeiner.-\ — Three  grams  of  the  solu- 
tion are  weighed  into  a  tall  Erlenmeyer  flask,  to  which  is  then  added 
from  25  to  30  cc.  of  twice-normal  sodium  hydroxide.  50  cc.  of  pure 
2.5  to  3  per  cent  hydrogen  peroxide  solution  are  next  gradually  run  in 
during  a  space  of  from  three  to  ten  minutes,  through  a  funnel  placed  in 
the  neck  of  the  flask  to  prevent  spurting,  and  the  solution  is  allowed  to 
stand  for  two  or  three  minutes,  after  which  the  funnel  is  washed  with 
water. 

Finally  the  unused  sodium  hydroxide  is  titrated  with  twice-normal 
sulphuric  acid,  using  litmus  as  an  indicator.  The  less  formaldehyde 
in  the  sample,  the  longer  the  mixture  should  stand  after  addition  of  the 
hydrogen  peroxide,  to  complete  the  reaction.  When  less  than  30%  is 
present,  it  should  stand  at  least  ten  minutes. 

Ascertain  the  percentage  of  formaldehyde,  by  multiplying  by  2  the 
number  of  cubic  centimeters  of  soda  solution  used,  when  3  grams  of  the 
sample  are  taken. 

(3)  Ammonia  Method.X — Weigh  10  grams  of  the  formaldehyde  solu- 
tion into  a  flask,  and  treat  with  an  excess  of  ammonia.  Cork  the  flask 
and  shake  frequently  during  several  days.  The  formaldehyde  is  by  this 
process  converted  into  hexamethylamine. 

Transfer  the  solution  to  a  tared  platinum  dish,  and  evaporate  nearly 

*  Zeits.  anal.  Chem.,  1897,  36,  pp.  18-24;   abs.  Analyst,  22,  p.  221, 

t  Ber.,  31  (17),  2979. 

X  Conn.  Exp.  Sta.,  .\anual  Re[)ort,  1899,  p.  143. 


820  FOOD  INSPECTION  AND   ANALYSIS. 

to  dnncss  on  the  lop  of  a  closed  \vatcr-balh.  Finally  the  dish  is  trans- 
ferred to  a  desiccator,  and  the  drying  continued  over  sul|)huric  acid  to 
constant  weight.  The  per  cent  of  formaldehyde  is  calculated  from  the 
weight  cf  the  hexamethylamine,  making  a  correction  for  the  residue  left 
by  the  formaldehyde  itself  by  direct  evaporation: 

6CH,0  +  4NH,OH  =  (CH,)6N,+  ioH,0. 

Or  an  excess  of  a  standardized  ammonia  solution  may  be  added  in 
the  first  ])lace,  the  excess  of  ammonia  being  distilled  off  and  titrated  with 
standard  acid,  calculating  the  per  cent  of  formaldehyde  by  the  amount 
of  ammonia  absorbed. 

Detection  of  Formaldehyde. — Methods  have  jjreviously  been  given 
for  the  detection  of  formaldehyde  in  milk.  Pure  milk  furnishes  a  con- 
venient reagent  for  the  detection  of  forinaldehyde  in  various  preparations. 
A  solution  (if  the  sample  to  be  tested  is  acidified  with  ])hosphoric  acid, 
subjected  to  distillation,  and  the  first  few  cubic  centimeters  of  the  dis- 
tillate are  tested  for  formaldehyde  as  follows: 

(i)  Hydrochloric  Acid  and  Ferric  Chloride  Test. — Add  a  few  drops 
of  the  suspected  distillate  to  about  lo  cc.  of  pure  milk  (previously  proved 
free  from  formaldehyde)  in  a  porcelain  casserole,  and  carn.^  out  the  test 
as  described  on  page  i8o. 

(2)  Hehnefs  Sulphuric  Acid  Test. — Apply  the  test  as  described  on 
page  180  to  10  cc.  of  pure  milk  to  which  a  few  drops  of  the  suspected 
distillate  have  been  added. 

(3)  Resorcin  or  Carbolic  Acid  Test. — To  about  10  cc.  of  the  distillate 
to  be  tested,  add  a  few  drops  of  a  1%  solution  of  carbolic  acid  or  resorcin, 
mix  thorf)Ughly,  and  carefully  pour  the  liquid  down  the  side  of  a  test-tube 
containing  concentrated  sulphuric  acid.  In  the  presence  of  formaldehyde, 
a  rose-rerl  zone  is  formed  at  the  junction  of  the  two  liquids,  sensitive  to 
I  part  in  200,000.  If  formaldehyde  be  present  to  an  extent  exceeding 
I  part  in  100,000,  a  white  turbidity  or  precipitate  is  formed  above  the 
colored  zone. 

(4)  Phenyl  hydrazine  Hydrochloride  Test* — One  gram  of  phenyl- 
hydrazine  hydrochloride  and  i\  grams  sodium  acetate  are  dissolved  in 
10  cc.  of  water.  Add  2  to  4  drops  of  this  reagent,  and  an  equal  amount 
of  sulphuric  acid,  to  i  or  2  cc.  of  the  distillate  to  be  tested  in  a  test-tube. 
A  green  coloration  is  produced  in  the  presence  of  formaldehyde. 

*  Jour.  Am.  Chem.  Soc,  22,  p.  135. 


FOOD  PRESERy/ITiyES.  827- 

If  present  in  a  vcr)'  small  amount  (say  i  j>art  formaldehyde  in  200,000), 
heat  is  necessary  to  bring  out  the  color. 

Determination  of  Formaldehyde. — The  exact  quantitative  determina- 
tion of  formaldehyde  in  food  products  is  difficult,  owing  to  its  extreme 
volatility  as  well  as  the  uncertainty  of  the  compounds  which  it  forms  with 
proteins.  A  rough  idea  of  the  amount  present  may  often  be  gained  by 
the  intensity  of  the  colorations  produced  in  carr}dng  out  the  various 
c^ualitative  tests. 

Formaldehyde  in  the  small  amount  present  in  food  products  may  be 
roughly  determined  by  the  potassium  cyanide  method  (p.  181),  on 
separate  portions  of  the  distillate  of  about  20  cc.  each,  collecting  the 
distillate  as  long  as  an  appreciable  amount  of  formaldehyde  is  shown 
therein. 

BORIC  ACID. 

Boric  or  boracic  acid  is  commonly  obtained  in  impure  form  from 
lagoons  or  fumaroles  of  volcanic  origin  in  Tuscany.  It  is  afterwards 
purified  by  recrystallization.  It  is  weakly  acid,  and  readily  soluble  in 
water  and  in  alcohol.  Its  alcoholic  solution,  even  when  the  acid  is  present 
in  small  quantity,  burns  with  a  characteristic  green  flame.  The  acid 
is  quite  volatile  with  steam. 

Borax,  the  most  commonly  known  salt  of  boric  acid,  is  found  native- 
in  Italy,  California,  and  elsewhere,  and  is  also  made  from  boric  acid. 
It  is  mildly  alkaline,  and  readily  soluble  in  water. 

Boric  acid  and  borax,  either  used  separately  or  mixed,  have  long  been 
used  as  preservatives,  especially  in  animal  foods,  A  mixture  of  3  parts 
boric  acid  and  i  part  borax  has  been  found  ver}^  effective  as  a  milk  and 
butter  preservative,  as  well  as  for  meat  products. 

Determination  of  Boric  Anhydride  in  Commercial  Preservatives. — 
Gladding  Method.'^ — A  150-cc.  flask,  Fig.  117,  is  arranged  with  a  doubly 
perforated  stopper  having  two  tubes,  one  of  which,  the  inlet-tube  reach- 
ing nearly  to  the  bottom,  connects  it  with  a  larger  flask,  while  the  other 
or  outlet-tube  communicates  with  a  Liebig  condenser,  which  in  turn 
delivers  into  a  receiving-flask.  In  the  150-cc.  flask,  i  gram  of  the 
powdered  sample  is  placed,  with  about  20  cc.  of  95%  methyl  alcohol  and 
5  cc.  of  85%  phosphoric  acid.  The  larger  flask  is  then  filled  two-thirds 
full  of  methyl  alcohol,  and  heated  on  the  water-bath  after  the  apparatus 
has  been   connected  up.     Heat   is  also  applied  to   the  150-cc.  flask,  the 

*  Jour.  Am.  Chem.  Soc.,  20,  1S98,  p.  288. 


828 


FOOD  INSPECTION  AND  ANALYSIS. 


whole  arrangement  being  such  that  a  continuous  current  of  methyl  alcohol 
vapor  bubbles  through  the  liquid  in  the  smaller  flask,  the  heat  being  so 
regulated  that  from  15  to  25  cc.  of  methyl  alcohol  remains  in  the  150- 
cc.  flask,  while  about  100  cc.  of  distillate  passes  into  the  receiving-flask 
in  half  an  hour.  Continue  the  distillation  till  all  the  acid  has  passed 
over,  which  is  usually  accomplished  by  distilling  100  cc.  By  a  gentle 
aspiration  upon  the  receiving- flask,  loss  by  leaking  may  be  avoided. 


Fig.    117. — Apparatus  for  Determining  Eoric  Acid  According  to  Gladding. 

Prepare  a  mixture  of  40  cc.  of  glycerin  and  100  cc.  of  water,  and  care- 
fully neutralize,  using  j)henolphthalein  as  an  indicator.  Add  this  mixture 
to  the  distillate,  and  titrate  the  whole  with  tenth-normil  sodium  hydroxide. 
Run  a  blank  with  the  reagents  alone,  deducting  any  acidity.  For  the  fac- 
tors for  calculation  sec  page  830. 

Detection  of  Boric  Acid  and  Borates. — These  are  best  tested  for  in 
most  cases  in  a  solution  of  the  ash  of  the  sample,  the  quantity  to  be  used 
for  the  test  depending  largely  on  the  case  in  hand.  With  meat  products 
and  canned  goods,  about  25  grams  are  taken  for  the  test,  being  flrst  made 
distinctly  alkaline  with  lime  water,  dried  over  the  water-bath,  and  burned. 
The  ash  is  boiled  wiili  from  10  to  15  cc.  of  water,  and  tests  made  on  ihe 
solution.  With  such  jjroducts  as  salt  codflsh,  which  is  preserved  by 
brushing  or  coating  with  boric  mixture,  i)ortions  of  the  coating  may  be 
scraped  off  and  boiled  in  water,  the  tests  being  made  on  the  aqueous 
solutions. 


FOOD  PRESERl^ATli^ES.  829 

(i)  The  Turmeric-paper  TeJ. — The  most  delicate  test  for  boric  acid, 
'free  or  combined,  is  made  by  the  aid  of  turmeric-paper,  prepared  by  soak- 
ing a  smooth,  thin  grade  of  filter-paper  in  an  alcoholic  tincture  of  pow- 
dered turmeric.  The  paper  is  afterwards  dried  and  cut  into  strips,  which 
are  kept  for  convenience  in  a  wide-mouthed  bottle  in  a  dark  place. 

Slightly  acidulate  the  ash  of  the  sample  to  be  tested  with  a  few  drops 
of  dilute  hydrochloric  acid,  avoiding  an  excess  of  acid.  Then  dissolve  the 
ash  in  a  few  drops  of  water  and  thoroughly  saturate  a  strip  of  the  tur- 
meric-paper in  the  solution.  On  drying  the  paper,  if  boric  acid  cither  free 
or  combined  be  present,  a  cherry-red  coloration  will  be  imparted  to  the 
paper,  the  depth  of  color  depending  on  the  amount  j^resent.  As  a  con- 
firmatory test,  apply  a  drop  of  dilute  alkali  to  the  reddened  paper,  and 
a  dark-olive  color  will  be  due  to  boric  acid,  sharply  to  be  distinguished 
from  the  deep-red  color  produced  when  an  alkaline  solution  is  applied 
to  ordinar}'  turmeric-paper.  The  turmeric-paper  reaction  is  delicate  to 
I  part  in  8,000. 

(2)  Tincture  oj  Turmeric  Test. — To  the  solution  to  be  tested,  slightly 
acidified  with  hydrochloric  acid,  add  an  equal  volume  of  saturated  tinc- 
ture of  turmeric  in  an  evaporating-dish,  and  heat  for  a  minute  or  two.  A 
red  color,  light  or  dark,  depending  on  the  amount  of  the  preservative, 
is  produced  if  boric  acid  be  present,  changed  to  an  olive  color  by  the 
addition  of  dilute  alkali,  after  cooling. 

(3)  The  Flame  Test. — A  few  cubic  centimeters  of  alcohol  are  added  to 
the  dish  containing  the  slightly  acidulated  ash  of  the  sample  to  be  tested,  or 
to  the  acidulated  dried  residue  from  the  evaporation  of  the  aqueous  solution 
of  the  suspected  preservative,  and  after  mixing  by  the  aid  of  a  stirring- 
rod,  the  alcohol  is  ignited.  In  the  presence  of  any  considerable  portion 
-of  free  or  combined  boric  acid,  a  greenish  tinge  will  be  observed  in  the 
flame  of  the  burning  alcohol,  especially  at  the  first  flash,  due  to  the  boric 
ether  formed.     This  test  is  by  no  means  as  delicate  at  the  paper  test. 

Determination  of  Boric  Acid  in  Foods. — (i)  Tliompson's  Method. "^ — 
Add  I  or  2  grams  of  sodium  hydroxide  to  100  grams  of  the  sample,  and 
evaporate  to  drj-ness  in  a  platinum  dish.  Char  the  residue  thoroughly,  and 
boil  with  20  cc.  of  water,  adding  hydrochloric  acid  drop  by  drop  till  all  but 
the  carbon  is  dissolved.  In  burning,  avoid  too  high  a  heat,  simply  charring 
sufficiently  to  insure  a  clear  solution  with  water.  Transfer  bv  washing 
to  a  loo-cc.  graduated  flask,  taking  care  that  the  volume  does  not  exceed 
50  or  60  cc.     Add  half  a  gram  of  dr\^  calcium  chloride,  then  a  few  drops 

*  Analyst,  18,  p.  184. 


830  FOOD  INSPECTION  AND  ANALYSIS. 

of  phenolphthalein  solution,  and  next  a  10%  solution  of  sodium  hydroxide, 
till  a  permanent  pink  color  persists.  Finally  add  25  cc.  of  lime-water. 
By  this  means  all  phosphoric  acid  is  precipitated  in  the  form  of  calcium 
phosphate.  Make  up  to  the  loo-cc.  mark  with  water,  shake,  and  pour 
upon  a  dr}'  filter.  To  50  cc.  of  the  filtrate  add  sufficient  normal  sulphuric 
acid  to  remove  the  pink  color.  Then  add  a  few  drops  of  methyl  orange, 
and  continue  the  addition  of  sulphuric  acid  till  the  yellow  is  just  turned 
to  pink.  Tenth-normal  sodium  hydroxide  is  then  added  *  till  the  liquid 
takes  on  a  faint  yellow,  excess  of  alkali  being  avoided.  The  salts  of  the 
acids  present  at  this  time  are  all  neutral  to  phenolphthalein  except  boric 
acid  and  carbon  dioxide.  Boil  the  solution  to  expel  the  carbon  dioxide, 
cool,  add  a  little  more  phenolphthalein,  and  a  quantity  of  glycerin  equal 
in  volume  to  the  solution.  Finally  titrate  with  tenth-normal  sodium 
hydroxide  to  a  permanent  pink  color.  Each  cubic  centimeter  of  tenth- 
normal sodium  hydroxide  equals  0.0062  gram  crystallized  boric  acid, 
H3BO3,  or  0.0035  gram  boric  anhydride,  B2O3,  or  0.00955  gram  crystal 
lized  borax,  NanB407,ioH20. 

(2)  GoocWs  Method. — Mix  400  to  500  grams  of  the  substance  with 
10  grams  of  calcium  hydrate,  evaporate  to  dr\'ness  over  a  water-bath  in 
a  platinum  dish,  and  burn  cautiously  to  an  ash.  Dissolve  the  residue  in 
cold  nitric  acid,  and  add  an  excess  of  silver  nitrate  to  precipitate  the  chlo- 
rine. Filter,  make  up  to  500  cc.  with  water,  shake,  and  measure  out  25  cc. 
\nto  a  200-CC.  flask  fitted  with  a  stopper  provided  with  an  outlet-tube, 
and  with  a  separator)^  funnel  forming  virtually  a  thistle-tube,  caj)able  of 
being  closed  with  a  glass  stop-cock.  Through  the  outlet-tube  connect 
the  flask  wnth  a  Liebig  condenser  provided  with  an  adapter  which  can 
clip  below  the  liquid  in  the  receiver.  As  a  receiver,  use  a  150-cc.  tared 
J  latinum  dish,  which  contains  a  weighed  quantity  of  ignited  lime  in  water. 

Add  through  the  thistlc-ti.bc  10  cc.  of  methyl  alcohol  to  the  contents 
of  the  flask,  close  the  stop-cock  therein,  and  distill  the  contents  in  a  paraf- 
fin-bath at  a  temperature  of  140°  C,  constantly  stirring  the  liquid  in  the 
receiver  to  keep  it  alkaline  during  the  distillation.  Add  five  successive 
portions  of  methyl  alcoh<;l  of  12  cc.  each  to  the  distilling-flask,  and  con- 
tinue the  di.stillation  till  all  the  alcohol  has  passed  over.  Finally  evaporate 
to  dr}-ness  the  contents  of  the  platinum  dish,  and  ignite  over  a  blast-lamp 
to  constant  weight.  Multiply  the  increased  weight  due  to  boric  oxide  by 
2.728  to  give  the  cfjuivalcnt  in  borax. 

*  If  the  value  of  the  standard  alkali  solution  is  not  ahsolulely  ( crtain,  it  had  best  be- 
restandardized  against  pure  crystallized  boric  acid,  0.31  gram  of  which  should  neutralize 
50  cc.  of  tenth-normal  alkali. 


FOOD  PRESERl^ATiyES.  8.u 


SALICYLIC  ACID. 

Salicylic  acid  (HC7H5O3)  is  a  white,  crystalline,  strongly  acid  powder, 
made  synthetically  by  treatment  of  carbolic  acid  with  sodium  hydroxide 
and  carbon  dioxide,  or  naturally  from  methyl  salicylate  (which  occurs  in 
oil  of  wintergreen  to  the  extent  of  about  90%),  by  treatment  of  the  winter- 
green  oil  with  strong  potash  lye.  Most  of  the  commercial  salicylic  acid  is 
of  the  synthetic  variety.  Pure  salicylic  acid  crystallizes  from  alcoholic 
solutions  in  4-sidcd  prisms,  and  from  aqueous  solution  in  long,  slender 
needles.  It  melts  at  155°  to  156°  C.  It  is  slightly  soluble  in  cold  water 
(i  part  in  450),  and  much  more  so  in  hot  water.  It  is  readily  soluble  in 
ether,  alcohol,  and  chloroform. 

It  is  frequently  found  on  the  market  as  a  food  preservative  in  the  form 
of  the  much  more  soluble  sodium  salt,  sodium  salicylate,  (NaCyHjOg), 
which  is,  however,  converted  into  salicylic  acid  when  added  to  acid- 
fruit  preparations,  condiments,  and  liquors. 

Sodium  salicylate  is  a  white,  amorphous  powder,  soluble  in  0.9  parts 
water  and  in  6  parts  alcohol.  It  is  prepared  by  treating  salicylic  acid 
with  a  strong,  aqueous  solution  of  sodium  carbonate,  and  afterwards 
purifying.  If  a  known  weight  of  the  powdered  preservative  be  ignited, 
and  a  solution  of  the  ash  titrated  with  tenth-normal  sulphuric  acid,  using 
cochineal  as  an  indicator,  each  cubic  centimeter  of  the  acid  is  equivalent 
to  0.0160  gram  of  sodium  salicylate. 

Salicylic  acid  is  largely  used  as  a  preservative  of  jellies,  jams,  and 
fruit  preparations,  canned  vegetables,  ketchups,  table  sauces,  wines, 
beer,  and  cider.     It  is  rarely  used  in  milk  and  milk  products,  or  in  meats. 

Bucholz  has  shown  that  0.15%  of  salicylic  acid  is  sufficient  to  prevent 
bacteria  from  developing  in  ordinary  organic  substances,  while  as  small 
a  quantity  as  0.04%  produces  a  marked  restraining  influence. 

Small  amounts  of  salicylic  acid  occur  naturally  in  grapes,  straw- 
berries, and  other  fruits,  but  the  amounts  are  too  small  to  give  distinct 
color  reactions  when  only  50  grams  of  the  fruit  products  are  used  for 
tests. 

Detection  of  Salicylic  Acid. — If  the  samj^lc  to  be  tested  is  of  a  similar 
nature  to  jelly,  jam,  ketchuj),  cider,  etc.,  or  capable  of  getting  into  acjue- 
ous  solution,  slightly  acidify  the  liquid  or  pasty  material,  diluted,  if  neces- 
sary, with  weak  sulphuric  (if  not  already  acid),  and  shake  directly  with 
an  equal  bulk  of  ether,  petroleum  ether,  or  chloroform,  in  a  corked  flask, 
or  in  a  separatory  funnel.     If  the  sample  be  too  thick  in  consistency  10 


S^Z  FOOD    INSPECTION  AND   ANALYSIS. 

shake  directly,  macerate  in  a  mortar  with  alkahnc  water,  and  strain  through 
cloth.  Acidify  the  fihrate  with  dilute  sulphuric  acid,  and  then  proceed 
to  shake  with  the  immiscible  solvent  as  above.  Separate  by  decanlalion  or 
otherwise  the  immiscible  solvent  containing  the  preservative,  if  present,  and 
allow  it  to  evaporate  in  an  open  siuillow  dish,  either  at  room  temperature 
or  at  a  k)\v  heat.  In  case  an  emulsion  forms  on  shaking,  which  is  quite 
apt  to  hapjien,  especially  with  ether  for  a  solvent,  divide  the  whole  mixture 
between  two  tubes  of  a  centrifuge  of  the  form  shown  in  Fig.  ii,  and 
whirl  for  three  minutes  at  a  high  rate  of  speed.  This  usually  serves  to 
break  up  the  most  obstinate  emulsion,  so  that  it  is  easy  to  separate  by 
decantation.  If  a  considerable  amount  of  salicylic  acid  be  present,  it 
will  sometimes  appear  in  the  residue  in  the  form  of  fibrous  crv'stals. 

(i)  To  a  portion  of  the  dr}-  residue  add  a  drop  of  ferric  chloride  solu- 
tion. A  deep  purple  or  violet  color  indicates  salicylic  acid.*  If  doubt 
exists  as  to  the  color,  dilute  with  water,  which  often  serves  to  bring  out 
a  distinctive  purple  coloration  otherwise  unobservable. 

(2)  Another  portion  of  the  residue  may  be  heated  with  methyl  alcohol 
and  sulphuric  acid.  If  salicylic  acid  be  present,  the  well-known  odor  of 
methyl  salicylate  will  be  produced. 

(3)  A  portion  of  the  dr}^  ether  extract  is  warmed  gently  with  a  drop 
of  concentrated  nitric  acid,  and  two  or  three  drops  of  ammonia  are  added. 
Yellow  ammonium  picrate  will  be  formed  if  a  considerable  quantity  of 
salicylic  acid  be  present,  and  a  thread  of  wool  free  from  fat  may  be  dyed 
by  soaking  therein.  This  test  is  by  no  means  as  delicate  as  the  ferric 
chloride  color  test. 

Instead  of  evaporating  the  ether  solution  of  the  salicylic  acid  to 
dryness,  the  author  prefers  to  shake  out  the  salicylic  acid  from  the  ether 
with  dilute  ammonia,  evaporate  the  solution  of  ammonium  salicylate  nearly 
to  dryness,  and  ajjply  the  tests  given  above  to  the  concentrated  solution. 
In  this  case  the  ether  may  be  rccovcrcfl. 

Determination  of  Salicylic  Acid.  —Dubois  Method.^ — In  the  case  of 
ketchups  and  similar  pulped  materials  place  50  grams  in  a  graduated 
2CO-CC.  flask,  make  slightly  alkaline  with  ammonia,  add  15  cc.  of  milk 

*  Peters  (U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  160)  advises  the  use  of  chloro- 
form as  more  convenient  for  extraction  when  testing  for  salicylic  acid,  and  recommends  that 
the  chloroform  extract  without  evaporation  be  shaken  in  a  test-tube  with  a  drop  of  ferric 
chloride  reagent  and  a  little  water.  In  the  presence  of  salicylic  acid,  the  violet  color  will 
be  apparent  in  the  sufx;rnatant  aqueous  layer. 

t  Jour.  .'Km.  Chem.  .Soc.,  28,  1906,  p.  1616.  V.  S.  Dept.  of  .\gric.,  Bur.  of  Chem.,  Bui. 
107  (rev.;,  p.  179. 


FOOD   PRESERyATlVES.  833 

of  lime  (200  grams  of  quicklime  in  2000  cc.  water),  complete  the  volume, 
shake  and  tllter.  Transfer  150  cc.  of  the  filtrate  to  a  separatory  funnel, 
acidify  with  hydrochloric  acid,  and  extract  with  four  portions  of  75  to 
100  cc.  of  ether.  Wash  the  combined  extract  twice  with  25  cc.  of  water, 
and  distil  off  the  ether  slowly,  allowing  the  last  20  to  25  cc.  to  evaporate 
spontaneously.  Dissolve  the  residue  in  a  small  amount  of  hot  water, 
make  up  to  a  definite  volume  with  water,  and  add  to  an  aliquot  portion 
a  few  drops  of  a  2%  solution  of  ferric  alum  to  develop  the  color.  Esti- 
mate the  amount  of  salicylic  acid  by  matcliing  the  color  thus  obtained 
with  that  produced  in  a  solution  containing  i  mg.  of  salicylic  in  50  cc, 
using  either  a  colorimeter  or  Ncssler  tubes  for  making  the  comparison. 

In  the  case  of  semisolid  materials,  such  as  mince  meat,  jams,  etc., 
macerate  50  grams  with  water  in  a  mortar  previous  to  treatment  as 
above  described. 

Liquids  and  solutions  of  jellies  and  other  materials  free  from  pulp 
may  be  extracted  with  ether  directly  after  acidifying. 

BENZOIC  ACID 

Benzoic  Acid  (HC7H5O2)  is  produced  by  the  oxidation  of  a  large 
number  of  organic  substances,  particularly  toluene.  It  is  also  extracted 
by  sublimation  from  gum  benzoin,  which  exudes  from  the  bark  of  the 
Styrax  benzoin,  a  tree  growing  in  Java,  Sumatra,  Borneo,  and  Siam. 
IMost  of  the  commercial  benzoic  acid  is  made  from  toluene  by  treat  mem 
with  chlorine  and  subsequent  oxidation. 

Benzoic  acid  crystallizes  in  leaflets,  having  a  silky  luster.  It  is  odor- 
less when  cold,  is  soluble  in  200  parts  of  cold,  and  25  parts  of  boiling 
water,  and  readily  dissolves  in  alcohol,  ether,  and  chloroform.  Its  melt- 
ing-point is  120°,  and  it  sublimes  at  a  slighdy  higher  temperature.  It 
occurs  naturally  in  the  cranberry  and  other  berries  of  the  Erlcacecc. 

Sodium  Benzoate  (NaC7H502)  is  the  salt  most  largely  used  in  commer- 
cial preservatives,  being  much  more  soluble  than  the  acid  itself,  into 
which,  however,  it  is  converted  when  put  into  acid  fruit  preparations. 
Sodium  benzoate  is  prepared  Ijy  adding  benzoic  acid  to  a  concentrated 
hot  solution  of  sodium  carbonate  till  there  is  no  longer  effervescence, 
and  then  cooling,  and  allowing  the  sodium  benzoate  to  crystallize  out. 
In  titrating  solutions  of  ignited  sodium  benzoate  with  tenthnormal 
sulphuric  acid,  each  cubic  centimeter  of  the  standard  acid  is  ecjuivalent 
to  0.0 T 44  gram  of  the  benzoate. 

Sodium  benzoate  is  a  Avhite  amorphous  powder,  having  a  sweetish. 


834  FOOD   INSPECTION  ^ND  ^N. ■I LYSIS. 

astringent  taste,  and  is  soluble  in  1.8  parts  of  cold  water,  and  in  45  parts 
of  alcohol.  It  is  used  as  a  preservative  of  ketchups,  fruit  products,  soft 
drinks,  codtish.  and  less  often  of  wines. 

Long.  Herter,  and  Chittenden  of  the  Referee  Board  of  Consulting 
Scientific  Experts,  after  independent  experiments,  conclude  that  sodium 
ben/.oate  in  small  doses  (less  than  0.5  gram  per  day)  is  not  injurious  to 
health  and  in  large  doses  (up  to  4  grams  per  day)  has  not  been  found  to 
exert  any  deleterious  effects  on  the  general  health  nor  to  act  as  a  poison 
in  the  general  acceptance  of  the  term.  Accordingly  this  preservative  is 
allowed  under  the  federal  law  provided  the  presence  and  amount  are 
d'.'clared  on  the  label.* 

Detection  of  Benzoic  Acid.— Extract  with  ether  or  chloroform  as 
directed  for  salicylic  acid.  If  it  is  desired  to  test  for  both  preservatives 
divide  the  extract  into  two  parts  and  evaporate  in  separate  dishes.  A 
considerable  amount  of  benzoic  acid  is  apparent  in  the  residue  as  shining 
cr)'stalline  scales  or  needles. 

In  the  author's  experience  a  better  procedure  than  evaporating  the 
ether  solution  is  to  extract  the  benzoic  acid  from  the  ether  by  shaking 
with  dilute  ammonia,  evaporate  the  solution  of  ammonium  benzoate  nearly 
to  dryness,  and  apply  tests  to  the  concentrated  solution. 

(i)  Ferric  Chloride  Test. — A  portion  of  the  residue  from  the  ether 
extract  is  dissloved  in  ammonia,  and  evaporated  over  the  water-bath  until 
neutral  to  test  paper.  The  residue  is  stirred  in  a  few  drops  of  warm  water, 
and  filtered  through  a  small  filter  into  a  narrow  test  tube.  A  drop  of 
neutral  ferric  chloride  (prepared  by  precipitating  a  portion  of  the  iron 
from  a  solution  of  the  salt  by  ammonia  and  filtering)  is  added,  and 
in  the  presence  of  benzoic  acid  a  flesh-colored  precipitate  of  ferric 
benzoate  is  produced,  very  characteristic  and  unmistakable,  because 
of  its  peculiar  color,  when  the  solution  in  which  the  test  is  made  is  color- 
less. It  occasionally  happens,  however,  in  the  case  of  jellies,  jams,  and 
ketchups,  that  these  preparations  are  artificially  colored  with  a  dyestuff 
that  persists  by  its  depth  of  color  in  obscuring  that  of  the  ferric  benzoate, 
especially  when  only  a  small  amount  of  benzoic  acid  is  present.  Again, 
in  such  products  as  sweet  pickles,  a  precipitate  of  basic  ferric  acetate 
might  also  come  down  with  the  ferric  benzoate,  and  thus  confuse.  In 
such  cases  one  of  the  following  methods  should  be  carried  out. 

(2)  Sublimation  Method.'^ — Evaporate  an  ammoniacal  solution  of  the 

•  Food  Insjjection  Decision  104. 

t  Annual  Report,  Mass.  State  Board  of  Health,  1902,  p.  486. 


FOOD   PRFSERy^TiyES.  835 

ether  extract  till  neutral  in  a  large  watch-glass,  by  the  aid  of  a  gentle 
heat.  Fasten  with  clips  or  othenvise  a  second  watch-glass  to  the  first, 
edge  to  edge,  so  as  to  form  a  double  convex  chamber,  with  a  cut  filter- 
paper  between.  Place  upon  a  small  sand-bath  and  heat.  Benzoic  acid, 
if  present,  will  sublime  upon  the  surface  of  the  upper  glass  in  minute 
needles,  recognizable  under  the  microscope.  It  may  further  be  tested 
by  determining  the  melting-point,  or  by  treating  with  ammonia,  evapo- 
rating, and  applying  the  ferric  chloride  test  as  above. 

(3)  Mohler  Method  Modified  by  Heide  and  Jakob.* — Evaporate  the 
ether  extract  to  dryness,  take  up  the  residue  in  i  to  3  cc.  of  third-normal 
sodium  hydroxide,  and  evaporate  to  dryness.  To  the  residue  add  5  to 
10  drops  of  concentrated  sulphuric  acid  and  a  small  crystal  of  potassium 
nitrate.  Heat  for  ten  minutes  in  a  glycerol  bath  at  120°  to  130°  C.  (never 
higher),  or  for  twenty  minutes  in  a  boiling  water-bath,  thus  forming  meta- 
di-nitro  benzoic  acid.  After  cooling  add  i  cc.  of  water  and  make  decidedly 
ammoniacal;  boil  the  solution,  to  break  up  any  ammonium  nitrite  which 
may  have  been  formed.  Cool  and  add  a  drop  of  fresh  colorless  ammonium 
sulphide,  without  allowing  the  layers  to  mix.  A  red-brown  ring  (ammo- 
nium meta-di-amido  benzoic  acid)  indicates  benzoic  acid.  On  mixing, 
the  color  diffuses  through  the  whole  liquid;  on  heating  it  finally  changes 
to  greenish  yellow,  owing  to  the  decomposition  of  the  amido  acid,  thus  dis- 
tinguishing benzoic  from  salicylic  or  cinnamic  acids.  Both  the  latter 
form  amido  compounds,  which  are  not  destroyed  by  heating.  The  presence 
of  phenolphthalein  interferes  with  this  test. 

(4)  Peter  Oxidation  Method. ■\  —  This  method,  depending  on  the 
formation  of  salicylic  acid,  is  not  applicable  in  the  presence  of  this  acid 
or  saccharin  which  also  oxidizes   to  salicylic  acid. 

Transfer  a  portion  of  the  residue,  say  o.i  gram,  from  the  ether  or  chloro- 
form extraction  to  a  large  test-tube,  and  dissolve  in  from  5  to  8  cc.  of 
concentrated  sulphuric  acid.  Add  from  0.5  to  0.8  gram  of  barium  per- 
oxide in  successive  small  portions,  shaking  the  tube  in  cold  water.  This 
should  produce  a  permanent  froth  on  the  sulphuric  acid  solution.  After 
standing  for  half  an  hour,  fill  the  test-tube  three-quarters  full  of  water, 
shake,  cool  quickly,  and  filter.  Extract  the  filtrate  with  ether  or  chloro- 
form, and  test  the  extract  for  salicylic  acid. 

Determination  of  Benzoic  Acid. — La  Wall  and  Bradshaw  Method. 
Modified. — This   process   is   based   on   principles   brought   to   notice   by 

*  Zeits.  Unters.  Nahr.  Genuss.,  19,  1910,  p.  137.     A.  O.  A.  C.  Method, 
t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  65,  p.  160. 


836  FOOD   INSPECTION  AND   ANALYSIS. 

Moerck.*  Although  originally  devised  for  catsup, f  it  has  been  modified 
by  Bigelow  +  and  Dunbar, §  so  as  to  be  applicable  to  various  classes  of 
foods.  The  details  which  follow  are  those  elaborated  by  Dunbar  and 
adopted  by  the  A.  O.  A.  C. 

1.  Pre paration  of  Solution. — {a)  General. — Grind  in  a  sausage-machine, 
if  solid  or  semi-solid,  and  thoroughly  mix.  Transfer  about  150  grams  to 
a  500-cc.  flask,  add  enough  pulverized  sodium  chloride  to  saturate  the 
water  in  the  sample,  make  alkaline  with  sodium  hydroxide  or  milk  of 
lime,  and  dilute  to  the  mark  with  saturated  salt  solution.  Allow  to  stand 
at  least  two  hours  with  frequent  shaking  and  filter.  If  the  sample  contains 
large  amounts  of  matter  precipitable  by  salt  solution  follow  a  method 
similar  to  that  given  under  (e);  if  large  amounts  of  fats  are  present  it  is 
well  to  make  an  alkaline  extraction  of  the  filtrate  before  proceeding  as 
directed  under  "  Extraction  and  Titration." 

{b)  Catsup. — To  150  grams  of  the  sample  add  15  grams  of  pulverized 
sodium  chloride.  Transfer  the  mixture  to  a  500-cc.  graduated  flask, 
using  about  150  cc.  of  saturated  salt  solution  for  rinsing.  Make  slightly 
alkaline  to  litmus  paper  with  strong  sodium  hydroxide  and  complete  the 
dilution  to  500  cc.  with  saturated  salt  solution.  Allow  to  stand  at  least 
two  hours  with  frequent  shaking  and  then  filter  through  a  large  folded 
filter.  If  difficulty  is  experienced,  centrifuge  or  squeeze  the  mixture  through 
a  muslin  bag  before  filtering. 

(f)  Jellies,  Jams,  Preserves,  and  Marmalades. — Dissolve  150  grams  of 
the  sample  in  about  300  cc.  of  saturated  salt  solution.  Add  15  grams  of 
pulverized  sodium  chloride.  Make  alkaline  to  litmus-paper  with  milk 
of  lime.  Transfer  to  a  500-cc.  graduated  flask,  and  dilute  to  the  mark 
with  saturated  salt  solution.  Allow  to  stand  at  least  two  hours  with 
frcfjuent  shaking,  centrifuge,  if  necessary,  and  filter  through  a  large  folded 
filter. 

{d)  Cider  and  Similar  Products  Containing  Alcohol. — Make  250  cc.  of 
the  samyjle  alkaline  to  litmus-paper  with  sodium  hydroxide  and  evaporate 
on  the  steam-bath  to  about  100  cc.  Transfer  to  a  250-cc.  flask,  add 
30  grams  of  pulverized  sodium  chloride  and  shake  until  dissolved.  Dilute 
to  the  mark  with  saturated  salt  solution,  allow  to  stand  at  least  two 
hours  with  frequent  shaking,  and  filter  through  a  folded  filter. 

♦  Prrx:.  Pcnn.  Pharm.  .^ssn.,  1905,  p.  181. 

t  Am.  Jour.  Pharm.,  80,  1908,  p.  171. 

X  A.  O.  A.  C.  Pror.  1908,  U.  S.  Dept.  of  -Agrir.,  Bur.  of  Chem.,  Eul.  122,  p.  68. 

§  Ibid.,  Proc,  1909,  Bui.  132,  p.  138;  Circ.  66,  p.  14. 


FOOD  PRFSFMyATl^ES.  837- 

{e)  Salt  or  Dried  Fw/z.— Transfer  50  grams  of  the  ground  sample  to  a 
500-cc.  flask  with  water.  Make  slightly  alkaline  to  litmus-paper  with 
strong  sodium  hydroxide  and  dilute  to  the  mark  with  water.  Allow  to 
stand  at  least  two  hours  with  frequent  shaking  and  filter  through  a  folded 
filter.  Pipette  at  least  300  cc.  of  the  filtrate  into  a  second  500-cc.  flask. 
add  30  grams  of  pulverized  sodium  chloride  for  each  100  cc,  shake  until 
dissolved,  and  dilute  to  the  mark  with  saturated  salt  solution.  Mix 
thoroughly  and  filter  ofT  the  precipitated  protein  matter  on  a  folded 
filter. 

2.  Extraction  and  Titration. — Pipette  a  convenient  portion  of  the 
filtrate  (100  to  200  cc),  obtained  as  above,  into  a  separator}'  funnel. 
Neutralize  to  litmus-paper  with  hydrochloric  acid  (1:3)  and  add  an  excess 
of  5  cc.  In  the  case  of  salt  fish,  protein  matter  usually  precipitates  on 
acidifying,  but  this  does  not  interfere  with  the  extraction.  Extract  care- 
fully with  chloroform,  using,  for  200-cc.  aliquots,  successive  portions  of 
70,  50,  40,  and  30  cc,  and  proportional  quantities  for  smaller  aliquots. 
To  avoid  emulsion,  shake  each  time  cautiously.  The  chloroform  layer 
usually  separates  readily  after  standing  a  few  minutes.  If  an  emulsion 
forms,  stir  the  chloroform  layer  with  a  glass  rod.  If  this  does  not  break 
up  the  emulsion,  draw  it  off  into  a  second  funnel  and  shake  sharply  once 
or  twice.  If  this  also  fails,  centrifuge  the  emulsion  for  a  few  moments. 
Draw  off  with  great  care  as  much  of  the  clear  chloroform  solution  as 
possible  after  each  extraction.  If  not  contaminated  with  the  emulsion, 
it  is  unnecessary  to  wash  the  chloroform  extract. 

Transfer  the  combined  chloroform  extract  to  a  dish,  linsing  with 
chloroform,  evaporate  to  dryness  at  room  temperature,  either  sponta- 
neously or  in  a  current  of  dry  air,  and  dr}'  over  night  (or,  in  case  of  catsup, 
until  no  odor  of  acetic  acid  can  be  detected)  in  a  sulphuric  acid  desiccator. 
Dissolve  the  residue  of  benzoic  acid  in  30  to  50  cc.  of  neutral  alcohol, 
add  about  one-fourth  this  volume  of  water,  a  drop  or  two  of  phenolphtha- 
lein  solution  and  titrate  with  twentieth-normal  sodium  hydroxide.  One 
cc.  of  the  standard  solution  is  equivalent  to  0.0072  gram  anhydrous  sodium 
benzoate. 

In  the  absence  of  a  blast  an  electric  fan  may  be  used  for  evaporating 
the  extract.  If  it  is  impracticable  to  evaporate  the  chloroform  sponta- 
.neously  or  by  means  of  a  blast  it  may  be  transferred  from  the  separatory 
funnel  to  a  300-cc.  Erlenmeyer  flask,  rinsing  the  separatory  funnel  three 
times  with  5  or  10  cc  of  chloroform.  Distil  very  carefully  to  about  one- 
fifth  the  original  volume,  keeping  the   temperature   down   so   that   the 


S38  FOOD  INSPECTION  ^ND   ANALYSIS. 

chloroform  comes  over  in  drops,  not  in  a  steady  stream.  Then  transfer 
the  extract  to  a  porcelain  evaporating  dish,  rinsing  the  flask  three  times 
with  5  or  ID  cc.  portions  of  chloroform,  and  evaporate  to  drj^ness  spon- 
taneously. 

The  evaporation  of  the  chloroform  is  best  effected  by  delivering  to  the 
dish  a  blast  of  air  dried  by  means  of  a  calcium  chloride  bottle. 

Hilycr  Method*  —  This  method  is  valuable  as  a  check  on  the  La 
Wall  and  Bradshaw  method.  After  titrating  the  benzoic  acid  obtained 
as  described  in  the  preceding  section,  proceed  as  follows: 

Evaporate  to  drj'ness  the  accurately  neutralized  solution  (which 
should  not  have  even  a  slight  alkaline  reaction),  and  redissolve  in  a  few  cc. 
of  alcohol  saturated  with  silver  .benzoate.  Filter  i!  not  clear,  wash  with 
a  few  drops  of  alcohol,  and  treat  with  10  to  15  cc.  of  a  saturated  solution 
of  silver  nitrate  in  alcohol.  Collect  the  precipitate  in  a  Gooch  crucible, 
care  being  taken  that  the  asbestos  filter  is  so  prepared  as  to  afford  as 
rapid  a  filtration  as  possible,  wash  with  alcohol,  and  finally  with  a  little 
ether,  heat  in  a  water-oven  until  the  ether  is  removed,  cool,  and  weigh. 
Care  must  be  taken  to  perform  all  the  operations  as  quickly  as  possible 
to  avoid  separation  of  silver  oxide. 

West's  Distillation  Method. -f — i.  Apparatus. — The  special  form  of 
double  flask  for  distillation  in  a  current  of  steam  is  the  same  as  that 
employed  by  Hortvet  %  in  determining  the  volatile  acids  of  wine  (Fig.  115). 
The  steam  tube  leading  from  the  outer  to  the  inner  flask,  being  intro- 
duced half-way  up  the  side  of  the  inner  flask,  makes  it  i)ossible  to 
connect  the  apparatus  in  such  a  way  that  at  the  beginning  of  the 
operation  the  water  in  the  outer  flask  will  reach  to  the  height  of  the 
contents  of  the  inner  flask.  The  side  tube  leading  from  the  neck  of 
the  outer  flask  is  provided  with  a  rubber  tube  and  pinch-cock  for  use 
in  relieving  the  steam  pressure  and  avoiding  the  danger  of  drawing  the 
contents  of  the  inner  flask  over  into  the  outer  flask. 

2.  Process. — Weigh  into  the  inner  flask  of  the  apparatus  10  grams, 
add  1.5  to  2.0  grams  of  paraflln  free  from  volatile  matter,  and  connect 
■with  the  condenser.  Add  10  cc.  of  concentrated  sulphuric  acid,  drop 
by  drop,  through  the  funnel  tube  at  such  a  rate  as  to  complete  the  addition 


*  A.  O.  ,'\.  C.  Proc.  1908,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  p.  74;    Circ, 
66,  p.  15. 

t  Jour.  InfL  Kng.  Chcm.,  i,  1909,  p.  190. 
X  Ibifl.,  I,  1909,  p.  31. 


FOOD    PRESERyATiyES.  8,39 

in  two  to  three  minutes,  mix  thoroughly  by  gentle  agitation,  and  allow 
to  stand  five  to  ten  minutes  after  all  apparent  action  of  the  sulphuric 
acid  has  stopped.  Measure  150  cc.  of  distilled  water  into  the  outer 
flask,  heat  the  water  slowly  to  boiling,  and  continue  the  boiling  until 
100  cc.  of  distillate  have  been  collected,  the  rate  of  distillation  being 
such  as  to  yield  this  amount  in  25  to  30  minutes. 

Filter  the  distillate  into  a  sei)aratory  funnel,  and  rinse  receiver  and 
filter  with  two  lo-cc.  portions  of  water.  Shake  with  three  portions  of  ether, 
using  50  cc,  30  cc,  and  20  cc,  and  wash  the  combined  ether  extracts 
by  shaking  with  four  50-cc  portions  of  water  and  a  last  portion  of 
25  cc,  which  portion  should  not  require  more  than  a  drop  of  tenth-normal 
alkali  for  neutralization,  indicating  the  complete  removal  of  volatile 
acids.  Transfer  the  ether  extract  to  a  tared,  wide-mouthed  flask,  and 
distil  off  the  ether  on  the  water-bath  as  quickly  as  possible.  At  just  the 
point  where  ebullition  of  the  ether  ceases,  remove  the  flask  from  the 
bath,  blow  air  into  it  to  remove  the  last  traces  of  ether,  and  dry  in  a 
desiccator  over  night,  or  until  constant  weight  is  secured. 

The  benzoic  acid  may  also  be  determined  by  titration,  in  which  case 
the  filtration  of  the  distiUate,  also  the  drying  and  weighing  of  the  acid, 
may  be  omitted.  The  crystals  of  benzoic  acid  are  dissolved  in  alcohol 
carefully  neutralized  immediately  before  each  analysis,  and  the  solution, 
titrated  with  tenth-normal  alkaU. 

SULPHUROUS  ACID    AND   THE  SULPHITES. 

Free  sulphurous  acid  in  the  form  of  sulphur  fumes  is  extensivel}:- 
employed  to  bleach  molasses,  to  disinfect  wine  casks,  and  to  bleach 
and  preserve  dried  fruits.  This  process  is  known  as  "  sulphuring."  It 
is  stated  that  the  sulphur  dioxide  combines  with  the  acetaldehyde  of 
wines  forming  aldehyde-sulphurous  acid,  which  is  comparatively  harm- 
less. In  the  case  of  dried  fruits  it  is  believed  to  form  compounds  with 
the  sugars. 

The  sulphurous  acid  salts  most  commonly  employed  as  food  pre- 
servatives are  the  bisulphites  of  sodium  and  calcium,  NaHSOs  and 
Ca(HSO.i)2.  Others  used  to  some  extent  are  the  normal  sodium  sul- 
phite, and  also  potassium  and  ammonium  sulphite.  The  sulphites  are 
usually  commercially  prepared  by  passing  sulphurous  acid  gas  through 
strong  solutions  of  the  carbonates.  Acid  sulphites  are  formed  by  an 
excess  of  the  sulphurous  acid  in  the  solution  of  the  sulphite.  The  acid 
sulphites  are  distinguishable  from  the  sulphites  by  their  reaction  with 


S^o  FOOD   INSPECTION  AND    ANALYSIS 

litmus  paj>or.  the  fornuT  being  acid,  while  llu'  latter  are  neutral  or  feebly 
alkaline.  All  of  these  salts  have  a  bitter,  salty,  and  highly  sulphurous 
taste,  and  possess  a  very  pungent,  irritating  odor.  W  itii  the  exception 
of  normal  calcium  sulphite^  all  of  the  above  are  readily  soluble  in  water. 

The  sulphites  are  most  commonly  u.sed  as  preservatives  of  fruit  juices, 
ketchups,  fruit  and  \-egetable  pulps,  wind's,  mall  licpiors  and  meat 
products.  They  are  frequently  mixed  witli  other  antise])tics,  as  with 
the  salts  of  salicylic  and  benzoic  acids. 

Detection  and  Determination  of  Sulphurous  Acid. — The  same  methods 
are  used  for  the  detection  of  sul])hurous  acid  as  for  its  (piantitative 
determination,  except  that  in  the  former  case  weighed  cpiantities  need 
not  be  employed,  and  the  precipitate  obtained  by  the  barium  sulphate 
method  need  not  be  weighed. 

Distillation  Method. — This  method  is  adapted  to  all  food  ])roducts 
whether  solid  or  liquid. 

Place  50  to  200  grams  of  the  material  in  a  500-cc.  tlask,  add  water, 
if  necessary,  and  5  cc.  of  a  20^^^  solution  of  ])hosphoric  acid,  and  distil 
in  a  current  of  carbonic  acid  into  water  containing  a  few  drops  of  bromine, 
until  150  cc.  have  passed  over.  Tf  sulphides  are  present,  as  is  true  of 
decomposed  meat  ])roducts  and  possibly  other  f(X)ds,  the  steam  from 
the  distilling-flask  before  entering  the  condenser  should  be  passed  through 
a  flask  containing  40  cc.  of  a  2%  neutral  solution  of  cadmium  chloride  * 
or  a  i^(  solution  of  copper  sulphate. f  These  solutions  effectually  remove 
the  hydrogen  sulphide,  without  retaining  any  appreciable  amount  of 
suljjhurous  acid.  To  avoid  escape  of  sulphurous  acid  the  condenser 
tube  should  dip  below  the  surface  of  the  bromine  solution. 

The  method  and  aj)paratus  may  be  sim])lified  without  material  loss 
in  accuracy  by  omitting  the  current  of  carbon  dioxide,  adding  10  cc.  of 
[phosphoric  acid  instead  of  5  cc,  and  dropping  into  the  distilling-flask  a 
7>iece  of  sodium  bicarbonate  weighing  not  more  than  a  gram,  immediately 
before  attaching  the  condenser. 

When  the  distillation  is  finished,  boil  off  the  excess  of  bromine,  dilute 
to  about  250  cc,  add  i  cc.  of  concentrated  hydrochloric  acid,  heat  to 
boiling,  and  add,  drop  by  drop  while  boiling,  an  excess  of  barium 
chloride  solution,  .\llow  to  stand  over  night  in  a  warm  place,  filter 
(preferably  on    a    Gooch    crucible   with    a    compact    mat    of   woolly  as- 

*  H«mc,  r.  S.  \)v]}\.  Ill  Agri( .,  Hur.  Chem.,  Bui.  105,  \>.  125. 
t  WintDD  antl  Hailcy,  Jour.  Am.  Cht-m.  Sfjc,  29,  1907,  \).  1499. 


FOOD   PRESERyATiypS.  841 

bcstos),  wash  with  hot  water,  ignite  at  a  dull  red  heal,  and  weigh  as 
barium  sulj^hate. 

Direct  Tilration  Method.^ — This  method  is  apphcable  to  sauternes 
and  other  white  wines  and  to  beer,  but  should  not  be  used  for  other 
materials,  unless  found  by  experiment  to  yield  accurate  results. 

To  25  grams  of  the  sample,  finely  divided  in  water  if  solid  or  semi- 
solid, add  25  cc.  of  a  normal  solution  of  potassium  hydroxide  in  a  200-cc. 
flask.  Shake  thoroughly,  and  set  aside  for  at  least  fifteen  minutes 
with  occasional  shaking.  10  cc.  of  sulphuric  acid  (1:3)  are  then  added 
with  a  httle  starch  solution,  and  the  mixture  is  titrated  with  N/50 
iodine  solution,  introducing  the  iodine  solution  quite  rapidly,  and  adding 
it  till  a  distinct  fixed  blue  color  is  produced,  i  cc.  of  the  iodine  solution 
is  the  equivalent  of  0.00064  gram  SO2. 

FORMIC  ACIDo 

Formic  acid  (HCOOH)  is  a  colorless  liquid  at  temperatures  above 
8.3°  C.  It  boils  at  101°  C.,has  a  pungent  odor  and  strong  caustic  action 
when  applied  to  the  skin,  causing  great  pain  and  ulceration.  It  occurs 
naturally  in  the  bodies  of  certain  ants  (hence  the  name)  and  in  small 
quantities  in  various  vegetable  and  animal  substances. 

On  a  commercial  scale  formic  acid  is  usually  prepared  Ijy  lieating 
glycerol  with  oxalic  acid,  the  glycerol  ester  first  formed  being  saponified 
by  a  fresh  portion  of  the  oxalic  acid  and  the  formic  acid  separated  by 
distillation. 

Formerly  this  acid  was  considered  to  be  less  active  as  a  preservative 
than  acetic  acid,  but  more  recently  it  has  been  shown  to  be  very  powerful, 
a  water  solution  containing  less  than  0.1%  entirely  preventing  the  growth 
of  yeasts  and  certain  bacteria.  Recently  a  60%  solution  has  come  into 
use  as  a  preservative  for  fruit  products. 

Detection  of  Formic  Acid. — Bacon  Method.'^ — Strongly  acidify  the 
solution  (^which  must  not  contain  formaldehyde)  with  phosphoric  acid 
and  distil  about  one-third  of  it.  To  the  distillate  add  dilute  sulphuric 
acid  and  magnesium  filings  in  sufficient  c^uantities  to  cause  a  vigorous  but 
not  a  violent  evolution  of  hydrogen.     In  case  quite  a  large  quantity  of 

*  U.  S.  Dept.  of  .\gric.,  Bur.  of  Chem.,  Bui.  65,  p.  90. 
t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  74. 


S42  FOOD   INSPECTION  AND  ANALYSIS. 

acid  is  present  in  the  distillate  it  is  not  necessary  to  add  any  sulphuric 
acid.  If  the  amount  of  formic  acid  is  small  (about  o.i^c)  continue  the 
action  for  one  liour;  if  larger  quantities  are  present  the  reaction  will  be 
complete  in  a  few  minutes.  Test  the  solution  for  formaldehyde  by  the 
methods  given  on  page  826.. 

Shannon  Method  * — Distil  in  a  current  of  steam  about  1000  cc.  of  the 
solution,  collecting  2500  cc.  of  distillate  in  a  receiver  containing  5  cc.  of 
lead  cream.  (The  latter  is  prepared  by  adding  sodium  hydroxide  to  a 
solution  of  lead  nitrate  until  a  faint  pink  color  appears  with  phenolph- 
thalein  and  washing  the  precipitate  8  to  10  times  by  decantation.) 
Shake  and  as  the  lead  dissolves  add  a  few  cc.  more  of  the  cream  until 
all  the  formic  acid  is  combined.  Evaporate  to  about  50  cc,  filter  and 
allow  to  crystalli/-e  in  a  desiccator.  Wash  the  needle-like  crystals  of 
lead  formate  with  absolute  alcohol  and  dry  on  filter-paper. 

An  acjueous  solution  of  the  crystals  should  reduce  silver  nitrate,  mer- 
curic or  platinum  chloride  solution  on  warming  and  should  yield  with 
sulphuric  acid  on  warming  in  a  test  tube,  carbon  monoxide,  which  bums 
in  the  tube.  Distilled  with  concentrated  phosphoric  acid,  the  crystals 
yield  formic  acid,  identified  by  the  acid  reaction,  the  reducing  action  on 
the  metallic  salts  as  given  above,  and  the  formation  of  formaldehyde  when 
treated  according  to  the  Bacon  test. 

Determination  of  Formic  Acid. — Fincke  Method. f — Dilute  215  to 
^o  grams  ut  the  material  to  100  cc,  add  i  gram  of  tartaric  acid  and  distil 
in  a  current  of  steam  until  the  distillate  amounts  to  1000-1500  cc  Render 
slightly  alkaline  with  sodium  hydroxide  and  evaporate  to  300  cc. 

To  the  neutral  or  slightly  acid  solution  add  3-5  grams  of  sodium 
acetate  and  sufficient  mercuric  chloride  solution  (100  grams  of  mercuric 
chloride  and  30  grams  of  sodium  chloride  per  literj  so  that  the  amount  of 
mercuric  chloride  added  is  at  least  15  times  the  amount  of  formic  acid 
present  Heat  on  a  steam  bath  under  a  reflux  condenser  for  two  hours. 
Collect  the  mercurous  chloride  on  a  Gooch  crucible,  wash  with  water  and 
finally  with  alcohol  and  ether,  dry  at  100°  C.  for  one  hour  and  weigh. 
Calculate  the  formic  acid,  using  the  factor  0.0977. 

If  sulphurous  acid  is  contained  in  the  material,  oxidize  in  an  alkaline 
solution  with  hydrogen  peroxide  and  remove  the  excess  of  peroxide  with 
freshly  precipitated  mercuric  oxide.  In  case  salicylic  acid  is  present  add 
I  gram  of  sodium  chloride  for  each  50  cc.  of  the  distillate. 

*  Jour.  Ind.  Eng.  Chem.,  4,  1912,  p.  526. 

t  Zeits.  Unters.  Nahr.  Genussm.,  21,  191 1,  p.  i. 


FOOD  PRESERVATiyES.  843 

To  separate  from  formaldehyde  or  other  aldehydes  pass  the  vapor 
from  the  distilling  flask  througli  a  boiling  suspension  of  i  gram  of  calcium 
carbonate  in  100  cc.  of  water  before  condensing.  Separate  the  suspended 
calcium  carbonate  by  filtering  and  treat  the  filtrate  as  described. 

Bacon  Method.'^ — Distil  the  solution  containing  the  formic  acid  with 
a  small  cjuantity  of  phosphoric  acid  until  the  distillate  is  no  longer  acid. 
If  the  volume  of  the  distillate  is  too  large  to  be  con\enicnlly  handled, 
neutralize  it  with  sodium  hydroxide  and  evaporate  to  a  convenient  volume. 
Add  an  excess  of  platinic  chloride  and  sufl^ient  acetic  acid  to  make  the 
solution  strongly  acid  (usually  about  i  or  2  cc.  of  glacial  acetic  acid 
for  less  than  i  gram  of  formic  acid),  and  boil  the  solution  for  one  hour, 
using  a  reflux  condenser.  Collect  the  reduced  platinum  in  the  usual 
manner  and  weigh.  The  weight  of  the  platinum  multiplied  by  0.472 
equals  the  formic  acid  present. 

FLUORIDES,   FLUOSILICATES,    AND   FLUOBORATES. 

These  substances  all  possess  strong  antiseptic  equalities,  and  while 
no  instances  are  recorded  of  the  use  of  the  last  two  classes  of  compounds 
in  this  country,  the  use  of  fluorides  as  a  preservative  of  beer  is  practiced 
to  some  extent.  The  salt  most  commonly  used  is  ammonium  fluoride 
(NH4F),  preparations  of  this  salt  being  sold  commercially  under  various 
trade  names  as  beer  preservatives.  Ammonium  fluoride  exists  as  small,, 
deliquescent,  hexagonal,  flat  crystals.  Its  taste  is  strongly  saline.  It 
is  soluble  in  water,  and  slightly  soluble  in  alcohol.  Sodium  fluoride 
(NaF)  occurs  as  clear,  lustrous  crystals,  soluble  in  water. 

Detection  of  Fluorides. — Modification  of  Blarez'  Method. i — Thor- 
oughly mix  the  sample  and  heat  150  cc.  to  boiling.  Add  to  the  boihng 
liquid  5  cc.  of  a  10%  solution  of  barium  acetate.  Collect  the  precipitate 
in  a  compact  mass,  using  to  advantage  a  centrifuge,  wash  upon  a  small 
filter,  and  dry  in  the  oven.  Transfer  to  a  platinum  crucible,  first  break- 
ing up  the  dry  precipitate  and  then  addmg  the  filter  ash  to  the  crucible. 
Prepare  a  glass  plate  (preferably  of  the  thin  variety  commonly  used  for 
lantern-slide  covers)  as  follows:  First  thoroughly  clean  and  polish,  and 
coat  on  one  side  by  carefully  dipping  while  hot  in  a  mixture  of  equal 
parts  of  Canauba  wax  and  paraflin.  Near  the  middle  of  the  plate  make 
a  small  cross  or  other  distinctive  mark  through  the  wax  with  a  sharp 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  74. 

t  Mass.  State  Board  of  Health  An.  Rep.,  1905.  p.  498.     Chem.  News,  91,  1905,  p.  39. 


S44  FOOD    INSPECTION   .4ND   ANALYSIS. 

insiruniont,  such  as  a  pointed  {)icce  of  wood  or  ivory,  which  will  remove 
the  wax  and  expose  the  glass  without  scratching  the  latter.  Add  a  few 
drops  of  concentrated  sulphuric  acid  to  the  residue  in  the  crucible,  and 
cover  with  the  waxed  plate,  having  the  mark  nearly  over  the  center,  and 
making  sure  that  the  crucible  is  firmly  imbedded  in  the  wax.  Place 
in  close  contact  with  the  top  or  unwaxed  surface  of  the  plate  a  cooling 
device,  consisting  of  a  glass  cylinder  the  bottom  of  which  is  closed  with 
a  thin  sheet  of  pure  rubber.  Keep  the  cylinder  hlled  with  ice  water,  so 
that  the  wax  does  not  melt.  Heat  the  bottom  of  the  crucible  gently 
over  a  low  llame  or  on  an  electric  stoN'e  for  an  hour.  Remove  the  glass 
plate  and  indicate  the  location  of  the  distinguishing  mark  on  the  unwaxed 
surface  of  the  ])late  by  means  of  gummed  strips  cf  uapcr,  melt  off  the 
wax  by  heat  or  a  jet  of  steam,  and  thoroughly  clean  the  glass  with  a 
soft  cloth.  A  distinct  etching  will  be  apparent  on  the  glass  where  it 
was  exjwsed,  if  lluoride  be  j)rcsent. 

Detection  of  Fluoborates  and  Fluosilicates.* — Two  hundred  cc.  of 
the  wine  or  other  sample  are  made  alkaline  with  lime  water,  evaporated 
to  dr}ness,  and  ignited.  The  crude  ash  is  first  extracted  with  water 
acidified  with  acetic  acid,  and  the  solution  filtered.  The  insoluble  residue 
is  again  ignited  and  extracted  with  dilute  acetic  acid,  which  is  filtered  off 
and  added  to  the  first  extract.  The  filtrate  contains  the  boric  acid,  if 
present,  and  this  is  tested  for  as  directed  on  page  829.  Calcium  silicate 
or  fluoride,  if  present,  is  in  the  insoluble  portion. 

Incinerate  the  filter  with  the  insoluble  portion,  transfer  the  ash  to  a 
test-tube,  mix  with  some  silica,  and  add  a  little  concentrated  sulphuric 
acid.  A  small  U-tube  should  be  attached  to  the  test-tube,  containing 
a  ver\'  little  water.  The  test-tube  is  immersed  for  half  an  hour  in  a 
beaker  of  w^atcr  kept  hot  on  a  steam-bath.  In  the  presence  of  fluoride, 
silicon  fluorifle  will  be  generated,  and  will  be  decomposed  ])y  the  water, 
forming  a  gelatinous  deposit  on  the  walls  of  the  tube. 

If  both  boric  anrl  hydrofluoric  acids  are  found,  the  compound  present 
is  undoubtedly  a  borofluoridc.  If  no  boric  acid  is  found,  but  silicon 
fluoride  is  detected,  repeat  the  operation,  but  without  the  added  silica. 
If  the  silicon  skeleton  is  then  formed,  fluosilicate  is  probably  present. 

♦  U.  S.  Dcpt.  of  Agri( .,  Bur.  of  Chcm.,  Bui.  59,  p.  63. 


FOOD  PRESERl^ATiyES.  845 

BETA-NAPHTHOL. 

Beta-naphthol  (CjoHjOH)  is  a  phenol,  occurring  naturally  in  coal- 
tar,  but  the  commercial  product  is  more  commonly  prepared  artificially 
from  naphthalene  by  digesting  the  latter  with  sulphuric  acid,  and  fusing 
the  product  with  alkali.  It  is  a  colorless,  or  pale  buff-colored  powder, 
with  a  faint  phenolic  odor  and  a  sharp  taste.  It  is  slightly  soluble  in  water, 
and  readily  soluble  in  alcohol,  ether,  and  chloroform.  Its  melting-point 
is  122°  C.     In  alcoholic  solution  it  is  neutral  to  litmus. 

It  is  used  to  some  extent  in  alcoholic  solution  as  a  preservative  of 
cider. 

Detection  of  Beta-Naphthol. — Bube  *  states  that  if  an  ethereal  extract 
of  beta-naphthol  is  evaporated  to  dryness,  and  the  residue  dissolved  in 
hot  water  made  first  faintly  alkaline  with  ammonia,  and  then  faintly  acid 
with  very  dilute  nitric  acid,  a  beautiful  rose  color  will  be  developed  on 
the  addition  of  a  drop  of  fuming  nitric  acid  or  of  a  nitrite.  He  declares 
the  test  to  be  a  delicate  one,  but  it  is  apparently  sometimes  obscured  by 
interfering  substances,  which  the  ether  may  dissolve.  It  should  also  be 
carried  out  in  a  faint  light,  as  strong  sunlight  affects  the  color. 

Ferric  chloride,  when  applied  to  an  aqueous  solution  of  beta-naph- 
thol, produces  a  greenish  coloration. 

Shake  about  50  grams  of  the  sample  to  be  tested  with  chloroform  in 
a  separatory  funnel,  evaporate  the  chloroform  extract  to  a  small  volume 
(say  I  or  2  cc),  transfer  to  a  test-tube,  add  5  cc.  of  an  aqueous  solution 
of  potassium  hydroxide  (1:4),  and  warm  gently.  If  beta-naphthol  is 
present,  a  deep-blue  color  will  appear  in  the  aqueous  layer,  turning  through 
green  to  light  brown. 

ASAPROL,  OR   ABRASTOL. 

These  are  trade  names  for  calcium  a-mono-suiphonate  of  beta- 
naphthol,  Ca(C,oHeS030H)2,  a  white,  odorless,  scaly  powder,  sometimes 
slightly  reddish,  obtained  by  the  action  of  heated  sulphuric  acid  on  beta- 
naphthol,  the  resulting  compound  being  afterwards  treated  with  a  calcium 
salt.  It  is  readily  soluble  in  water  and  alcohol,  and  is  neutral  in  reaction. 
Its  taste  is  at  first  slightly  bitter,  but  rapidly  changes  to  sweet.  It  decom- 
poses at  about  50°  C. 

*  Analyst,  13  (1888),  p.  52. 


S46  FOOD   INSPECTION  AND   ANALYSIS. 

The  writer  is  unaware  of  any  instance  of  the  presence  of  this  substance; 
in  foods,  but  its  character  is  such  as  to  adapt  it  for  use  as  a  preservative 
of  wines  and  possibly  other  food  products.  It  has  long  been  regarded 
as  a  possible  preser\'ative,  and  the  analyst  should  be  prepared  to 
encounter  it  at  any  lime. 

Detection  of  Asaprol. — SinabalJi's  Method.'^ — The  portion  of  the 
solution  to  lie  tested  (say  50  cc.)  is  made  slightly  alkaline  with  ammonia, 
and  shaken  with  10  cc.  of  amyl  alcohol  in  a  separator)^  funnel.  Alcohol 
is  often  useful  in  breaking  up  an  emulsion  if  there  is  one.  Separate  the 
amyl  alcohol  extract,  which  if  turbid  is  filtered,  and  evaporate  to  dry- 
ness. Wet  the  residue  with  about  2  cc.  of  nitric  acid  (i :  i),  heat  on  the 
water-bath  till  the  volume  is  about  i  cc,  and  wash  with  a  few  drops  of 
water  into  a  narrow  test-tube.  Next  add  about  0.2  gram  of  ferrous  sul- 
phate and  ammonia  in  excess,  a  drop  at  a  time,  constantly  shaking  the 
solution.  If  a  reddish-colored  precipitate  is  formed,  it  is  dissolved  by 
the  addition  of  a  little  sulphuric  acid,  and  further  additions  of  ferrous 
sulphate  and  ammonia  are  made  as  before.  When  a  dark-colored  or 
green  precipitate  appears,  add  5  cc.  of  alcohol,  dissolve  in  sulphuric 
acid,  shake,  and  filter.  If  abrastrol  be  present  to  the  extent  of  0.0 1  gram 
or  more,  a  red  coloration  is  observed,  while  in  its  absence,  the  filtrate 
is  colorless  or  faintly  yellow. 

If  the  solution  to  be  tested  is  a  fat,  it  should  be  melted  and  extracted 
with  hot  20%  alcohol,  which  is  evaporated  to  dryness,  and  the  above  test 
carried  out  on  the  dr}'  residue. 

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septica.     Hyg.  Runds.,  1901,  265-281. 
Anxett,  H.  E.     Horic  Acid  and  Formaline  as  Milk  Preservatives.     Thompson  Yates 

Lab.  Reports,  Liverpool,  Vol.  II,  1900,  pp.  5767. 
Baldwin,  H.   B.     Toxic  Action  of  Sodium   Fluoride.     Jour.  \m.   Chem.   Soc,   21, 

1899,  p.  517. 
BEXEDiCE>m.     .\ction  of  Formaldehyde  on  Various  Proteid  Substances.     Archw.  f. 

.\nat.  u.  Physiolog.,  1897,  p.  219. 
Behre,  a.,  u.  Secin,  a.     Ueber  die  Wirkung  der  Konservierungsmittel.    Zeits.  Unters. 

Xahr.  Genuss.,  12,  1906,  p.  461. 

*  Mon.  Sj!.,  1703  ,(4),  7,  p.  842;    U.  S.  Dept.  Agric,  Bur.  of  Chem.,  Bui.  59,  p.  91. 


FOOD  PRFSEKVATiyES.  847 

BiscHOFF,    H.,  and   Wintgen,  U.     Heitriige    zur    Konsen-cnfabrikation.     Ztsch.    fur 

Hyg.,  Bd.  34,  1900,  Heft  3,  496-513- 
Bliss  and  Now.     Action  of  Formaldehyde  on  Enzymes.     Jour.  Exp.  Med.,  4,  47. 
Chittemden,  R.  H.     Influence  of  iiorax  and  Boracic  Acid  on  Digestion.     Diet,  and 

Hyg.  Gazette,  9,  1893,  25. 
Chittenden  and  Gies.     Effects  of  Borax  and  Boric  Acid  on  Nutrition.     New  York 

Med.  Jour.,  Feb.,  1898. 

Experiments  with  Borax  and  Boric  Acid  on  the  Lower  Animals.     Am.  Jour,  of 

Phys.,  Vol.  I,  No.  I,  1898. 
DiGHT,  C.  F.     Effect  of  Boric  Acid  and  Borax  on  the  Human  Body.     Minneapolis, 

1902. 
FouN  and  Flanders.     Determination  of  Benzoic  Acid.     J.  Am.  Chem.  Soc,  2>2>j 

1911,  p.  161. 
GoOTN,  R.     Le  Beurre  et  I'Acide  Borique.     Jour.  d'Agricult  prat.,  1900,  p.  14-16. 
Grltber.     Ueber  die  Zulassigkeit  der  Verwendung  der  Fluoride  zur  Konservnerung 

von  Lebensmittel.     Das  Oesterr.  Sanitatsw.,  1900,  4. 

Ueber  die  Zulassigkeit  der  Verwendung  von  Chemikalien  zur  Konserv'ierung  von 

Lebensmittel.     Das   Oesterr.    Sanitatsw.,    1900. 

GrxJnbaum,  a.  S.     Note  on  the  Value  of  Experiments  in  the  Question  of  Food  Pre- 
servatives.    Brit.  Med.  Jour.,  1901,  p.  1337. 

Halliburton,  W.  D.     Remarks   on  the  Use  of  Borax  and  Formaldehyde  as  Preserva 
tives  of  Food.     Brit.  Med.  Jour.,  1900,  pp.  1-2. 

Heffter,  a.     Ueber  den  Einfluss  der  Borsaure   auf  die  Ausnutzung  der  Nahrung. 
Arbeiten  aus  dem  kaiserlichen  Gesundheitsamte,  Bd.  19,  Part  i,  1902,  p.  97. 

Hill,  A.     Antiseptics  in  Food.     Pub.  Health  Jour.,  London,  11  (1901),  527. 

Hope,  E.  W.     Preservatives  and  Coloring  Matters  in  Foods.     Thompson  Vates  Lab. 
Reports,  Vol.  Ill  (1900),  pp.  75-78. 

T.ACOBj,  C,  u.  Walbaum,  H.     Zur  Bestimmung  der  Grenze  der  Gesundheitsschadlich- 
keit  der  Schwefligen   Saure  in  Nahrungsmitteln.     Arch.   Exp.   Path.    Pharm., 

54,  1906,  p.  421. 
Kickton,    a.     Ueber    die    Wirkung    einiger    sogenannter  Konservierungsmittel    auf 

Hackfleisch.     Zeits.  Unters.  Nahr.  Genuss.,  13,  1907,  p.  534. 
Kister,  J.     Ueber  Gesundheitschadlichkeit  der  Borsauer  als  Konservierungsmittel  fur 

Nahrungsmittel.     Zeit.  f.  Hygiene,  Bd.  37,  1901,  Heft  2,  p.  225. 
Lauge,  L.     Beitrage  zur  Frage  der  Fleischkonservierungmittel.     Borsaure,  Borax  und 

SchwefeUgsauren    Natronzusatzen.     Mit     einem    .Unhang.    Milchkonservierung 

betr.     Arch.  f.  Hygiene,  Bd.  40,  1901,  2,  pp.  143-186. 
Lebbin,  G.     Die  Konsen'ierung  und  Farbung  von  Fleischwaaren.     Hyg.  Rund.,  11, 

No.  23. 
Lebbin  u.  Kalljiann.     Ueber  die  Zulassigkeit  Schwefeligsauer  Salze  in  Nahrungsmit- 
teln.    Zeits.  fiir  offentl.  Chem.,  7,  17,  324-334. 
Lebbin,    G.     Preservation   and    Coloring  of  Meat   Produce.     Translated   from   the 

German. 

Should  the  Use  of  Boric  Acid  as  a  Food  Preservative  be  Permitted  ?     Translated 

from  the  German  of  Die  medicinische  Woche,  Sept.,  1901. 
Leffmann,  H.     Food  Preservatives.     Penn.  Board  of  Agric,  An.  Rep.,  1897,  535. 


848  FOOD  INSPECTION  AND  ANALYSIS. 

Leffmann,  H.  Intlucnce  of  Preservatives  on  Digestive  Enzymes.  Diet,  and 
Hyg.  Gazette,  14,  71S. 

Hygienic  Relations  of  Boric  .\cid  and  Borax.    Diet,  and  Hyg.  Gazette,  14,  171. 

Digestive  Ferments  and  Preservatives.     Jour.  Frankl.  Inst.,  147  (1899),  97. 

Lf,pierre.  Action  of  Formaldehyde  on  Proteids.  Bui.  Soc.  Chem.,  21  (1899), p.  729. 
LiEBREiCH,  O.  Effects  of  Borax  and  Boric  Acidon  theHuman  System.  London,  1902. 
The  So-called  Danger  from  the  Use  of  Boric  Acid  in  Preserved  Foods.  Lancet, 

1900.  pp.  13-15. 

Die  \'er\vendung  von  Formalin  zur  Konservierung  von  Nahrungsmitteln.     Therap. 

Monatsh.,  18,  1904,  p.  59. 

Zur  Frage  der  Bor-Wirkungtn.     Berlin,  1906. 

LoEW.     .\ction  of  Formaldehyde   on  Pepsin  and  Diastase.     Jour.  f.  prakt.  Chcm.,  37, 

1S8S,  p.   lOI. 
Low,    W.    H.     Boric   .\cid:     its   Defection   and   Dctermiiuuion    in   Small   and    J^arge 

Amounts.     Jour.  Am.  Chem.  Soc,  28,  1906,  p.  807. 
Nei'^i.a.nn,  R.  O.     Ueber  den  Einfluss  des  Borax  auf  dem  Stoffwechsel  des  Menschen. 

Arbeiten  aus  dem  kaiscrlichen  Gesundheit-samtc,  Bd.  19,  Pt.  i,  1902,  p.  89. 
FoLENSKE.     Ueber  den  Borsauregehalt  von  frischen  und  geriiucherten  Schweineschin- 

ken.     Loc.  cit.,  167. 
Price,   J.    M.     Die   Einwirkung   einiger   Konservierungsmittel   auf  die   Wirksamkeit 

der  Verdauungsenzvme.     Ccnlralb.  Bakt.  H  Abt.,  14,  1905,  p.  65. 
Ride.^l,  S.     Formalin  as  a  Milk  P re.se rvative.     .Analyst,  20,  p.  157. 

Disinfection  and  the  Preservation  of  Food.     London  and  New  York,  1903. 

On  the  Use  of  Boric  Acid  and  Formic  .Aldehyde  as  Milk  Preservatives.     Public 

Health  Jour.,  London,   11,   1901,  p.  554. 
RoHARPT,  \V.     Ueber  Konservierung  von  frischem  Fleisch  und  iiber  Fleischkonserven 

von  Hygienischen-  und  Sanitats-polizeilichem  Standpunkt  aus.     Vierteljahres- 

schrift  f.  gerichtl.  Med.,  1901,  Heft  2,  p.  321. 
RosT,  V\.     Ueber  die  Wirkungen  der  Bonsaure  und  des  Borax  auf  den  thierischen  und 

men.schlichen  Korper,  mit  besonderer  Beriicksichtigung  ihrer  Verwendung  zum 

Konservicren  von  Xahrung.smitteln.     .\rbeiten  aus  dem   kai.serlichen   Gesund- 

hcitsamte,  Bd.  19,  Part  i,  1902,  p.  i. 
Zur  Kenntnis  der  Ausscheidung  der  Borsaure.     Arch,   internal,   f^harm.  Thi'r., 

15,  1905,  P-  291- 
RosT,  E.,  u    Franz,  F.     F'harmakologische  Wirkungen  der  Schwefligen  Saure.     Arb. 

Kaiserl-Gesundsheitsamt,  21,  1904,  p.  312. 
kiHNKK.     Ueber  die   Wirkung  der   Borsaure  auf   den    Stoffwechsel   des  Menschen. 

I>5C.  cit.,  Bd.  19,  Part  I,  1902,  p.  70. 
SoNNTAG,  G.     Ueber  die  Quantitative  Untersuchung  des  .\blaufs  der  Borsaureaus- 

schcidung  aus  dem  menschlichen  Korper.     Loc.  cit.,  no. 
Stroscher,  a.     Konservierung  u.   Keimzahlen  des  Hackflei.shes.     Arch.  f.  Hyg.,  40, 

1901,  pp.  291-319. 

TUNINCLIFFE,  F.  W.,  and  Rosenhklvi,  C).  f)n  the  Influence  of  lormaldehyde  u|xjn 
the  Metafx)li.sm  of  Children.     Jour,  of  Hygiene  (London),  Vol.  I,  3,  1901. 

On  the  Influence  of   lioric  .Acid  and   liorax  u\xm   the  General  Metabolism  of 

Children.     Loc.  cit.,  supra,  1901,  Vol.  I,  \o.  2,  pp.  168-202. 


FOOD  PRFSERy/tTiyES.  849 

Vaughan,  v.  C,  and  Veenboer,  W.    H.       The  Use  of  Boric  Acid  and  Borax  as 

Food  Preservatives.     Am.  Medicine,  March,  1Q02. 
Vaillard,  L.      Les  Conserves   aliment  aires  de   Viande.      Rev.  d'Hyg.,  iqoo,  pp. 

789-792. 
Walbaum,  H.     Die  Gesundheitsschiidiichkeit  der  Schwelligen   Siiure  und  ihrcr  Ver- 

bindungcn    unter  besondcrer    Bcriicksichtigung   dcr   freien    Schwefligen  Saure. 

Arch.  Hyg.,  57,  iqo6.  p.  87. 
Weitzel,  A.     Ueber  die  Labgerinnung  der  Kuhmilch  unter  dem  Einfluss  von  Borpra- 

paraten    und    anderen    chcmischen    Stoffen.     .\rbeiten    aus    dem    kaiscrlichen 

Gesundheitsamte,  Bd.  19,  Part  i,  1902,  p.  126. 
Wiley,  H.  W.     Influence  of  Food  Preservatives  and  Artificial  Colors  on  Digestion 

and  Health.     U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  84.     Part  I,  Boric 

Acid  and  Borax;    Part  II,  Salicylic  .Acid  and  Salicylates;    Part  III,  Sul[)hurous 

Acid  and  Sulphites;    Part  IV,  Benzoic  Acid  and  Benzoates;    Part  V,  I-'ormal- 

dehyde. 
Report  of  the  Departmental  Committee  appointed  to  Inquire  into  the  Use  of 

Preservatives  and  Coloring  Matters  in  the  Preserving  and  Coloring  of  Food. 

497  pp.     London. 
Report  of  Referee   Board  of  Consulting  Experts  appointed  by  the  Secretary 

of  Agriculture,  on    the   Influence  of   Sodium    Benzoate  on   the   Nutrition   and 

Health   of  :Man.     Chittenden,  R.   H.,  Long,  J.  H.,  and  Hertsr,  C.  A.     U.  S. 

Dept.  of  Agric,  Report  No.  88,  Washington,  1909. 
U.  S.  Food  Inspection  Decisions:    No.  76,  Dyes,  Chemicals,  and  Preservatives  in 

Foods.     No.  89,  Amendment  to  No.  76.     No.  101,  Benzoate  of  Soda.     No.  104, 

Amendment  to  Nos.  76  and  89. 


CHAPTER  XIX. 
ARTIFICIAL  SWEETENERS. 

Under  this  head  are  included  the  intensely  sweet  coal-tar  derivatives, 
such  as  saccharin,  dulcin,  and  glucin,  that  possess  no  food  value  whatever 
in  themselves.  From  their  high  sweetening  power,  in  some  cases  several 
hundred  times  that  of  cane  sugar,  they  are  capable,  when  used  in  minute 
quantity,  of  imparting  an  appropriate  degree  of  sweetness  to  food  products, 
which,  on  account  of  the  use  of  inferior  materials,  or  by  reason  of  the 
presence  of  inert  or  less  sweet  adulterants,  would  otherwise  be  lacking 
in  this  property. 

Such  canned  vegetables  as  sweet  corn  and  peas  are  subject  to  treat- 
ment with  saccharin,  especially  if  by  their  age  and  condition  before  can- 
ning they  are  wanting  in  the  sweet,  succulent  taste  inherent  in  the  fresh 
product. 

The  sweetening  power  of  commercial  glucose  is  considerably  less 
than  that  of  cane  sugar,  so  that  when  large  admixtures  of  the  glucose  are 
used  in  such  products  as  jcUics,  jams,  honey,  molasses,  maple  syrup, 
etc.,  to  the  exclusion  of  cane  sugar,  the  presence  of  the  glucose  might  in 
some  cases  be  suggested  by  the  bland  taste  of  the  food,  unless  reinforced 
by  one  of  the  artificial  sweeteners. 

The  analyst  should  therefore  be  on  the  outlook  for  one  or  another 
fif  these  concentrated  sweetening  agents  in  all  of  the  above  classes  of 
ffxjds,  especially  in  saccharine  products  wherein  glucose  is  found  to  pre- 
dominate largely  over  the  cane  sugar,  while  the  taste  is  not  lacking  in 
sweetness.  The  use  of  saccharin  in  foods  other  than  those  specially  de- 
signed for  invahds  is  not  allowed  under  the  federal  law. 

SACCHARIN. 

Saccharin  or  Cluside,  Benzoyl  sulphimidc  (C6H4.CO.SO2NH),  is  a 
white  powder,  composed  of  irregular  crystals,  whose  melting-point,  when 

850 


yiRTlFlClAL   SIVEETENERS.  851 

pure,  is  about  224°  C.  It  is  prepared  from  toluene,  which  by  treatment 
with  concentrated  sulphuric  acid  is  first  converted  into  a  mixture  of 
ortho-  and  para-toluene  sulphonic  acids.  These  are  further  converted  into 
corresponding  chlorides,  and  from  the  orthochloride,  by  treatment  with 
-ammonia,  the  imide  is  formed.  It  is  soluble  in  230  parts  of  cold  water, 
30  parts  of  alcohol,  and  3  parts  of  ether.  It  is  sparingly  soluble  in  chloro- 
form, but  readily  soluble  in  dilute  ammonia.  It  is  from  300  to  500  times  as 
sweet  as  cane  sugar,  and,  unlike  cane  sugar,  it  is  not,  when  pure,  charred 
by  the  action  of  concentrated  sulphuric  acid  even  on  heating.  Its  aque- 
ous solution  is  distinctly  acid  in  reaction.  Pure  saccharin,  when  heated 
under  diminished  pressure,  can  be  sublimed  without  decomposition. 

The  addition  of  i  part  of  saccharin  to  1,000  parts  of  commercial 
.glucose  renders  the  latter  as  sweet  as  cane  sugar. 

A  sodium  salt  of  saccharin  is  found  on  the  market,  prepared  by  neutral- 
izing a  solution  of  saccharin  with  sodium  hydroxide  or  carbonate.  The 
sodium  salt  cr}^stallizes  in  the  form  of  rhombic  plates,  forming  a  white 
powder  readily  soluble  in  water,  and  possessing  nearly  the  same  sweeten- 
ing power  as  saccharin.  It  is  sometimes  put  up  in  the  form  of  tablets 
for  the  use  of  diabetic  patients  as  a  substitute  for  sugar. 

Saccharin,  aside  from  its  sweet  taste  possesses,  according  to  Fahlberg 
and  List,*  antiseptic  properties,  and  on  this  account  it  is  sometimes  used 
in  beer  and  other  liquors.  Squibb  states  that  saccharin  has  about  the 
same  power  as  boric  acid  as  an  antifcrment 

Detection  of  Saccharin  in  Foods. — If  the  sample  to  be  tested  is  a  solu- 
tion or  syrup,  render  it  acid,  if  not  already  such,  with  phosphoric  acid, 
and  extract  with  ether.  In  case  of  canned  vegetables  and  similar  goods, 
finely  divide  the  material  by  pulping  or  maceration  in  a  mortar,  dilute 
with  water,  and  strain  through  muslin.  Acidify  the  filtrate,  and  extract 
with  ether.f  If  an  emulsion  forms,  use  a  centrifugal  machine  (p.  25), 
Separate  the  extract,  evaporate  off  the  ether,  and  test  the  residue  for 
saccharin  as  follows : 

(i)  Add  to  the  residue,  if  it  tastes  sweet,  a  few  cubic  centimeters  of 
hot  water^  or  preferably  a  very  dilute  solution  of  sodium  carbonate,  in 
which  saccharin  is  more  soluble.  An  intensely  sweet  taste  is  indicative 
of  its  presence.  This  test,  if  applied  directly,  will  sometimes  fail,  espe- 
cially in  the  case  of  beer,  by  reason  of  the  extraction  by  the  ether  of  various 

*  Jour.  Soc.  Chem.  Ind.,  IV,  p.  608. 

t  Allen  states  that  a  purer  residue  is  obtained  if  the  sample  of  beer  be  treated  with  lea<i 
acetate,  and  filtered  before  extraction  with  ether. 


852  FOOD  INSPECTION  AND   ANALYSIS. 

bitter  principles,  such  as  hop  rosins,  which  by  their  strong,  bitter  taste 
mask  the  sweet  taste  of  saccharin  in  the  residue.  Spaeth  *  recommends 
that  such  bitter  substances  be  removed  before  extraction,  which  is  done 
bv  treatment  of  500  cc.  of  the  beer  with  a  few  crystals  of  copper  nitrate, 
or  \\\\.\\  a  solution  of  copper  sulphate.  The  flocculent  precipitate  formed 
need  not  be  filtered  off,  but  the  liquid  is  preferably  concentrated  by  evap- 
oration to  syrupy  consistency,  acidified  with  phosphoric  acid,  and  ex- 
tracted whh  three  successive  portions  of  a  mixture  of  ether  and  petro- 
leum ether.  After  extraction,  separation,  and  evaporation  of  the  solvent, 
dissolve  the  rcsidiU'  in  weak  sodium  carbonate.  As  small  a  quantity 
as  o.ooi^,^-  of  saccharin  can  be  detected  in  the  final  alkaline  solution  by 
its  sweet  taste. 

(2)  Bornstein's  Tcsl.\ — Heat  the  residue  from  the  ether  extraction 
of  the  acidified  sample  with  resorcin  and  a  few  drops  of  sulphuric  acid 
in  a  test-tube  till  it  begins  to  swell  up.  Remove  from  the  flame,  and, 
after  cooling  till  the  action  quiets  down,  again  heat,  repeating  the  heating 
and  cooling  several  times.  Finally  cool,  dilute  with  water,  and  neutralize 
with  sodium  hydroxide.  A  red-green  fluorescence  indicates  saccharin. 
Gantter  %  states  that  it  is  useless  to  apply  this  test  to  beer,  in  view  of  the 
fact  that  ordinary'  hop  resin  gives  the  same  fluorescence. 

(3)  Schmidt'' s  Tesl.^ — The  residue  is  heated  in  a  porcelain  dish  with 
;ibout  a  gram  of  sodium  hydroxide  ||  for  half  an  hour  at  a  temperature 
Df  250°  C,  either  in  an  air-oven  or  in  a  linseed  oil  bath.  This  converts 
ihe  saccharin  if  jjresent  into  sodium  salicylate.  Dissolve  the  fused  mass 
in  water,  acidify,  and  extract  the  solution  with  ether.  Test  the  ether 
residue  in  the  regular  manner  for  salicylic  acid  with  ferric  chloride 
(p.  831).  This  test  can  obviously  be  applied  only  in  the  absence  of 
salicylic  acid,  which  should  first  be  directly  tested  for. 

It  is  recommended  that  a  mixture  of  equal  parts  of  ether  and  petroleum- 
ether  is  j^referable  to  the  use  of  ether  alone  as  a  solvent  of  saccharin,  as 
such  a  mixture,  while  readily  dissolving  saccharin,  does  not,  like  ether, 
dissolve  other  substances,  which  might  form  salicylic  acid  when  fused 
with  '-odium  hydroxide. 

Determination  of  Saccharin. — When  saccharin  is  fused  with  an  alkali 
and  potassium  nitrate,  the  sulphur  is  oxidized  to   sulphuric  acid.     On 

•  Zcits.  angcwandte  Chem.,  1893,  p.  579. 

t  Zt-its.  anal,  f^hcm.,  27,  p.  165. 

X  I  hid..  32,  309. 

%  Rep.  \na.\.  Chem.,  30;   AV;s.  Analyst,  12,  p.  200. 

y  Potassium  hydroxide  cannot  be  used  instead  of  sodium  hydroxide  for  the  fusion. 


/fRTlFJCML   SWEETENERS.  855 

this  principle  depends  the  following  method  of  Reischauer:*  A  knowni 
quantity  of  the  beer  or  other  liquid  to  be  tested  is  concentrated  by  evapo- 
ration to  about  one-third  its  original  volume,  acidified  with  phosphoric 
acid,  and  extracted  by  repeated  portions  of  ether.  The  combined  ether 
extract  is  evaporated  to  small  volume,  and  transferred  to  a  platinum 
crucible,  in  which  it  is  further  brought  to  dr}'ness.  It  is  then  cautiously 
ignited  with  a  mixture  of  about  6  parts  sodium  carbonate  and  i  part  potas- 
sium nitrate.  Dissolve  the  fusion  in  water,  acidulate  with  hydrochloric 
acid,  and  determine  the  sulphuric  acid  in  the  usual  manner  with  barium 
chloride.  The  weight  of  the  precipitated  barium  sulphate,  multiplied 
by  0.785,  gives  the  weight  of  saccharin.  In  view  of  the  fact  that  only 
small  quantities  of  saccharin  are  used  in  beer  and  other  foods,  it  is  best 
to  employ  a  large  portion  of  the  sample  for  analysis. 

DULCIN. 

Dulcin  or  sucrol,  para-phenetol  carbamide  (C2H5O.CeH4.NH. CO. NHj) 
is  a  white  powder,  composed  of  needle-like  crystals,  sparingly  rol  ible 
in  cold  water,  ether,  petroleum  ether,  and  chloroform.  It  dissolves  in 
800  parts  of  cold  water,  50  parts  of  boiling  water,  and  25  parts  of  95% 
alcohol.  It  is  readily  soluble  in  acetic  ether.  Its  melting-point  is  about 
173°  C.  It  is  not  readily  sublimed  without  decomposition.  Dulcin  is 
about  four  hundred  times  sweeter  than  cane  sugar. 

When  a  mixture  of  dulcin  and  dilute  sodium  hydroxide  is  subjected  to 
distillation,  phenetidin  goes  over  with  the  steam  into  the  distillate.  When 
this  is  heated  with  glacial  acetic  acid,  phenacetin  is  formed,  which  may 
be  tested  for  as  follows:  Boil  with  hydrochloric  acid,  dilute  with  water, 
cool,  filter  if  turbid,  and  add  a  few  drops  of  a  solution  of  chromic  acid. 
A  deep-red  color  indicates  phenacetin. 

Detection  of  Dulcin  in  Foods. — In  view  of  the  comparatively  slight 
solubility  of  dulcin  in  ether  and  chloroform,  acetic  ether  is  the  best  solvent 
for  purposes  of  removing  it  from  foods,  first  making  it  alkaline. 

(i)  Bellier's  Method.-\ — A  portion  of  the  sample  to  be  tested  is  made 
alkaline  and  extracted  with  acetic  ether.  In  the  case  of  certain  produc;? 
it  is  best  to  subject  them  to  varied  preliminary  treatment,  depending  on 
the  case  in  hand.  With  such  products  as  thin  fruit  syrups,  simply  make 
alkaline  and  shake  out  with  acetic  ether.  In  the  case  of  thick  fruit  syrups, 
confectioner)',  and  preserves,  dilute  with  water,  add  an  excess  of  basic 

*  Abst.  Analyst,  11,  p.  234. 

t  Ann.  de  Chim.  Anal.,  1900,  V,  pp.  ^SSSST,  Abs.  Analyst,  26,  p.  43. 


S54  FOOD  INSPECTION  AND  ANALYSIS. 

lead  acetate,  remove  the  lead  by  precipitation  with  sodium  sulphate, 
filter,  and  make  the  filtrate  alkaline. 

With  wines,  add  2  grams  of  mercuric  acetate  and  a  slight  excess  of 
ammonia,  shake,  and  filter. 

With  beer,  add  to  200  cc.  2  or  3  grams  of  powdered  sodium  phospho- 
tungstate,  and  a  few  drops  of  sulphuric  acid,  shake,  allow  to  stand  for  a 
few  minutes,  and  filter.     ^Make  the  filtrate  alkaline  with  ammonia. 

Having  thus  obtained  a  clarified  solution,  use  from  50  to  200  cc.  of 
neutral  acetic  ether  to  say  500  cc.  of  the  alkaline  solution,  and  shake 
in  a  separator)'  funnel.  Separate  the  extract,  filter,  and  evaporate  to 
dr}'ness.  If  the  dulcin  exceeds  0.04  gram  per  liter,  crystals  will  be  appar- 
ent in  the  residue.  If  fats  and  resins  are  present  in  the  residue,  make 
repeated  extractions  with  hot  water,  and  evaporate  to  dryness.  The 
purified  residue  is  finally  brought  to  drj'ness  in  a  porcelain  dish,  and 
treated  with  i  or  2  cc.  of  sulphuric  acid  and  a  few  drops  of  a  solution 
of  formaldehyde.  Let  it  stand  for  fifteen  minutes,  and  afterwards  dilute 
\\ith  5  cc.  of  water.     A  turbidity  or  precipitate  indicates  dulcin. 

(2)  Jorissen's  Test* — The  residue  from  the  acetic  ether  extract  of 
an  alkaline  solution  of  the  sample  is  treated  with  2  or  3  cc.  of  boiling 
water  in  a  test-tube,  and  a  few  drops  of  mercuric  nitrate  f  are  added. 
Heat  the  tube  and  its  contents  for  five  minutes  in  a  boiling  water-bath, 
withdraw,  and  disregarding  any  precipitate,  add  a  small  quantity  of  lead 
peroxide.  On  the  subsidence  of  the  precipitate,  which  quickly  occurs, 
a  fine  violet  color  appears  for  a  short  time  in  the  clear  upper  layer  in 
presence  of  o.ooi  gram  of  dulcin. 

(3)  M  or  purge's  Method.X — To  the  acetic  ether  residue,  evaporated  to 
dryness  in  a  porcelain  dish,  add  a  few  drops  of  phenol  and  concentrated 
sulphuric  acid,  and  heat  a  few  minutes  on  the  water-bath.  After  cooling, 
transfer  to  a  test-tube,  and  with  the  least  possible  mixing  pour  ammonia 
or  .sodium  hydroxide  over  the  surface.  A  blue  zone  at  the  plane  of  con- 
tact between  the  two  layers  indicates  dulcin. 

Determination  of  Dulcin. — For  a  quantitative  determination,  Bellier's 
method  i.^  carried  out  on  a  weighed  or  measured  portion  of  the  sample, 
as  follows:  In  the  case  of  alcoholic  beverages  first  exjjcl  the  alcohol  by 

*  Chem.  2icit.  Rcfi.,  1896,  p.  114. 

t  The  mercuric  nitrate  is  prepared  by  dissolving  2  grams  of  mercuric  oxide  in  dilute 
nitric  acid,  adding  s^jdium  hydroxide  solution  till  a  slight  permanent  precipitate  is  formed, 
diluting  to  15  cc,  and  decanting  the  clear  li()uid. 

X  'Lp'\\a.  anal.  Chem.,  1896,  35,  p.  104;  U.  S.  iJejit.  of  Agri* .,  Bur.  of  Chem.,  Bui.  65, 
p.  89. 


ARTIFICIAL  SIVEETENERS.  '855 

evaporation,  and  make  up  to  the  original  \oIume  with  water.  Treat 
the  various  food  preparations  with  the  appropriate  clarifying  reagents, 
as  in  Bellier's  qualitative  test  (p.  853),  and,  after  filtering  and  making 
alkaline,  extract  twice  with  50  cc.  each  of  acetic  ether.  The  residue 
is  purified  if  necessary  by  extraction  with  hot  water  as  above  descril^cd, 
and  the  final  residue  is  dissolved  in  i  to  5  cc.  of  concentrated  sulphuric 
acid.  A  few  drops  of  formaldehyde  are  added.  The  solution  is  allowed 
to  stand  for  fifteen  minutes,  and  then  diluted  to  ten  times  its  volume 
with  distilled  water.  After  twenty-four  hours,  collect  the  precipitate  on  a 
tared  filter,  wash  with  water,  dr^',  and  weigh. 

GLUCIN. 

This  comparatively  new  sweetening  agent  is  the  sodium  salt  of  a 
mixture  of  the  mono-  and  di-sulphonic  acids  of  a  substance  having  the 
composition  CigH^N^.  In  the  market  it  appears  as  a  light-brown  powder, 
readily  soluble  in  water.  It  is  insoluble  in  ether  and  chloroform.  It 
decomposes  without  melting  at  about  250°  C.  It  is  three  hundred  times 
sweeter  than  cane  sugar. 

A  color  reaction  with  glucin  is  obtained  by  dissolving  it  in  dilute 
hydrochloric  acid,  cooling  by  immersing  the  test-tube  in  water,  and  to 
the  cold  solution  adding  a  little  sodium  nitrite  solution.  Finally,  to  the 
liquid  is  added  a  few  drops  of  an  alkaline  solution  of  beta-naphthol,  and 
a  red  coloration  is  produced.  With  resorcin  or  salicylic  acid  in  alkaline 
solution,  the  color  will  be  yellow. 

REFERENCES  ON  ARTIFICIAL  SWEETENERS. 

Allen,  A.  H.     The  Detection  of  Saccharin  in  Beer.     Analyst,  13  (1888),  p.  105. 
Bellier,  J.     The  Detection  and  Estimation  of  Dulcin  in  Beverages.     Ann.  de  Chem. 

Anal.,  1900,  5,  2,33'>  ^bs.  Analyst,  26,  1901,  p.  43. 
Berlioz,  F.     Influence  of  Saccharin    upon    Digestion.     Chem.  Zeit.,  1900,    p.    416; 

Abs.  Analyst,  25,  1900,  p.  233. 
BucHKA,  K.  V.     Kunstliche  Siissstofle.     Vereinbarung.  v.  Nahr.  u.  Genuss.  f.  d.  deuts. 

Reich.,  Heft  II,  p.  134.      Berlin,  1899. 
CoHN,  G.     Ueber  kunstliche  Sussstoffe.     Apoth.  Ztg.,  1898,  13,  pp.  796  and  804. 
Defournel,  H.     Determination  of  Saccharin  in  Food  Products.     Abs.  Analyst,  26, 

1901,  p.  268. 
Dennhardt.     Versuche  zum  Nachweise  des  Dulcins.     Ber.  d.  deutsch.  pharm.  Ges., 

1898,  6,  p.  287. 
FOLIN,  O.     Effect  of  Saccharin  on  the  Health,  Nutrition,  and  General  Metabolism  of 

Man.     U.  S.  Dept.  of  Agric,  Rep.  94. 


S56  FOOD   INSPECTION  AND  ANALYSIS. 

Gantter.  F.     The  Detection  of  Saccharin  in  Beer.     Abs.  .\nalyst,  18,  1893,  P-  184, 
CiRAViLL,  E.  D.     Notes  on  Saccharin.     Pharm.  Jour.,  8,  1887  (3),  pp.  18,  337. 
Herter.  C.  a.     Influence  of  Saccharin  on  Digestion,  Metaboh'sm,  Nutrition,  and 

General  Health.     U.  S.  Dept.  of  Agric,  Rep.  94. 
HER2FELX),  A.,  and  Wolff,  F.    Ueber  die  Bestimmung  der  kiinstlichen  Siissstoffe  in 

Nahrungsmitteln.     Zeits.  f.  Unters.  d.  Nahr.  u.  Genussm.,  1898,  i,  p.  839. 
JORISSEX,  A.     Neue  Mcthode  zum  Nachwcisc  von  Dulcin  in  Getranken.      Jour,  de 

Pharm.  de  Liege;  Chem.  Ccntr.,  1896,  i,  p.  1084;  Abs.  Analyst,  21,  1896,  j).  164. 
Leys,  A.     A  New  Test  for  Saccharin.     Ann.  de.  Chim.  anal.,  1901,  6,  p.  201;  Abs. 

Analyst,  26,  1901,  p.  321. 
Reid,  E.  E.    Valuation  of  Saccharin.    Am.  Chem.  Jour.,  1899,  21,  p.  461. 
RuGER,  C.     Ueber  das  Fahlberg'sche  Saccharin.     Gesundheit,  1888,  13,  p.  241. 
ScHMiTT,  C.     Ueber  den   Nachweis   der  o.    Sulfamin-benzocsiiucr,    genannt    "Fahl- 

berg'sches  Saccharin."     Rep.  fiix  anal.  Ch.,  1887,  7,  p.  437. 
Spath,  E.    Ueber  den  Nachweis  des  Saccharins  im  Bier.    Zeits.  f.  angew.  Chemie, 

1S93.  P-  579- 
Sutherland,  D.  A.     Saccharin.    Jour.  Soc.  Chem.  Ind.,  6,  1887,  p.  808. 
Taylor,  W.  A.  H.     Commercial  Saccharine.     Phann.  Jour.,  1887,  88  (3),  18,  377. 
Thoms,  H.     Ueber  Dulcin.     Ber.  d.  deutsch.  pharm.  Gesellsch.,  1893,  3,  133. 
VVanters,  J.    Nachweis  des  Saccharins  im  Bier.    Moniteur  scientifique,  4,  1896,  10, 

146. 
Rep.  of  the  Referee  Board  of  Consulting  Scientific  Experts.     U.  S.  Dept. 

of  Agric,  Rep.  94,  Washington,  1911. 
U.  S.  Food  Inspection  Decisions:  Nos.  135,  142,  and  146,  Saccharin  in  Food. 


CHAPTER   XX. 

FLAVORING    EXTRACTS  AND  THF.IR  SrBSTITUTES. 

Or  the  three  great  groups  of  organic  compounds  essential  for  nutri- 
tion, the  fats  and  proteins  in  a  state  of  purity  are  almost  tasteless,  as  is 
also  true  of  starch,  dextrin,  and  cellulose  of  the  carbohydrate  group. 
Only  the  sugars  have  a  pronounced  taste.  The  flavor  of  food  products, 
aside  from  their  sweetness,  is  largely  due  to  minor  constituents,  such 
as  organic  acids,  ethers,  essential  oils,  etc.,  which  serve  chiefly  to  render 
the  products  acceptable  to  the  palate,  thereby  contributing  to  their 
digestibility.  Many  culinary  preparations  lacking  in  flavor,  but  not  in 
nutritive  value,  are  commonly  mixed  with  substances  which  su[)[)ly  this 
deficiency.  Si)iccs  and  flavoring  extracts  belong  to  the  class  of  materials 
added  mainly  if  not  entirely  for  their  zest-giving  properties. 

By  far  the  most  extensively  used  flavoring  extracts  are  those  of  vanilla 
and  lemon,  and  in  comparison  with  these  the  sale  of  all  other  varieties 
is  comparatively  insignificant.  These  two  favorite  extracts  are  employed 
in  nearly  every  household,  and  form  a  necessary  adjunct  to  almost  all 
forms  of  desserts,  cakes,  and  confections,  as  well  as  to  a  wide  variety 
of  commercial  preparations.  Others  of  some  importance  are  extracts  of 
orange,  almond,  wintergreen,  peppermint,  rose,  and  certain  spices.  Imita- 
tion fruit  flavors  are  used  in  cheap  confectionery,  ice  cream,  etc.,  and 
are  of  questionable  wholesomeness. 

VANILLA  EXTRACT. 

The  Vanilla  Bean  is  the  source  of  pure  vanilla  extract,  besides  being 
used  in  chopped  form  directly  as  a  flavoring  agent.  It  is  the  fruit  of 
the  plant  of  the  Vanilla  planijolia,  or  flat-leaved  vanilla.  This  climbing, 
perennial  plant  belongs  to  the  orchid  family,  and  is  indigenous  to  Central 
and  South  America  and  the  West  Indies,  but  by  far  the  highest  prized 
beans  are  cultivated  in  Mexico.  While  different  varieties  differ  in  some 
details,  the  best  cured  beans  of  commerce,  as  a  rule,  are  from  20  to  25  cm. 
in  length  and  from  4  to  8  mm.  thick,  drawn  out  at  their  ends  and  curved 

857 


S58  FOOD   INSPECTION  AND   .ANALYSIS. 

at  the  ba^^e.  'I'licy  arc  rich  thirk  brown  in  color,  of  a  .soapy  or  wax}- 
nature  to  the  touch,  deeply  rifled  lengthwise,  and  covered  with  fine  frost- 
like  crystals  of  vanillin.  When  cut  cross-wise,  the  bean  exudes  a  thick, 
odorless  juice,  containing  calcium  oxalate  crystals. 

The  cross-section  of  the  bean  is  ellii)soidal  in  shajje.  The  thick 
brown  widls  inclose  a  triangular  cavity,  in  which  are  the  lo])ed  placentas. 
Between  these  are  papilhe,  secreting  a  finely  granular,  yellow,  balsam- 
like substance  that  contributes  much  to  the  flavor  of  the  extract,  and 
helps  to  give  the  cut  bean  its  delicious  odor. 

\\hen  first  gathered,  the  beans  are  yellowish  green,  fleshy,  and  with- 
out odor,  developing  their  peculiar  consistency,  color,  and  smell  by  the 
jjrocess  of  fermentation  or  "  sweating,"  which  differs  in  various  countries. 
According  to  the  best  methods  the  beans  are  sun-dried  for  nearly  a  month, 
being  alternately  pressed  lightly  between  the  folds  of  blankets,  and 
exposed  to  the  air.     After  the  curing,  they  are  packed  in  bundles. 

Quicker  methods  of  curing  consist  of  the  use  of  artificial  heat  and 
calcium  chloride  for  drying,  but  the  jjroducts  so  prepared  are  considered 
inferior  in  quality. 

The  Mexican  vanilla  beans  are  of  the  choicest  grade,  and  command 
a  high  price,  sometimes  reaching  fifteen  dollars  per  pound.  The  Bourbon 
beans,  grown  in  the  Isle  of  Reunion,  are  next  in  grade.  These  beans 
are  shorter  than  the  Mexican  and  much  less  expensive.  They  resemble 
the  Tonka  bean  in  odor.  Beans  from  Seychelles  and  Mauritius  are 
even  shorter  than  the  Bourbon  beans,  and  are  largely  exported  to  England. 
Cheaper  varieties  are  those  from  South  America,  which  do  not  bring 
half  the  j^rice  of  the  Mexican  beans,  and  the  cheapest  are  the  Tahiti  beans 
and  so-called  "  vanillons,"  or  beans  of  the  wild  vanilla  {Vanilla  pompona). 
These  latter  are  used  more  in  sachet  powders  and  perfumes,  possessing 
an  odor  not  unlike  heliotroi)c. 

Composition  of  the  Vanilla  Bean. — The  following  arc  results  of  the 
analyses  of  two  varieties  of  vanilla  beans,  according  to  Konig: 

A.  B. 

Water 25 . 

Nitrogen  bodies 4. 

Fat  and  wax C . 

Rcflucing  sugar 7 

Non-nitrogen  substances 30. 

Cellulose 19. 

Ash 4 


.»5 

30.94 

.87 

2.56 

■74 

4.68 

.07 

9.12 

■50 

32.90 

.60 

15-27 

-73 

4-53 

FLAVORING   nXTRACTS    AND    THEIR   SUBSTITUTES.  859- 

Vanillin. — Under  "non-nitrogen  substances"  in  thr  abcnx-  table  \a 
included  vanillin,  the  principle  to  which  vanilla  owes  its  peculiar  odor. 
This  body  (CsHgOa)  is  the  methyl  ether  of  protocatechuic  aldehyde,  and 
is  found  on  the  surface  of  the  bean  in  fine  cr}^stalline  needles.  It  has  a 
sharp  but  pleasant  flavor,  is  soluble  with  difficulty  in  cold  water,  but 
readily  soluble  in  hot  water,  ether,  alcohol,  and  chloroform.  Its  melting- 
point  is  80°  to  81°  C.  and  it  sublimes  at  280°.  It  is  present  in  vanilla 
beans  to  an  amount  varying  from  i  to  2|  per  cent,  and  it  is  a  curious  fact 
that  varieties  of  bean  most  highly  prized  possess  the  least  vanillin.  This 
is  shown  by  Tiemann  and  Harmann  as  follows: 

Mexican  beans i  .69%  vanillin 

Bourbon  beans 2 .  48%         " 


Java  beans 2 . 


I  D  /  0 


While  vanillin  may  be  readily  extracted  by  alcohol  and  other  solvents- 
from  the  beans,  such  a  product  would  be  far  too  expensive  to  compete 
with  the  commercial  synthetic  vanillin,  an  artificial  product,  chemically 
identical  with  the  vanillin  from  the  bean.  Synthetic  vanillin  was  formerly 
made  from  the  glucoside  coniferin  by  oxidation  with  chromic  acid.  It 
is  now  largely  obtained  by  oxidizing  the  eugenol  of  clove  oil  with  alkaline 
potassium  permanganate. 

If  ferric  chloride  be  added  to  an  aqueous  solution  containing  vanillin. 
a  dark-blue  coloration  will  be  produced. 

Besides  vanillin,  the  bean  contains  notable  quantities  of  wax,  fat,, 
sugar,  tannin,  gum,  and  resin. 

Exhausted  Vanilla  Beans  are  sometimes  found  on  sale,  which  have 
been  deprived  of  their  vanillin  by  being  soaked  in  alcohol,  after  which 
they  are  coated  with  some  artificial  substitute,  presenting  the  same  frosty 
appearance  as  the  natural  vanillin  crystals.  This  may  be  accomplished 
by  rolling  the  beans  in  benzoic  acid.  Benzoic  acid  crystals  are  readily 
distinguished  from  those  of  vanillin  under  the  microscope. 

Composition  of  Vanilla  Extract. — Vanilla  extract  is  a  dilute  alcoholic 
tincture  of  the  vanilla  bean,  sweetened  by  cane  sugar.  To  be  perfectly 
pure  it  should  contain  no  other  added  substances,  with  the  possible  excep- 
tion of  glycerin,  and  many  of  the  best  brands  are  free  from  this.  la 
practice  it  is  variously  prepared,  but  the  following  method  of  the  U.  S. 
Pharmacopoeia  is  a  typical  one: 

"Vanilla,  cut  into  small  pieces  and  bruised,   100  grams. 

"Sugar,  in  coarse  powder,  200  grams. 


86o  FOOD    l\SPECTION  AND  ANALYSIS 

"Alcohol  and  water,  each,  a  sufficient   quantity  to  make   i,ooo  cc. 

"Mix  alcohol  and  water  in  the  proportion  of  650  cc.  of  alcohol  to 
350  cc.  of  water.  Macerate  the  vanilla  in  500  cc.  of  this  mixture  for 
twelve  hours,  then  drain  off  the  liquid  and  set  it  aside.  Transfer  the 
vanilla  to  a  mortar,  beat  it  with  the  sugar  into  a  uniform  powder,  then 
pack  it  in  a  percolator,  and  pour  upon  it  the  reserved  liquid.  When  this 
has  disappeared  from  the  surface,  gradually  pour  on  the  menstruum, 
and  continue  the  percolation,  until  1,000  cc.  of  tincture  are  obtained." 

U .  S.  P.  Extracts. — The  table  on  page  861,  gives  a  summary  of  analyses 
by  Winton  and  Berry  *  of  vanilla  extracts  prepared  in  the  laboratory  by 
the  U.  S.  P.  process  from  different  varieties,  grades,  and  lengths  of  vanilla 
beans.  -\s  the  process  employed  did  not  exhaust  the  beans  as  thoroughly 
as  certain  commercial  processes  involving  soaking  the  beans  for  weeks 
or  even  months,  the  residues  after  preparing  the  U.  S.  P.  extracts  were 
further  exhausted  by  soaking  for  five  months  in  60%  alcohol  and  the 
extracts  thus  obtained  analyzed  with  the  results  summarized  at  the  bottom 
of  the  table. 

.\  study  of  the  average  figures  for  the  ditTerent  grades  and  different 
lengths,  irrespective  of  variety,  showed  an  increase  of  vanillin  but  a  decrease 
in  normal  lead  number  and  color  value  from  the  lowest  to  the  highest 
grade  and  also  from  the  shortest  to  the  longest  bean. 

Extracts  Prepared  with  Different  Menstrua. — Winton  and  Berry 
further  found  that  the  composition  of  the  extract  was  not  affected  by 
omission  of  the  sugar  entirely,  and  also  that  when  glycerin  was  substituted 
for  sugar  the  only  constant  affected  was  the  color  value,  which  was  some- 
what increased.  WTien  35*"^/  alcohol  was  substituted  for  the  62%  alcohol 
of  the  U.  S.  P.  process  the  percentage  of  vanillin  was  not  altered,  but  the 
normal  lead  number,  the  percentages  of  color  in  the  lead  filtrate  and 
insoluble  in  amyl  alcohol  were  increased  while  the  color  value  of  the  extract 
itself  was  decreased.  In  the  preparation  of  a  pure  extract  the  use  of 
alcohol  weaker  than  45%  is  not  commercially  practicable  owmg  to  dif- 
ficulties in  percolation. 

Use  of  Alkali. — Some  manufacturers  employ  dilute  alkali,  generally 
potassium  bicarbonate,  to  aid  in  dissolving  out  the  resinous  matter  from 
the  bean,  and  to  enable  them  to  use  a  more  dilute  alcohol.  The  resulting 
pro<'lurt  marie  )jy  this  process  is  distinctly  inferior,  both  in  taste  and  odor. 

The  Tonka  Bean  forms  the  basis  of  many  of  the  cheaper  so-called 
vanilla  extracts  on  the  market.  It  is  the  seed  of  the  large  tree,  native  to 
•  A.  O.  A.  C.  Pror.,  1911,  U.  S.  Dept.  of  Agric .,  Bur.  of  Chem.,  Bui.  152,  p.  146. 


FLAVORING    EXTRACTS   AND    THF.IR   SUBSTITUTES. 


U.  S.   P.    VAXILLA    EXTRACTS   MADE    IX    THE    LABORATORY 


Variety 

of 

Bean. 


Color  Value. 


Extract 
(Total 
Color). 


Lead 
Filtrate.* 


Per  Cent 
of  Total 
Color  in 

Lead 
Filtrate. 


Ratio  of 
Red  to 
Yellow. 


030 

0)  o  >. 


13 


16 


16 


Mexican 

Maximum.  .  .  . 

Minimum .... 

.\verage 

Bourbon 

Maximum.  .  . . 

Minimum.  .  .  . 

Average 

Seychelles 

Maximum. .  .  . 

Minimum.  .  .  . 

Average 

Madagascar.  .  .  . 

Maximum.  .  .  . 

Minimum .... 

Average. ..... 

Com  jres ....... 

Maximum .... 

Minimum.  .  .  . 

Average 

South  .\merican. 

Maximum.  .  .  . 

Minimum.  .  .  . 

Average 

Ceylon 

Maximum.  .  .  . 

Minimum .... 

.Average 

Java 

Maximum.  .  .  . 

Minimum.  .  .  . 

.\verage 

Tahiti 

Maximum  .... 

Minimum .... 

Average 

Vanillons 

Tonka  Beans  f-  • 

Ma.ximum.  .  .  . 

Minimum.  .  .  . 

.\verage 

All  Analyses  % 71 

Maximum.  .  .  . 

Minimum .... 

.\verage 

All  Analyses  J. .  . 

(2d  Extraction) 

Maximum.  .  .  . 

Minimum .... 

Average 


71 


16 

23 
II 
16 


16 


23 
10 
16 


23 
10 
16 


0.20 
o.is 
o.  17 

0.22 
0.13 
0.18 

O.  21 

o.  16 
o.  19 

0.30 

O.  16 

0.22 

0.31 
O.  12 
0.18 

0.23 

0. 19 


0.08 
0.07 
0.08 


0.06 


0.31 
O.  II 

o.  19 


0.68 

0.47 

o.s8 

0.63 
0.44 
0.52 

0.60 
0.4s 
o.si 

0.63 
o.  40 
0.50 


0.61 

0.44 
0.50 


0.  II 


•  74 
.40 

•54 


0.071    O. II 

o.oi    0.03 
0.03    0.05 


.S6 


47 
25 
34 


0.74  40 

O.40I  22 

0.59  31 

0.58  50 

o.  49  42 

0.52  46 

0.67  61 

0.S7  40 

0.62  4S 


45 
44 
44 


0.50  17 

0.44  15 

0.471  16 

0.52;  42 


154 
55 
97 

127 
6S 
94 

162 

77 
107 

148 
85 

II I 

140 
70 
99 

155 
117 
134 

195 
145 
162 


130 
150 

SO 
40 

45 
107 

19 


177 
40 
102 


2.4 
1-4 
1.9 


2.6 


2.6 
1.4 
1.9 


7.6 
1-4 
43 


0.6 
0.6 
0.6 
1.4 

0.5 
0.5 
0.5 

3.4 
0.6 
1.8 


8.0 
4.8 
6.5 


5.8 
7.0 

14.6 
S-O 
7.9 


6.2 
8.7 


6.0 

7.7 

10.4 
6.8 
8.S 

32.6 
6.4 
18.2 

13.4 
10.4 
I.I 

3.5 
31 
3.3 
6.6 

2.4 
2.4 
2.4 


2.2 
0.8 


3.8 
2.6 


3-9 
2.3 
3.2 

3.6 
2.5 
3.2 

3.5 
2.7 
3.2 

3.8 


3.1 
2.5 
2.9 

3.6 
3-2 

3.4 

3-9 
3.0 

3.4 

30 
2.7 

2.9 

2.5 


5.7 

2.5 

3^4 


6^5 
30 
4.6 


24.4 
19.0 


30.3 
21.3 
26.6 

29.4 

22.  7 
25.6 

30.3 

23.  2 
26.8 

30.3 

20.4 
26.  7 


50.0 
22.  7 
36.1 

35.7 
32.2 
34-5 

18.8 
16.0 

17.4 


31.2 
30.3 
30.8 

35.7 
16.0 
25.5 


*  Calculated  to  volume  of  extract. 

t  Coumarin:   Maximum,  0.27%  ;  minimum,  0.22%;  average,  o.  25%. 

X  Excluding  Ceylon.  Vanillons,  and  Tonka  Beans. 


862  FOOD   INSPECTION  AND   ANALYSIS. 

Guiana,  known  as  Diptcrix  (or  Coumarjuna)  odorata.  The  pods  are 
almond-shaped,  and  contain  a  single  seed,  from  3  to  4  cm.  long,  shaped 
like  a  kidney  bean,  of  a  dark-brown  color,  having  a  thin,  shiny,  rough, 
brittle  skin,  and  containing  a  two-lobed  oily  kernel. 

Coumarin  (CgHgOo),  the  active  principle  of  the  Tonka  bean,  is  the 
anhydride  of  coumaric  acid.  It  occurs  in  the  crystalline  state  between 
the  lobes  of  the  seed  kernel.  Coumarin  occurs  also  in  many  other  plants. 
It  may  be  extracted  from  the  beans  by  treatment  with  alcohol.  It  crys- 
tallizes in  slender,  colorless,  needles,  melting  at  67°  C.  It  has  a  fragrant 
odor  and  burning  taste.  It  is  very  slightly  soluble  in  cold  water,  but 
readily  soluble  in  hot  water,  ether,  chloroform,  and  alcohol.  One  pound 
of  cut  beans  yields  by  alcoholic  extraction  about  108  grains  of  coumarin. 
The  latter  may  be  synthetically  prepared  by  heating  sahcylic  aldehyde 
with  sodium  acetate  and  acetic  anhydride,  forming  aceto-coumaric  acid, 
which  decomposes  into  acetic  acid  and  coumarin. 

The  author  has  found  that  an  aqueous  solution  of  coumarin,  unlike 
vanillin,  forms  a  precipitate  when  iodine  in  potassium  iodide  is  added  in 
excess,  the  precipitate  being  at  first  brown  and  fiocculent,  afterwards, 
on  shaking,  clotting  together  to  form  a  dark-green,  curdy  mass,  leaving 
the  liquid  perfectly  clear. 

U.  S.  Standards. —  Vanilla  extract  is  the  flavoring  extract  prepared 
from  the  vanilla  bean,  with  or  without  sugar  or  glycerin,  and  contains  in 
TOO  cc.  the  soluble  matters  from  not  less  than  10  grams  of  the  vanilla  bean. 

Vanilla  bean  is  the  dried,  cured  fruit  of  Vanilla  planifolia  Andrews. 

Tonka  extract  is  the  flavoring  extract  prepared  from  tonka  bean,  with 
or  without  sugar  or  glycerin,  and  contains  not  less  than  0.1%  by  weight 
of  coumarin  extracted  from  the  tonka  bean,  together  with  a  correspond- 
ing jjroportion  of  the  other  soluble  matters  thereof. 

Tonka  bean  is  the  seed  of  Coumarouna  odorata  Aublet  {Dipteryx 
odorata  (Aubl.)  Willd.). 

The  Adulteration  of  Vanilla  Extract  consists  chiefly  in  the  use  of 
coumarin  or  extract  of  the  Tonka  bean,  and  in  the  substitution  of  artifi- 
cial vanillin,  either  alone  or  with  coumarin,  for  the  true  extractives  of 
the  vanilla  bean.  Imitation  vanilla  flavors  more  often  consist  of  a 
mixture  of  either  tincture  of  Tonka  or  coumarin  with  vanillin  in  weak 
alcohol,  colored  with  caramel,  or  occasionally  witli  coal-tar  colors.  Or 
the  exhausted  marc  from  high-grade  vanilla  extract  is  macerated 
with  hot  water  and  extracted,  the  extract  being  reinforced  with 
artificial  vanillin  or  coumarin,  or  both.     A  j)ure  vanilla  extract  possesses 


FLAVORING   EXTRACTS  AND    THHIR  SUBSTITUTES.  863 

certain  peculiarities  with  rcgacd  to  its  resins  and  gums  that  distinguish 
it  from  the  artificial,  or  indicate  whether  or  not  it  has  been  tampered 
with.  While  it  is  possible  to  introduce  artificial  resinous  matter  in  the 
adulterated  brands  with  a  view  to  deceiving  the  analyst,  it  is  almost 
impossible  to  do  this  without  detection,  since  different  reactions  are 
readily  apparent  in  this  case  from  those  of  the  pure  extracts. 

Prune  juice  is  said  to  be  used  to  give  body  and  flavor  to  vanilb 
extract.  The  writer  has  found  sj)irit  of  myrcia  or  bay  rum  in  a  sampL. 
of  alleged  vanilla  extract,  containing  also  vanillin  and  coumarin.  The 
adulterant  in  this  sample  was  present  to  such  an  extent  as  to  be  unmis- 
takable by  reason  of  the  odor. 

Factitious  Vanilla  Extracts  are  ordinarily  indicated  (i)  by  the  presence 
of  coumarin,  (2)  by  the  peculiar  reactions  of  the  resinous  matter,  or  by 
the  entire  absence  of  these  resins,  (3)  by  the  scanty  precipitate  with  lead 
acetate,  and  (4)  by  the  abnormally  low  or  high  content  of  vanillin. 

The  following  figures  show  the  content  of  vanillin  and  coumarin  in 
a  few  typical  cheap  "  vanilla  "  extracts,  selected  from  a  large  number 
examined  by  the  author.  All  of  these  were  entirely  artificial,  and  ranged 
from  5  to  20  per  cent  by  weight  of  alcohol. 

Vanillin,  Coumarin, 

Per  Cent.  Per  Cent. 

A 0.040  0-074 

B None  0.172 

;  C None  0-330 

D 0-250  None 

E., 0-025  0.144 

As  a  rule  these  cheap  artificial  preparations  possess  considerable  body 
and  flavor,  but  the  latter  is  of  a  much  grosser  nature  than  the  genuine 
vanilla  extract,  with  the  delicate  and  refined  flavor  of  which  they  are  not 
to  be  mistaken  by  any  one  at  all  familiar  with  both  varieties. 

Winton  and  Bailey*  have  found  as  high  as  2.55%  of  vanillin  in 
imitation  extracts.  They  also  have  detected  the  presence  of  acetanihde 
in  amounts  varying  up  to  0.15%.  This  substance  at  one  time  was 
extensively  employed  as  an  adulterant  of  vanillin,  hence  its  presence  in 
imitation  extracts  prepared  from  such  vanillin.  It  is  not  only  worthless 
as  a  flavor,  but  is  a  menace  to  health. 

*  Conn.  Agric.  Exp.  Sta.,  Rep.  1905,  p.  131. 


S64  FOOD   INSPECTION   AND  ANALYSIS. 

_n  the  limits  of  composition  for  standard  vanilla  extract  given  on  page 
870,  the  range  in  vanillin  content  is  from  o.io  to  0.35%. 

METHODS   OF   ANALYSIS   OF   VAMI.LA    EXTRACT 

Detection  of  Artificial  Extracts. — The  presence  of  coumarin  or  Tonka 
tincture  to  any  appreciable  extent  in  \anilla  extract  is  usually  recognizable 
by  the  odor,  to  one  skilled  in  examining  these  flavors.  The  odor  of  cou- 
marin is  more  pungent  and  penetrating  than  that  of  vanillin,  and  in  mix- 
tures is  apt  to  predominate  over  the  milder  and  more  delicate  odor  of 
vanillin. 

Add  normal  acetate  of  lead  solution  to  a  suspected  extract.  The 
absence  of  a  precipitate  is  conclusive  evidence  that  it  is  artificial.  If 
a  precipitate  is  formed,  much  information  may  be  gained  by  its  character. 
A  pure  vanilla  extract  should  yield  with  lead  acetate  a  heavy  precipitate, 
due  to  the  various  extractives.  The  precipitate  should  settle  in  a  few 
minutes,  leaving  a  clear,  supernatant,  partially  decolorized  liquid.  If 
only  a  mere  cloudiness  is  formed,  this  may  be  due  to  the  caramel  present, 
and  in  any  event  is  suspicious. 

Examination  of  the  Resins. — Resin  is  present  in  vanilla  beans  to  the 
extent  of  from  4  to  11  per  cent,  and  the  manufacturer  of  high-grade 
essences  endeavors  to  extract  as  much  as  possible  of  this  in  his  product. 
This  he  can  do  by  the  use  of  50%  alcohol,  in  which  all  the  resin  is  readily 
soluble,  or  by  employing  less  alcohol  and  relying  on  the  use  of  alkali 
to  dissolve  it.  A  pure  extract  free  from  alkali  should  produce  a  precip- 
itate, when  a  portion  of  the  original  sample  is  diluted  with  twice  its  volume 
of  water  and  shaken  in  a  test-tube. 

WTien,  moreover,  the  alcohol  is  removed  from  such  an  extract,  the 
excess  of  resin  is  naturally  precipitated. 

The  character  of  the  resins  extracted  from  the  vanilla  bean  is  so  dif- 
ferent from  that  of  other  resins  as  to  furnish  conclusive  tests,  worked 
out  by  Hess  *  as  follows:  25  to  50  cc.  of  the  extract  are  de-alcoholizcd  by 
heating  in  an  evaporating-dish  on  the  water-bath  to  about  onc-;hird  its 
volume.  Make  up  to  the  original  volume  with  water,  and,  if  no  alkali 
has  been  used  in  the  manufacture  of  the  preparation,  the  resin  will  be  in 
the  form  of  a  brown,  flocculent  precipitate.  To  entirely  set  free  the  resin, 
acidify,  after  cooling,  with  dilute  hydrochloric  acid,  and  allow  to  stand 
till  all  the  resin  has  settled  out,  leaving  a  clear  supernatant  liquid.  The 
resin  may  be  quantitatively  determined,   if  desired,  by  filtering,  wash- 

*  Jour.  Am.  Chem.  Soc,  21  (1899),  p.  721. 


FLAVORING   EXTRACTS   AND    THllIR   SUBSTITUTES.  865 

ing,  diying,  and  weighing,  but  in  this  case  should  stand  for  a  long  lime 
before  filtering. 

The  resin  is  collected  on  a  filter,  washed,  and  subjected  to  various 
tests.  A  piece  of  the  filter  with  the  attached  resin  is  placed  in  a  beaker, 
containing  dilute  potassium  hydroxide.  Pure  vanilla  resin  dissolves 
to  a  deep-red  color,  and  is  reprecipitated  on  acidifying  with  hydrochloric 
acid.  Dissolve  another  portion  of  the  j)recipitate  in  alcohol,  and  divid3 
the  alcoholic  solution  into  two  portions,  to  one  of  which  add  a  few  drops 
of  ferric  chloride,  and  to  the  other  hydrochloric  acid.  Pure  vanilla  resin 
shows  no  marked  coloration  in  either  case,  but  foreign  resins  nearly  all 
give  color  reactions  under  these  conditions. 

Tannin. — Test  a  portion  of  the  filtrate  from  the  resin  for  tannin  by 
the  addition  of  a  few  drops  of  a  solution  of  gelatin.  A  small  quantity 
of  tannin  only  should  be  indicated,  if  the  extract  is  pure,  a  large  excess 
tending  to  show  added  tannin. 

Determination  of  Vanillin  and  Coumarin. — Modified  Hess  and  Prescott 
Method. — This  process,  in  its  original  form  devised  by  Hess  and  Prescott  * 
has  been  modified  by  Winton,  collaborating  with  Silverman, f  Bailey, J 
Lott,§,  and  Berry, |1  in  order  to  prevent  loss  of  coumarin,  detect  the 
presence  of  acetanilide,  and  permit  the  determination  of  normal  lead 
number  in  the  same  weighed  portion.  It  depends  on  the  principle  that 
ammonia  water,  acting  on  the  ether  solution  of  vanillin  and  coumarin, 
forms  with^  the  aldehyde  vanillin  a  compound  soluble  in  water,  but 
does  not  affect  the  coumarin,  which  remains  in  solution  in  the 
ether. 

Weigh  50  grams  of  the  extract  directly  into  a  tared  250-cc.  beaker 
with  marks  showing  volumes  of  80  and  50  cc,  dilute  to  80  cc,  and  evapo- 
rate to  50  cc.  in  a  water-bath  kept  at  70°  C.  Dilute  again  to  80  cc.  with 
water  and  evaporate  to  50  cc.  Transfer  to  a  100-cc.  flask,  rinsing  the 
beaker  with  hot  water,  add  25  cc.  of  standard  lead  acetate  solution 
(80  grams  of  C.  P.  crystallized  lead  acetate,  made  up  to  one  liter),  make 
up  to  the  mark  with  water,  shake,  and  allow  to  stand  eighteen  hours  at  a 
temperature  of  from  37°  to  40°  C,  in  a  bacteriological  Incubator,  in  a 
water-bath  provided  with  a  thermostat,  or  in  any  other  suitable  apparatus. 

*  Jour.  .A.m.  Chem.  Soc,  21,  1899,  p.  256. 

t  Ibid.,  24,  1902,  p.  1128. 

X  Ibid.,  27,  1905,  p.  719. 

§  A.  O.  A.  C.  Proc.  1909,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bu!.  132,  p.  109. 

II  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  66. 


866  FOOD   INSPECTION   AND  ANALYSIS. 

Filter  through  a  small  6iy  tilter  and  pipette  off  50  cc.  of  the  filtrate  into 
a  separatory  funnel. 

If  a  determination  of  normal  lead  number  is  desired,  pipette  oflf  10  cc. 
of  the  filtrate  into  a  beaker,  and  proceed  as  described  on  page  867.  In 
the  latter  case,  the  water  used  tliroughout  the  process  should  be  boiled 
until  free  from  carbon  dioxide.  If  coloring  with  caramel  is  suspected 
determine  the  color  value  of  the  original  extract  and  the  filtrate  (p.  86g). 

To  the  50  cc.  of  the  filtrate  in  the  separatory  funnel,  add  20  cc.  of  ether 
and  shake.  Draw  off  carefully  the  aqueous  liquid,  together  with  any 
ether  emulsion  and  then  remove  the  clear  ether  solution  to  another  sepa- 
rator)- funnel.  Repeat  the  shaking  of  the  aqueous  liquid  with  ether 
three  times,  using  15  cc.  each  time. 

Shake  the  combined  ether  solutions  four  or  five  times  with  2%  ammo- 
nium hydroxide,  using  10  cc.  for  the  first  shaking  and  3  cc.  for  each 
subscc[ucnt  shaking.  In  drawing  off  the  ammoniacal  solution,  care  should 
be  taken  not  to  allow  any  of  the  ether  solution  to  pass  through  with  it. 
Resen-e  the  ammoniacal  solution  for  the  determination  of  vanillin. 

Transfer  the  ether  solution  to  a  weighed  dish  and  allow  the  ether 
to  evaporate  at  room  temperature.  Dry  in  a  sul])huric  acid  desiccator 
and  weigh.  If  the  residue  is  pure  coumarin,  it  should  have  a  melting- 
point  of  67°  C,  respond  to  the  Leach  test,  and  be  completely  soluble  in 
three  or  four  portions  of  petroleum  ether  (boiling-point  30°  to  40°  C), 
stirring  with  each  portion  fifteen  minutes. 

If  a  residue  remains  in  the  dish  after  decanting  off  the  last  portion 
of  the  petroleum  ether  solution,  acetanilide  should  be  looked  for  (p.  868). 

Add  to  the  ammoniacal  solution  10%  hydrochloric  acid  to  slightly 
acid  reaction.  This  should  be  done  without  delay,  as  the  ammoniacal 
solution  on  standing  grows  slowly  darker  with  a  loss  of  vanillin.  Cool, 
and  shake  out  in  a  separatory  funnel  with  four  portions  of  ether,  as 
described  for  the  first  ether  extraction.  Evaporate  the  ether  solution  at 
room  temperature  in  a  weighed  dish,  dry  over  sulphuric  acid,  and  weigh. 
The  residue  should  be  pure  vanillin  free  from  any  appreciable  amount  of 
color  and  with  a  melting-point  of  80'^  C. 

If  the  percentage  of  vanillin  is  not  desired,  and  coumarin  only  is  to  be 
separated  for  gravimetric  deterrhination,  the  author  has  found  that  good 
results  arc  usually  obtained  by  simply  treating  the  dealcoholized  original 
sample  with  ammonia,  extracting  it  with  3  or  4  portions  of  chloroform  in 
a  separatory  funnel,  and  evaporating  the  combined  chloroform  extract  in 
a  tared  dish  at  a  temperature  not  exceeding  60°  in  the  oven. 


FLAVORING    EXTRACTS   AND    THBIR   SUBSTITUTES.  867 

Many  of  the  precautions  employed  in  carrying  out  the  above  processes 
for  vanilHn  and  coumarin  determination  may  l)e  dispensed  with  if  these 
substances  are  simply  to  be  tested  for  (|ualitatively. 

Leach  Test  for  Coumarin. — The  residue,  believed  to  be  coumarin, 
obtained  as  described  in  the  preceding  section,  is  identified  by  the  follow- 
ing test:  Add  a  few  drops  of  water,  warm  gently,  and  add  to  the  solu- 
tion a  little  iodine  in  potassium  iodide,  reagent  No.  143.  In  presence 
of  coumarin  a  brown  precipitate  will  form,  which,  on  stirring  with  the 
rod,  will  soon  gather  in  dark-green  flecks.  The  reaction  is  especially 
marked  if  done  on  a  white  plate  or  tile. 

Wichmann  Test  for  Coumarin. — Dilute  25  cc.  of  the  extract  with  25 
cc.  of  water,  slightly  acidify,  if  alkaUne,  with  sulphuric  acid,  and  distil 
to  dryness.  To  the  distillate,  containing  the  vanillin  and  coumarin,  add 
15  to  20  drops  of  I :  I  potassium  hydroxide,  hastily  evaporate  to  5  cc, 
transfer  to  a  test  tube  and  heat  over  a  free  flame  until  the  water  com- 
pletely evaporates  and  the  residue  fuses  to  a  colorless,  or  nearly  colorless 
mass.  Cool  the  melt  and  dissolve  in  a  few  cubic  centimeters  of  water,  trans- 
fer to  a  50  cc.  Erlenmeyer  flask  and  acidify  slightly  with  25%  sulphuric 
acid.  Finally  distil  the  solution  (which  should  not  exceed  10  cc.)  into 
a  test  tube  containing  four  or  five  drops  of  neutral  0.5%  ferric  chloride. 
If  coumarin  is  present  in  the  original  extract,  a  purj^le  color  will  develop, 
the  intensity  being  proportional  to  the  amount  of  coumarin. 

Vanillin  and  Coumarin  Crystals  under  the  Microscope. — These  sub- 
stances are  best  examined  when  crystallized  from  ether  solution,  and 
several  crystallizations  may  be  found  necessary,  before  the  best  results 
are  obtained.  For  examination,  pour  a  few  drops  of  the  ether  solution 
of  the  purified  vanillin  or  coumarin  directly  on  a  slide,  and  allow  to 
evaporate  spontaneously.  Under  best  conditions  vanillin  cr}^stallizes 
from  ether  in  long,  slender  needles,  often  radiating  from  central  points, 
or  forming  star-shaped  bundles. 

Coumarin  crystals  are  shorter  and  thicker  than  vanillin. 

With  polarized  light  pure  vanillin  crystals  give  a  brilliant  play  of 
colors  between  crossed  nicols,  even  without  the  selenite  plate,  while  pure 
coumarin  crystals  without  the  selenite  are  almost  lacking  in  varying 
colors,  and  show  very  little  play,  even  when  the  selenite  is  employed. 
This  sharp  distinction  is  not  true  when  crystallized  from  chloroform. 

Determination  of  Normal  Lead  Number. — Winton  and  Lott  Method. — 
Mix  the  lo-cc.  aliquot  of  the  filtrate  from  the  lead  acetate  precipitate, 
obtained  in  the  determination  of  vanillin  and  coumarin  (p.  866),  with 


868  FOOD   INSPECT  J  ON   ^ND   .-^N^  LYSIS. 

25  cc.  of  water,  boiled  until  free  from  carbon  dioxide,  and  a  moderate 
excess  of  sulphuric  acid.  Add  100  cc.  of  95%  alcohol,  and  mix  again. 
Let  stand  over  night,  filter  on  a  Gooch  crucible,  wash  with  95%  alcohol, 
dr}'  at  a  moderate  heat,  ignite  at  low  redness  for  three  minutes,  taking 
care  to  avoid  the  reducing  flame,  and  weigh.  The  normal  lead  number 
is  calculated  by  the  following  formula: 

„     loo    0.6851(5-110  _     ^^     „,^ 

P= f- -=13.662  (5-Tf), 

5 

in  which  P  =  normal  lead  numl)er,  .S'  =  grams  of  lead  sulphate  corre- 
sponding to  2.5  cc.  of  the  standard  lead  acetate  solution  as  deter- 
mined m  blank  analyses,  and  W''  =  grams  of  lead  sulphate  obtained 
in  10  cc.  of  the  filtrate  from  the  lead  acetate  precipitate,  as  above 
described. 

The  standard  of  the  lead  acetate  solution  as  determined  by  blank 
analyses  does  not  change  appreciably  on  standing;  it  should,  however, 
be  checked  from  time  to  time,  especially  if  the  bottle  is  opened  frequently, 
thus  permitting  absorption  of  carbon  dioxide.  Tn  all  steps  of  the  process 
only  water  free  from  carbon  dioxide  should  be  used. 

Pure  vanilla  extract  of  standard  strength  should  have  a  normal  lead 
number  not  less  than  0.40.  Dilution  diminishes  the  number  propor- 
tionately. For  example,  a  mixture  containing  50%  of  vanilla  extract 
should  have  a  normal  lead  number  not  less  than  0.20  and  so  on. 

Determination  of  Acetanilide. — Winton  and  Bailey  Method. — If  in  the 
determination  of  vanillin  and  coumarin  (p.  865)  a  residue  is  found  after 
thoroughly  stirring  the  coumarin  with  three  or  four  15-cc.  portions  of 
petroleum  ether  and  decanting  off  the  licjuid;  allow  this  residue  to 
stand  at  room  temperature  until  apparently  dry  and  finish  the  dry- 
ing in  a  sulphuric  acid  desiccator.  Weigh  and  deduct  the  weight 
from  that  previously  obtained,  thus  obtaining  the  true  amount  of 
coumarin. 

The  residue,  if  acetanilide,  should  melt  at  112°  C.  and  respond  to 
Ritsert's  tests  as  given  below. 

If  acetanilide  is  found  in  the  coumarin  it  will  also  be  present  in  the 
vanillin,  although  in  smaller  amount.  Dissolve  the  weighed  residue  of 
impure  vanillin  in  15  cc.  of  10%  ammonium  hydroxide  solution,  shake 
twice  with  ether,  evaporate  the  ether  solution  at  room  temperature,  dry 
in  a  sulphuric  acid  desiccator,  and  weigh.     Deduct  this  weight  from  the 


hLAyORING   EXTRACTS  AND    1 HHIR   SUBSTITUTES.  8j^ 

weight  of  impure  vanillin,  thus  correcting  for  the  amount  of  acetanilide 
present. 

The  total  weight  of  acetanilide  is  found  by  adding  the  weight  of 
the  portion  separated  from  the  coumarin  to  that  separated  from  the 
vanillin. 

Ritsert's  Tests  for  Acetanilide.* — Boil  the  acetanilide,  obtained  as 
described  above,  in  a  small  beaker  for  two  or  three  minutes  with 
2  to  3  cc.  of  concentrated  hydrochloric  acid,  cool,  divide  into  three  por- 
tions, and  test  in  small  tubes  (4  to  5  mm.  inside  diameter),  or  by  spotting 
on  a  porcelain  plate,  as  follows: 

(i)  To  one  portion  add  carefully  i  to  3  drops  of  a  solution  of  chlorinated- 
lime  (1:200)  in  such  a  manner  that  the  two  solutions  do  not  mix.  A 
beautiful  blue  color  formed  at  the  juncture  of  the  two  liquids  indicates 
acetanilide. 

(2)  To  another  portion  add  a  small  drop  of  potassium  j)crmanganate 
solution,  A  clear  green  color  is  formed  if  any  appreciable  amount  of 
acetanilide  is  present. 

(3)  Mix  the  third  portion  with  a  small  drop  of  3%  chromic  acid 
solution.  Acetanilide  gives  a  yellows-green  solution,  changing  to  dark 
green  on  standing  five  minutes,  and  forming  a  dark  blue  precipitate 
on  addition  of  a  drop  of  caustic  potash  solution. 

These  tests  are  conclusive  only  when  taken  in  conjunction  with  the 
melting-point. 

Determination  of  Glycerin. — The  presence  of  any  considerable  quantity 
of  glycerin  is  apparent  by  the  character  of  the  residue  obtained  on  evaporat- 
ing 5  grams  to  dryness,  in  the  determination  of  total  solids.  The 
residue,  if  glycerin  is  present  in  notable  amount,  appears  of  a  moist 
consistency,  even  when  a  practically  constant  weight  has  been  attained 
at  100°  C. 

To  determine  glycerin,  proceed  as  with  wines  (p.  703). 

Determination  of  Alcohol. — Measure  out  25  cc.  of  the  sample,  dilute 
to  50  cc.  with  water,  and  distil  off  about  20  cc.  in  a  25-cc.  graduated 
receiver.  Make  up  to  the  mark  with  water,  determine  the  specific  gravity 
at  15.6°,  and  find  from  the  alcohol  table  the  per  cent  corresponding. 

Cane  Sugar  and  Glucose  are  determined  as  in  the  case  of  preserves 
and  jellies. 

Detection  of  Caramel. — Lead  Acetate  Method. — Dealcoholize,  precipi- 
tate with  lead  acetate,  and  filter,  as  described  for  the  determination  of 
vanillin  and  coumarin  (page  865).     If  the  extract  is  pure,  the   nltrcta 

*  Pharm.  Ztg.  33,  1888,  p.  383;  Abs.  Zeits.  anal.  Chem.,  27,  1888,  p.  667. 


SjO  FOOD   INSPECTION  AND  ANALYSIS. 

will  be  light  yellow;  if  colored  with  caramel,  the  filtrate  will  be  yellow 
brown  or  deep  brown,  according  to  the  amount  present. 

More  definite  conclusions  may  be  reached  by  determining  the  color 
values  of  the  original  extract  and  the  lead  acetate  filtrate  in  terms  of 
yellow  and  red  of  the  Lovibond  scale  and  calculating  the  ratio  of  the 
two  colors,  also  the  percentage  of  each  color  remaining  in  the  filtrate. 
The  reading  of  the  extract  is  made  in  the  i-inch  cell  after  diluting  2  cc.  to 
50  cc.  with  50%  alcohol,  while  that  of  the  filtrate  is  made  directly  in  a  i- 
inch  cell  or.  if  very  dark,  in  a  half  or  quarter  inch  cell. 

Color  Insoluble  in  Amyl  Alcohol. — Evaporate  25  cc.  of  the  extract  on 
a  water-bath  until  no  odor  of  alcohol  is  apparent  and  the  liquid  is  reduced 
to  a  thick  sirup,  then  proceed  as  described  on  page  753. 

Limits  of  Composition  for  Standard  Vanilla  Extract. — The  following 
are  suggested  by  Winton  and  Berry: 

Vanillin,  o.io  to  0.35%. 

Normal  lead  number,  0.40  to  0.80%. 

Percent  of  total  color  in  lead  filtrate,  not  more  than  io%red  or  i2%yeUow, 

Ratio  of  red  to  yellow  in  the  extract,  not  less  than  i :  2.2. 

Color  insoluble  in  amyl  alcohol,  not  more  than  40%. 

Coal-tar  Colors  are  detected  by  the  usual  tests  (pp.  795  to  818). 

LEMON   EXTRACT. 

Spirit  or  essence  of  lemon  of  the  National  Formulary  and  former 
editions  of  the  Pharmacopeia,  is  a  5%  solution  (by  volume)  of  lemon 
oil  in  deodorized  alcohol,  colored  with  lemon  peel. 

This  preparation  was  dropped  from  the  8th  revision  of  the  Phar- 
macop''cia,  and  Tinclura  limonis  corticis  or  tincture  of  lemon  peel  added. 
The  following  are  the  directions  for  the  preparation  of  the  latter: 

"Lemon  j)eel,  from  the  fresh  fruit,  in  thin  shavings  and 

cut  in  narrow  shreds 500  grams 

"Alcohol,  a  sufficient  quantity  to  make 1000  cc. 

"  Macerate  the  lemon  peel  in  a  stoppered,  wide-mouthed  container, 
in  a  moderately  warm  place,  with  1000  cc.  of  alcohol  during  forty-eight 
hours,  with  frequent  agitation;  then  filter  through  purified  cotton,  and, 
•when  the  liquor  has  drained  off  completely,  gradually  pour  on  enough 
alcohol  to  make  1000  cc.  of  tincture,  and  filter." 

U.  S.  Standards. — Lemon  Extract  is  the  flavoring  extract  prepared 
from  oil  of  lemon,  or  from  lemon  peel,  or  both,  and  contains  not  less 
than  5%  by  volume  of  oil  of  lemon. 


FLAVORING   EXTRACTS  AND    THEIR   SUBSTITUTES.  871 

Oil  of  Lemon  \s  the  volatile  oil  obtained,  by  expression  or  alcoholic 
solution,  from  the  fresh  peel  of  the  lemon  {Citrus  limonum  L.),  has  an 
optical  rotation  (25°  C.)  of  not  less  than  +60°  in  a  loo-mm.  tube,  and 
contains  not  less  than  4%  by  weight  of  citr^l, 

Terpendess  Extract  of  Lemon  is  the  flavoring  extract  prepared  by 
shaking  oil  of  lemon  with  dilute  alcohol,  or  by  dissolving  terpeneless  oil 
of  lemon  in  dilute  alcohol,  and  contains  not  less  than  0.2%  by  weight 
of  citrai  derived  from  oil  of  lemon. 

Terpeneless  Oil  of  Lemon  is  oil  of  lemon  from  which  all  or  nearly 
all  of  the  terpenes  have  been  removed, 

The  U.  S.  standard  for  lemon  extract  (5%  of  lemon  oil  by  volume) 
is  a  fair  one.  In  fact  there  are  commercial  extracts  on  the  market 
containing  as  high  as  12%.  An  extract  of  lemon  to  contain  5%  of 
lemon  oil  must  contain  at  least  80%  by  volume  of  alcohol,  lemon  oil 
being  insoluble  in  dilute  alcohol.  Deodorized,  or  purified  alcohol,  com- 
monly known  as  cologne  spirits  or  perfumers'  alcohol,  is  used  in  the 
highest-grade  preparations,  since  the  odor  of  ordinary  commercial  alcohol 
produces  a  slightly  deleterious  effect. 

Adulteration  of  Lemon  Extracts. — For  making  a  cheap  extract  the 
cost  of  the  lemon  oil  is  not  so  important  an  item  as  that  of  the  alcohol, 
and  as  little  as  possible  of  the  latter  is  employed,  though  pure  oil 
is  doubtless  used.  These  terpeneless  extracts  are  made  by  rubbing 
the  oil  in  carbonate  of  magnesia  in  a  mortar,  stirring  in  slowly  a 
little  strong  alcohol,  and  allowing  the  mixture  to  soak  for  some 
time.  A  varying  amount  of  water  is  added  a  little  at  a  time,  and 
the  whole  is  shaken  and  again  allowed  to  stand,  sometimes  for  a  week, 
before  filtering.  Finally  the  extract  is  filtered,  and  the  coloring  matter 
added,  consisting  sometimes  of  turmeric  tincture  an^l  sometimes  of  coal- 
tar  dyes.  In  these  cheap  extracts  the  per  cent  of  alcohol  often  runs 
below  40,  and  as  little  as  4.5%  by  volume  of  alcohol  has  been  found 
by  the  author  in  a  commercial  extract.  With  less  than  45%  of  alcohol 
by  volume,  no  appreciable  amount  of  oil  is  dissolved,  only  a  portion 
of  citrai,  though  such  preparations  are  sometimes  bottled  as  "  pure 
extract  of  lemon."  Time  and  again  manufacturers  have  protested  to 
the  author  that  the  purest  oil  was  used  by  them,  when  notified  that  their 
brand  contained  no  oil,  or  when  prosecuted  in  court,  and  were  with 
difficulty  convinced  that  the  trouble  with  their  goods  was  that,  on  account 
of  weak  alcohol  employed,  the  lemon  oil  used  failed  to  get  into  the  final 
product.  It  is  true  that  a  certain  taste  or  odor  of  the  lemon  is  present, 
even  in  cheap  varieties  wherein  no  oil  is  found,  due  to  the  fact  that 


872  FOOD   INSPECTION  ^ND    ANALYSIS. 

even  dilute  alcohol,  when  slowly  percolating  through  the  magnesia  in 
which  the  oil  is  finely  distributed,  does  abstract  therefrom  a  certain 
amount  of  citral,  which  is,  however,  but  a  mere  shadow  of  the  sub- 
stance and  body  possessed  by  a  strong  alcoholic  solution  of  oil  of 
lemon. 

In  many  instances,  where  formulas  appear  stating  the  name  and 
j_)cr  cent  of  ingredients,  these  formulas  are  entirely  deceptive  and  mis- 
leading, in  that  the  statements  are  not  borne  out  on  analysis. 

The  flavor  of  the  cheap  extracts  is  sometimes  reinforced  by  the 
addition  of  such  substances  as  citral,  oil  of  citronella,  and  oil  of  lemon- 
grass,  but  minute  quantities  only  of  these  pungent  materials  can  be  used, 
not  exceeding  0.33%  in  the  case  of  citral,  and  0.1%  in  the  case  of  the 
two  last  mentioned  oils.  Cane  sugar  and  glycerin  are  sometimes 
found. 

U.  S.  P.  tincture  of  lemon  peel  owes  its  color  to  natural  substances 
extracted  by  the  alcohol.  This  color,  however,  readily  fades  on  exposure 
to  light.  Other  coloring  matters  employed  are  largely  coal-tar  dyes, 
and  occasionally  tincture  of  turmeric  or  saffron. 

During  1901  practically  all  the  brands  of  lemon  extract  sold  in  Massa- 
chusetts were  collected  and  analyzed.  167  samples  were  examined, 
representing  about  100  brands,  and  139  samples  were  classed  as  adul- 
terated, based  on  5%  lemon  oil  as  a  standard,  and  depending  on  whether 
or  not  the  contents  conformed  to  the  labels  on  the  bottles. 

The  typical  analyses,  given  in  tables  on  p.  873,  are  selected  from  the 
tabulated  results  of  the  above  examination.* 

PVjrty-two  .samples  contained  no  lemon  oil,  ranging  in  content  of 
alcohol  from  4  to  45  per  cent. 


METHODS    OF    ANALYSIS   OF   LEMON   EXTRACT. 

A.  S.  Mitchell  was  the  earliest  among  food  chemists  to  systematically 
examine  lemon  extract,  anri  to  him  are  due  the  methods  for  determin- 
ing oil  of  lemon,  as  well  as  various  other  tests  now  adojjted  jirovision- 
ally  by  the  A.  O.  A.  C.f 

Detection  of  Oil  of  Lemon. — If  on  adding  a  large  excess  of  water 
to  a  little  of  the  extract  in  a  te.st-tuVje  no  cloudiness  occurs,  the  oil  may 


♦An.  Rep.  Mass.  State  Board  of  Health,  1901,  p.  459;    Food  and  Drug  Reprint,  p.  41. 
t  Jour.  Am.  Chem.  Soc.,  21,  1899,  p.  1132;    U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bu!. 
65,  p.  73;  Bui.  107  (rev.),  p.  159. 


FLAVORING    EXTRACTS    AND    THEIR  SUBSTITUTES. 


873 


LEMON  EXTRACTS  OF  STANDARD  QUALITY. 


Polarization 

Lemon  Oil, 

Specific 

Alcohol. 

in  200-rnm. 

Per  Cent  by 

Gravity  at 

Per  Cent  by 

Foreign  Ingredient*. 

Tube. 

Volume. 

1S.6-C. 

Volume. 

30.8 

9.1 

0.8280 

84-39 

Turmeric 

26.0 

7-6 

0.8402 

80.49 

23-5 

6.9 

0.8352 

81.74 

Diiiitrocresol 

21.8 

6.4 

0.8396 

82.88 

20.0 

5-9 

0-833.S 

84.24 

18.0 

5-3 

0.8268 

86.82 

17.0 

5-0 

0.8496 

80.06 

INFERIOR  OR  ADULTERATED  LEMON  EXTRACTS. 

Polarization 

Lemon  Oil, 

Specific 

Alcojiol, 

in  200-mm. 

Ter  Cent  by 

Gravity  at 

Per  Cent  by 

Foreign  Ingredients. 

Tube. 

Volume. 

15-6°  C. 

Volume. 

14.0 

4-1 

0.8592 

77.62 

Dinitrocresol 

12.2 

3-6 

0.8644 

76.08 

" 

II. 0 

3-1 

0.8620 

77-50 

A  coal-tar  dye 

9-9 

2.9 

0.8615 

77.90 

8.0 

2-3 

0-8531 

81.61 

Dinitrocresol 

6.8 

2.0 

0.8416 

87-55 

Troptcolin 

5-0 

1-5 

0.8832 

71. 10 

" 

3.5 

I.O 

0.8939 

67.68 

2.8 

o.S 

0.8995 

65-23 

Dinitrocresol 

2.2 

0.6 

0.8941 

67.69 

" 

1-4 

0.4 

0.9136 

59-40 

A  nitro  dve 

^■i 

0.1 

0.9408 

46.40 

Dinitroc  resol 

0.0 

0.0 

0.9937 

4-49 

Tropffiolin 

-8.0 

0.0 

Invert  sugar 

27.0 

0.0 

27.49 

Cane  sugar 

0.0 

0.0 

47-35 

Oil  other  than  lemon 

fairly  be  inferred  to  be  absent.  The  degree  of  cloudiness  produced  is 
proportional  to  the  amount  of  lemon  oil  present. 

Determination  of  Lemon  Oil. — Mitchell's  Methods. — (i)  By  Polariza- 
tion.— Polarize  the  undiluted  extract  in  a  200-mm.  tube  at  20°  C.  Divide 
the  reading  on  the  Ventzke  cane  sugar  scale  by  3.4,  and  if  cane  sugar 
or  other  optically  active  substances  arc  absent,  the  quotient  expresses 
the  per  cent  of  lemon  oil  by  volume.  With  instruments  reading  in  circular 
degrees,  divide  the  rotation  in  minutes  at  20°  C.  by  62.5.  If  the  Laurent 
instrument  with  sugar-scale  is  used,  divide  the  sugar-scale  reading  by  4.8. 

Cane  sugar,  though  rarely  found  in  lemon  extract,  is  occasionally 
used  in  small  amount.  It  is  St  id  to  aid  in  the  solution  of  the  oil.  If  it 
is  present,  wash  the  solid  residue  from  10  cc.  of  the  sample  (dried  on 
a  water-bath)  with  three  portions  of  5  cc.  each  of  ether,  to  remove  waxy 


874  FOOD   INSPECTION   AND   ANALYSIS. 

and  fatty  matters,  dn*  and  weigh  the  residue  of  cane  sugar,  deducting 
0.38  from  the  reading  for  each  0.1%  of  sugar  so  found. 

(2)  By  Precipitation. — Transfer  by  a  pipette  20  cc.  of  the  extract 
to  a  Babcock  milk-flask,  add  i  cc.  of  dilute  hydrochloric  acid  (1:1);  add 
25  to  28  cc.  of  water  previously  unarmed  to  60°  C;  mix,  and  stand  in 
water  at  60°  for  five  minutes;  whirl  in  a  centrifuge  for  five  minutes;  fill 
with  warm  water  to  bring  the  oil  into  the  graduated  neck  of  the  flask, 
and  repeat  the  whirling  for  two  minutes;  stand  in  water  at  60°  for  a  few 
minutes,  and  read  the  per  cent  of  oil  by  volume.  Where  the  oil  of  lemon  is 
present  in  amounts  over  2%,  add  to  the  percentage  of  oil  found  0.4% 
to  correct  for  the  oil  retained  in  solution.  Where  less  than  2%  and  more 
than  i^  is  present,  add  0.3'^   for  correction. 

Save  the  precipitated  oil  for  the  determination  of  refraction. 

When  the  extract  is  made  in  accordance  with  the  U.  S.  Pharma- 
copoeia, the  results  by  the  two  methods  just  given  should  agree  within 
0.2%. 

To  obtain  per  cent  by  weight  from  per  cent  by  volume,  as  found 
by  either  of  the  above  methods,  multij^ly  the  volume  percentage  by 
0.86,  and  divide  the  result  by  the  sijccific  gravity  of  the  original  ex- 
tract. 

Howard^ s  Modification  of  Mitchell's  Precipitation  Method.* — Pipette 
10  cc.  of  the  extract  in  a  Babcock  milk  bottle,  and  add  in  the  following 
order,  25  cc.  of  cold  water,  i  cc.  hydrochloric  acid  (specific  gravity  1.2), 
and  0.5  cc.  chloroform.  Close  the  mouth  of  the  bottle  with  the  thumb, 
and  shake  vigorously  for  not  less  than  one  minute.  Whirl  the  bottle 
in  a  centrifuge  for  one  and  one-half  to  two  minutes,  thus  forcing  the  chloro- 
form and  oil  to  the  bottom  of  the  bottle,  and  remove  all  but  3  or  4  cc.  of 
the  clear  su[;ernatant  liquid  by  means  of  a  glass  tube  of  small  bore 
connected  with  an  aspirator. 

To  the  residue  add  i  cc.  of  ether,  agitate  thoroughly,  ])lunge  the 
bottle  to  the  neck  in  a  boiling-water  bath,  holding  at  slight  angle,  and 
rotate  in  the  bath  for  exactly  one  minute.  This  step  is  best  carried  out 
by  removing  one  of  the  small  rings  from  a  water-  or  steam-bath  and 
holding  the  bottle  in  the  live  steam.  The  ether  serves  the  purpose 
of  steadily  and  rapidly  .sweeping  out  every  trace  of  chloroform  with- 
out   appreciable    lo.ss    of    oil.      Finally,  cool    the    bottle,  fill  nearly    to 

*  Jour.  Am.  Chem.  Soc,  30,  1908,  p.  608. 


FLAVORING   t:XTRyiCTS  AND    THEIR  SUBSTITUTES.  875 

the  top  of  the  neck  with  water  at  room  temperature,  centrifuge 
for  one-half  minute,  read  the  column  of  separated  oil  to  the  top 
m2niscus,  and  multiply  the  reading  by  two,  thus  obtaining  the  per 
cent  of  oil. 

This  method  may  also  be  used  for  determining  the  oil  in  extracts 
of  orange,  peppermint,  clove,  cinnamon,  and  cassia,  employing  in  the 
case  of  the  heavier  oils  dilute  sulphuric  acid  (1:2),  instead  of  water, 
in  filling  the  bottles  before  the  last  centrifuging. 

Determination  of  Alcohol. — Mitchell  has  shown  that  the  difference 
in  specific  gravity  between  oil  of  lemon  and  stronger  alcohol  is  not  so 
great,  but  that  a  very  close  approximation  to  the  true  percentage  of  alcohol 
in  lemon  extracts  may  be  obtained  from  the  specific  gravity  itself,  assum- 
ing, of  course,  that  foreign  substances,  such  as  sugar,  glycerin,  etc.,  are 
absent.  In  the  absence  of  such  foreign  substances  determine  the  specific 
gravity  of  the  sample,  ascertain  from  the  alcohol  tables  on  pages  661— 
674,  the  per  cent  of  alcohol  by  volume  corresponding.  This  gross  figure 
includes  the  lemon  oil,  the  per  cent  of  which  should  be  deducted  for 
the  correct  per  cent  of  alcohol. 

In  the  absence  of  oil  of  lemon,  a  measured  portion  of  the  original 
sample  may  be  distilled,  and  the  percentage  of  alcohol  determined  from 
the  distillate  in  the  usual  manner,  but  when  lemon  oil  is  present,  this 
should  first  be  removed  by  diluting  50  cc.  of  the  extract  with  water 
to  2CO  cc.  exclusive  of  the  oil  in  the  sample,  and  shaking  the  mixture 
with  5  grams  of  magnesium  carbonate  in  a  flask,  filtering  through 
a  dry  filter,  and  determining  the  alcohol  by  distillation  in  a  por- 
tion of  the  filtrate.  The  result  is  multiplied  by  4  to  correct  for  the 
dilution. 

Determination  of  Total  Aldehydes. — Chace's  Method* — i.  Reagents, 
—{a)  Aldehyde-free  Alcohol. — Allow  alcohol  (95%  by  vol.)  containing 
5  grams  of  metaphenylene  diamine  hydrochloride  per  liter  to  stand  for 
twenty-four  hours  with  frequent  shaking.  Previous  treatment  with 
potassium  hydroxide  is  unnecessary.  Boil  under  a  reflux  cooler  for  at 
least  eight  hours,  allow  to  stand  over  night  and  distil,  rejecting  the 
first  10  and  the  last  5  per  cent  which  come  over.  Store  in  a  dark, 
cool  place  in  well-filled  bottles.  25  cc.  of  this  alcohol,  on  standing 
for  twenty  minutes   in    the    cooling    bath    with     the    fuchsin   solution 

*  Jour.  Am.  Chem.  Soc,  28,  1906,  p.  1472.  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui. 
122,  p.  32. 


S;5  FOOD  INSPECTION   AND   ANALYSIS. 

(20  cc),  should  develop  only  a  faint  pink  coloration.  If  a  stronger 
color  is  developed,  treat  again  with  metaj)henylcne  diamine  hydro- 
chloride. 

{b)  Fuchsin  Solution. — Dissolve  0.5  gram  of  fuchsin  in  250  cc.  of 
water,  add  an  aqueous  solution  of  sulphur  dioxide  containing  16  grams 
of  the  gas,  and  allow  to  stand  until  colorless,  then  make  up  to  1  liter 
with  distilled  water.  This  solution  should  stand  twelve  hours  before 
using,  and  should  be  discarded  after  three  days. 

(<")  Standard  Citral  Solution. — Use  i  mg.  of  c.  p.  citral  per  cc.  in 
50^^  bv  volume  aldehyde-free  alcohol.  This  solution  deteriorates  on 
standing,  and  should  not  be  kept  over  three  or  four  days. 

2.  Apparatus. — (a)  A  Cooling  Bath. — Keep  at  from  14  to  16°  C. 
The  aldehyde-free  alcohol,  fuchsin  solution,  and  comparison  tubes  are 
to  be  kept  in  this  bath. 

{b)  Colorimeter. — Any  form  of  colorimeter,  using  a  large  volume  of 
solution  and  adapted  to  rapid  manipulation,  may  be  used. 

The  comparison  may  also  be  made  in  Nessler  or  Hehncr  tubes. 

3.  Manipulation. — Weigh  in  a  stoppered  weighing  flask  approxi- 
mately 25  grams  of  extract,  transfer  to  a  50-cc.  flask,  and  make  up  to 
the  mark  at  room  temperature  with  aldehyde-free  alcohol.  Measure  at 
room  temperature  and  transfer  to  a  comparison  tube  2  cc,  of  this  solution. 
.VJd  25  cc.  of  the  aldehyde-free  alcohol  (previously  cooled  in  a  bath), 
then  20  cc.  of  the  fuchsin  solution  (also  cooled),  and  finally  make  up  to 
the  50-cc.  mark  with  more  aldehyde-free  alcohol.  Mix  thoroughly,  stopper, 
and  place  in  the  cooling  bath  for  fifteen  minutes.  Prepare  a  standard 
for  comparison  at  the  same  time  and  in  the  same  manner,  using  2  cc.  of 
the  standard  citral  solution.  Remo^•e  and  compare  the  colors  developed. 
Calculate  the  amount  of  citral  jjrescnt  and  repeat  the  determination, 
using  a  quantity  sufficient  to  give  the  sample  approximately  the  strength 
of  the  standard.  From  this  result  calculate  the  amount  of  citral  in  the 
.sam[>le.  If  the  comparisons  are  made  in  Nessler  tubes,  standards  con- 
taining I,  1.5,  2,  2.5,  3,  3.5,  and  4  mg.  should  be  prepared,  and  the  trial 
comparison  made  again.st  these,  the  final  comjjarison  being  made  with 
standards  between  1.5  and  2.5  mg.,  varying  but  0.25  mg. 

It  is  ab.solutely  cs.scntial  to  keep  the  reagents  and  comj)arison  tubes 
at  the  required  temperature.  Comparisons  should  be  made  within  one 
minute  after  removing  the  tubes  from  the  bath.  Where  the  comparisons 
are  made  in  the  bath  (this  being  possible  only  where  the  bath  is  glas.s), 
the    standards    should    be    discarded    within    twenty-five    minutes    after 


FLAVORING  EXTRACTS  AND    THEIR  SUBSTITUTES.  877 

adding   the   fuchsin  solution.      Give    samples    and    standards    identical 
treatment. 

Determination  of  Citral.  —  Hiltne/s  Method* — i.  Reagents. — (a) 
Metaphenylene  Diamine  Hydrochloride  Solution. — Prepare  a  1%  solution 
in  50%  ethyl  alcohol.  Decolorize  by  shaking  with  fuller's  earth  or  animal 
charcoal,  and  filter  through  a  double  filter.  The  solution  should  be 
bright  and  clear,  free  from  suspended  matter  and  practically  colorless. 
It  is  well  to  prepare  only  enough  solution  for  the  day's  work,  as  it  darkens 
on  standing.  The  color  may  be  removed  from  old  solutions  by  shaking 
again  with  fuller's  earth. 

(b)  Standard  Citral  Solution. — Dissolve  0.250  gram  of  c.  p.  citral 
in  50%  ethyl  alcohol  and  make  up   the  solution  to  250  cc. 

(c)  Alcohol. — For  the  analysis  of  lemon  extracts,  90  to  95  per  cent 
alcohol  should  be  used,  but  for  terpeneless  extracts  alcohol  of  40  to  50 
per  cent  strength  is  sufficient.  Filter  to  remove  any  suspended  mat- 
ter. The  alcohol  need  not  be  purified  from  aldehyde.  If  not  prac- 
tically colorless,  render  slightly  alkaline  with  sodium  hydroxide  and 
distil. 

2.  Apparatus. — The  Schreiner  colorimeter  (page  77)  or  Eggertz 
tubes  may  be  used.  With  this  latter  apparatus,  alcohol  is  added,  small 
quantities  at  a  time,  to  the  stronger  colored  solution  until  after  shaking 
and  viewing  transversely,  the  colors  in  the  two  tubes  are  exactly  matched. 
Calculations  are  then  made  by  establishing  a  proportion  between  the 
volumes  of  samples  taken  and  the  final  dilutions. 

3.  Manipulation. — All  of  the  operations  may  be  carried  on  at  room 
temperature.  Weigh  into  a  50-cc.  graduated  flask  25  grams  of  the 
extract,  and  make  up  to  the  mark  with  alcohol  (90-95  per  cent).  Stopper 
the  flask  and  mix  the  contents  thoroughly.  Pipette  into  the  colorimeter 
tube  2  cc.  of  this  solution,  add  10  cc.  of  metaphenylene  diamine  hydro- 
chloride reagent,  and  complete  the  volume  to  50  cc.  (or  other  standard 
volume)  with  alcohol.  Compare  at  once  the  color  with  that  of  the 
standard,  which  should  be  prepared  at  the  same  time,  using  2  cc.  of 
standard  citral  solution  and  10  cc.  of  the  metaphenylene  diamine  reagent, 
and  making  up  to  standard  volume  with  alcohol.  From  the  result  of 
this  first  determination,  calculate  the  amount  of  standard  citral  solution 
that  should  be  used  in  order  to  give  approximately  the  same  citral 
strength  of  the  sample  under  examination,  then  repeat  the  determination. 

*  A.  O.  A.  C.  Proc,  1908,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  122,  p.  34.    Jour. 
Tnd.  Eng.  Chem.,  i,  iqog,  p.  798. 


S78  FOOD  INSPECTION  AND  ANALYSIS. 

Methyl  Alcohol  has  been  used  by  unscrupulous  manufacturers  in 
lemon  extracts.  It  is  detected  and  determined  by  the  refractometer 
method  of  Leach  and  Lythgoe  (page  749). 

As  a  confirmatory  test  for  methyl  alcohol  the  distillate,  after  testing 
bv  the  Leach  and  Lythgoe  method,  may  to  advantage  be  subjected  to 
the  method  of  MuUiken  and  Scudder,*  which  depends  on  the  conversion 
of  the  methyl  alcohol  to  formaldehyde.  The  latter  method  is  also  useful 
as  a  rough  preliminary  test  on  the  original  extract  without  distillation, 
the  extract,  being,  however,  first  diluted  until  the  liquid  contains  a])proxi- 
mately  12%  by  weight  of  alcohol,  shaking  with  magnesium  carbonate, 
and  tiltering  when  lemon  oil  is  present. 

Oxidize  10  cc.  of  the  liquid  in  a  test-tube  as  follows:  Wind  copper 
wire  I  mm.  thick  uj)on  a  rod  or  pencil  7  to  8  mm.  thick,  in  such  a  manner 
as  to  inclose  the  fixed  end  of  the  wire,  and  to  form  a  close  coil  3  to  3.5  cm. 
long.  Twist  the  two  ends  of  the  wire  into  a  stem  20  cm.  long,  and  bend 
the  stem  at  right  angles  about  6  cm.  from  the  free  end,  or  so  that  the 
coil  may  be  plunged  to  the  bottom  of  a  test-tube,  preferably  about  16  mm. 
wide  and  16  cm.  long.  Heat  the  coil  in  the  upper  or  oxidizing  flame  of 
a  Bunsen  burner  to  a  red  heat  throughout.  Plunge  the  heated  coil  to 
the  bottom  of  the  test-tube  containing  the  diluted  alcohol.  Withdraw 
the  coil  after  a  second's  time  and  dip  it  in  water.  Repeat  the  operation 
from  three  to  five  times,  or  until  the  film  of  copper  oxide  ceases  to  be 
reduced.  Cool  the  liquid  in  the  test-tube  meanwhile  by  immersion  in 
cold  water. 

Test  for  Formaldehyde. — Divide  the  oxidized  liquid  in  the  test-tube 
into  two  parts,  testing  one  for  formaldehyde  with  pure  milk  by  the 
hvdrochloric  acid  and  ferric  chloride  test.  Test  the  other  portion  by 
Mulliken  and  Scudder's  resorcin  test  for  formaldehyde,  page  826,  avoid- 
ing an  excess  of  the  reagent. f 

Tests  for  Colors. — Evaporate  a  portion  of  the  sample  to  dryness^, 
disbolvc  the  residue  in  water,  and  extract  coal-tar  colors  if  present  by 
Arata's  method,  page   796,  or  with  hydrochloric  acid. 

Much  information  may  ofien  be  gained  by  treatment  of  the  original 
extract  with  strong  hydrochloric  acid.  If  the  color  employed  be  turmeric^ 
no  change  in  color  will  be  evident  on  addition  of  the  acid.  If  tropaeolin 
or  methyl  orange  is  present,  the  solution  will  turn  pink,  while  partial 
decoloration  of  the  .solution  indicates  naphthol  yellow  S,  and  complete 
decoloration  shows  presence  of  dinitrocresols  or  naphthol  yellow. 

*  .\m.  Chcm.  Jour.,  23,  1899,  p.  26O.  f  I^^'d  .  24,  1900,  p.  451. 


FLAVORING  EXTRACTS   AND    THEIR  SUBSTITUTES.  879 

Test  for  turmeric  by  boric  acid,  page  791. 

Detection  of  Lemon  and  Orange  Peel  Coloring  Matter.— A Ibrech 
Method* — Place  a  few  cubic  centimeters  of  the  extract  in  a  test-tube 
and  add  slowly  3  or  4  volumes  of  concentrated  hydrochloric  acid.  Place 
a  few  cubic  centimeters  of  the  extract  in  a  second  lube  and  add  several 
drops  of  concentrated  ammonia.  In  the  presence  of  lemon  or  orange 
peel  color  the  yellow  tint  of  the  original  extract  will  be  materially  deep- 
ened in  both  cases. 

Determination  of  Total  Solids  and  Ash. — Total  Solids  are  estimated 
by  evaporating  on  the  waler-bath  10  grams  of  the  sample  in  a  tared  dish, 
and  drying  at  100°  to  constant  weight.  If  glycerin  be  present,  it  is  dif- 
ficult if  not  impossible  to  get  a  constant  weight.  Cane  sugar  and  glycerin, 
if  present,  will  be  apparent  in  the  residue.  If  capsicin  has  been  used, 
it  will  be  noticed  by  the  taste. 

Burn  to  an  ash  the  residue  from  the  solids  in  a  muffle  at  a  low  red 
heat,  cool  in  a  desiccator,  and  weigh. 

Glycerin  is.  determined  as  in  wine,  page  703. 

Detection  of  Tartaric  or  Citric  Acid. — To  a  portion  of  the  extract 
in  a  test-tube  add  an  equal  volume  of  water  to  precipitate  the  oil.  Filter 
and  add  one  or  two  drops  of  the  filtrate  to  a  test-tube  half  full  of  cold, 
clear  lime  water.  If  tartaric  acid  is  present,  a  precipitate  will  come 
down,  which  is  soluble  in  an  excess  of  ammonium  chloride  or  acetic  acid. 

Filter  off  the  precipitate,  or,  if  no  precipitate  is  visible,  heat  the  con- 
tents of  the  tube.  Citric  acid  will  precipitate  in  a  large  excess  of  hot 
lime  water. 

Examination  of  Lemon  Oil. — The  oil  separated  from  the  extract  in 
the  process  of  determining  the  lemon  oil  by  precipitation  (p.  874) ,  is 
most  readily  examined  for  its  purity,  after  drying  with  calcium  chloride, 
by  determination  of  its  specific  gravity,  its  index  of  refraction,  or  its 
refractometric  reading  with  the  Zeiss  butyro-refractometer,  and  its  polari- 
scopic  reading. 

The  specific  gravity  and  refractometric  readings  are  determined  as 
with  fixed  oils,  using  with  the  butyro-refractometer  a  sodium  flame  or 
yellow  bichromate  color-screen,  which  gives  perfectly  sharp  readings 
without  dispersion. 

The  first  table  on  page  880  shows  readings  on  the  Zeiss  butyro- 
refractometer  of  pure  lemon  oil  at  various  temperatures,  using  the 
sodium  hght. 

*  A.O.A.C.  Method,  Proc.  for  19 10,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  137,  p.  71. 


88o 


FOOD  INSPECTION  AND   ANALYSIS. 


For  examination  of  high  polarizing  essential  oils  like  oil  of  lemon, 
the  author  employs  a  50-mm.  tube,  in  order  to  get  the  readings  on  the 
undiluted  oil  well  within  the  limits  of  the  cane  sugar  scale  on  the  polar- 
iscope.  If  such  a  tube  is  not  available,  dilute  the  oil  with  an  equal 
volume  of  alcohol,  and  use  the  loo-mm.  tube.  The  second  table  given 
below  expresses  constants  of  pure  lemon  oils  and  of  various  commonly 
employed  adulterants,  as  determined  in  the  laboratory  of  the  Massa- 
chusetts State  Board  of  Health. 


READINGS  ON  ZEISS  BUTYRO-REFRACTOMETER  OF  LEMON   OIL. 


Tempera- 

1 
Scale      ' 

Tempera- 

Scale 

Tempera- 

Scale 

Tempera- 

Scale 

ture. 
Centigrade. 

Readinig.  ' 

[ 

ture, 
Centigrade. 

Reading. 

ture, 
Centigrade. 

Reading. 

ture. 
Centigrade. 

Reading. 

40.0 

i 
59-4      1 

35-0 

62.8 

30.0 

66.3 

25.0 

69.7 

39-5 

59-7 

,       34-5 

63.1 

29-5 

66.6 

24-5 

70.0 

39-0 

60.1 

34-0 

63-5 

29.0 

67.0 

24.0 

70.4 

38.5 

60.4 

33-5 

63.8 

28.5 

67-3 

23-5 

70.7 

3S.0 

60.8 

2,:>,-o 

64.2 

28.0 

67-7 

23.0 

71. 1 

37-5 

61.0 

32-5 

64-5 

27-5 

68.0 

22.5 

71.4 

37-0 

61-S 

32.0 

64.9 

27.0 

68.4 

22.0 

71.8 

36.5 

61.8 

31-5 

65-1 

26.5 

68.7 

21.5 

72.1 

36.0 

62.1 

31.0 

65.6 

26.0 

69.0 

2I-0 

7^-5 

35-5 

62.4 

30-5 

65-9 

25-5 

69-3 

20.5 

72.8 

iS-^ 

•62.8 

30.0 

66.3 

25.0 

69.7 

20.0 

73-2 

CONSTANTS  OF  SOME  ESSENTIAL  OILS. 


OiL 


Oil  of  lemon  (lowest) 

"    "       "      (highest) 

"    "       "      grass  {.\.  Gicse) 

"    "  citronella  (A.  Giese) 

Terpeneless  oil  of  lemon  (Hansel's) 

"  grass  (Hansel's) 

Cilral  {.\.  Giese) 


Butyro-refractometer 

(Sodium  Light)  at — 


Temp. 


Reading. 


71.2 
96.9 
87.1 

87-9 
91.0 

95 -o 


Rotation 
in  100- 
Millimeter 

Tube, 

Ventzke 

Scale. 


173-0 

184.5 

-10.8 

—  10.2 

—  22.0 
-5-6 
-^.6 


Specific 

Gravity 

at  i5.6°C. 


0.8580 
0.S610 
0.9309 

0-Q437 
0.9463 
0.9232 
0.9296 


Oil  of  Lemon  is  a  light-yellow  liquid,  having  the  pleasant  odor  of 
ircsh  lemons,  and  an  aromatiq,  mild,  .somewhat  bitter  after  taste.  It 
is  obtained  from  the  grated  rind  of  the  lemon  either  by  treatment  with 
hot  water,  skimming  off  the  oil  which  rises  to  the  surface,  or  by  pressure, 
or  by  distillation  with  water.  It  is  rapidly  changed  by  action  of  air  and 
light,  Vxrcoming  "terpeney,"  and  under  these  conditions  its  solubility 
in  alcohol  seems  to  increase.     Its  composition  is  somewhat  uncertain, 


FLAVORING  EXTRACTS  AND    THEIR  SUBSTITUTES.  88l. 

but  according  to  Wallach  *  nearly  90%  consists  of  hydrocarbons,  mostly 
terpenes,  the  most  important  of  n-hich  is  the  terpene  limonene  t  of  the 
dextro-gyrate  variety,  also  known  as  citrene. 

Another  important  constituent  of  lemon  oil  is  the  aldehyde  citral, 
present  to  the  extent  of  from  4  to  5  per  cent.  To  this  the  odor  of  the 
oil  is  largely  due.     A  second  aldehyde,  citronellal,  is  also  present. 

A  frequent  adulterant  of  lemon  oil  is  turpentine  oil,  which  lowers 
the  rotation  considerably,  and  is  thus  most  easily  rendered  apparent. 

Chace  %  detects  small  quantities  of  turpentine  by  the  difference  in 
crystalline  form  of  ])inene  nitroso-chloride  from  that  of  limonene  nitroso- 
chloride. 

Citral  (CioH,gO)  is  an  aldehyde  present  in  lemon  oil  and  in  oil  of 
lemon-grass,  and,  while  it  may  be  separated  from  these  oils,  is  prepared 
artificially  by  oxidizing  geraniol  with  chromic  acid.§  It  is  a  mobile  oil,  and 
when  perfectly  pure  is  optically  inactive.  The  commercial  citral  is, 
however,  slightly  laevo-rotary,  due  no  doubt  to  impurities. 

Oil  of  Lemon-grass  is  distilled  from  lemon-grass,  Andropogon  citratus 
(D.  C),  cultivated  in  India.  It  is  reddish  yellow  in  color,  and  has  an 
intense  lemon-like  odor  and  taste.  Very  little  is  known  of  its  composi- 
tion, but  it  seems  to  contain  several  aldehydes,  one  of  which  is  citro- 
nellal, and  another  citral.  The  latter,  however,  is  its  chief  constituent, 
being  present  to  the  extent  of  70  to  75  per  cent. 

Citronellal  (CioHjgO)  is  an  aldehyde  found  in  various  oils,  especially 
in  citronella  oil,  from  which  it  is  readily  separated.  It  is  made  artificially 
by  the  oxidation  of  the  primary  alcohol  citronellol  (CjoHjoO).  It  is 
quite  strongly  dextro-rotar}-. 

Oil  of  Citronella  is  distilled  from  the  grass  Andropogon  nardus  (L.), 
growing  chiefly  in  Ceylon,  India,  and  tropical  East  Africa.  It  is  a  yel- 
lowish-brown liquid  with  a  pleasant  and  lasting  odor.  Citronellal  is 
present  in  this  oil  to  the  extent  of  from  10  to  20  per  cent,  and  the  oil 
contains  also  from  10  to  15  per  cent  of  terpenes,  among  which  are 
camphenc. 

Tests  for  Citral,  Citronellal,  and  Limonene.  || — Shake  2  cc.  of  the 
sample  to  be  examined  in  a  corked  test-tube  with  5  cc.  of  a  solution  of 

*  Liebig's  Annalen,  227,  p.  290. 

t  There  are  two  limoncnes,  one  of  which  is  dextro-  and  the  other  lavo-rotary.     The 
two  are  completely  alike  in  their  behavior,  differing  only  in  their  optical  rotation. 
X  Jour.  Am.  Chem.  Soc,  30,  190S.  p.   1475. 
§  Tiemann,  Berichte,  31,  p.  2>i^^- 
II  Burgess,  Chem.  and  Drugg.,  57,  p.  73-2. 


SSz  FOOD    INSPECTION  AND    ANALYSIS. 

I 

lo  grams  of  mercuric  sulphate  in  sutVicient  25'^;,  sulphuric  acid  to  make 
100  cc.  Citral  yields  a  bright-red  color,  which  rapidly  disappears,  leav- 
ing a  whitish  compound,  which  floats  on  top.  Citronellal  forms  a  bright- 
yellow  color,  remaining  for  some  time.  Limonene  forms  an  evanescent^ 
faint  flesh  color,  and  leaves  a  white  compound. 

METHODS  OF  ANALYSIS  OF  LEMON  OIL. 

The  following  are  the  methods  of  the  A.O.A.C.*  They  apply  to 
orange  as  well  as  lemon  oil. 

Determination  of  Specific  Gravity. — Determine  the  specific  gravity 
by  means  of  a  pvcnonieler  or  a  S})rengel  tube  at  15.6°  C. 

Determination  of  Index  of  Refraction. — Determine  the  index  of  refrac- 
tion with  any  standard  instrument,  making  the  reading  at  20°  C, 

Determination  of  Rotation. — Determine  the  rotation  at  20°  C.  with 
any  standard  instrimient  using  a  50-mm.  tube  and  sodium  light.  The 
results  should  be  stated  in  angular  degrees  on  a  100-mm.  basis,  if 
instruments  having  the  sugar  scale  are  used,  the  reading  on  orange  oils 
is  above  the  range  of  the  scale,  but  readings  may  be  obtained  by  the  use 
of  standard  laevo  reading  (juartz  plates. 

Determination  of  Citral. — Kleber  Method. — i.  Reagents. — (a)  Phenyl 
Hwirazin. — A  loVo  solution  of  the  purified  chemical  in  absolute  alcohol. 
A  sufliciently  pure  product  can  be  obtained  by  rectiiication  of  the  com- 
mercial article,  rejecting  the  first  portions  coming  over  which  contain 
ammonia. 

(b)  Hydrochloric  Acid. — A  half  normal  solution. 

2.  Manipulation. — Weigh  15  grams  of  the  sample  into  a  small  glass- 
stoppered  flask;  add  jo  cc.  of  the  phenyl  hydrazin  solution.  After  allow- 
ing to  stand  for  half  an  hour  at  room  tem])eraturc,  titrate  with  half 
normal  hydrochloric  acid,  using  either  methyl  or  ethyl  orange  as  indicator. 
Titrate  10  cc.  of  the  phenyl  hydrazin  reagent  in  the  same  manner.  The 
diflerence  in  cubic  centimeters  of  half  normal  ac  ids  between  this  titra- 
tion and  that  of  the  sam[)le,  multiplied  by  the  factor  0.076,  gives  the 
weight  of  citral  in  the  sample. 

If  difficulty  is  experienced  in  detecting  the  end  jjoint  of  the  reaction, 
carrv'  out  the  titration  until  the  solution  is  distinctly  acid,  transfer  to 
a  scparatory  funnel,  and  draw  off  the  alcoholic  portion.  Wash  the  oil 
with  water,  ad.iing  the  washings  t(;  the  alcoholic  solution,  and  titrate 
back  with  half  normal  alkali,  making  the  necessary  corrections. 
*U.  S.  Dept.  of  Agric,  Hul.  1.37,  igii,  p.  72. 


FLAVORING   EXTRACTS    AND    THEIR    SUBSTITUTES.  883 

Hiltner  Method. — Proceed  a3  under  lemon  extract  (p.  877)  weighing 
2  grams  of  the  oil,  diluting  to  100  cc,  and  using  2  cc.  of  this  solution  for 
the  comparison. 

Determination  of  Total  Aldehydes. — Proceed  as  under  lemon  extract 
(p.  875),  using  from  2  to  5  grams  of  the  sample  in  100  cc.  of  aldehyde- 
free  alcohol.  This  method  should  be  used  on  orange  oils  the  aldehydes 
of  which  are  not  determined  by  the  other  methods,  although  valuable 
information  as  to  the  content  of  added  citral  in  the  oil  can  be  obtained  by 
use  of  the  Hiltner  method. 

Determination  of  Physical  Constants  of  the  Ten  Per  Cent  Distillate. 
Schimmel  &  Co.  M etJiod. —Flace  50  cc.  of  the  sample  in  a  3-bulb  Laden- 
burg  flask  in  which  the  main  bulb  has  a  diameter  of  6  cm.  and  is  of 
200  cc.  capacity  and  which  has  the  condensing  bulbs  of  the  following 
dimensions:  5.5  cm.,  5  cm.,  2.5  cm.,  and  in  which  the  distance  from 
the  bottom  of  the  flask  to  the  opening  of  the  side  arm  is  20  cm.  Distil 
the  oil  at  the  rate  of  2  cc.  per  minute  until  5  cc.  have  been  distilled. 
Determine  the  refractive  index  and  rotation  of  this  distillate  as  directed 
above. 

Detection  of  Pinene. — Chace  Method. — Mix  the  io%  distillate  as 
obtained  above  with  5  cc.  of  glacial  acetic  acid,  cool  the  mixture  thoroughly 
in  a  freezing  bath,  and  add  10  cc.  of  ethyl  nitrite;  then  add  slowly,  with 
constant  shaking,  2  cc.  of  a  mixture  of  2  parts  concentrated  hydrochloric 
acid  and  i  part  water  which  has  been  previously  cooled.  Keep  this 
mixture  in  the  freezing  bath  during  this  operation  and  allow  it  to  remain 
therein  for  15  minutes.  Filter  off  the  crystals  formed,  using  vacuum  and 
washing  with  strong  alcohol.  Return  the  filtrate  and  washings  to  the 
freezing  bath  and  allow  them  to  remain  for  15  minutes.  Filter  off  the 
crystals  formed,  using  the  original  filter-paper.  Wash  the  two  crops  of 
crystals  thoroughly  with  alcohol.  Dry  at  room  temperature  and  dis- 
solve in  the  least  possible  amount  of  chloroform.  Reprecipitate  the  nitroso- 
chloride  crystals  with  methyl  alcohol  and  mount  for  examination  under 
the  microscope  with  olive  oil.  Pinene  nitroso-chloride  crystals  have 
irregular  pyramidal  ends  while  limonene  nitroso-chloride  crystallizes  in 
needle  forms. 

Determination  of  Alcohol.— The  amount  of  alcohol  present  in  oils 
which  have  been  used  for  the  manufacture  of  terpeneless  extracts  may 
be  approximately  determined  by  washing  repeatedly  with  small  portions 
•of  saturated  sodium  chloride  solution  and  determining  the  alcohol  in 
these  washings  in  the  usual  way. 


SS4  FOOD  INSPECTION   AND  ANALYSIS. 

ORANGE  EXTRACT. 

Orange  Oil  is  a  yellowish  li(]uid,  having  the  characteristic  odor  of 
orange,  and  a  mild  aromatic  taste.  It  is  prepared  from  orange  peel  in 
an  analogous  manner  to  that  of  lemon  oil,  which  it  somewhat  resembles 
in  chemical  comj)osition.  At  least  90%  of  orange  oil,  according  to 
Walach.  consists  of  dextro-hmonene  (citrene).  It  has  a  much  higher 
specific  rotatory  ])ower  than  lemon  oil. 

U.  S.  Standards. — Oil  of  Orange  is  the  volatile  oil  obtained,  by 
expression  or  alcoholic  solution,  from  the  fresh  peel  of  the  orange  {Citrus 
auraniium  L.)  and  has  an  optical  rotation  at  25°  C.  of  not  less  than 
+  95°  in  a  loo-mm.  tube. 

Terperteless  Oil  of  Orange  is  oil  of  orange  from  which  all  or  nearly 
all  of  the  terpcnes  have  been  removed. 

Orange  Extract  is  the  flavoring  extract  prepared  from  oil  of  orange, 
or  from  orange  peel,  or  both,  and  contains  not  less  than  5%  by  volume 
of  oil  of  orange. 

Tcrpenclcss  Extract  of  Orange  is  the  flavoring  extract  prepared  by 
shaking  oil  of  orange  with  dilute  alcohol,  or  by  dissolving  terpeneless 
oil  of  orange  in  dilute  alcohol,  and  corresponds  in  flavoring  strength 
to  orange  extract. 

Method  of  Analysis,— Orange  oil  and  orange  extract  are  analyzed  by 
the  same  methods  as  lemon  oil  (p.  882)  and  lemon  extract  (p.  872). 

In  the  determination  of  orange  oil  by  Mitcheirs  polariscopic  method 
divide  the  direct  reading  on  the  Ventzke  scale,  calculated  for  the  200  mm. 
tube,  by  5.3  to  obtain  the  \)Qx  cent  of  orange  oil  by  volume.  To  obtain 
the  per  cent  by  weight,  multiply  the  per  cent  by  volume  by  0.85  and 
divide  by  the  specific  gravity  of  the  extract. 

ALMOND   EXTRACT. 

Oil  of  Bitter  Almonds  is  obtained  by  distilling  crushed  bitter  almonds, 
peach  .seeds,  or  apricot  seeds  with  water.  It  should  be  remembered  that 
both  sweet  and  bitter  almonds  yield  a  bland  fixerl  oil  on  pressure,  which  is 
not  to  be  confounded  with  the  volatile  oil  yielded  on  distillation  of  the  bitter 
almonds  after  the  fixed  oil  has  been  pressed  out.  Bitter  almonds  contain 
a  glucoside,  amygdalin,  together  with  a  ferment  known  as  emulsin  or 
s>Tiaptase,  which,  acting  on  the  amygdalin  in  the  distillation,  produces 
benzaldehydc  and  hydrocyanic  acid  as  follows: 


FLAyORlNG    EXTRACTS   AND    THEIR   SUBSTITUTES.  88$ 

C20H27NO11   +   2H2O   -   C^H^O   +  HCN    f   2C6H,20e. 

Amygdalin  Benzalde-  Hydro-  Glucose 

hyde  cyanic  acid 

The  unpurified  oil  of  bitter  almonds  consists  largely  of  bcnzaldehyde, 
with  a  small  amount  of  the  poisonous  hydrocyanic  acid.  Nearly  all 
of  the  commerical  oil  is  made  from  the  cheaper  ajjricot  and  peach  seeds 
rather  than  those  of  the  bitter  almond,  but  the  j;roduct  is  practically 
identical.  The  oil  is  freed  from  hydrocyanic  acid  by  agitating  with 
calcium  hydrate  and  a  solution  of  ferrous  chloride,  distilling  the  mixture, 
and  drying  the  oil  which  comes  over  with  calcium  chloride. 

Benzaldehyde  constitutes  90  to  95  per  cent  of  oil  of  bitter  almonds, 
having  a  bitter,  acrid,  burning  taste,  and  a  marked  almond  odor.  The 
specific  gravity  of  the  crude  oil  varies  from  1.052  to  1.082,  while  that 
of  the  purified  oil  (benzaldehyde)  at  20°  is  1.0455.  Its  boiling-point  is 
180°  C,  On  standing  it  becomes  readily  oxidizable  to  benzoic  acid.  It 
is  readily  soluble  in  alcohol  and  ether.  Its  solubility  in  water  is  slight, 
1:300.  Its  index  of  refraction  at  20°  C.  is  1.5446.  It  should  be  noted 
that  the  refractive  indices  of  almond  oil,  whether  with  or  without  hydro- 
cyanic acid,  and  of  artificial  benzaldehyde  are  nearly  the  same. 

Benzaldehyde  is  produced  artificially  in  a  variety  of  ways,  but  is 
chiefly  prepared  by  the  action  of  chlorine  on  hot  toluene.  The  result- 
ing benzyl  chloride  is  distilled  with  lead  nitrate  and  water  in  an  atmos- 
phere of  carbon  dioxide,  which  forms  benzoic  aldehyde.  Synthetic 
benzaldehyde  has  the  same  properties  as  the  purified  oil  of  bitter  almonds, 
and  has  largely  displaced  it  in  the  market,  not  the  least  of  its  advantages 
being  its  freedom  from  hydrocyanic  acid. 

Almond  Extract. — Essence  of  bitter  almonds,  or  Spirilus  amygdalcB 
amar(2,  is  thus  prepared  according  to  the  U.  S.  Pharmacopoeia: 

Oil  of  bitter  almonds 10  cc. 

Alcohol 800  cc. 

Distilled  water  sufiicient  to  make 1000  cc. 

Thus  1%  of  almond  oil  is  present  in  the  product. 

U.  S.  Standards. — Oil  of  Bitter  Almonds,  commercial,  is  the  volatile 
oil  obtained  from  the  seed  of  the  bitter  almond  (Amygdalus  communis 
L.),  the  apricot  {Prunus  armeniaca  L.),  or  the  peach  {Amygdalus  persica 

Almond  Extract  is  the  flavoring  extract  prepared  from  oil  of  bitter 


SS6  FOOD  INSPECTION   AND   ANALYSIS. 

almonds,  free  from  hydrocyanic  acid,  and  contains  not  less  than  i% 
by  vokime  of  oil  of  bitter  almonds. 

Adulteration  of  Almond  Oil. — The  official  essence  of  the  Pharma- 
copoeia does  not  specify  that  the  almond  oil  used  be  perfectly  free  from 
hydrocyanic  acid,  in  spite  of  the  fact  that  its  highly  poisonous  nature  is 
well  known,  and  that  it  exists  in  the  crude  oil  to  the  extent  of  from  4  to 
b  per  cent.  True,  but  little  of  it  is  found  in  the  extract,  but  in  these  days, 
when  the  unannounced  jjresence  in  foods  of  such  substances  as  antiseptics 
and  coloring  matters  is  regarded  as  questionable  from  a  sanitary  stand- 
point, in  spite  of  the  fact  that  their  toxic  effects  on  man  are  still  matters 
of  controversy,  there  thould  be  little  hesitancy  in  pronouncing  the  presence 
of  prussic  acid  objectionable,  especially  when  a  pure  almond  oil  entirely 
free  from  it  is  readily  obtainable. 

The  presence  of  nitrobenzol  or  oil  of  mirbane  as  a  substitute  of 
almond  oil  is  to  be  looked  for.  This  substance  is  sometimes,  though 
incorrectly,  called  artificial  oil  of  bitter  almonds.  It  is  a  heavy,  yellow 
liquid  of  the  composition  CgHgNOg,  readily  soluble  in  water.  Its  specific 
gravity  at  20°  C.  is  1.2039.  ^^s  boihng-point  is  205°  C.  It  is  formed 
by  the  action  of  nitric  acid  on  benzol.  It  possesses  a  highly  pungent 
odor,  somewhat  like  that  of  oil  of  bitter  almonds,  though  more  penetrating 
and  less  refined.     Its  index  of  refraction  at  20°  C.  is  1.55 17. 

METHODS    OF   ANALYSIS    OF  ALMOND    EXTRACT. 

Determination  of  Benzaldehyde. — Denis  and  Dunbar  Method.'^ — i. 
Reagent. — Mix  30  cc.  of  glacial  acetic  acid  with  40  cc.  of  water,  then 
pour  in  2  cc.  of  phenyl  hydrazine.  The  reagent  should  be  made  up 
immediately  before  use  and  discarded  when  more  than  an  hour  old. 

2.  Method. — Measure  out  two  portions  of  10  cc.  each  of  the  extract 
into  300-cc.  Erlenmeyer  flasks  and  add  10  cc.  of  the  reagent  to  one  flask 
and  15  cc.  to  the  other.  Shake,  stopper  tightly,  and  allow  to  stand  in  a 
dark  place  over  night.  Add  200  cc.  of  distilled  water  and  filter  the 
precipitate  of  hydrazone  on  a  tared  Gooch  crucible  provided  with  a  thin 
coat  of  asbestos.  Wash  first  with  cold  water,  finally  with  10  cc.  of  10% 
alcohol,  and  dr>'  for  three  hours  in  a  vacuum-oven  at  70°  C,  or  to  con- 
stant weight  over  sulphuric  acid.  The  weight  of  the  precipitate  multi- 
plied by  the  factor  5.408,  will  give  the  weight  of  benzaldehyde  in  too  cc. 
of  the  sample.  If  duplicate  determinations  do  not  agree,  repeat  the 
operations,  using  a  larger  c^uantity  of  the  reagent. 

*  Jour.  Ind.  Eng.  Chem.,  i,  1909,  p.  256,  A.  O.  A.  C.  Method. 


FLAVORING    EXTRACTS   AND    THEIR   SUBSTITUTES.  087 

Hortvet  and  West  Method* — Measure  10  cc.  of  the  extract  into  a 
loo-cc.  flask,  add  10  cc.  of  a  10%  sodium  hydroxide  solution,  and  20  cc. 
of  a  3%  hydrogen  peroxide  solution,  cover  with  a  watch-glass  and  place 
on  a  water-oven.  Oxidation  of  the  aldehyde  to  benzoic  acid  begins 
almost  immediately  and  should  be  continued  from  five  to  ten  minutes 
after  all  odor  of  Ijcnzaldehyde  has  disappeared,  which  usually  requires 
from  twenty  to  thirty  minutes.  If  nitrobenzol  be  present,  it  will  be 
indicated  at  this  point  by  its  odor.  When  the  oxidation  of  the  aldehyde 
is  complete,  remove  the  flask  from  the  water-oven,  transfer  the  contents 
to  a  separatory  funnel,  rinsing  off  the  watch-glass,  add- 10  cc.  of  a  20% 
sulphuric  acid  solution,  and  cool  the  contents  of  the  funnel  to  room 
temperature  under  the  water  tap.  Extract  the  benzoic  acid  with  three 
portions  of  50,  30,  and  20  cc.  of  ether,  respectively,  wash  the  combined 
extracts  in  another  separatory  funnel  with  two  portions  of  from  25  to 
30  cc.  of  distilled  water,  or  until  all  the  sulphuric  acid  is  removed.  Filter 
into  a  tared  dish,  wash  with  ether,  allow  to  evaporate  at  room  tempera- 
ture, and  finally  dry  over  night  in  a  desiccator,  and  weigh.  The  per 
cent  of  benzaldehyde  (B)  is  obtained  from  the  weight  of  the  acid  (W) 
by  the  following  formula: 

^     0.869  X 10  XH' 
1.045 

If  desired  the  benzoic  acid  may  be  titrated,  and  the  benzaldehyde 
calculated  from  the  amount  of  standard  alkah  required  for  neutraliza- 
tion. The  process  is  as  follows:  Dissolve  the  benzoic  acid  obtained  as 
above  described,  except  that  it  need  not  be  dried  in  a  desiccator,  in  95% 
alcohol  made  neutral  to  phenolphthalein  with  tenth-normal  sodium 
hydroxide,  dilute  with  an  equal  volume  of  water,  and  titrate  with  tenth- 
normal sodium  hydroxide,  using  phenolphthalein  as  indicator.  The 
per  cent  of  benzaldehyde  (B)  is  calculated  from  the  cc.  of  tenth-normal 
alkali  (F)  by  the  following  formula: 

FXo.oio6iXto 
B— . 

I-045 
Detection  of  Nitrobenzol.t — Boil   15  cc.  of  the  extract  in  a  test-tube 
with  a  few  drops  of  a  strong  solution  of  potassium  hydroxide.     Nitro- 
benzol produces  a  blood-red  coloration. 

*  Jour.  Ind.  Eng.  Chem.,  i,  1909,  p.  86. 

t  Holde,  Jour.  Soc.  Chem.  Ind.,  13,  1S93,  p.  906. 


888  FOOD   JNSPECTIOK  AND   ANALYSIS. 

Distinction  between  Benzaldehyde  and  Nitrobenzol. — Treat  20  cc. 
of  ihe  extract  with  5  to  10  cc.  of  a  cold,  saturated  ac|ueous  solution  of 
sodium  bisulphite  in  a  test-tube,  and  shake  vigorously.  Transfer  to 
an  evaporating-dish,  and  heat  on  the  water-bath  till  the  alcohol  is  driven 
oflf.  At  this  stage  benzaldehyde  remains  in  the  hot  solution  as  a  crystal- 
line salt,  and  the  solution  gives  off  no  almond  odor. 

Nitrobenzol,  on  the  contrar}-,  does  not  combine  wi.h  the  bisulphite 
and  is  insoluble,  forming  globules  of  oil  on  the  surface  of  the  hot  liquid, 
and  in  addi.ion  giving  off  the  pungcni  odor  so  characteristic  of  the  sub- 
s  ancc. 

Separation  of  Nitrobenzol  and  Benzaldehyde. — If  by  the  qualitative 
test  nitrobenzol  is  found,  shake  vigorously  as  before  5c  cc.  of  the  extract 
Kith  10  cc.  of  the  saturated  sodium  bisulphite  solution  in  a  corked  flask, 
and  transfer  with  100  cc.  of  water  to  a  large  separatory  funnel.  Shake 
out  the  nitrobenz-ol  from  the  solution  with  four  successive  portions  of 
petroleum  ether  of  15  to  20  cc.  each,  and  after  washing  with  water  the 
combined  petroleum  ether,  transfer  it  to  a  tared  dish,  in  which  it  is  allowed 
to  evaporate  spontaneously. 

It  is  extremely  difficult  to  avoid  loss  of  some  of  the  nitrobenzol  by 
this  process,  but  even  if  the  weighed  residue  fails  to  shew  the  full  amount 
originally  used,  enough  will  usually  be  extracted  to  admit  of  testing  on 
the  refractometer,  and  of  otherwise  verifying  its  character. 

After  removal  of  the  nitrobenzol,  make  the  residual  solution  in  the 
separatory  funnel  strongly  alkaline  with  sodium  hydroxide,  and  shake 
out  the  benzaldehyde,  if  present,  with  petroleum  ether  as  previously 
described.  If  after  making  the  solution  alkaline  no  odor  of  benzalde- 
hyde is  apparent,  the  absence  of  benzaldehyde  may  be  inferred. 

Distinction  between  Artificial  Benzaldehyde  and  Pure  Almond  Oil. — 
Test  the  final  residue  from  the  ether  extract  by  shaking  with  an  equal 
volume  of  concentrated  sulphuric  acid  in  a  test-tube.  Wi.h  natural 
oil  of  almonds  a  clear,  brilliant,  but  dark  currant-red  color  is  produced, 
while  with  artificial  benzaldehyde,.  the  acid  produces  a  dirty  brown  color 
wiih  the  format ifjn  of  a   precijjitate. 

Determination  of  Alcohol. — In  the  absence  of  other  flavoring  sub- 
stances than  nitrobenzol  and  Ix-nzaldehyde,  which  are  rarely  present 
to  an  extent  exceeding  1%,  a  sufficiently  close  apj)roximation  for  most 
purfxjscs  can  be  gained  by  estimating  the  alcohol  from  the  direct  specific 
gravity  of  the  extract. 

Detection    of    Hydrocyanic    Acid. — To    a    few    cubic    centimeters    of 


FLAVORING    EXTRACTS   AND    THEIR  SUBSTITUTES.  889 

extract  in  a  test-tube  add  a  few  drops  of  a  mixture  of  solutions  of  ferrous 
sulphate  and  ferric  chloride,  the  ferrous  salt  being  in  excess.  Make 
alkaline  with  sodium  hydroxide,  and  add  enough  dilute  hydrochloric 
acid  to  dissolve  the  precipitate  formed  by  the  alkali.  Presence  of  a  blue 
coloration  or  precipitate,  due  to  the  formation  of  Prussian  blue,  indicates 
hydrocyanic  acid.     The  reaction  is  very  delicate. 

Determination  of  Hydrocyanic  Acid.* — Hydrocyanic  acid  may  be 
determined  by  titration  with  tenth-normal  silver  nitrate  solution.  25  cc. 
of  the  extract  are  measured  into  a  tlask,  and  5  cc.  of  freshly  prepared 
magnesium  hydroxide  suspended  in  water  are  added,  or  enough  to 
make  the  reaction  alkaline. 

A  few  drops  of  a  solution  of  potassium  chromate  are  then  introduced, 
and  the  tenth-normal  silver  nitrate  solution  added  till,  with  shaking,  the 
formation  of  the  red  silver  chromate  indicates  the  end-point,  i  cc.  of 
silver  solution  equals  0.0027  gram  of  hydrocyanic  acid. 

WINTERGREEN    EXTRACT. 

Wintergreen  Oil. — True  oil  of  wintergreen  is  obtained  by"  distillation 
from  the  leaves  of  the  wintergreen  plant  {GauUheria  procumhens  L.). 
Gildermeister  and  Hoffman  f  state  that  the  specific  gravity  at  15°  is 
1. 180  to  1.187,  the  boiling-point  218  to  221°  C.  It  is  slightly  laevo- 
rotatory   (a^=— 0.0^25'  to   — 1°). 

Oil  of  betula  or  sweet  birch  is  distilled  from  the  bark  of  the  black 
birch  {Betula  tenia  L.).  It  has  the  same  specific  gravity  and  boiling- 
point  as  oil  of  wintergreen,  but  unlike  the  latter  is  optically  inactive. 
It  differs  somewhat  from  oil  of  wintergreen  in  taste  and  odor,  but  is 
hardly  distinguishable  in  these  respects  from  synthetic   methyl  salicylate. 

Both  oil  of  wintergreen  and  oil  of  sweet  birch  consist  almost  entirely 
of  methyl  salicylate,  the  former  containing,  according  to  Power  and 
Kleber,J  as  much  as  99.8%  of  this  substance. 

U.  S.  Standards. — Oil  of  Wintergreen  is  the  volatile  oil  distilled  from 
the  leaves  of  the  GauUheria  procumbens  L. 

Wintergreen  Extract  is  the  flavoring  extract  prepared  from  oil  of 
wintergreen,  and  contains  not  less  than  3%  by  volume  of  oil  of  winter- 
green. 

*  Vielhaber,  Arch.  Pharm.  (3),  13,  408. 

t  The  Volatile  Oils.     Translated  by  Kremers,  Milwaukee,  1900,  p.  588. 

X  Pharm.  Rund  ,  13,  p.  228. 


S90  FOOD   INSPECTION  AND  ANALYSIS. 

Spirit  of  Gauthcria  of  ihc  U.  S.  P.  is  a  mixture  of  50  cc.  of  oil  of 
•wintcrgreen  and  Q50  cc.  of  alcohol.  It  accordingly  contains  5%  by  volume 
of  the  essential  oil. 

Adulteration  of  Wintergreen  Extract. — Synthetic  methyl  salicylate 
is  \er)'  commonly  subsiiiuted  for  bolh  \vintcrgreen  and  sweet  birch  oil, 
and  sweet  birch  oil  in  turn  for  wintergreen  oil.  The  production  of  true 
Avintergreen  oil  is  small,  the  so-called  natural  wintergreen  oil  of  com- 
merce being  usually  sweet  birch  oil.  The  sense  of  smell  is  the  best 
means  of  distinguishing  the  two  oils;  polarization  is  of  rather  uncertain 
value,  owing  to  low  rotatory  power  of  the  wintergreen  oil. 

Determination  of  Wintergreen  Oil. — Hortvet  and  West's  Method*- 
— Measure  10  cc.  of  the  extract  into  a  100-cc.  beaker,  add  10  cc.  of  10% 
potassium  hydroxide  solution,  and  heat  the  mixture  over  a  boiling  water- 
bath  until  the  odor  of  oil  of  wintergreen  has  disappeared  and  the  liquid 
is  reduced  to  about  one-half  its  original  volume.  By  this  treatment 
the  methyl  salicylate  is  converted  into  the  potassium  salt.  Liberate  the 
salicylic  acid  by  the  addition  of  an  excess  of  10%  hydrochloric  acid, 
cool,  and  extract  in  a  separatory  funnel  with  three  portions  of  40,  30, 
and  20  cc.  of  ether  respectively.  Pour  the  combined  ether  extracts 
through  a  dry  filter  into  a  weighed  dish,  wash  the  filter  with  10  cc.  of 
ether,  evaporate  filtrate  and  washings  slowly  at  50°  C,  dry  one  hour 
in  a  desiccator,  and  weigh.  The  per  cent  of  wintergreen  oil  by  volume 
{M)  is  obtained  from  the  weight  of  salicylic  acid  (5)  by  the  foUownng 
formula : 

i.ioiXioX5 


M=- 


1.18 


Howard's  Method. — Proceed  as  described  on  page  874,  except  that 
the  heavy  oil  is  brought  into  the  graduated  portion  of  the  Babcock  bottle 
by  addition  of  dilute  sulphuric  acid  (1:2),  taking  care  that  the  acid  is 
not  over  25°  C.  and  avoiding  agitation. 


PEPPERMINT    EXTRACT 

Peppermint  Oil  is  obtained  from  various  plants  of  the  genus  Mentha, 
which  are  commonly  classed  as  sub-species  or  varieties  of  M.  piperita. 
Owing  in  large  part  to  the  botanical  differences  in  the  plants  from  which 

*  Jour.  Ind.  F.ng.  ("hem,  i,  1909,  p.  90. 


FLAVORING   H XT R ACTS   AND    THEIR   SUBSTITUTES. 


891 


it  is  made,  peppermint  oil  from  dilTerent  regions  dilTers  greatly  in  its 
chemical  and  physical  constants  as  shown  by  the  following  table  com- 
piled from  figures  given  by  Gildermeister  and  Hoffmann:* 


specific  Gravity. 


Rotation,  ar\. 


Total  Menthol, 
Per  Cent. 


American 
ICnglish  .  . 
Japanese , 
Sa.xon  .  .  . 
German  . 
French  .  . 
Russian  .. 


0.905  to  0.920 
0.900  to  0.910 
0.895  to  0.900 
0.900  to  0.915 
0.899  ^^  °-93° 
0.918  to  0.920 
0.905  to  0.910 


■18°  to  -33° 
■22°  to  —22,° 
■30°  to  —42° 
•25°  to -33° 

■27°  to -33° 
■  5°  to  -  9° 
•17°  to  -22° 


48  to  60 
56  to  66 
70  to  91 
54  to  68 

43  to  46 
50.2 


U.  S.  Standards. — Peppermint  is  the  leaves  and  flowering  tops  of 
Mentha  piperita  L. 

Oil  of  Peppermint  is  the  volatile  oil  obtained  from  j)eppermint,  and 
contains  not  less  than  50%  by  weight  of  menthol. 

Peppermint  Extract  is  the  l^avoring  extract  prepared  from  oil  of  pepper- 
mint, or  from  peppermint,  or  both,  and  contains  not  less  than  3%  by 
volume  of  oil  of  peppermint. 

Analysis  of  Peppermint  Extract. — Owing  to  the  wide  variation  in  the 
rotatory  power  of  peppermint  oil,  only  a  roughly  approximate  idea  of 
the  oil  content  of  peppermint  extract  can  be  gained  by  polarization. 
The  variation  in  the  percentage  of  menthol  in  the  oil  is  also  too  great 
to  perm.it  of  a  method  based  on  the  amount  of  this  constituent.  Mitchell's 
precipitation  method,  as  originally  described  (page  873),  does  not  effect 
a  complete  separation  of  the  oil,  but  Howard's  modification  (page  S74) 
gives  satisfactory  results,  and  is  well  adapted  for  purposes  of  inspection. 

SPEARMINT  EXTRACT. 

U.  S.  standards. — Spearmint  is  the  leaves  and  flowering  tops  of  Mentha 
spicata  L. 

Oil  of  Spearmint  is  the  volatile  oil  obtained  from  spearmint. 

Spearmint  Extract  is  the  flavoring  extract  prepared  from  oil  of  spear- 
mint, or  from  spearmint,  or  both,  and  contains  not  less  than  3%  by 
volume  of  oil  of  spearmint. 


*  The  Volatile  Oils.     Translated  by  Edward  Kremers,  Milwaukee,  igoo. 


S92  FOOD   INSPECTION  AND    ANALYSIS. 

SPICE  EXTRACTS. 

Alcoholic  solutions  of  the  essential  oils  of  spices  are  used  to  some 
extent  instead  of  the  spices  themselves.  The  following  are  the  definitions 
of  these  extracts  and  the  oils  from  which  they  are  prepared,  as  adopted 
by  the  joint  committee  on  standards  and  the  U.  S.  Secretary  of  Agri- 
cuhurc: 

U.  S.  Standards. — Anise  Extract  is  the  flavoring  extract  prepared 
from  oil  of  anise,  and  contains  not  less  than  3%  by  volume  of  oil  of 
anise. 

Oil  of  Anise  is  the  volatile  oil  obtained  from  the  anise  seed. 

Celery  Seed  Extract  is  the  flavoring  extract  prepared  from  celery  seed 
or  the  oil  of  celery  seed,  or  both,  and  contains  not  less  than  0.3%  by 
volume  of  oil  of  celery  seed. 

Oil  of  Celery  Seed  is  the  volatile  oil  obtained  from  celery  seed. 

Cassia  Extract  is  the  flavoring  extract  prepared  from  oil  of  cassia, 
and  contains  not  less  than  2%  by  volume  of  oil  of  cassia. 

Oil  of  Cassia  is  the  lead-free  volatile  oil  obtained  from  the  leaves 
or  bark  of  Cinnamomum  cassia  Bl.,  and  contains  not  less  than  75%  by 
weight  of  cinnamic  aldehyde. 

Cinnamon  Extract  is  the  flavoring  extract  prepared  from  oil  of  cinna- 
mon, and  contains  not  less  than  2%  by  volume  of  oil  of  cinnamon. 

Oil  of  Cinnamon  is  the  lead-free  volatile  oil  obtained  from  the  bark 
of  the  Ceylon  cinnamon  {Cinnamomum  zeylanicum  Breyne),  and  contains 
not  less  than  65%  by  w^eight  of  cinnamic  aldehyde  and  not  more  than 
10%  by  weight  of  eugenol. 

Clove  Extract  is  the  flavoring  extract  prepared  from  oil  of  cloves,  and 
contains  not  less  than  2%  by  volume  of  oil  of  cloves. 

Oil  of  Cloves  is  the  lead-free,  volatile  oil  obtained  from  cloves. 

Ginger  Extract  is  the  flavoring  extract  prepared  from  ginger,  and 
contains  in  each  100  cc.  the  alcohol-soluble  matters  from  not  less  than 
20  grams  of  ginger. 

Nutmeg  Extract  is  the  flavoring  extract  prepared  from  oil  of  nutmeg, 
and  contains  not  less  than  2%  by  volume  of  oil  of  nutmeg. 

Oil  of  Nutmeg  is  the  volatile  oil  obtained  from  nutmegs. 

Savory  Extract  is  the  flavoring  extract  i)reparcd  from  oil  of  savory, 
or  from  savory,  or  both,  and  contains  not  less  than  0.35%  by  volume  of 
oil  of  savory. 

Oil  of  Savory  is  the  volatile  oil  obtained  from  savory. 


FL/ll/ORING   EXTRACTS   AND    THEIR   SUBSTITUTES.  893 

Star  Anise  Extract  is  the  flavoring  extract  prepared  from  oil  of  star 
anise,  and  contains  not  less  than  3%  by  volume  of  oil  of  star  anise. 

Oil  of  Star  Anise  is  the  volatile  oil  distilled  from  the  fruit  of  the  star 
anise  (Illicium  verum  Hook). 

Sii'eet  Basil  Extract  is  the  flavoring  extract  prepared  from  oil  of 
sweet  basil  or  from  sweet  basil,  or  both,  and  contains  not  less  than  0.1% 
by  volume  of  oil  of  sweet  basil. 

Sweet  Basil,  Basil,  is  the  leaves  and  tops  of  Ocymmn  basilicum  L. 

Oil  of  Sweet  Basil  is  the  volatile  oil  obtained  from  basil. 

Sweet  Marjoram  Extract,  Marjoram  Extract,  is  the  flavoring  extract 
prepared  from  the  oil  of  marjoram,  or  from  marjoram,  or  both,  and  con- 
tains not  less  than  1%  by  volume  of  oil  of  marjoram. 

Oil  of  Marjoram  is  the  volatile  oil  obtained  from  marjoram. 

Thyme  Extract  is  the  flavoring  extract  prepared  from  oil  of  thyme, 
or  from  thyme,  or  both,  and  contains  not  less  than  0.2%  by  volume  of 
oil  of  thyme. 

Oil  of  Thyme  is  the  volatile  oil  obtained  from  thyme. 

Determination  of  Essential  Oil  in  Cinnamon,  Cassia,  and  Clove 
Extracts. — Howard's  Method. — Proceed  as  with  wintergreen  extract, 
page  890. 

Hortvet  and  West's  Method.* — Place  10  cc.  of  the  extract  and  50  cc. 
of  water  in  a  separatory  funnel,  and  extract  with  three  portions  of  ether 
measuring  respectively  50,  30,  and  20  cc.  Wash  the  combined  extracts 
successively  with  25  and  30  cc.  of  distilled  water,  and  fdter  through  a 
dry  funnel  into  a  wide-mouth  flask,  washing  out  the  funnel  and  fiher 
with  a  little  ether.  In  the  case  of  cinnamon  extract,  transfer  the  ether 
extract  before  filtering  to  a  150-cc.  flask,  shake  for  a  few  minutes  with 
some  granulated  calcium  chloride,  then  fiher  in  the  manner  described. 
Evaporate  off  the  ether  as  rapidly  as  possible  on  a  boiling  water-bath 
until  only  a  few  drops  remain.  At  this  point  remove  the  flask  from  the 
bath,  and  rotate  rapidly  for  a  few  minutes,  spreading  the  residue  over 
the  sidcc  of  the  flask.  The  rapid  evaporation  of  the  remaining  ether  cools 
the  flask  to  near  room  temperature.  When  the  odor  of  ether  has  dis- 
appeared, stopper  the  flask  and  weigh. 

In  the  case  of  cassia  and  clove  oils,  where  the  ether  extract  is  not 
first  dried  with  calcium  chloride,  a  slight  cloudiness  gathers  on  the  flask 
as  the  last  traces  of  ether  disappear,  due  to  the  presence  of  a  little 
moisture.    In  such  case   allow  the   flask  to  stand  on  the    balance-pan 

*  Jour.  Ind.  Eng.  Chem.,  i,  1909,  p.  88. 


Sq4  food  inspection  AND  ANALYSIS.} 

until  the  film  disappears,  requiring  not  longer  than  two  to  three  minutes, 
then  stopper,  and  weigh. 

The  per  cent  of  oil  by  volume  (F)  is  calculated  from  the  weight  of 
oil  {W)  by  the  following  formula: 

looXW 
F=- 


loX  1.050 


The  oil  thus  extracted  may  be  used  for  determination  of  the  refractive 
Index.  After  dissolving  in  a  little  alcohol  it  may  be  tested  with  ferric 
chloride  solution.  By  this  test  cinnamon  oil  gives  a  green,  cassia  oil  a 
brown,  and  clove  oil  a  deep  blue,  coloration. 

Determination  of  Essential  Oil  in  Nutmeg  Extract. — Follow  Mitchell's 
precipitation  method,  page  873.  t 

Determination  of  Solids  in  Ginger  Extract.*^ — Evaporate  10  cc.  on 
a  boiling  water-bath  to  dryness,  dry  for  2  hours  in  a  boiling  water  oven 
and  weigh. 

Determination  of  Alcohol  in  Ginger  Extract.* — Proceed  as  with 
vanilla  extract  (p.  86n). 

Detection  of  Ginger  in  Ginger  Extract.* — Seeker  Method. —  Dilute 
10  cc.  of  the  eJitract  to  30  cc,  evaporate  off  20  cc,  decant  into  a  separatory 
funnel  and  extract  with  an  equal  volume  of  ether.  Evaporate  the  ether 
spontaneously  in  a  porcelain  dish  and  to  the  residue  add  5  cc.  of  75% 
sulphuric  acid -and  5  mg.  of  vanillin.  Allow  to  stand  for  15  minutes  and 
add  an  equal  volume  of  water.  In  the  presence  of  ginger  extract  an  azure 
Ijluc  color  develops. 

Detection  of  Capsicum  in  Ginger  Extract. — La  Wall  Method  Modified 
by  Doyle.-\ — To  10  cc  of  the  extract  cautiously  add  dilute  sodium  hydroxide 
until  the  solution  reacts  very  slightly  alkaline  with  htmus  paper.  Evapor- 
ate at  about  70°  C.  to  about  one-quarter  of  the  original  volume,  render 
slightly  acid  with  dilute  sulphuric  acid,  testing  with  litmus  paper.  Trans- 
fer to  a  separatory  funnel,  rinsing  the  evaporating  dish  with  water,  and 
extract  with  an  equal  volume  of  ether,  avoiding  emulsification  by  shak- 
ing the  funnel  gently  for  a  minute  or  two.  Draw  off  the  lower  layer  and 
wash  the  ether  extract  once  with  about  10  cc.  of  water.  Transfer  the 
washed  ether  extract  to  a  small  evaporating  dish,  render  decidedly  alkaline 
with   alcoholic   potassium   hydroxide,  and  evaporate   at  about  70°  until 

•  A.O.A.C.  Mcthfxl.  Proc.  for  1910,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  137,  p.  75. 
t  A.O.A.C.  Method,  Proc.  for  191 1,  Bui.  152,  p.  145. 


FLAyORING   EXTRACTS  AND    THEIR  SUBSTITUTES.  895 

the  residue  is  pasty;  then  add  about -20  cc.  more  of  half-normal  alcoholic 
potash  and  allow  to  stand  on  a  steam  bath  until  the  gingerol  is  com- 
pletely saponified,  which  usually  requires  about  one-half  hour.  Dis- 
solve the  residue  in  a  little  water  and  transfer  with  water  to  a  small  sepa- 
ratory  funnel.  The  volume  should  not  exceed  50  cc.  Extract  the  alkaline 
solution  with  an  equal  volume  of  ether.  Wash  the  ether  extract  repeatedly 
with  small  amounts  of  water  until  no  longer  alkaline  to  litmus.  Transfer 
the  washed  extract  to  a  small  evaporating  dish,  allow  the  ether  to  evaporate 
spontaneously,  and  finally,  t^st  the  residue  for  capsicum  by  moistening 
the  tip  of  the  finger,  rubbing  it  around  on  the  bottom  and  sides  of  the 
dish,  and  then  applying  the  finger  to  the  end  of  the  tongue.  A  hot,  stinging, 
or  prickly  sensation,  which  persists  for  several  minutes,  indicates  capsicum 
or  other  foreign  pungent  substances. 

ROSE  EXTRACT. 

U.  S.  standards.— 7?05e  Extract  is  the  flavoring  extract  prepared  from 
otto  of  roses,  with  or  without  red  rose  petals,  and  contains  not  less  than 
0.4%  by  volume  of  otto  of  roses. 

Otto  of  Roses  is  the  volatile  oil  obtained  from  the  petals  of  Rosa 
damascena  Mill.,  R.  centifolia  L.,  or  R.  moschata  L. 

Determination  of  Rose  Oil. — Hortvet  and  Wcst^s  Method* — Measure 
25  cc.  of  the  extract  into  a  separatory  funnel,  add  50  cc.  of  water,  mix 
thoroughly,  acidify  with  i  cc.  of  hydrochloric  acid  (1:1),  and  extract 
with  three  portions  of  20  cc.  each  of  ether.  Transfer  the  combined 
ether  extracts  to  a  150-cc.  flask,  shake  for  a  few  minutes  with  some 
granulated  calcium  chloride,  allow  to  settle  until  clear,  then  decant 
through  a  dry  filter  into  a  flat  bottom  glass  dish  previously  weighed 
together  with  a  cover-glass.  Wash  the  calcium  chloride  and  filter  twice 
with  10  cc.  of  ether,  and  add  the  washings  to  the  glass  dish.  Cover 
the  dish,  place  in  a  vacuum  desiccator  over  sulphuric  acid,  allow  to 
remain  until  all  traces  of  ether  and  alcohol  are  removed,  and  weigh. 
Repeat  the  drying  in  the  desiccator,  for  one  hour  periods,  until  the  weight 
is  practically  constant.  The  final  weight,  divided  by  0.86  and  multiplied 
by  5,  gives  the  per  cent  of  oil  of  rose  by  volume. 

IMITATION    FRUIT    FLAVORS. 

Nearly  all    the  fruits  possess  distinctive  flavors,  which  are  desirable 
in  food  [preparations,  and  which  may  be  made  to  impart  their  flavor  to 
*  Jour.  Ind.  Eng.  Chem.,  i,  1909,  p.  89. 


896  FOOD  INSPECTION  AND  ANALYSIS. 

such  substances  as  confections,  ice  cream,  dessert  mixtures,  jellies,  etc., 
by  simply  mixing  with  these  foods  the  fresh  or  preserved  fruit  or  fruit 
juice  in  sutiicient  quantity.  In  many  cases,  however,  it  is  not  found 
possible  or  practicable  to  prepare  from  the  fruits  themselves  an  extract 
sutTiciently  concentrated  to  give  the  dislinaive  fruit  flavor,  when  used 
in  moderate  quantity,  and  hence  the  use  of  artificial  fruit  essences  made 
up  of  compound  ethers,  mixed  in  varying  combinations  and  proportions 
to   imitate   more   or  less  closely  various  fruit   flavors. 

These  ethers  are  usually  much  more  pungent  and  penetrating  than 
the  fruits  which  they  imitate,  and,  while  lacking  the  delicacy  and  refine- 
ment of  the  original  fruits,  serve  to  impart  a  certain  semblance  of  the 
genuine  flavor  in  a  convenient  and  highly  concentrated  form. 

Some  of  the  single  compound  ethers  possess  a  remarkable  resemblance 
to  particular  fruits,  while  to  imitate  other  fruits  a  mixture  of  various 
ethers  and  flavoring  materials,  such  as  lemon  and  other  volatile  oils, 
vanilla,  organic  acids,  chloroform,  etc.,  is  necessary.  These  artificial 
essences  should  in  all  cases  be  sold  as  such,  and  not  as  "pure  fruit  flavors." 

Imitation  Pineapple  Essence  is  made  up  by  dissolving  in  alcohol  butyric 
ether,  Q^^{C■^^}02,  which  possesses  a  disJnct  pineapple  flavor,  and 
is  prepared  by  mixing  100  pans  of  butyric  acid  (C^HgOz),  100  parLs  of 
alcohol,  and  50  parts  of  sulphuric  acid,  and  shaking.  Butyric  ether  is 
sparingly  soluble  in  water,  and  boils  at  121°  C. 

Imitation  Quince  Essence  depends  as  a  basis  on  ethyl  pelargonate, 
sometimes  called  pelurgonic  or  cenanthic  ether,  C2H5,CaHi702,  dissolved 
in  alcohol.  Pclargonic  ether  is  formed  by  digestion  wiih  the  aid  of  heat 
of  pelargonic  acid  and  alcohol.  Pclargonic  acid,  CjH^gOa,  is  first  obtained 
by  the  action  of  nitric  acid  on  oil  of  rue.  Pelargonic  ether  is  a  colorless 
liquid,  having  a  specific  gravity  of  0.8635  ^t  17.5°  C.  Its  boiling-point 
is  227°  to  228°  C.     It  is  insoluble  in  water. 

Imitation  Jargonelle  Pear  Essence  consists  of  an  alcoholic  solution 
of  amyl  or  pentyl  acetate,  C^\.{i^,C^WJ^}2-  This  is  prepared  by  distilling 
a  mixture  of  one  part  of  amyl  alcohol,  two  parts  of  potassium  acetate, 
and  one  part  of  concentrated  sulphuric  acid.  It  is  a  colorless  liquid, 
insoluble  in  water,  and  having  a  boiling-point  of  137°  C. 

Imitation  Banana  Essence  is  made  up  of  a  mixture  of  amyl  acetate 
and  butyric  ether. 

Imitation  Apple  Essence  is  composed  of  an  alcoholic  solution  of  amyl 
valerianate,  sometimes  called  apple  oil,  CjHipCsHgOz,  prepared  by  mixing 
four  parts   of  amyl   alcohol    with   four    of   sulphuric  acid,  and  adding 


FLAyORlNG   EXIKACTS  AND    THEIR  SUBSTITUTES.  897 

COMPOSITION  OF  IMITATION  ESSENCES. 


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I 

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I 

I 

5 
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Pear 

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5 

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Lemon 

I 

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Cherry 

Plum         

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898  FOOD  INSPECTION  AND   ANALYSIS. 

the  niLxture  when  cold  to  live  parts  of  valerianic  acid.  The  specific 
granty  of  amyl  valerianate  is  0.879  at  0°  C.  and  its  boiling-point  is 
1 88°  C. 

The  table  on  p.  897,  prepared  by  Kletzinsky,  shows  the  composition 
of  a  large  variety  of  these  artificial  essences.  The  numerals  in  the  various 
columns  indicate  the  parts  by  volume  to  be  added  to  100  parts  of  deodor- 
ized alcohol. 

Determination  of  Esters.— Add  to  25  grams  of  the  extract  2  cc.  of 
sodium  hydroxide  solution  (100  grams  in  100  cc.  of  water),  100  cc.  of 
water  and  heat  under  a  retiux  condenser  one  half-hour.  Acidify  with 
5  cc.  of  dilute  sulphuric  acid  (1:4),  add  a  few  pieces  of  pumice  stone, 
distil  in  a  current  of  steam  and  titrate  the  distillate  with  tenth-normal 
alkali,  using  phenophthalein  as  indicator.  The  number  of  cc.  required 
represents  the  total  volatile  acids  free  and  combined.  Determine 
free  volatile  acids,  if  present  by  direct  distillation  and  titration  of  the 
distillate.  The  difference  between  the  two  titrations  is  calculated  as 
ethyl  acetate. 

REFERENCES  ON   FLAVORING   EXTRACTS. 

Chace,  E.  M.     .\  Method  for  the  Determination  of  Citrai  in  Lemon  Oils  and  E.xtracts. 

Jour.  Am.  Chem.  Soc,  28,  1906,  p.  1472. 
The  Detection  of  Small  Quantities  of  Turpentine  in  Lemon  Oil.     Ibid.,  30,  1908, 

P-  1475- 
Denis,  W.,  and  Dunbar,   P.   B.     The  Determination  of  Benzaldehyde  in  Almond 

Flavoring  Extract.     Jour.  Ind.  Eng.  Chem.,  i,  1909,  p.  256. 
GiLDEMEiSTER,  E.,    and   Hoffmann,    F.     The   Volatile    Oils.     Trans,    by  Edward 

Kremer.     Milwaukee,  1900. 
Hess,  \V.  H.     The  Distinction  of  True  Extract  of  Vanilla  from  Licjuid  IVeparations 

of  Vanillin.     Jour.  Am.  Chem.  Soc,  21,  1899,  P-  1^9- 
Hess,  W.  H.,  and  Prescott,  A.  B.     Coumarin  and  Vanillin,  their  Separation,  Estima- 
tion and  Identification  in  Commercial  Flavoring  Extracts.     Jour.  Am.  Chem. 

Soc,  21,  1899,  p.  256. 
Heusler,  F.     The  Chemistry  of  the  Terpenes.   Trans,  by  V.  J.  Pond.     Philadelphia, 

1902. 
Hiltner,  R.  S.     The  Determination  of  Citrai  in  Lemon  Extract.    A.  O.  A.  C.  Proc, 

1908,  U.  S.  Dept.  of  .Agric,  Bur.  of   Chem.,  Bui.    122,  p.  34.      Jour.  Ind.  Eng. 

Chem.,  I,  1909,  p.  798. 
Hortatt,  J.,  and  West,  R.  M.     The  Determination  of  Essential  Oils  and  Alcohol 

in  Flavoring  Extracts.     Jour.  Ind.  fc^ng.  Chem.,  i,  1909,  p.  84. 
Howard,  C.  D.     The  Precipitation  Method  for  the  F^.stimation  of  Oils  in  Flavoring 

Extracts  and  Pharmaceutical  Preparations.     Jour.  Am.  Chem.  Soc,  30,  1908, 

p.   608. 


FLAyORlNG   EXTRACTS  AND    THEIR   SUBSTITUTES.  899 

Mitchell,  A.    S.      Lemon    Flavoring   Extract   and  its  Substitutes.      Jour.  Am. 

Chem.  Soc,  21,  1899,  p.  1132. 

Flavoring  Extracts.     U.  S.  Dept.  of  Agric,  Bur.  of  Chcm.,  Bui.  65,  p.  69. 

WiNTON,  A.  L.,  and  Silverman,  M.    The  Analysis  of  Vanilla  Extract.     Jour.  Am. 

Chem.  Soc,  24,  1902,  p.  11 29. 
WiNTON,  A.  L.,  and  Bailey,  E.  M.     The  Determination  of  Vanillin,  Coumarin,  and 

Acetanilide  in  Vanilla  E.xtract.      Jour.  Am.  Chem.  Soc,  27,  1905,  p.  719. 
WiNTON,  A.  L.,  and  Lott,  C.  I.     Distinction  of  Vanilla  Extract  and  its  Imitations. 

U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  1.32,  p.  109. 


\ 


CHAPTER   XXI. 
VEGETABLE   AND  FRUIT  PRODUCTS. 

CANNED   VEGETABLES  AND  FRUITS. 

Strictly  speaking  all  varieties  of  canned  foods  found  in  the  market^ 
whether  meats,  fruits,  or  vegetables,  in  order  to  be  enlircly  beyond  criti- 
cism, should  not  differ  from  the  corresponding  freshly  cooked  varieties 
which  they  are  intended  to  replace,  excepting  that  they  are  free  from 
bacteria.  Such  a  degree  of  perfection  is,  however,  difficult,  even  if  pos- 
sible, to  attain,  and  nearly  all  commercial  canned  products,  even  if  made 
from  the  best  materials,  are  liable  to  contain  either  antiseptic  substances 
or  coloring-matter  intentionally  added  by  the  manufacturer,  or  metallic 
impurities  accidentally  derived  from  the  vessels  in  which  they  arc  pre- 
pared, or  from  the  containers  in  which  they  are  sealed.  In  spite  of  these 
objections,  canned  foods  form  a  convenient,  and  in  some  cases  indispensa- 
ble means  of  furnishing  both  necessities  and  luxuries  for  the  table.  The 
canning  of  foods  is  especially  useful  for  preserving  them  during  long 
periods  of  time,  for  enabling  certain  fruits  and  vegetables  to  be  enjoyed 
out  of  season,  and  for  furnishing  supplies  in  a  convenient  manner  to  inac- 
cessible places  where  fresh  foods  are  not  readily  obtainable,  as  in  the 
case  of  armies  in  the  field,  of  vessels  at  sea,  of  campers  in  the  woods,  etc. 
Canned  goods  in  great  variety  are  used  in  nearly  every  household. 

WTien  it  is  considered  that  in  the  United  States  alone  something  like 
one  hundred  million  cans  of  corn  are  packed  in  a  single  year,  about  the 
same  quantity  of  peas,  and  one  hundred  and  fifty  million  cans  of  tomatoes, 
to  sav  nothing  of  an  ever-increasing  variety  of  other  foods,  some  idea  may 
be  gained  of  the  enormous  proportions  to  which  the  canning  industry 
has  grown.  It  is  comforting  to  Vnow  that,  in  view  of  their  wide-spread 
consumption,  the  greater  portion  of  such  foods  found  on  the  market  are 
comparatively  harmless,  as  is  evidenced  Ijy  the  fact  that  few  cases  of  injury 
to  health  have  been  directly  traceable  to  their  use. 

Method  of  Canning  Food. — V'arious  modifications  as  to  details  exist 
with  different  products  and  in  different  localities,  but  in  general  the  prin- 

900 


yEGETABLE  /1ND  ERUIT  PRODUCTS.  por 

ciple  of  canning  in  tin  is  the  same  in  all  cases.  The  fresh  proiduct  is 
cleaned  carefully,  and  packed  in  cans  with  the  requisite  amount/of  water. 
The  cans  arc  then  sealed,  and  subjected  to  the  effect  of  steam  or  boiling 
water  till  the  contents  are  thoroughly  cooked.  Each  can  is  then  tapped 
or  punctured  at  one  end  to  expel  the  air,  and  again  heated,  after  which 
the  hole  is  closed  by  a  lump  of  solder,  thus  forming  a  vacuum  in  the  can, 
which  is  afterwards  heated  for  a  sufficient  time  to  destroy  the  bacteria, 
usually  for  several  hours. 

The  above  mode  of  procedure  is  the  time-honored  one,  and  is  still  in 
vogue  in  most  localities,  but  a  more  modern  method,  much  in  use  at  present, 
consists  in  first  cooking  the  food  at  a  temperature  of  82°  to  88°  C.  before 
transferring  to  the  cans,  and  afterwards  subjecting  the  cans  when  sealed 
to  a  high  heat  of  about  125°  C.  in  dry  air  in  so-called  retorts,  this  heating 
or  "processing,"  as  it  is  termed,  being  carried  on  for  a  sufficient  length 
of  time  to  completely  sterilize  the  contents  of  the  can.  Obviously  a  much 
shorter  time  is  required  for  this  than  when  the  temperature  of  boiling 
water  is  employed,  and  the  sterilization  is  much  more  effective. 

Cooked  vegetables  and  fruit  products  put  up  in  glass  jars  or  bottles 
are  tightly  sealed  when  hot,  cither  with  screw-caps  or  with  some  form  of 
cover  held  by  a  clamp,  or  with  metal  or  hard-rubber  caps  fitting  over  a 
flanged  mouth.  Frequently  a  soft-rubber  ring  is  inserted  between  the 
cover  and  the  mouth  of  the  jar  or  bottle.  The  material  of  the  cover  is 
generally  either  glass,  porcelain,  or  metal.  Cork  stoppers  are,  however, 
sometimes  pressed  into  the  mouths  of  the  bottles,  and  made  extra  tight . 
therein  with  sealing-wax.  These  stoppers  are  occasionally  soaked  in 
paraffin.  Thus  the  contents  of  the  jar  may  be  exposed  to  porcelain, 
glass,  metal,  rubber,  or  cork,  according  to  the  material  of  the  cover  and 
the  method  of  sealing. 

The  preservation  of  food  by  canning  was  long  thought  to  be  due  to 
the  perfect  exclusion  of  air,  but  is  now  known  to  depend  on  the  perfect 
sterilization,  or  destruction  of  bacteria,  and  it  has  been  proved  that  as 
far  as  keeping  qualities  are  concerned,  it  makes  no  difference  whether 
or  not  air  is  present  in  the  can,  if  the  contents  are  sterile,  though  for  pur- 
poses of  inspection  the  vacuum,  in  tlie  case  of  tin  cans,  is  of  great 
use,  in  that  as  a  natural  consequence  of  the  vacuum,  when  the  goods 
are  sound,  the  ends  of  the  cans  are  usually  concave.  The  highest 
aim  of  the  canner  should  be  to  retain  in  his  product  as  far  as  possible 
the  appearance,  palatabiUty,  and  nutritive  value  of  the  freshly  cooked 
food. 


9©  2 


FOOD   INSPECTION   ^ND   ANALYSIS. 


PROXIMATE  COMPOSITION  OF  CANNED  VEGETABLES  AND  FRUITS* 


CANNKn  VEGETABLKS 

Anichokcs 

Asparar  js 

Beans,  uakcil 

"       string 

"        Lima 

Brussels  sprouts 

Com,  green 

Peas,  green 

Pumjjkin 

Squash 

Succotash 

Tomatoes 

CANNED    FRUITS. 

Apples,  crab 

Apple  sauce 

Apricots 

Blackberries 

Bluclx;rries 

Cherries 

Peaches 

Pears 

Pineapples 

Strawberries 


4.< 


14 

21 
29 
16 


88 
7 


12 
19 


9-'- 5 
94-4 
68.9 

93-7 
79-5 
93-7 
76.1 

85-3 
91.6 
87.6 

75-9 
94.0 


42.4 
61. 1 
81.4 
40.0 
85.6 

77-2 
88.1 
81. 1 
61.8 
74-8 


.8 

0.9 
I.I 
4.0 

1-5 
2.8 

3-6 

.8 

•  9 
3-6 


2.4 


19.0 

3-« 
14.6 

3-4 

IQ.O 

9.8 

6.7 

10. > 

18.6 

4.0 


54-4 
37-2 
17-3 
56.4 
12.8 
21. 1 
10.8 
18.0 

36.4 
24.0 


-7 
1.2 
2.1 

1-3 
1.6 

1-3 
-9 

I.I 

•7 
•5 
.9 
.6 


.5 
.7 
.4 
.7 
.4 
•5 
.3 
•3 
.7 
.5 


>     c 

o  5;  o 


no 

600 

95 
360 

95 
455 
255 
150 
235 
455 
105 


1,120 

730 

340 

i>i50 
275 
415 
220 

355 
715 
460 


•  U.  S.  Dept.  of  Agric,  Exp.  Sta.  Bui.  2S,  p.  70. 


DECOMPOSITION. 

Nature  and  Detection  of  Spoilage. — In  the  case  of  canned  vegetables 
and  fruit  products,  decomposition  rarely  results  in  the  formation  of 
ptomaines  even  after  the  can  has  long  been  open,  though  these  toxins 
are  sometimes  formed  in  canned  meat  and  fish.  Decomposition  is  readily 
apparent  after  opening  a  can,  from  a  cursory  examination  of  its  contents. 
The  appearance,  taste,  and  odor  will  not  fail  to  indicate  the  unfitness 
of  the  contents  for  food,  if  decomposition  is  at  all  advanced.  It  is,  how- 
ever, often  of  great  advantage  to  detect  spoiled  cans  without  opening. 
As  a  rule,  when  a  can  is  spoiled,  it  is  usually  in  the  condition  termed 
''  blown,"  i.e.,  with  its  ends  convex,  instead  of  normal  or  concave. 

.\ccording  to  Prescott  and  Underwood, f  although  nearly  all  forms  of 
bacterial  decomposition  are  accompanied  by  bulging  of  the  ends  of  the 
cans,  there  are  some  exceptions.     In  the  souring  of  canned  sweet  com, J 

t  Tech.  Quart.,  i  r,  1898,  pp.  6-30;  also  10,  1897,  p.  183. 

X  These  experimenters  found  at  least  twelve  varieites  of  bacteria  to  which  the  s«uring  of 
com  is  apparently  due. 


l^EGETABLE   AND   FRUIT  PRODUCTS. 


903 


for  instance,  it  is  exceptional  that  swelling  occurs.  Ordinarily,  in  the 
factory  inspection  of  canned  goods  before  shipping,  not  only  are  the 
bulged  cans  or  "  swells,"  as  they  are  termed,  sifted  out,  but  the  condition 
of  the  cans  is  tested  by  sounding  or  striking  the  cans.  If  the  contents  are 
sweet, a  peculiar  note  is  produced  when  the  can  is  struck,  readily  distinguish- 
able from  the  dull  tone  of  the  unsound  can  by  any  one  familiar  with  the  work. 

As  stated  above,  concavity  in  the  ends  of  the  can  indicates  that  the 
contents  are  in  good  condition. 

Prescott  and  Underwood  further  state  that  sound  cans  may  be  dis- 
tinguished from  unsound  in  a  lot  of  suspicious  goods,  when  the  swelling 
of  the  ends  is  not  apparent,  by  the  following  method: 

Boil  the  cans  for  an  hour,  causing  the  ends  of  all  to  swell,  then  cool,  and 
set  aside  for  eight  hours,  during  which  the  sound  cans  will  snap  back,  while 
the  unsound  will  continue  convex,  by  reason  of  the  fact  that  the  swell- 
ing in  this  case  is  due  to  the  generation  of  gas  by  the  bacteria  present. 

Examination  of  Gases  from  Spoiled  Cans. — When  the  tops  of  blown 
cans  are  punctured  in  the  process  of  opening,  an  outflow  of  gas  is  usually 
to  be  noted.     Doremus  *  has  studied  the  character  of  these  gases  and 


Fig.  118. — Apparatus  for  Collecting  Gases  from  Spoiled  Cans.     (After  Doremus.) 

found  that  when  the  contents  have  become  putrid,  carbon  dioxide  and 
hydrogen  are  the  chief  gases  to  be  found.  Often  60  to  80  cc.  of  gas 
may  be  collected  from  a  can.     For  the  collection  of  the  gases,  Doremus 

*  Jour.  Am.  Cham.  Soc.,  19,  1897,  p.  733. 


904  FOOD   INSPECTION   ^ND  AN/i LYSIS. 

uses  the  device  sho\NTi  in  Fig.  118.  An  adjustable  clamp  has  attached 
to  its  upper  arm  a  beveled,  hollow,  steel  needle.  A  perforated  rubber 
stopper  covers  the  needle  and  serves  as  a  cushion.  A  fine  tube 
connects  the  needle  with  the  receiver  of  a  eudiometer,  both  tube  and 
receiver  being  filled  with  water  or  mercury.  Either  the  stop-cock  form 
of  eudiometer,  as  here  shown,  or  the  kind  with  attached  leveling-tube 
may  be  used.  The  can  is  adjusted  between  the  arms  of  the  clamp, 
and  by  turning  the  screw  the  needle  is  brought  into  contact  with  the 
top  of  the  can  and  caused  to  puncture  it,  the  rubber  stoj)per  serving: 
to  make  a  gas-tight  joint.  The  gas  passes  through  the  tube  into  the 
eudiometer,  and  its  constituents  are  determined  in  the  usual  manner,, 
either  by  introducing  the  reagents  directly  into  the  eudiometer-tube  in 
the  proper  order,  or  by  transferring  the  gases  to  pipettes.*  Hydrogen, 
sulphide  is  tested  for  by  subjecting  a  filter-paper  moistened  with  lead 
acetate  solution  to  the  gas.  If  it  turns  black,  the  presence  of  hydrogen 
sulphide  is  indicated. 

METALLIC   IMPURITIES. 

Salts  of  Lead  and  Tin  are  commonly  met  with  in  varying  amounts 
in  nearly  all  classes  of  products  put  up  in  tin.  The  quantity  dissolved 
depends  largely  on  the  character  of  the  tin  plate  used  in  the  manufacture 
of  the  can,  as  well  as  on  how  the  solder  is  applied.  Much  depends 
also  on  the  nature  of  the  food  product  and  its  acidity.  Formerly 
much  danger  was  apprehended  from  the  use  of  the  so-called  terne  plate 
as  a  material  for  cans.  This  consists  of  an  alloy  of  lead  and  tin, 
coated  on  iron  plate  and  intended  for  use  as  roofing.  Sometimes  two 
parts  of  lead  to  one  part  of  tin  are  found  in  terne  plate.  Only  the  better 
grades  of  bright  tin  plate  should  be  used  in  canning.  There  is  reason 
to  believe  that  no  terne  plate  is  at  present  used  in  cans.  In  1892  the 
plating  alloy  of  47  samples  of  tin  cans  in  which  peas  had  been  put 
up  were  examined  in  the  Bureau  of  Chemistry  of  the  U.  S.  Dcj)artment 
of  Agriculture,!  and  the  amount  of  lead  found  varied  from  o  to  13  per 
cent.  Only  4  samples  were  found  to  exceed  5  ])er  cent,  and  24  contained 
less  than  i  per  cent. 

The  construction  (;f  the  can  should  be  such  that  j)ractically  no  soldered 
surface  is  exposed  to  the  contents,  the  joints  being  lapped  and  soldered 
on  the  outside.     In  spite  of  this,  however,  it  is  not  unu.sual  to  find  cans 

*  .See  Thorpe's  dictionary  of  App'd  C'hcm.,  Vol.  i,  pp.  232-243. 
-      -t  Bui.  13,  p.  1036. 


VEGETABLE    AMD   ERUIT   PRODUCTS. 


905 


soldered  on  the  inside,  or  lumps  of  solder  in  the  can  from  the  sealing  of 
the  tapi)ed  hole.  From  51  to  65' <',  of  lead  was  found  in  the  solder  taken 
from  the  interior  of  twenty-four  of  the  cans  mentioned  in  the  j^receding 
paragraph.* 

.  Cans  laccjuered  on  the  inside  to  prevent  contact  of  the  metal  with  the 
food  arc  coming  into  use  l:)ut  as  yet  are  not  an  unqualified  success.  Some 
of  the  lacquers  which  have  proved  most  efficient  are  objectionable  because 
of  their  lead  content. 

Action   of   Fruits   and  Vegetables   on  Tin  Plate.     A  large  variety  of 
canned  products  have  been  examined  in  the  laboratory  of  the  Massachu- 


FiG.  119. — Interior  of  Blueberry  Cans,  Cut  Open  to  Show  the  Corrosion  by  .\c\d  of  the 

Fruit  Juice. 

setts  State  Board  of  Health,  with  a  view  to  determining  the  quantity  of 
tin  contained  in  solution.  The  results  have  shown  that  though  notable 
traces  of  tin  were  found  in  acid  fruits  and  rhubarb,  and  large  traces  in 
some  green  vegetables,  canned  blueberries  were  found  to  contain,  as  a 
rule,  much  more  tin  in  solution  than  any  other  canned  goods  examined. 
It  is  assumed  that  the  tin  was,  at  least  in  considerable  part,  still  held  in 
solution  by  the  fruit  acids,  inasmuch  as  the  metal  was  found  in  the  filtered 
juice.  In  every  instance  the  inner  tin  lining  w^as  found  to  be  exten- 
sively corroded,  and  in  some  cases  it  had  been  almost  entirely  dis- 
solved off,  leaving  the  underlying  iron  bare.     Fig.  119  shows  the  appear- 

*  Bui.  13,  p.  1038. 


9o6 


FOOD  INSPECTION  AND  ANALYSIS. 


ance  of  tAvo  of  these  cans,  split  open  to  show  the  inner  surfaces.  The 
corrosion  is  apparent.  Eleven  samples  of  canned  blueberries,  represent- 
ing seven  brands,  were  examined  in  1894  by  Worcester,  showing  an  amount 
of  tin  in  solution  (calculated  as  SnOj)  varying  from  0.066  to  0.27  gram 
per  can  of  615  cc.  capacity. 

In  1899  samples  of  various  canned  products  were  examined  for  lead 
and  tin  in  the  author's  laborator}-,  the  results  of  which  are  thus  summar- 
ized :  * 


Strawberries 

Highest 

Lowest 

Raspberries 

Highest 

Lowest 

Blueberries 

Highest 

Lowest 

Tomatoes 

Highest 

Lowest 

String  beans 

Highest 

Lowest 

Peas 

Highest 

Lowest I 

Com 

Highest 

Lowest j 

Lima  beans 

Succotash I 

Squash I 

Highest I 

Lowest i 

Pumpkin 

Rhubarb 1 

Asparagus ; 

Mutton  broth ! 

Tomato  soup I 

Salmon 

lobster 


Tin,  Grams. 

Lead,  Grams. 

Capacity  of 
Can,  cc. 

615 

-0393 

.0004 

.0124 

.0000 

615 

.0848 

.0002 

•0725 

.0001 

61S 

.2226 

.0021 

.0056 

.0004 

950 

.0515 

.0004 

.0146 

.0001 

650 

-0499 

•  0003 

.0065 

.0008 

.0046 
.0024 

-oior 

.0045 
.0064 
.0039 

-1793 
■  1.^77 
-1844 
-3506 
.1249 
.0114 
.0023 
.0319 
.0411 


.0000 
.0001 

.0011 
.0001 
.0004 
.0001 

.0087 
-  0003 
.0019 
.0002 
.0001 
.0001 
.0002 
.0001 
.0001 


61S 
615 


650 
650 
950 


950 
615 
930 
950 
370 
470 
430 


A  wide  range  of  variation  exists  in  the  amount  of  tin  dissolved. 
Pumpkin  and  sfjuash,  for  example,  dissolve  surprisingly  large  (juantities. 
considering  the  supposed  inert  nature  of  these  vegetables. 

In  samples  of  canned  sardines  put  up  in  mustard,  vinegar,  and  oil, 
the  Massachusetts  Board  has  found  as  high  as  0.376  gram  of  tin  in  a 


*  An.  Rep.  Mass.  State  Board  of  Health,  1899,  p.  623. 


yEGETABLE  AND    FRUIT    PRODUCTS. 


907 


half-pound  can.  In  these  cases  the  corrosion  of  the  interior  of  the  cans 
was  very  marked.* 

Effect  of  Time  on  Amount  of  Tin  Dissolved. — A  series  of  experi- 
ments was  conducted  by  the  author  in  1899  t  o'^  the  action  of  various 
fruit  acids  on  tin,  with  a  view  to  ascertaining,  among  other  facts,  whether 
or  not  the  element  of  time  exerts  an  appreciable  difference  in  the  results. 

Samples  of  various  canned  fruits  and  vegetables  were  titrated  for 
their  acidity.  It  was  found  that  certain  samples  of  canned  blueberries, 
for  instance,  had  an  rxidity  of  about  one-twentieth  normal.  In  the  case 
of  strawberries,  the  acidity  was  about  one-sixth  normal.  Canned  rasp- 
berries were  found  to  be  about  one-tenth  normal  in  acidity,  while  the 
acidity  of  canned  tomatoes  varied  from  one-tenth  to  one-fourteenth  normal. 
Solutions  of  one-fifth,  one-tenth,  and  one-fifteenth-normal  mahc  acid, 
one-tenth  and  one-fifteenth-normal  tartaric  acid,  one-tenth  and  one- 
fifteenth-normal  citric  acid,  and  one-tenth-normal  acetic  acid  were 
prepared  and  sealed  in  pint  glass  jars,  having  about  the  same  capacity 
as  the  ordinary-sized  tin  fruit  cans,  each  jar  containing  an  amount  of 
tin  plate  equivalent  to  the  interior  exposed  surface  of  a  can.  Solutions 
thus  sealed  were  kept  for  three  months,  six  months,  and  a  year,  and 
examined  at  the  end  of  these  respective  periods  for  tin.  The  results 
showing  the  amount  of  tin  found  at  the  end  of  three  months  in  each 
case  are  given  in  the  following  list: 

ACTION  OF  FRUIT  ACIDS  ON  TIN  IN  THREE  MONTHS. 


Acid. 

Grams  of  Tin 

in  One  Pint  of 

Solution. 

Acid. 

Grams  of  Tin 

in  One  Pint  of 

Solution. 

0.0578 
0.0201 
0.0197 
0.0382 

N/15  tartaric 0.0246 

N/io  citric o.o?7J. 

N/io      V      

N/i:;      "       

N/15     "    

0.0236 
0.0019 

N/io  acetic 

It  was  found  that,  as  a  rule,  the  amount  dissolved  in  three  months  was 
the  same  as  in  six  months  or  even  a  year. 

Tenth-normal  acetic  acid  sealed  in  jars  with  tin  plate,  as  in  the  case 
of  the  fruit  acids,  dissolved  in  three  months  0.0019  Z^^^^  ^^^  '^^  six  months 


*  The  U.  S.  Government,  pending  further  investigation,  permits  joo'mg.  of  tin  per  kilo 
in  canned  goods.     F.  I.  D.  No.  126. 

t  Ann.  Rep.  Mass.  State  Board  of  Health,  1899,  p.  624. 


Qo8 


FOOD   INSPECTION   AND   ANALYSIS. 


0.00S3  gram  of  tin,  which  is  much  less  than  was  obtained  with  fruit  acids 
of  the  same  strength,  and  witli  the  samples  of  sardines  referred  to  on. 
page  90b. 

Bigelow  and  Bacon  find  that  shrimps  contain  monomethylamin,  which 
corrodes  the  cans  in  which  they  are  packed.  Their  experiments  with 
volatile  alkalis  and  amino  acids  present  in  vegetables  of  low  acidity  indicate 
that  the  corrosive  action  of  certain  vegetables  is  due  to  substances  of  this 
group. 

Salts  of  Lead. — While  it  is  a  fact  that  the  material  of  the  tin  plating 
usuallv  found  in  cans  is  comparatively  low  in  lead,  the  same  is  not  always 
true  of  the  metal  caps  used  to  cover  some  of  the  bottled  goods.  The 
French  "haricots  verts"  are  usually  sold  in  w'ide-mouthed  bottles,  closed 
bv  a  disk  of  ver\-  soft  metal.  In  one  instance  this  metal  cap,  which  came 
in  contact  with  the  licjuid  contents  of  the  bottle,  was  found  to  contain 
93^%  of  lead.  Of  the  various  kinds  of  bottles  in  which  are  sold  cheap 
carbonated  drinks  known  as  "pop,"  one  style  has  a  stopper  consisting  of 
a  metallic  button  surrounded  by  a  rubber  ring.  These  metallic  buttons 
consist  of  tin  and  lead  in  varying  proportions.  Inasmuch  as  the  inclosed 
liquor  was  usually  found  to  be  quite  acid  in  reaction,  the  danger  of  pro- 
longed contact  with  the  metallic  portion  of  the  stopper  is  evident. 

The  following  table  gives  the  percentage  of  lead  found  in  the  stoppers 
of  this  character,  together  with  the  amount  of  lead  contained  in  the  liquor;* 


Character  of  Sample. 

Amount  of  Lead 
Per  Cent  of         in  Contents  of 
Lead  in  Stopper.    Btittle  in  Milli- 
grams.t 

Blood  orange 

50-7 
35-0 
32.2 

8.8 
6-5 
8-5 
3-5 
7-5 

50-3 
3-8 

0-31 
Large  trace 
0.40 
0.20 
0.30 

O.IQ 
0.17 
0.27 

1.05 
O.OI 

Birch  beer 

Ginger 

Strawljcrr^'  A 

Strawberry  B 

Sarsaparilla  A 

.Sarsaparilla  B 

Lemon 

Miscellaneous  (20  samples) 
Maximum ............. 

Minimum 

t  Capacity  of  bottle  about  i  pint. 


Besides  the  above  tabulated  samples,  twenty  were  found  with  stoppers 
containing  less  than  3%  of  lead.     While  the  amount  of  lead  found  in  the 


•  An.  Rep.  Mass.  State  Board  of  Health,  1897,  p.  571, 


[VEGET/IBLE  ^ND   FRUIT  PRODUCTS.  909 

contents  of  the  bottles  was  in  no  case  very  large,  it  was  enough  to  con- 
demn the  use  of  lead  in  the  manufacture  of  such  stoppers.  That 
the  amounts  of  lead  found  in  the  contents  of  the  bottles  vary  quite  irre 
spective  of  the  percentage  of  lead  in  their  stoppers,  may  be  ascribed  to 
various  causes,  such  as  the  difference  in  the  acidity  of  the  liquors,  and 
the  length  of  time  that  the  liquor  has  been  in  contact  with  the  stopper. 
Furthermore,  the  more  soluble  metal  of  an  alloy  is  attacked  by  an  acid 
with  an  energy  which  is  not  proportional  to  the  percentage  of  that  metal 
in  the  alloy. 

Salts  of  Zinc. — The  presence  of  zinc  salts  in  canned  foods  is  largely 
accidental,  and  is  generally  due  either  to  the  contact  of  the  acid  fruits 
and  vegetables  with  galvanized  iron  in  the  canneries,  to  the  occasional 
use  of  brass  vessels,  or  to  the  zinc  chloride  used  as  a  soldering  fluid. 
Hilgard  and  Colby  *  have  examined  empty  tin  cans  fresh  from  the  manu- 
facturer, and  found  zinc  chloride  in  notable  quantity  in  the  seams,  and 
especially  in  the  empty  space  of  the  lap  at  the  bottom  of  the  can,  where 
it  could  easily  be  acted  on  by  the  contents.  The  average  amount  of 
soluble  zinc  chloride  found  in  the  "lap"  alone  amounted  to  three-fourths 
of  a  grain  per  can.  It  was  furthermore  ascertained  that  it  was  not  the 
practice  of  canners  to  wash  the  cans  before  packing,  so  that  zinc  present 
in  canned  goods  may  thus  readily  be  accounted  for. 

Zinc  chloride  is  commonly  used  in  machine  soldering,  but  should  be 
displaced  by  rosin. 

Hilgard  and  Colby  found  in  some  spoiled  cans  of  asparagus,  where 
the  acidity  was  unusually  high,  an  average  of  6.3  grains  of  zinc  chloride 
per  large  can. 

Zinc  salts  are  said  to  have  been  used  for  greening  peas,  but  their  use 
for  this  purpose  is  not  common.  Zinc  chloride  is  the  salt  used,  and  a 
natural  yellowish-green  tint  is  imparted  when  properly  applied.  The 
process  has  been  kept  secret. 

Salts  of  Copper. — While  copper  in  canned  goods  is  sometimes  acci- 
dental, its  presence  being  due  to  the  vise  of  copper  or  brass  vessels  in  the 
canneries,  its  chief  interest  to  the  food  analyst  lies  in  the  use  of  copper 
sulphate  for  greening  peas  and  other  vegetables.  The  artificial  greening 
of  vegetables  is  much  more  commonly  practiced  in  France  than  in  the 
United  States. 

French  canners  of  peas,  beans,  Brussels  sprouts,  etc.,  are  frequently 
so  lavish  in  the  use  of  sulphate  of  copper  that  the  goods  as  found  on  our 

*  Rep.  Cal.  Agric.  Exp.  Sta.,  1897-8,  p.  159. 


9IO  FOOD    INSPECTION   AND    ANALYSIS. 

markets  can  in  some  cases  hardly  be  said  to  resemble  the  freshly  cooked 
products  in  color.  Oftentimes,  indeed,  they  possess  such  a  deep  green 
as  to  be  positively  distasteful  to  the  average  American  palate,  though 
evidently  this  unnatural  hue  is  craved  in  Europe.  The  use  of  copper 
in  such  foods  is  often  rendered  apparent  by  the  most  cursory  examina- 
tion. 

In  this  countr)-,  when  copper  is  used,  smaller  quantities  are  usually 
emploved.  with  an  attempt  to  imitate  more  closely  the  color  of  the  natural 
product. 

Complaint  in  court  for  this  form  of  adulteration  under  the  general 
food  law  as  it  exists  in  most  states  would  naturally  be  brought  under  one 
of  two  clauses : 

ist.  As  being  colored,  whereby  the  product  appears  of  greatei  value 
than   it   really  is,  or 

2d.  As  containing  an  ingredient  injurious  to  health. 

An  ingenious  claim  is  sometimes  advanced  by  the  defendant  in  oppo- 
shion  to  clause  i,  to  the  effect  that  copper  sulphate  is  added,  not  to  give 
an  artificial  green  color,  but  to  preserve  the  original  green  of  the  chloro- 
phvl  or  natural  color  of  the  fresh  peas,*  so  that  it  will  not  be  destroyed 
by  subsequent  boiling. 

This  jjoint  was  argued  in  a  strongly  contested  court  case  brought  in 
Massachusetts  for  copper  in  French  peas.| 

As  Worcester  %  has  shown,  the  fallacy  of  this  argument  can  be  easily 
demonstrated.  If  it  were  true  that  the  copper  acts  as  a  preservative  of 
the  chlorophyl,  a  jjure  extract  of  chloroj^hyl  should,  by  the  addition  of 
copper  sulphate,  be  prevented  from  destruction  on  boiling,  and  again, 
on  once  destroying  the  color  of  the  chlorophyl  by  boiling,  it  would  be 
impossible  to  restore  it  by  further  Ijoiling  it  with  copper  sulphate. 

As  a  matter  of  fact,  if  an  extract  of  chlorophyl  is  boiled  with  a  dilute 
solution  of  copper  sulphate,  its  color  is  at  once  destroyed,  and  a  brown 
precipitate  is  thrown  down.  On  the  other  hand,  if  yellow  or  white  peas 
or  beans  devoid  of  chlorophyl  are  boiled  with  copper  sulphate,  they  are 
colored  green,  the  depth  of  color  depending  on  the  strength  of  the  copper 
solution.  When  peas  or  other  vegetables  are  thus  colored,  very  little 
copper  is  found,  as  a  rule,  in  the  liquid  contents  of  the  can,  but  the  copper 
is  chiefly  confined  to  the  solid  portions.     Green  compounds  are  produced 

*  The  term  used  by  the  French  to  describe  this  process  is  reverdissage  or  "regreening." 
t  An.  Rep.  Mass.  State  Board  of  Health,  1892,  p.  605. 
X  Loc  cit.,  supra,  p.  641. 


l^EGETABLE  AND   FRUIT   PRODUCTS.  911 

by  boiling  albumins  with  copper  sails,  due  to  the  fcrmation  of  albuminate, 
or  in  the  case  of  peas,  Icguminate  of  copper.  Harrington  *  states  that  it  is 
possible  to  color  eggs  an  intense  green  by  boiling  with  copper  sulphate. 

Examination  of  a  large  number  of  brands  of  canned  vegetables  greened 
by  copper,  as  bought  in  Massachusetts,  showed  that  the  amount  used 
varied  from  a  trace  to  2.75  grams  per  can,  calculated  as  copper  sulphate. 
In  justice  to  the  consumer,  who  may  be  cautious  about  taking  into  his 
system  copper  salts,  as  well  as  to  those  who  are  indifferent  to  their  use, 
it  is  no  more  than  fair  that  all  cans  should  have  a  label,  plainly  stating 
the  quantity  present.  In  the  Massachusetts  market,  labels  like  the  fol- 
lowing are  not  uncommon :  ' '  This  package  of  French  Vegetables  con- 
tains an  equivalent  of  Metallic  Copper  not  exceeding  three-quarters  of 
a  grain." 

Copper  as  a  coloring  matter  has  been  most  commonly  found  in  peas, 
beans,  and  Brussels  sprouts.  Copper  salts  in  minute  quantity  have  been 
found  in  Massachusetts  in  canned  tomatoes,  clams,  and  squash,  as  well 
as  in  pickles. 

Salts  of  Nickel. — Sulphate  of  nickel  has  been  employed  instead  of 
sulphate  of  copper  for  greening  vegetables.  According  to  Harrington  f 
0.25  gram  of  nickelous  sulphate  per  kilogram  of  peas  is  used.  The  peas 
or  other  vegetables  are  boiled  in  a  solution  of  the  salt,  made  slightly  alka- 
line with  ammonia. 

Toxic  Effects  of  Metallic  Salts. — Divergence  of  opinion  is  so  great 
as  to  the  toxic  effects  of  salts  of  the  heaw  metals  on  the  human  system, 
when  present  in  the  small  amounts  commonly  found  in  food  products, 
that  it  is  extremely  difficult  to  maintain  a  complaint  in  court  based 
entirely  on  the  harmful  effects  of  these  salts.  Since  the  question  is  one 
for  the  toxicologist  or  physiological  chemist  rather  than  the  analyst  to 
settle,  it  will  not  be  discussed  here  at  length ;  suffice  it  to  say  that  experi- 
ments made  by  the  Referee  Board  indicate  that  while  as  much  as  150  mg. 
of  copper  may  be  contained  in  the  coppered  beans  or  peas  eaten  in  a  day 
as  little  as  10  mg.  under  certain  conditions  may  have  a  deleterious  action 
and  must  be  considered  injurious  to  health.  Accordingly  foods  greened 
with  copper  are  considered  adulterated  by  the  federal  authorities.  J 

*  Practical  Hygiene,  p.  203. 
t  Ibid.,  p.  205. 
X  Food  Inspection  Decisioa  148.  j 


912  FOOD   INSPECTION  AND  ANALYSIS. 


PRESERVATIVES. 


No  class  of  food  products  stands  so  little  in  need  of  these  added  sub- 
stances to  arrest  fermentation  as  canned  foods,  if  properly  prepared 
and.  as  a  matter  of  fact,  the  use  of  antiseptics  has  been  almost  entirely 
discontinued. 

The  Bleaching  of  Corn  by  artificial  means  before  canning  is  usually 
accomplished  by  boiling  the  corn  with  sulphite  of  soda,  thus  giving  to 
tiie  product  an  unnaturally  white  color.  The  practice  seems  to  have  been 
more  in  vogue  some  years  ago  than  at  present,  the  popular  taste  now  appar- 
ently preferring  the  natural  rich  yellow  of  fresh  corn. 

Saccharin  is  claimed  to  possess  antiseptic  powers  and  is  used  in  canned 
goods,  but  its  primary  purpose  is  as  a  sweetener. 

Salicylic  acid,  sodium  henzoate,  and  heta-naphthol,  although  formerly 
used,  are  now  seldom  found  in  canned  goods. 

"soaked  goods." 

It  has  become  quite  common,  especially  in  the  case  of  peas,  beans,, 
and  com,  to  utilize  for  canning  purposes  those  that  have  grown  old  and. 
dried,  after  soaking  them  for  a  long  time.  The  presence  of  soaked  peas 
in  the  market  is  generally  more  common  in  years  when  there  is  a  scarcity 
in  the  pea  crop.  By  the  process  of  soaking,  dried  and  matured  field  corn 
may  be  softened  to  such  an  extent  as  to  be  substituted  for  green  or  sweet 
corn  in  the  canned  product.  These  goods,  frequently  sold  at  a  very  lovr 
price,  under  some  such  tempting  name  as  "Choice  Early  June  Peas,"  are 
entirely  devoid  of  that  succulent  property  so  highly  prized  in  the  fresh 
goods,  and  are  altogether  so  inferior  in  quality  that  their  sale  may  justly 
be  considered  as  fraudulent,  unless  their  character  is  specified.  In  some 
states  the  law  provides  that  such  a  product,  to  be  legally  sold,  shall 
have  f)lainly  markerl  on  the  label  of  the  can  the  words  "Soaked  Goods" 
in  letters  of  prescribed  size. 

Detection. — Methods  of  detecting  soaked  goods  are  distinctly  physi- 
cal rather  than  chemical.  The  appearance  and  taste  of  the  goods  furnish 
in  most  cases  an  unmistakable  clue  to  their  nature.  Soaked  goods  are 
entirely  lacking  in  juiciness,  and  in  the  flavors  so  characteristic  of  the- 
varif)us  vegetables,  when  gathered  anrl  canned  before  becoming  dry. 
The  process  of  soaking  is  also  said  to  develop  the  growth  of  the  rudi- 
mentar)'  stem  of  the  embr>'o  in  the  dried  pea  and  bean.  Peas  and  beans 
of  the  soaked  variety  are  almost  entirely  lacking  in  the  green  color  o£ 


VEGETABLE  AND  FRUIT  PRODUCTS.  913 

the  fresh  vegetables,  unless  the  color  has  been  artificially  supplied.     The 
licjuid  is  commonly  milky. 

In  all  cases  it  will  be  found  that  the  solid  grains  or  kernels  of  the 
peas,  beans,  and  corn  that  have  once  been  dried,  though  softened  by 
the  process  of  soaking,  have  much  less  water  than  the  grains  of  the  cor- 
responding vegetables  that  were  gathered  while  still  soft  and  succulent. 

METHODS  OF  ANALYSIS. 

Methods  of  Proximate  Analysis. — As  a  rule,  the  contents  of  canned 
goods  are  intended  to  be  entirely  edible  throughout,  and  contain  little 
or  no  refuse  or  portions  to  be  rejected.  An  exception  to  this  is  the  occa- 
sional canning  of  certain  fruits  with  stones  or  pits,  which  are,  of  course, 
to  be  removed.  The  can  or  package  is  first  weighed  before  opening,  and 
later  the  cleaned  receptacle  is  weighed  after  its  contents  have  been  removed. 
The  weight  of  the  contents  is  thus  ascertained  by  difference. 

For  the  analytical  determinations,  the  contents  of  the  can  cr  bottle 
are  intimately  mixed  to  form  a  homogeneous  pulp,  so  that  parts  taken 
for  analysis  are  fairly  representative  of  the  whole.  If  considerable  liquid 
is  present,  with  some  solid  masses  held  in  suspension  therein,  the  liquid 
is  best  drained  off,  and  the  solid  portions  pulped  separately  in  any  con- 
venient manner,  as  by  the  use  of  a  mortar,  or  by  means  of  a  household 
food-chopper.  The  whole  is  then  thoroughly  mingled  together.  If 
desired,  the  weight  of  the  liquid  and  solid  portions  may  be  separately 
ascertained  before  mixing. 

The  analyst  should  use  judgment  and  discrimination  as  to  how 
various  portions  of  the  mass  are  to  be  best  measured  out  for  the  deter- 
minations. Much  depends  on  the  consistency  of  the  pulpy  mass.  It 
is  often  convenient  to  make  a  20%  solution  or  mixture  of  the  material 
with  water,  using  say  50  grams  of  the  pulped  sample  in  250  cc.  of  water, 
su'jh  of  the  sample  as  is  insoluble  being  disintegrated  by  shaking. 

Methods  for  determining  water,  ether  extract,  crude  fiber,  protein, 
and  ash  do  not  differ  materially  from  those  employed  in  the  case  of  cor- 
responding fresh  fruits  and  vegetables. 

These  determinations,  in  the  case  of  canned  products,  while  useful 
in  showing  their  food  value,  give  little  information  as  to  their  adulteration 
by  the  substitution  of  foreign  vegetable  or  fruit  pulp. 

Determination  of  Lead  in  Tin  Alloy. — Method  of  Paris  Municipal 
Laboratory.'^ — The  material,  if  soft,  is  hammered  into  a  thin  plate,  and 

*Analyse  des  Matieres  Alimentaires  et  Recherche  de  leurs  Falsifications,  1894,  p.  695. 


QI4  FOOD   ISSrECTlOt/   AND   ANALYSIS. 

2^  grams  are  weighed  out,  transferred  to  a  250-cc.  flask,  and  dissolved 
in  7  to  S  cc.  of  concentrated  nitric  acid.  Evaporate  to  dryness  on  the 
sand-bath,  add  10  drops  of  nitric  acid  and  50  cc.  of  boihng  water,  cool, 
and  make  up  to  250  cc.  with  water.  Let  the  residue  settle  and  pour  of! 
through  a  filter  100  cc.  of  the  clear,  supernatant  liquid,  corresponding 
to  I  gram  of  the  material.  This  contains  the  lead,  while  the  tin  is  left 
behind  in  the  residue,  together  with  antimony  if  present. 

Add  10  cc.  of  a  standard  solution  of  potassium  bichromate  (7.13  grams 
to  the  liter)  and  shake.  Each  cubic  centimeter  of  this  standard  solution 
is  sufficient  to  precipitate  0.0 1  gram  of  lead.  Allow  the  lead  chromate 
formed  to  settle,  and,  if  the  solution  is  colorless,  add  10  cc.  more  of  the 
bichromate,  or  sufficient  to  be  present  in  excess,  as  indicated  by  the  yellow 
color.  Filter,  wash,  and  titrate  the  excess  of  bichromate  with  a  standard 
iron  solution,  containing  57  grams  of  the  double  sulphate  of  iron  and 
ammonia  and  125  grams  of  sulphuric  acid  per  liter.  This  iron  ^olution 
should  be  kept  under  a  layer  of  petroleum,  and  standardized  against 
the  potassium  bichromate  before  use. 

Add,  drop  by  drop,  the  iron  solution  to  that  containing  the  excess  of 
bichromate.  The  color  of  the  latter  passes  from  pale  green  to  bright 
green,  when  the  chromate  is  completely  reduced.  Determine  the  end- 
point  with  a  freshly  prepared  dilute  solution  of  potassium  ferricyanide, 
a  drop  of  which  is  placed  on  a  porcelain  plate  or  tile  in  contact  with  a 
little  of  the  solution  titrated.  A  blue  color  is  produced  when  the  iron 
is  present  in  excess.  If  the  standard  iron  and  bichromate  solutions 
exactly  correspond,  i  cc.  of  the  iron  solution  is  equivalent  to  1%  of  lead, 
but  the  latter  solution  is  usually  a  little  weak. 

If  n  =  number  of  cubic  centimeters  of  iron  solution  necessary  10 
reduce  10  cc.  of  the  standard  bichromate, 

I  cc.  of  the  iron  solution  =  — . 

n 

If,  now,  r  =  number  of  cubic  centimeters  of  iron  solution  necessary 
to  reduce  the  excess  of  bichromate  in  the  determination,  and  5  =  number 
of  cubic  centimeters  of  bichromate  used, 

s  —  — r  =  per  cent  of  lead  in  the  allov. 

Separation   and   Determination   of  Tin,   Copper,   Lead,   and   Zinc  in 

Canned    Goods.  —  Munsun's   Mclhud* —  The  contents    of    the    can    are 


•  U.  S.  Dept.  of  Agrir.,  Bur.  of  Chem.,  Bui.  107  rev.,  p.  62. 


yHGF.TABLh:   AND   FRUIT  PRODUCTS.  915 

first  evaporated  to  dryness,  and  from  10  to  15  cc.  of  concentrated  sul- 
phuric acid  or  enough  to  carbonize  arc  added  to  the  dry  residue  contained 
in  a  porcelain  evaporating-dish,  which  is  very  gently  heated  over  the  flame 
till  foaming  ceases.  Then  ignite  to  an  ash  in  a  muffle,  or  carefully  over 
the  free  flame,  using  a  little  nitric  acid,  if  necessary,  for  oxidation  of  the 
organic  matter.  Add  20  cc.  of  dilute  hydrochloric  acid,  and  evaporate 
over  the  water-bath  to  dryness.  Wash  the  residue  into  a  beaker,  slightly 
acidify  with  hydrochloric  acid,  and  saturate  with  hydrogen  sulphide 
without  previous  filtration.  Heat  the  beaker  on  the  water-bath,  and 
pass  the  contents  through  a  filter.  Wash  the  precipitate,  which  contains 
sulphides  of  tin,  lead,  and  copper,  if  these  metals  are  present,  while  if  there 
is  zinc,  it  is  contained  in  the  filtrate.  The  precipitate  is  fused  with  sodium 
hydroxide  in  a  silver  crucible  for  half  an  hour,  to  increase  the  solubility 
of  the  tin,  which  would  otherwise  be  dissolved  with  difficulty.  The 
fusion  is  boiled  up  with  hot  water,  acidulated  with  hydrochloric  acid,  and 
transferred  without  filtering  to  a  beaker,  in  which  hydrogen  sulphide 
is  added  to  saturation.  This  precipitates  the  sulphides  of  tin,  lead,  and 
copper  (if  these  metals  are  present).  The  sulphide  precipitate  is  collected 
on  a  filter,  and  thoroughly  washed  with  hot  water,  the  washings  being 
rejected.  Pass  through  the  filter  several  portions  of  boiling  ammonium 
sulphide,  using  about  50  cc.  in  all,  or  till  all  the  tin  is  dissolved.  Precipi- 
tate the  tin  from  the  combined  filtrate  with  hydrochloric  acid,  filter, 
wash,  ignite,  and  weigh  as  stannic  oxide. 

The  residue  left  on  the  filter,  after  dissolving  out  the  tin  sulphide,  is 
then  dissolved  by  treatment  with  nitric  acid,  which  is  filtered,  and  to 
the  filtrate  and  washings  ammonia  is  added  nearly  to  the  point  of  neutral- 
ization. Then  add  ammonium  acetate.  Filter  off  any  precipitate  of 
iron  that  may  be  formed.  The  filtrate  is  divided  into  two  portions  for 
determination  of  copper  and  lead.  If  lead  is  absent,  determine  the 
copper  by  titration  with  potassium  cyanide  *  or  electrolytically  (p.  608). 
Copper  is  rarely  present  in  sufficient  amount  to  be  determined,  unless 
used  for  greening  the  vegetables.  If  notable  quantities  of  lead  are  present, 
the  solution  is  made  acid  with  acetic,  and  the  lead  precipitated  therefrom 
with  potassium  chromate,  collected  on  a  tared  filter,  washed  with  water 
acidified  with  acetic  acid,  dried  at  100°  C,  and  weighed  as  lead  chromate. 
Or  determine  the  lead  by  color-tests,  as  on  page  918. 

For  the  determination  of  zinc,  the  filtrate  from  the  first  hydrogen- 
sulphide  residue  is  evaporated  to  a  volume  of  about  60  cc,  and  treated 
*  Sutton,  Volumetric  Analysis,  8th  ed.,  p.  204. 


Cji6  FOOD  IXSPECTIOX  AND   ANALYSIS. 

uith  bromine  water  to  oxidize  the  iron,  as  well  as  any  excess  of  hydrogen 
sulphide  remaining,  the  excess  of  bromine  is  then  boiled  off,  and  a  few 
drops  of  concentrated  ferric  chloride  added,  to  make  the  solution  distinctly 
yellow,  if  not  already  so.  Nearly  neutralize  with  ammonia,  and  precipi- 
tate the  iron  wiih  ammonium  acetate.  Filter,  wash,  acidify  the  filtrate 
with  acetic  acid,  and  preci])itate  the  zinc  with  hydrogen  sulphide. 
Filter,   wash,   ignite,   and  weigh  as   zinc   oxide. 

The  metals  may  be  determined  separately,  as  follows: 
Determination  of  Tin.* — Evaporate  the  contents  of  the  can  to  dry- 
ness, and  ignite  in  j)orcelain.  Fuse  the  ash  with  sodium  hydroxide  in  a 
silver  crucible,  boil  the  fusion  witli  several  portions  of  water  acidulated 
with  hydrochloric  acid,  filter,  and  precipitate  the  tin  from  the  acid  solu- 
tion with  hydrogen  sulphide.  Dissolve  the  washed  precipitate  in  ammo- 
nium sulphide,  filter,  and  deposit  the  tin  directly  from  this  solution  by 
electrolysis  in  the  platinum  dish  which  contains  it,  using  a  current  of 
0.5  amjKTe  and  the  electrolytic  apparatus  described  on  page  608. 

Smith  and  Bartletf\  employ  the  following  method  of  solution:  Weigh 
50  grams  of  fish  or  100  grams  of  vegetables  in  a  porcelain  dish  and  dry 
over  night.  Heat  from  75  to  100  cc.  of  concentrated  sulphuric  acid  in  a 
Kjeldahl  flask  until  acid  fumes  are  visible,  then  add  gradually  small  por- 
tions of  the  food  product,  heating  the  acid  between  additions  until  frothing 
ceases.  Allow  to  cool,  then  add  gradually  to  the  charred  mixture  25  cc. 
of  concentrated  nitric  acid,  which  causes  the  evolution  of  red  fumes  and  the 
generation  of  heat.  Cool,  add  25  cc.  of  nitric  acid  and  heat  gently  until 
all  nitric  fumes  are  expelled  and  the  charred  material  is  dissolved  to  a 
homogeneous  solution.  Boil  this  solution  about  45  minutes,  then  add 
from  10  to  15  grams  of  potassium  sulphate  and  continue  boiling  from  three 
to  five  hours  until  decolorized.  Wash  the  digest  into  an  800  cc.  beaker, 
dilute  to  about  600  cc.  and  bring  to  a  boil.  Almost  all  of  the  tin  separates 
as  stannic  oxide,  partially  hydrated,  some  of  which  adheres  to  the  sides  of 
the  flask,  and  cannot  be  removed  by  washing.  Pllter  the  contents  of  the 
beaker,  thus  separating  the  hydrated  stannous  oxide  from  all  other  com- 
pounds. Place  the  filter  in  the  flask,  to  which  20  cc.  of  saturated  sodium 
hydroxide  and  an  equal  volume  of  water  have  been  added,  boil  for  several 
minutes,   then   wash   the  sodium  stannate  into  a  beaker.     Acidify  with 

*  Hilgcr  u.  Laband,   Zeits.     Unters.   Nahr.   Genussm.,  2,  1899,  p.  795;   An.  Rep.  Mass. 
State  Board  of  Health,  1899,  p.  625. 

t  A.O.A.C.  Proc.  1910,  U.  S.  Dept.  of  .\grif ..  Hur.  of  Chem.,  Fiul.  137,  p.  134. 


l^EGETABI.E  AND   FRUIT  PRODUCTS.  917 

hydrochloric  acid,  precipitate  with  hydrogen  sulphide  and  proceed  as 
abov^e  described. 

Hansen  and  Johnson  *  heat  a  quantity  of  the  material,  containing 
about  25  grams  of  solids,  with  a  mixture  of  200  cc.  of  water,  100  cc.  of 
concentrated  nitric  acid  and  50  cc.  of  concentrated  sulphuric  acid,  adding 
additional  nitric  acid  from  time  to  time  and  finally  25  grams  of  potassium 
sulphate. 

Baker  Melhod.'f — Treat  100  grams  of  the  material  with  nitric  and 
sulphuric  acid  as  described  in  the  preceding  sections.  Dilute  the  sulphuric 
acid  residue,  neutralize  with  ammonia,  add  hydrochloric  acid  until  the 
solution  contains  about  2%,  and  thoroughly  saturate  with  hydrogen 
sulphide  gas  Filter  the  impure  lead  sulphide  on  a  Gooch  crucible  with 
a  false  bottom,  wash  three  or  four  times  with  water,  then  transfer  precipitate 
and  asbestos  to  a  300-cc.  Erlenmeyer  flask,  washing  with  a  little  water, 
and  boil  with  strong  hydrochloric  acid,  adding  potassium  chlorate  from 
time  to  time  to  insure  complete  solution  of  the  tin  sulphide  as  well  as  the 
elimination  of  the  sulphur.  Add  a  few  strips  of  pure  aluminum  foil, 
free  from  tin,  until  all  the  chlorine  is  eliminated,  then  dilute  to  from 
30  to  40%  acid  strength  and  attach  to  a  carbon  dioxide  generator  provided 
with  a  scrubber  and  charged  with  pure  marble  and  hydrochloric  acid. 

A  bulb  tube  passing  through  one  opening  of  a  double -bore  stopper 
serves  to  deliver  the  gas  near  the  surface  of  the  liquid  and  another  bulb 
tube  provides  an  exit,  the  latter  being  connected  with  a  glass  tube  immersed 
in  water  to  the  depth  of  20  cm.,  forming  a  water  seal.  When  the  flask  is 
first  attached  to  the  carbon  dioxide  apparatus,  lift  the  exit  tube  out  of  the 
water  so  as  to  reduce  the  pressure  and  thus  force  a  large  amount  of  gas 
through  the  system,  expelling  all  air.  Then  raise  the  stopper  of  the  flask 
and  introduce  about  i  gram  of  aluminum  foil,  which  quickly  reduces  the 
tin  to  the  metallic  form  with  evolution  of  hydrogen. 

Heat  to  boiling  on  a  hot  plate  and  boil  for  a  few  minutes,  which  causes 
the  aluminum  to  disappear  and  changes  the  tin  into  stannous  chloride, 
then  cool  in  ice-water,  still  passing  carbon  dioxide  through  the  system. 
Remove  the  stopper  together  with  the  tubes,  washing  the  same  and  the 
sides  of  the  fiask  with  air-free  water,  prepared  l^y  boiling  distilled  water, 
adding  a  small  amount  of  sodium  bicarbonate  and  then  a  slight  excess  of 
hydrochloric  acid. 

*  A.O.A.C.  Proc.  iQii,  U.  S.  Dept.  of  .Agric,  Bur.  of  Chem.,  Bui.  152,  p.  117. 
t  8th  Intern.  Cong.  Appl.  Chem.,  18,  p.  35. 


91 8  i-OOD  INSPECTION  AND  ANALYSIS. 

Add  Starch  paste  and  titrate  directly  and  quickly  with  hundredth- 
normal  iodine  solution  until  a  faint  blue  color  is  obtained.  The  iodine 
solution  is  standardized  against  pure  tin  solution  or  a  food  mixture,  such 
as  apple  butter,  containing  an  added  amount  of  tin  salt. 

\n  alternate  procedure  is  to  add  an  excess  of  iodine  solution  to  the 
tlask  after  lifting  the  stopper,  but  while  the  carbon  dioxide  is  still  issuing 
from  the  neck,  and  titrate  the  excess  with  standard  sodium  thiosulphate 
solution. 

By  means  of  a  Y  tube  the  current  from  one  generator  may  be 
dinded  for  two  llasks  so  tliat  duplicates  may  be  conducted  at  ths  same 
time. 

Determination  of  Lead,  especially  applicable  if  lead  is  present  in  small 
amounts  only.  Boil  the  sulphated  ash  of  the  contents  of  the  can  (obtained 
as  on  page  915)  with  a  solution  of  ammonium  acetate,  having  an  excess  of 
ammonia.  The  tin,  zinc,  and  iron  remain  insoluble,  while  the  copper 
and  lead  are  dissolved.  Filter,  wash,  and  add  a  few  drops  of  potassium 
cyanide  to  the  filtrate,  to  prevent  precipitation  of  copper  when  hydrogen 
sulphide  is  subsequently  added.  If  the  solution  exceeds  40  cc,  concen- 
trate to  that  amount  by  evaporation,  and  transfer  to  a  50-cc.  Nessler 
tube.  Add  hydrogen  sulphide  water,  and  make  up  to  the  mark.  Com- 
pare the  brown  color  im])arted  by  the  lead  sulphide,  with  the  colors 
obtained  by  treating  with  hydrogen  sulphide  water  in  Nessler  tubes 
various  measured  amounts  of  a  standard  solution  of  lead  acetate,  made 
alkaline  with  ammonia. 

Determination  of  Copper. — (i)  Electrolytically . — Ash  the  contents  of 
the  can  as  on  page  015.  Wet  the  ash  with  concentrated  nitric  acid,  add 
water,  and  boil.  Then  make  strongly  alkaline  with  ammonia  and  filter. 
Unless  the  filtrate  is  colored  Ijlue,  copper  is  absent.  Transfer  the  filtrate 
to  a  bright  tared  platinum  dish  oi  roo-cc.  capacity,  neutralize  with 
concentrated  nitric  acid,  and  add  about  2  cc.  in  excess.  Nearly  fill  the 
dish  with  water,  and  clectrolyze  with  the  apparatus  described  on  page 
608,  using  a  current  of  abcjut  0.3  of  an  amjjcre. 

(2)  Colorimelrkally. — This  method  is  especially  applicable  for  —"all 
amounts  of  copper.  The  blue-colored  ammoniacal  solution  of  the  ash, 
filtered  as  in  (\),  is  transferred  to  a  Nessler  tube,  and  its  color  matched 
against  the  colors  of  a  series  of  measured  amounts  of  an  ammoniacal 
standard  solution  of  copper  sulphate. 

Determination  of  Nickel.  — Boil  the  ash  with  water  slightly  acidified 
with   hydrochloric   acid,    and   without   filtering,   saturate  with   hydrogen 


VECETABLR  AND   FRUIT  PRODUCTS.  919- 

sulphide,  thus  precipitating  out  any  copper,  tin,  or  lead.  Filter  and  wash. 
Zinc  and  nickel,  if  present,  are  in  the  filtrate.  Boil  the  filtrate  to  expel 
the  hydrogen  sulphide,  and  add  sodium  carbonate  till  slightly  alkaline. 
Add  acetic  acid  without  filtering  till  the  precipitate  produced  by  the 
alkaline  carbonate  is  dissolved,  and  then  add  a  considerable  excess  of 
acetic  acid.  The  zinc  is  precipitated  by  passing  hydrogen  sulphide 
through  the  cold  dilute  solution,  while  the  nickel  is  held  in  solution  by 
the  large  excess  of  acetic  acid.  Filter,  and  wash  with  hydrogen  sulphide 
water,  to  which  a  little  ammonium  acetate  has  been  added. 

Make  the  filtrate  alkaline  with  ammonia,  precipitate  the  nickel  with 
ammonium  sulphide,  filter,  wash,  ignite,  and  weigh  as  nickelous  oxide. 

KETCHUP. 

Standards. — The  following  are  the  standards  of  the  A.O.A.C.  and  the 
Assn.  of  State  and  Nat.  Food  and  Dairy  Depts. : 

Catchup  (Ketchup,  Catsup)  is  the  clean,  sound  product  made  from  the 
properly  prepared  pulp  of  clean,  sound,  fresh,  ripe  tomatoes,  with  spices 
and  with  or  without  sugar  and  vinegar;  Mushroom  Catchup,  Walnut 
Catchup,  etc.,  are  catchups  made  as  above  described,  and  conform  in 
name  to  the  substances  used  in  their  preparation. 

No  standard  is  given  for  Chili  Sauce,  a  product  made  from  tomatoes, 
peppers,  onions,  vinegar,  sugar,  and  spices  differing  from  ketchup  in  that 
it  is  not  strained. 

Process  of  Manufacture. — When  made  in  the  household  ripe  tomatoesj 
with  or  without  paring  and  coring,  are  cut  in  pieces  and  boiled  down  to 
a  thick  pulp,  strained  to  remove  seeds  and  other  coarse  tissues  and  finally 
heated  for  a  time  wath  vinegar,  spices  and  sugar.  The  product  is  bottled 
while  hot. 

Factory-made  ketchup,  of  good  quality,  is  prepared  by  practically 
the  same  process,  using  special  apparatus  for  washing,  pulping  and  con- 
centrating. In  many  factories  considerable  time  elapses  before  the  finish- 
ing processes  are  carried  out,  the  pulp  being  stored  in  barrels  or  better 
in  lacquered  tin  receptacles  until  needed.  Manufacturers  of  ketchup 
often  purchase  the  barrelled  or  canned  pulp  from  canning  factories,  con- 
fining their  attention  to  the  final  processes  and  bottling. 

In  the  so-called  gravity  process  the  pulped  material  is  allowed  to 
stand  until  fermentation  sets  in  and  the  cellular  matter  rises  to  the  surface. 
The  clear  liquid  is  then  removed  from  below.     In  Italy  it  is  a  common 


pro 


FOOD  INSPECTION  AND  ANALYS.S. 


CHEMICAL  COMPOSITION  OF  KETCHUP,  PICKLES,  AND  RELISHES.* 


Number 

of 
Analyses 

Refuse. 

Water. 

Protein.       Fat. 

Total    1 
Carbij-        Ash. 
hydrates 

Fuel 

Value 

per 
Pound. 

Tomato  ketchup 

Horseradish     

2 

....... 

27.0 
19.0 

82.8 
86.4 

58.0 
42.3 

64-7 
52-4 
92-9 
93-8 
77-1 

1-5 
1-4 

I.I 
.8 

1-7 

1-4 

.5 

I .  I 

-4 

.2 
.2 

27.6 
20.2 

25. g 

21 .0 

-3 

•4 

.  I 

12.3 
10-5 

II. 6 

8.5 

4-3 
3-5 
2.7 
4.0 
20.7 

3-2 
1-5 

1-7 
1 .2 

3-4 
2.7 

3-6 

■7 

1-7 

265 
230 

1,400 
1,025 

1,205 

975 

70 

no 

395 

Olives,  f^reen: 

Edible  portion 

.\s,  purchas,;d 

Olives,  ripe: 

Edible  portion 

As  purchased 

Cucumber  pickles 

Mixed  pickles 

Spiced  pickles 

*  U.  S.  Dept.  of  Agric,  Office  of  Exp.  Sta.,  Bui.  28,  p.  70. 


practice  in  the  manufacture  of  tomato  paste  to  allow  the  pulp  to  ferment 
for  a  time,  after  which  the  fermentation  is  checked  by  the  addition  of 
salt.f 

Decayed  Material.— According  to  Bacon  and  Dunbar  %  fresh  tomatoes 
contain  on  the  average  6.5%  total  solids,  of  which  3.5%  is  invert  sugar, 
0.5*^^  citric  acid,  0.6^^  ash,  0.9%  protein  (NX6.25),  0.85%  crude  fiber 
and  0.05^  fat.  During  spoilage  the  sugars  rapidly  disappear,  forming 
alcohol,  carbon  dioxide,  acetic  and  lactic  acids,  the  amounts  of  each 
formed  depending  on  the  organisms  [)resent.  Usually  the  citric  acid  is 
also  decomposed.  A  good  ketchup  is  accordingly  characterized  by  a 
high  citric  acid  content  and  little  lactic  acid,  while  one  made  from 
decomposed  material  will  usually  contain  little  or  no  citric  acid,  but  a  high 
per  cent  of  lactic  acid. 

Tomato  Refuse. — The  skins,  cores  and  other  refuse  from  tomato 
canneries  are  used  for  the  preparation  of  pulp  which  in  turn  is  made  into 
ketchup.  Even  with  the  use  of  such  materials,  when  {)ro[)erly  [irepared, 
and  before  advanced  fermentation  has  set  in,  with  clean  methods  of  hand- 
ling, the  product  may  not  be  unwholesome.  It  is,  however,  sometimes  the 
practice  to  allow  the  refuse  and  skins  to  accumulate  through  a  whole 
tomato-canning  season,  storing  them  all  in  large  vats,  and  working  them 
up,  after  they  have  become  badly  fermented,  for  "  fresh  tomato  ketchup." 


t  Daily  Consular  and  Trade  Reports,  14,  iqii,  p.  74. 
X  U.  S.  Dent.  r)f  At^ric.  Bur.  of  Chem.,  Circ.  78. 


VEGETABLE  AND   FRUIT    PRODUCTS.  921 

It  is  largely  for  this  reason  that  antiseptics  and  coloring  matters  are  so 
commonly  employed  in  ketchup.* 

Foreign  Pulp. — Pumpkin  pulp  and  apple  sauce,  the  latter  made  often 
from  unsound  material  or  even  pomace,  have  been  extensively  used  in 
cheap  ketchups.  At  the  present  time  such  compound  sauces  are  usually 
labelled  to  show  the  constituents  present. 

Preservatives. — SaHcylic  acid,  formerly  used  in  most  commercial 
ketchups,  more  recently  has  given  place  to  benzoate  of  soda.  Bitting  f 
has  shown  that  by  using  sound  tomatoes  and  exercising  proper  care  in 
the  process  of  manufacture,  ketchup  can  be  kept  without  a  presers^ative. 
Manufacturers  are  themselves  corroborating  this,  many  of  the  standard 
brands  being  entirely  free  from  any  antiseptic  material  other  than  spices 
and  vinegar. 

Artificial  Colors. — Of  ninety-five  samples  of  ketchup  examined  in 
1901  in  Connecticut  all  but  fifteen  contained  coal-tar  colors. J  This 
practice,  however,  is  now  decreasing  and  is  indeed  quite  unnecessary  if 
fresh  ripe  tomatoes  are  used,  dark-colored  spices  are  avoided,  and  sugar 
is  not  added  until  the  end  of  the  process. 

METHODS    OF    ANALYSIS. 

Ash,  Alkalinity  of  Ash,  and  Sodium  Chloride  are  determined  by  the 
methods  described  for  jams  and  jellies  (p.  936).  Total  Acidity  is 
calculated  as  citric  acid  from  the  number  of  cc.  of  N/io  alkali  used  in 
titration  (i  cc.  =  0.0064  gram  citric  acid).  Volatile  Acids,  as  acetic,  follow- 
ing the  method  for  vinegar  (p.  766).  Tests  for  Preservatives  and 
Colors  are  carried  out  as  described  in  Chapters  XVII  and  X\'I1I. 

Determination  of  Solids. — Weigh  10  grams  of  the  sample  into  a  flat- 
bottomed  metal  dish  6  cm.  in  diameter,  add  water  to  distribute  the  mate- 


*  The  writer  has  in  his  possession  a  circular  from  an  Indiana  commission  merchant,  ad- 
vertising for  sale  tomato  pulp  of  some  twelve  different  grades  for  ketchup.  Among  them  are 
listed  the  following:  "  100  bbls.  of  old  goods,  made  partly  from  whole  stock  and  partly  waste, 
boiled  down  nearly  to  ketchup  thickness;  has  preservaline  in  it;  fine  goods,  but  some  of 
it  is  fermented;  packed  in  good  oak  whiskey  and  wine  barrels.  Price  $2.00  per  bbl." 
"225  bbls.  new  goods,  made  from  waste;  has  benzoate  of  soda  in  it,  packed  in  uncharred 
whiskey  and  wine  barrels  at  $3.00  per  bbl.  net  cash."  "300  bbls.  old  goods,  partly  whole 
stock,  partly  waste,  has  salicylic  acid  in  it;  nice  goods,  etc.  Price  $2.00  per  bbl."  "400 
bbls.  new  goods,  Jersey  style;   solid  and  good  red  color,  fine  quality.     Price  Jf3.oo  per  bbl." 

t  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  119. 

%  Ann.  Rep.  Conn.  Exp.  Sta.,  1901. 


q:2  food  1\'SPECTI0N  AND  ANALYSIS. 

rial,  evaporate  to  dryness,  dry  4  hours  at  the  temperature  of  boiling  water, 
and  weigh. 

Determination  of  Insoluble  Solids.* — Shake  20  grams  of  the  material 
with  hot  water  in  a  narrow  eylinder,  centrifuge  and  decant  the  clear  liquid 
on  a  tared  lilter-paper  and  liltcr  with  the  aid  of  suction.  Repeat  the 
operation  several  times,  fmally  transferring  the  material  to  the  paper. 
Finish  the  washing  on  the  paper  and  dry  at  100°  C.  to  constant, 
weight. 

The  filtering  may  be  carried  on  to  advantage  on  a  Buchner  funnel, 
using  tAvo  or  more  tared  filters,  as^the  suction  is  liable  to  break  a  single 
layer. 

Determination  of  Sand.* — Weigh  100  grams  of  the  well-mixed  sample 
into  a  2-  or  3-littT  beaker,  nearly  fill  the  beaker  with  water,  and  mix  the 
contents  thoroughly.  Allow  to  stand  5  minutes  and  decant  the  super- 
natant liquid  into  a  second  beaker.  Refill  the  first  with  water  and  again 
mix  the  contents.  After  5  minutes  more  decant  the  second  beaker  into 
a  third,  the  first  into  the  second,  refill  and  again  mix  the  first.  Continue 
this  operation,  decanting  from  the  third  beaker  into  the  sink  until  the 
lighter  material  is  washed  out  from  the  ketchup.  Then  collect  the  sand 
from  the  three  beakers  into  a  tared  Gooch  crucible,  dry,  ignite,  and  weigh. 

The  method  for  the  determination  of  ash  insoluble  in  hydrochloric 
acid  is  not  applicable  to  the  determination  of  sand  in  tomato  products, 
because  the  percentage  present  is  so  small  and  the  sand  is  so  unevenly 
distributed  that  reliable  results  can  only  be  obtained  by  taking  a  larger 
sample  than  is  possible  in  the  determination  of  ash. 

Determination  of  Soluble  Solids. — Subtract  the  percentage  of  insoluble 
solid>  from  the  jjerientage  of  total  solids. 

Determination  of  Reducing  Sugars. — Direct. — Place  to  grams  of  the 
ketchup  in  a  loo-cc.  flask,  add  an  excess  of  normal  lead  acetate,  make 
up  to  the  mark  and  filter.  To  the  filtrate  add  powdered  sodium  sulphate 
or  carbonate  sufTicient  to  precipitate  the  excess  of  lead  and  again  filter. 
Determine  the  reducing  power  of  the  filtrate  by  the  Munson  and  Walker 
method  (p.  598)  and  calculate  as  invert  sugar. 

After  Inversion. — Mix  50  cc.  of  the  solution,  after  clarifying  and  removal 
of  the  lead,  as  described  in  last  paragraph,  with  5  cc.  of  concentrated  hydro- 
chloric acid,  invert  in  the  usual  manner  (p.  588),  nearly  neutralize  with 
sodium  hydroxide  and  determine  the  reducing  power  as  before  inversion. 

•.\.0..\.C.  Proc.  igii,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  152,  p.   il8. 


VEGETABLE  AND   FRUIT   PRODUCTS. 


923 


Determination  of  Citric  Acid. — Bacon  and  Dunbar  Method.* — Weigh 
25  grams  into  a  250  cc.  beaker,  make  up  to  approximately  200  cc.  with 
95  per  cent  alcohol,  allow  to  stand  with  frequent  stirring  for  four  hours, 
filter  through  a  folded  filter  and  wash  with  50  cc.  of  80  per  cent  alcohol. 
To  the  filtrate  add  sufTicicnt  water  to  dilute  the  alcohol  to  50  or  60  per 
cent  and  then  add  10  cc.  of  20  per  cent  barium  acetate  solution,  stir  well 
with  a  glass  rod,  and  allow  to  stand  over  night. 
In  the  morning  filter  on  a  Gooch  crucible,  washing 
with  50  per  cent  alcohol,  dry  for  from  3  to  4  hours 
in  an  oven  at  100°  C.  and  weigh.  Weight  of  pre- 
cipitate times  0.51  equals  anhydrous  citric  acid. 
This  method  is  not  applicable  in  the  presence  of 
malic  acid,  hence  if  apple  pulp  is  a  constituent  of 
the  ketchup,  the  Pratt  method  (p.  951),  should  be 
employed. 

Determination  of  Lactic  Acid.  —  Bacon  and 
Dunbar  Method.*— To  100  grams  of  ketchup  add 
10  cc.  of  20  per  cent  normal  lead  acetate  solution, 
make  up  to  500  cc,  shake  well  and  centrifuge.  To 
400  cc.  of  the  clear  portion  add  a  moderate  excess 
of  sulphuric  acid,  filter,  wash  the  precipitate  with  a 
small  amount  of  water,  and  evaporate  the  filtrate 
on  the  steam  bath  to  about  100  cc.  Extract  for 
from  18  to  20  hours  in  a  Hquid  extractor  (Fig.  120) 
with  washed  ether.  In  case  the  quantity  of  lactic 
acid  present  is  greater  than  0.5  gram  it  is  usually  ne- 
cessary to  extract  for  a  longer  period.  In  any  case  it 
is  well  to  re-extract  for  from  8  to  10  hours  to  make 
sure  that  the  extraction  is  complete.  (Ether  suf- 
ficiently pure  for  this  purpose  may  be  prepared  by 
shaking  out  ordinary  ether  once  with  a  sodium 
hydrate  solution  and  then  ten  times  with  small 
quantities  of  water.)     Evaporate  on  the  steam  bath  ^ig.    120.  — Bacon    and 

until  the  ether   is   no   longer  evident,  and  take  up        P.""!'f  Extractor  for 
...  .  ^  ^         Liquids.       A,    jacket- 

the  residue  at  once  in  water  and  filter,  thus  remov-  flash;  B,  extract-tube- 
ing  a  small  amount  of  coloring  matter  and  sub-  C  funnel-tube,  D, 
stances    other    than    lactic    acid.    "'*->-»-     — -"  ^-^        condenser. 


B 


/ 


^\ 


3 


which    may  be 


U.  S.  Dept.  of  .\gric.,  Bur.  of  Chem.,  Circ.  78,  igir. 


924  FOOD  INSPECTION   AND   ANALYSIS. 

extracted  from  ketchup  by  ether,  but  which  are  insoluble  in  water.  Heat 
the  hltrate  on  the  steam  bath  for  some  time  to  remove  all  traces  of  ether 
or  alcohol.  Add  approximately  3  grams  of  sodium  hydroxide  and  50 
cc.  of  a  1.5',  t  solution  of  potassium  permanganate  from  a  pipette. 
Heat  on  a  water-bath  at  100°  C.  for  one-half  hour.  At  the  end  of  that 
time,  or  before,  if  the  color  is  not  a  decided  blue-black  or  purple,  but  is. 
green  or  colorless  above  the  layer  of  brown  precipitate,  add  more  standard 
permanganate  until,  after  heating  one-half  hour  on  a  boiling  water-bath, 
the  color  is  a  blue-black  or  purple.  The  oxidation  is  then  complete. 
Make  the  hot  solution  strongly  acid  with  10  per  cent  sulphuric  acid  (about 
50  cc.)  and  run  in  5  per  cent  standard  oxalic  acid  from  a  burette  until 
the  solution  is  decolorized.  Titrate  back  any  slight  excess  of  oxalic  acid 
with  the  standard  permanganate  solution.  (Any  standard  permanganate 
and  oxalic  acid  solution  may  be  used  within  reasonable  limits  of  strength.) 
In  alkaline  solution  the  permanganate  oxidizes  the  lactic  acid  quan- 
titatively to  oxalic  acid  according  to  the  equation: 

2C3H6O3  +  ioKMn04  =  2  (COOH)2+  4H2O  +  2CO2  +  5Mn02+  5K2Mn04, 

Then  in  acid  solution,  the  oxalic  acid  is  further  oxidized  by  the  per- 
manganate to  carbon  dioxide  and  water  according  to  the  equation: 
5  (COOHj2  +  2KMn04  ^  3H2SO4  =  10CO2  +  8H2O -f  K2SO4  +  2MnS04 . 

To  determine  the  total  weight  of  permanganate  used  in  the  oxidation 
of  the  lactic  acid  subtract  the  permanganate  equivalent  of  the  oxahc 
acid  used  from  the  total  amount  used.  The  weight  of  permanganate 
times  0.237  equals  the  weight  of  lactic  acid. 

Microscopic  Examination  for  Spoilage. — Howard  Method'^. — The 
apparatus  consists  of  a  comjjound  microscope  with  two  objectives  (f|  in. 
and  \  in. J  and  two  compensating  oculars  (X6  and  Xi8j,  a  Thoma-Zeiss 
blood-counting  cell,  slides  and  cover  glasses. 

1.  Eslimation  of  Molds. — Mount  a  drop  of  the  material  on  a  sHde 
and  press  down  the  cover  glass  until  the  film  is  about  0.1  mm.  thick. 
Examine,  with  a  magnification  of  90,  approximately  50  fields  and  calculate 
the  percentage  of  fields  showing  presence  of  mold  filaments. 

This  percentage  for  home-made  ketchups  is  practically  zero,  and  for 
factory -made  ketchups  should  be  kept  below  25. 

2.  Estimation  of  Yeasts  and  Spores. — These  are  counted  together 
because  of  the  difficulty  in  differentiation  without  making  cultures,  which 
is   impossiVjle   with   a  sterilized   product.     Thoroughly   shake    10  cc.   of 

*  U.  S.  Dept.  of  Agric,  Bur  of  Chem.,  Circ.  68,  191 1. 


yEGET/iBLE  AND   FRUIT  PRODUCTS.  925 

tHe  material  with  20  cc.  of  water,  and  after  standing  one  minute  for  the 
coarsest  particles  to  settle,  mount  a  drop  in  the  Thoma-Zeiss  cell  The 
material  should  not  overrun  the  moat  and  Newton's  rings  must  appear 
from  the  perfect  contact  of  the  glass  surfaces  to  insure  correct  depth  of 
licjuid.  With  a  magnification  of  180,  count  the  number  of  yeasts  and 
spores  in  one-half  of  the  ruled  squares,  which  gives  the  number-  present  in 
1/60  of  a  cubic  millimeter  of  the  original  material. 

The  number  in  home-made  and  best  factory-made  ketchups,  is 
practically  none;   the  allowed  limit  is  25^ 

3.  Estimation  of  Bacteria. — Only  rod-shaped  forms  are  considered, 
as  micrococci  are  easily  confused  with  particles  of  clay,  etc.  Employ- 
ing the  mount  used  for  yeasts  and  spores,  and  a  magnification  of  500, 
count  the  rod-shaped  organisms  in  several  areas  of  five  small  squares 
each  and  multiply  the  average  by  2,400,000  which  gives  the  number 
per  cc. 

The  limit  for  bacteria  is  25,000,000  per  cc. 

Microscopic  Examination  for  Foreign  Pulp. — Apple  is  identified  by 
the  window-like  cells  of  the  skin,  the  pitted  vessels  of  the  bundles,  quite 
unlike  the  vessels  of  the  tomato,  and  the  tissues  of  the  core.  Pumpkin 
may  be  detected  by  the  yellow  skin  of  the  fruit  with  colorless  stomata, 
somewhat  obscure  latex  tubes  and  the  peculiar  cactus-like  parenchyma 
of  the  seeds.  Although  only  the  fruit  pulp  is  used,  fragments  of  the  skin 
and  seeds  of  sufficient  size  to  be  of  diagnostic  importance  often  find  their 
way  into  the  product. 

PICKLES. 

A  large  variety  of  vegetables  and  fruits  are  preserved  in  the  form 
of  pickles  in  vinegar,  either  with  or  without  spices,  and  kept  in  wooden 
pails,  stoneware  pots,  kegs,  or  sealed  wide-mouthed  bottles.  The  con- 
tainers are  not  of  necessity  air-tight.  The  commoner  vegetables  are 
usually  pickled  without  cooking,  while  fruits  such  as  peaches,  pears, 
gooseberries,  etc.,  are  usually  cooked,  or  at  least  heated.  Analyses  of 
pickles  and  relishes  appear  in  the  table,  page  920. 

Cucumber  Pickles  are  the  m.ost  common,  and  are  prepared  by  soaking 
the  fresh  cucumbers  in  strong  salt  brine.  They  are  then  dried  on  frames, 
and  aftenvards  treated  with  boiHng  vinegar,  to  which  spices  may  or  may 
not  be  added.  Other  vegetables  pickled  in  similar  manner,  either  sepa- 
rately or  in  mixture  with  cucumbers  or  "  gherkins  "  to  form  "  mixtd 
pickles,"  are  cauliflower,  bean  pods,  white  cabbage,  young  nalnut?.  and 
onions. 


926  FOOD   INSPECTION  AND  ANALYSIS. 

Such  soft  vegetables  as  young  podded  beans  and  beets  are  not  treated 
with  brine,  but,  after  soaking  in  water,  are  directly  treated  with  vinegar. 
The  vinegar  used  for  the  finest  pickling  is  of  the  cider,  wine,  or  malt 
variety.  Cheaper  varieties  of  pickles  are  put  up  in  "white  wine"  or 
spirit  vinegar. 

Mustard  Pickles. — These  differ  from  plain  vinegar  pickles  in  the 
character  of  the  preserving  medium,  which  in  this  case  consists  of  a  mix- 
ture of  mustard  and  spices  with  the  vinegar  to  form  a  thin  paste. 

Piccalilli  consists  of  a  mixture  in  vinegar  of  various  chopped  vege- 
tables, such  as  cucumbers,  cauliflower,  green  pickles,  onions,  green  toma- 
toes, and  various  spices. 

Olives  for  pickling  are  picked  before  they  have  fully  ripened,  and  the 
inherent  bitter  taste  is  removed  by  soaking  in  a  solution  of  potash  and 
lime.  This  is  replaced  by  cold  water,  and  finally  the  olives  are  trans- 
ferred to  the  medium  in  which  they  arc  bottled,  which  consists  of  salt 
brine,  either  with  or  without  flavoring.  The  flavoring  materials  employed 
consist  of  such  substances  as  fennel,  coriander,  laurel  leaves,  and  occa- 
sionally vinegar.     Ripe  olives  in  brine  are  also  highly  esteemed. 

Capers. — ^These  are  the  flower  buds  of  the  shrub  Capparis  spinosa, 
which  are  ])ickled  in  vinegar.  Nasturtium  seeds,  when  similarly  pickled, 
possess  a  flavor  much  resembling  capers,  but  their  substitution  for  capers 
couhl  readily  be  detected  by  their  distinctive  appearance,  even  if  colored. 

Adulteration  of  Pickles. — Green  pickles,  such  as  cucumbers,  are 
not  uncommonly  colored  artificially  by  copper  salts,  either  through  the 
addition  of  copper  sulphate,  as  in  the  greening  of  peas,  or  by  the  use 
of  copj)er  vessels.  This  artificial  greening  is  to  be  looked  for  also  in  such 
products  as  capers  and  olives. 

For  methods  of  detection  and  estimation  of  copper,  see  page  902. 
Pickles  may  be  greened  by  boiling  with  much  less  harmful  substances 
than  copper  salts,  such,  for  example,  as  grape  leaves,  spinach,  or  parsley. 

Free  Sulphuric  Acid  has  been  found  in  a  number  of  cases  in  the  vine- 
gar of  pickles  bought  on  the  Massachusetts  market.  A  pronounced 
test  for  chloride  with  nitrate  of  silver  should  not  be  attributed  to  free 
hydrochloric  acid,  since  it  may  be  and  probably  is  due  to  the  salt  from 
the  brine  in  which  the  pickles  have  been  treated. 

Alum  is  sometimes  added  to  the  salt  solution  to  produce  hardness 
and  crisj)ness  in  pickles.  A  number  of  samj)les  of  cucumh)er  j)ickles 
have  been  found  by  the  author  to  contain  alum.  For  its  detection,  fuse 
the  ash  of  the  [tickles,  if  free  from  copper,  in  a  jjlatinum  dish  with  sodium 


yEGET^BLE  AND   FRUIT  PRODUCTS.  927 

oj.rbonalc,  extract  with  boiling  water,  filter,  and  add  ammonium  chlo- 
ride.    A  flocculent  precij)itate  shows  alum. 

Sodium  Benzoate  and  SaccJiarine  are  frequently  used  in  sweet  pickles. 

Horseradish. — This  condiment  is  prepared  by  grating  the  root  of 
the  perennial  herb  Nasturtium  armoricia,  and  preserving  in  vinegar. 
It  is  very  pungent  and  aromatic  when  first  prepared,  but  by  exposure  to 
light  ctnd  air  quickly  loses  strength.  Turnip,  an  occasional  adulterant  of 
gr^  ed  horseradish,  is  best  detected  by  the  microscope. 

PRESERVES. 

Under  this  head  are  included  various  fruit  products  prepared  with 
sugar  syrup  and  often  also  with  spices  and  vinegar.  Some  of  these  prod- 
ucts differ  little  from  canned  fruits  white  others  are  really  sweet  pickles. 
Mince  meat,  although  not  strictly  a  fruit  product,  and  fruits  in  cordials 
are  classified  for  convenience  as  preserves.  Jams  are  considered  with 
jellies  in  the  next  section,  as  are  also  methods  of  analysis. 

Fruit  Butter.— According  to  the  U.  S.  Standard,  "  fruit  butter  is  the 
sound  product  made  from  fruit  juice  and  clean,  sound,  properly  matured 
and  prepared  fruit,  evaporated  to  a  semi-solid  mass  of  homogeneous 
consistence,  with  or  without  the  addition  of  sugar  and  spices  or  vinegar, 
and  conforms  in  name  to  the  fruit  used  in  its  preparation." 

Apple  Butter  is  the  best-known  product  of  this  class.  Unfortunately 
it  is  sometimes  made  from  decayed  fruit  or  even  from  apple  pomace. 
Glucose  is  frequently  substituted  wholly  or  in  part  for  sugar,  in  which 
case  its  presence  should  be  declared  on  the  label. 

Mince  Meat. — As  prepared  in  the  household,  mince  meat,  the  filling 
for  mince  pies,  contains  from  10  to  20%  of  lean  meat  and  about  twice 
as  much  apple.  Other  constituents  appear  in  the  following  typical  for- 
mula with  statement  of  quantities  in  parts  by  weight:  2  parts  each  of 
meat,  raisins,  dried  currants,  and  sugar,  4  parts  of  apples,  i  part  each  of 
suet  and  candied  citron,  2  parts  of  sweet  cider,  wine  or  brandy,  i  to  2 
parts  of  seasoning  including  salt,  spices,  and  lemons  or  oranges. 

Standard  Mince  Meat  of  the  A.O.A.C.  and  the  Association  of  State  and 
National  Dairy  and  Food  Departments,  "  's  a  mixture  of  not  less  than  10% 
of  cooked  comminuted  meat,  with  chopped  suet,  apple  and  other  fruit,  salt, 
and  spices,  and  with  sugar,  syrup,  or  molasses,  and  with  or  without  vinegar, 
fresh,  concentrated,  or  fermented  fruit  juices,  or  spirituous  liquors." 

Adulteration. — ^There  has  been  some  conflict  between  food  ofiicials 
and  certain  manufacturers  as  to  the  proportion  of  meat  in  commercial 


9^8  FOOD  INSPECTION   AND  ANALYSIS. 

mince  meat,  die  manufacturers  claiming  that  lo' ^  is  too  much  for  the 
proper  keeping  of  the  product,  the  food  officials,  on  the  other  hand,  con- 
tending that  the  manufacturer  has  no  right  to  lower  the  recognized  standard 
of  the  housewife. 

As  a  matter  of  fact  the  greater  part  of  the  mince  meat  on  the  market 
contains  considerably  less  than  io%  of  meat  and  much  of  it  none  what- 
ever. Glucose  is  a  common  substitute  for  part  of  the  sugar,  wormy  or 
other  inferior  fruit  is  sometimes  used,  and  benzoate  of  soda  is  added  as 
a  preservative. 

Condensed  Mince  Meat  is  made  in  a  commercial  way  from  dried 
apples  and  other  desiccated  materials  and  is  sold  in  compressed  cakes 
with  instructions  for  preparing  from  the  cakes  moist  pie  filling.  As  in 
the  case  of  wet  mince  meat,  glucose,  wormy  fruit  and  benzoate  of  soda 
are  frequent  admixtures  and  true  meat  is  often  omitted  entirely.  Wheat 
or  rye  flour  is  a  common  adulterant. 

Examination  of  Mince  Meat. — Meat  and  cereal  flour  may  be  identified 
by  microscopic  examination.  Care  should  be  taken  not  to  confuse  apple 
starch,  which  is  always  present  in  the  immature  fruit,  with  cereal  starches. 
Meat  libers  are  recognized  by  their  yellow  brown  color,  the  delicate  trans- 
verse striations  and  their  occurrence  in  bundles. 

Determinations  of  nitrogen  are  of  ser\'ice  in  estimating  the  amount 
of  meat  present.  Glucose  and  sugar  are  calculated  from  the  polarization 
readings. 

Pie  Filling.  Bakers  and  hotel  cooks  are  supplied  by  manufacturers  with 
filling  prepared  ready  for  use  in  pies.  This  material  is  shipped  in  pails  or 
tubs  preserved  with  benzoate  of  soda,  and  may  contain  fruit  of  questionable 
quality  as  well  as  admixtures  such  as  starch,  glucose,  and  artificial  colors. 

Maraschino  Cherries. — This  name  has  been  apphed  indiscriminately 
lo  the  vivid  red  preser\'ed  cherries  used  in  cocktails,  punches,  ice  cream 
and  confectionery.  Investigation  by  the  Board  of  Food  and  Drug 
Inspection  has  led  to  the  decision  *  that  only  marasca  cherries,  preserved 
in  true  maraschino  cordial  prepared  by  fermentation  and  distillation 
from  marasca  cherries,  are  entitled  to  the  name  maraschino  cherries, 
although  cherries  of  other  types  preserved  in  pure  maraschino  cordial 
may  be  labelled:  "Cherries  in  Maraschino."  Ordin'ary  cherries  preserved 
in  syrup  flavored  with  maraschino  may  be  so  labelled,  but  if  the  flavoring 
is  oil  of  bitter  almonds  or  benzaldehyde  the  product  should  be  labelled 
as  an  imitation  if  the  word  maraschino  is  used. 


*  Ffx^d  Inspection,  Decision  141. 


VEGETABLE  AND  FRUIT    PRODUCTS.  929 

Enormous  quantities  of  white  cherries  of  the  Bigarreau  or  Royal 
Anne  type,  preserved  in  a  mixture  of  sulphurous  acid  and  brine,  are 
brought  into  the  United  States  from  Europe  and  transformed  into  red 
"  Maraschino  cherries  "  or  green  "  Crcme  de  menthe  cherries."  After 
removal  of  the  sulphurous  acid  and  brine  the  cherries  are  put  through  a 
dye  bath  and  then,  being  quite  without  taste,  are  flavored  with  oil  of  bitter 
almond  or  benzaldehyde,  or  else  peppermint,  and  packed  in  syrup. 
Scarcely  more  than  the  cellular  structure  of  the  original  cherry  remains, 
the  fruit  juice  with  its  sugars,  acids,  and  true  cherry  flavor  being  replaced 
by  the  syrup  with  its  sickening  flavor  and  aroma.  Even  if  flavored  with 
true  maraschino  the  metamorphoses  through  which  the  fruit  passes  leave 
it  a  sorry  substitute  for  the  natural  cherry. 

Woodman  and  Davis  *  have  shown  that  true  maraschino  contains 
very  little  benzaldehyde  and  that  cherries  flavored  with  maraschino 
should  not  contain  more  than  two  or  three  times  as  many  miUigrams  of 
benzaldehyde  per  100  cc.  as  there  are  grams  of  alcohol  in  that  volume, 
and  those  containing  over  20  mg.  of  benzaldehyde  but  no  alcohol  are 
evidently  entirely  artificial. 

Artificial  colors,  sulphurous  acid  and  other  preservatives  are  detected 
by  the  methods  given  in  the  chapters  on  colors  and  perservatives,  benzalde- 
hyde by  the  following  method : 

Determination  of  Benzaldehyde  in  Maraschino  Cherries. — Woodman 
and  Davis  Method.'^ — Reagent.— Mix  3  cc.  of  glacial  acetic  acid  with 
40  cc.  of  water,  add  2  cc.  of  C.P.  phenylhydrazine,  as  near  colorless  as 
possible,  shake  thoroughly,  and  filter  the  emulsion  through  several  thick- 
nesses of  filter-paper.  The  clear  filtrate  should  be  used  immediately 
as  a  turbidity  appears  on  standing  longer  than  five  minutes. 

Process. — Dilute  100  cc.  of  the  liquor  from  maraschino  cherries  (or 
50  cc.  of  maraschino  liqueur)  to  140  cc.  and  distill  off  iiocc.  Determine 
approximately  the  alcohol  in  the  distillate  by  the  pycnometer  or  immersion 
refractometer,  then  without  delay  transfer  100  cc.  to  a  300  cc.  Erlenmeyer 
flask  and  add  alcohol  or  water  so  that  the  solution  shall  contain  approx- 
imately 10%  of  alcohol.  Add  100  cc.  of  the  reagent,  stopper  tightly  with  a 
rubber  stopper,  and  shake  vigorously  for  ten  minutes.  Collect  the  precipi- 
tate in  a  tared  Gooch  crucible,  wash  with  cold  water  and  finally  with  about 
ID  cc.  of  io'"o  alcohol.  Dry  in  a  vacuum  desiccator  for  20-24  hours  at 
about  20  cm.  pressure,  or  in  a  vacuum  oven  at  70-80°  C.  for  3  hours. 
Throughout  the  process  avoid  exposure  of  the  precipitate  to  strong  light. 

*  Jour.  Ind.  Eng.  Chem.,  4,  1912,  p.  588. 


030  FOOD   IXSPECTION  AhD  /ANALYSIS. 

Run  a  blank  determination  at  the  same  time  and  deduct  the  weight 
obtained  from  that  found  in  the  actual  analysis.  Multiply  the  corrected 
weight  of  the  precipitate  by  0.5411,  thus  obtaining  the  weight  of  benzalde- 
hyde. 

JAMS    AND    JELLIES. 

Jams  or  marmalades  are  prepared  from  the  pulp  of  fruits,  and  jellies 
from  the  fruit  juices.  Both  jams  and  jellies,  to  be  considered  of  the  highest 
degree  of  purity,  should  contain  nothing  but  the  fruit  pulp  or  juice  named 
on  the  label,  mi.xed  with  pure  cane  sugar,  and,  in  the  case  of  jams,  the 
further  addition  of  spices  and  flavoring  materials  is  permissible. 

For  the  manufacture  of  jam,  apples,  quinces,  and  pears  are  peeled, 
freed  from  cores,  and  sliced;  berries  are  simply  stemmed;  and  stone  fruits, 
such  as  peaches  and  apricots,  are  peeled,  and  freed  from  stones.  The 
material,  properly  prepared,  is  cooked  with  as  much  water  as  is  necessary 
for  boiling,  and  with  the  addition  of  an  amount  of  sugar  varying  with 
ditTerent  manufacturers.  Some  prefer  to  use  equal  parts  of  sugar  and 
fruit,  others  one  part  sugar  to  two  parts  fruit. 

In  the  case  of  jelly,  the  fruit  is  cooked  in  a  small  amount  of  water 
till  soft,  transferred  to  a  bag  or  press,  and  the  juice  allowed  to  flow  out 
spontaneously,  or  is  squeezed  out  under  pressure,  according  to  the  grade 
of  jelly  desired,  the  clearest  and  tinest  varieties  being  made  from  the 
juice  that  flows  out  naturally.  This  juice  is  then  evaporated  down  with 
the  addition  of  sugar  to  a  density  of  from  30°  to  32°  B6.,  which  is  of  the 
proper  consistency  to  form  a  perfect  jelly  product  after  cooling,  and,  while 
still  hot,  is  poured  into  the  tumblers  in  which  it  is  to  be  kept.  Here,  as 
in  the  case  of  jams,  the  amount  of  sugar  varies,  some  using  pound  for 
pound,  and  others  only  half  as  much  sugar  as  fruit.  Some  manufacturers 
clarify  their  jellies  by  mixing  with  the  juice,  while  boiling,  elutriated 
chalk,  using  a  tcaspoonful  to  each  quart  of  juice.  The  impurities  come 
to  the  surface  with  the  chalk  as  a  scum,  and  are  skimmed  off.  This 
clarifying  process  is  somewhat  analogous  to  the  defecation  of  sugar  ju'ces 
with  lime,  and  is  commonly  carried  out  with  aijjjle  jelly. 

The  "jellying"  or  gelatinizing  of  the  final  i)roduct  is  due  to  the  presence 
in  the  fruit  juice  of  pectin,  or  so-called  vegetable  jelly  (C32H40O284H2O); 
see  page  276. 

The  high  content  of  added  sugar  in  jelly,  once  thought  to  be  essential 
for  keeping  it,  is  now  no  longer  considered  necessary,  and  much  less  sugar 


VEGETABLE  AND  FRUIT  PRODUCTS.  931 

is  at  present  adderl  than  formerly.     The  finest  grade  of  apple  jelly,  for 
instance,  is  made  without  any  added  sugar  whatever. 

In  making  the  better  grades  of  apple  jelly,  apple  juice  fresh  from 
the  press  is  run  directly  into  the  boiler  or  evaporator  before  any  fermenta- 
tion has  ensued,  and  gelatinized  by  concentration.  If  boiled  cider  is 
wanted  instead  of  jelly,  it  is  drawn  ofl  at  an  earlier  stage  than  in  the  case 
of  apple  jelly. 

Composition  of  EZnown-purity  Jellies  and  Jams. — In  the  tables  on 
pp.  932  and  933,  due  to  Tolman,  Munson,  and  Bigelow,*  are  given 
results  reached  on  the  examination  of  the  pure  finished  products,  as  well 
as  on  pure  fruit  juices  and  pulp  used  in  their  manufacture. 

Adulteration  of  Jams  and  Jellies. — As  a  matter  of  fact,  a  small  percent- 
age of  these  products  sold  in  the  United  States  are  honest  prototypes  of 
the  home-made  jams  and  jellies,  which  consist  exclusively  of  the  fruit 
specified  on  the  label,  in  mixture  with  pure  cane  sugar.  If  we  accept  as 
a  standard  the  product  of  the  housewife,  fully  90%  of  the  commercial 
brands  of  these  preparations  would  be  found  wanting.  So  great  is  the 
demand  for  cheap  sweets  of  this  variety,  that  the  market  is  flooded  with 
them  at  eight  and  ten  cents  per  half-pound  jar,  when  in  reality  abso- 
lutely pure  goods  cannot  be  produced  at  much  less  than  twice  that 
amount. 

The  cheap  substitutes  are  made  up  largely  of  apple  juice  and  com- 
mercial glucose,  sometimes  containing  no  fmit  whatever  of  the  kind 
specified  on  the  label.  Sometimes  an  attempt  is  made  to  imitate  the 
flavor  by  the  addition  of  artificial  fruit  essences,  but  more  often  the  same 
apple-glucose  stock  mixture  of  jelly,  put  out  under  a  particular  brand, 
serves  to  masquerade  as  damson,  strawberry,  raspberry,  current,  grape, 
etc.,  differing  from  each  other  only  in  color,  but  not  as  a  nde  in  flavor. 
A  variety  of  artificial  colors  are  employed,  mostly  coal-tar  dyes.  To 
compensate  for  the  lack  of  sweetness  of  the  glucose,  a  minute  quantity 
of  one  of  the  concentrated  sweetener.  ,  such  as  saccharin  or  dulcin,  is  some- 
times added.  Besides  artificial  colors,  antisejMic  substances  are  occasion- 
ally used,  especially  sodium  benzoate. 

All  grades  of  apple  stock  arc  found  in  ;hcse  preparations.  A  large 
source  of  supply  is  furnished  by  ihe  ])aring:>  and  cores  of  canning  estab- 
lishments, to  say  nothing  of  the  refuse  of  these  factories,  such  materials 
being  boiled  wi  h  wa'er,  and  the  extract,  variously  colored  to  imitate  the 
different  fruits,  being  evaoorated  with  commercial  glucose. 
*  Jour.  Am.  Chem.  Soc.  (1901),  pp.  349-351. 


93^ 


FOOD  INSPECTION  /iND  ANALYSIS. 


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VEGETABLE  AND  FRUIT   PRODUCTS. 


933 


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934  FOOD  INSPECTION  yfND  ANALYSIS. 

Adulterated  Jelly. — While  it  is  easy  to  make  an  excellent  apple  jelly 
by  simple  evaporation  of  the  pure  apple  juice,  even  without  the  addition 
of  sugar,  it  is  impossible,  or  at  least  difficul;,  to  obtain  the  proper  degree 
of  stiffness  with  a  mixture  of  apple  stock  and  commercial  glucose.  It  is 
customan,',  in  the  manufac:ure  of  cheap  jellies,  therefore,  to  employ 
what  is  technically  termed  a  "  coagulator."  Formerly  sulphuric  acid, 
sometimes  with  addition  of  alum  was  used,  but  at  present  phosphoric 
acid  is  preferred.  Citric  or  tartaric  acid  is  also  used  for  this  purpose, 
as  well  as  to  increase  the  acidity.  Less  than  i%  of  acid  will  cause  the. 
mass  to  gelatmizc  satisfactorily. 

The  lowest  grade  of  ap{)le  jelly  is  made  from  the  exhausted  j)omace, 
left  as  a  residue  after  pressing  out  the  juice  for  cider.  Such  stock  is  com- 
monly mixed  with  water,  and  boiled  down  with  glucose.  Having  been 
e.xhausted  of  its  malic  acid,  pectose,  and  other  soluble  constituents,  it 
lacks  much  of  the  flavor  inherent  in  pure  apple  jelly.  Various  foreign 
gelatinizing  agents  are  found  in  cheap  jellies  and  preserves,  such  as 
starch,  gelatin,  and  agar-agar.  In  the  low-priced  goods,  starch  paste 
has  been  employed.  It  should  be  remembered  that  starch  exists  in  unripe 
apples,  but  hardly  at  all  in  the  mature  fruit,  so  that  while  mere  traces  of 
starch  in  jelly  may  be  due  to  the  use  of  green  apples,  its  presence  in  large 
amounts  is  undoubted  evidence  of  the  admixture  of  starch  paste. 

Adulterated  Jams. — Most  of  the  cheap  jams  and  bottled  preserves 
sold  on  the  market,  though  reinforced  wich  apple  stock,  do  in  reality 
contain  masses  of  frui'.  and  berries  of  the  kind  stipulated  on  the  label,  as 
even  a  casual  megascopic  examination  will  show.  That  such  low-priced 
preparations  really  contain  genuine  fruit  i)ulp  is  not  to  be  wondered  at; 
when  it  is  considered  that  much  of  the  virtue  of  this  fruit  has  sometimes 
been  previously  extracted  by  boiling,  to  produce  fruit  juices  for  higher- 
priced  goods.  Or,  as  in  the  case  of  jams  containing  strawberries,  rasp- 
berries, and  other  small  fruits  with  seeds,  the  juice  is  apt  to  have  been 
previously  expressed  for  pure  jellies,  while  the  residues  are  afterwards 
worked  up  with  apple  stock  for  low-priced  jams.  Hence  the  presence  of 
pure  fruit  stock,  or  genuine  berry  seeds  and  pulp  in  jams,  is  in  itself  no 
criterion  of  purity,  and,  furthermore,  it  is  unnecessary  to  use  hay  seed  and 
other  alleged  foreign  seeds  as  adulterants  of  cheap  jam. 

Compound  Goods. — Many  states  have  a  law  legalizing  the  sale  of 
"compounrl"  goods,  providing  they  are  distinctly  so  labeled.  In  other 
states,  as,  for  instance,  Massachusetts,  the  label  must  plainly  state  the 
name  and  percentage  of  the  ingredients.     In  either  case  the  analyst  must 


VEGETABLE  AND  FRUIT  PRODUCTS.  935 

discriminale,  in  classifying  the  inferior  or  low-grade  preparations,  between 
those  that  are  labeled  in  accordance  with  the  law,  and  those  that  are  not. 
Only  those  not  properly  labeled  can  in  such  cases  be  classed  as  adulter- 
ated within  the  meaning  of  the  lav/.  Where  such  a  law  prevails,  probably 
no  class  of  food-products  is  so  extensively  affected  by  it  as  the  low-grade 
jams,  preserves,  and  jellies. 

The  restrictions  as  to  labeling  do  not  in  all  cases  eliminate  the  element 
of  deception.  It  is  hardly  justifiable,  for  example,  to  boldly  label  an 
alleged  "currant  jelly"  which  contains  no  currant,  in  the  following  man- 
ner: 

Fruit  juice 25% 

Cane  sugar 14% 

Corn  syrup 61% 

100% 

The  use  of  the  term  "fruit  juice"  surely  implies  to  the  unsuspecting 
purchaser  that  so  much  pure  currant  juice  has  entered  into  the  jelly,  else- 
where labeled  in  large  letters  "Currant,"  whereas  all  the  juice  is  apple, 
and  no  currant  juice  has  been  used. 

The  following  label  is  a  type  of  those  which  discriminate  between  pure 
fruit  and  apple  juice: 

Fruit 30% 

Corn  syrup 35% 

Granulated  sugar 15% 

Apple  juice 20% 

100% 

Composition  of  Cheaper  Grades. — Out  of  66  samples  of  jellies,  jams, 
and  preserves  analyzed  by  Winton,  Langley,  and  Ogden  in  Connecticut, 
the  samples  being  purchased  in  that  state,*  17  samples  contained  starch 
paste,  35  were  artificially  colored  with  coal-tar  dyes,  and  19  contained 
salicylic  or  benzoic  acid. 

The  following  table  has  been  cornpiled,  showing  the  sugar  content  of 
some  of  the  typical  commercial  jellies  and  jams  analyzed  in  the  laboratory 
of  the  Massachusetts  Slate  Board  of  Health.  Nearly  all  of  these  were 
artificially  colored,  and  found  to  contain  little  if  any  fruit,  other  than  apple. 

*  An.  Rep.  Conn.  Exp.  Sta.,  1901,  p.  130. 


036 


FOOD    INSPECTION   /1ND    ANALYSIS. 


Direct 
Polariza- 
tion. 


JELLY 

Apple 

Currant  A 

B 

Grape 

Peach 

Pineapple 

Raspberr.' 

JAM. 

Damson  A 

B 

Apricot 

Quince 

Raspberrv  A 

"       '   B 

C 

Pineapple 

Strawberry  A 

B 


+  64.0 

+  29.2 

+  41-6 

+  62.0 

+  119.S 

+ II4-0 

+  112.0 


+  107.0 
+  95-2 
+  99.0 
+  49-6 

+  123.6 
+  77-6 
+  66.0 

+  119. 8 
+  41.8 
+  83.6 


Invert  Polarization. 


At2o°C.      AtS^oC. 


+  28.0 
+  20.0 
+  33-9 
+  34-4 
+  108.8 
+ 107.6 
+  92.0 


+  94-4 
+  90.9 

+  93-5 

+  43-6 

+ 119. 2 

+  65 . 1 

+  29-5 

+  108.8 

+  21.3 

+  72-0 


+  36.0 
+  36.4 
+  40.8 
+  46.0 

+ IIO.O 
+ IIO.O 

+  93.6 


Per  Cent 
Sucrose. 


+  =;8.i 

9- 

+  83.6 

3- 

+  85.6 

4- 

+  42.0 

4- 

-1-102.5 

2. 

+  46.9 

9- 

+  37-2 

27. 

+ IIO.O 

8. 

+  32.6 

15- 

+  78.8 

8. 

26.8 

6.9 

5-7 

20.6 

8.2 

4-9 
14.9 


Per  Cent 
Commer- 
cial 
Glucose. 


22.3 
25.0 
28.2 
67.4 
67.4 
57-4 


35-6 
51-2 
52-4 
25-7 
62.8 
28.7 
22.8 

67.4 
20.0 

48.3 


METHODS  OF  ANALYSIS. 

.\.s  in  the  ca.se  of  canned  goods,  but  little  information  is  to  be  derived 
as  to  adulteration  of  jams,  jellies,  and  j^reserves  by  the  ordinary  deter- 
minations of  moi-sture,  ash,  and  nitrogen,  and  these  are  rarely  made  by 
the  public  analyst. 

Of  considerable  importance  in  this  regard,  however,  are  the  sugar 
determinations,  made  with  a  view  to  ascertaining  the  varieties  of  sugar 
em  ployed,  as  well  as  their  approximate  proportion  in  the  products  examined. 
Still  more  important  are  the  results  of  tests  for  preservatives,  dyes,  for- 
eign gchitinous  substances,  and  mineral  acids  used  as  coagulators. 

Preparation  of  the  Sample.*— In  the  case  of  jams,  marmalades,  and 
presen-es,  separate  and  weigh  the  stones,  if  present,  then  thoroughly  pulp 
the  sample.     Stir  well  before  weighing  out  the  portions  for  analysis. 

In  the  case  of  jellies  prepare  a  solution  of  the  thoroughly  mixed  sample 
containing  60  grams  in  300  cc.  and  make  the  determinations,  so  far  as 
practicable,  on  aliquots  of  this  "  20^0  solution."  If  starch  or  insoluble 
matter  is  present  shake  thfinjughly  before  aliquoting. 

Determination  of  Total  Solids.*— Weigh  4  to  5  grams  of  jam,  or  measure 
25  cc.  of  20'^  jc'lly  solution,  into  a  large  flat-bottomed  dish  (preferably 
of  platinum)  containing  from  4  to  5  grams  of  ignited  asbestos  and  add  in 
the  case  of  jam  enough  water  to  uniformly  distribute  the  material.     Evap- 


A.  O.  A.  C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chcm.,  Bui.  107,  rev.,  p.  77. 


VEGETABLE  AND   FRUIT   PRODUCTS.  937 

'orate  to  dryness  and  dry  for  from  20  to  24  hours  in  a  boiling  water- 
oven. 

The  results  by  this  method  are  not  strictly  accurate  owing  to  the 
dehydration  of  levulose,  but  for  practical  purposes  they  are  sufficiently 
close.  If  extreme  accuracy  is  required  dvyjn  vacuo  at  75°  or  in  a  McGill 
oven  (p.  586). 

The  solids  in  a  jelly  may  also  be  calculated  from  the  specific  gravity. 

Determination  of  Ash. — Burn  the  residue  from  the  determination  of 
solids,  or  else  a  new  portion,  in  a  platinum  dish  at  dull  redness. 

Alkalinity  of  ash  is  determined  as  described  for  insoluble  ash  in  maple 
products  (p.  627). 

Chlorides  and  Sulphates  are  detected  in  the  ash  by  the  usual  tests. 
If  the  portion  used  for  determination  of  alkalinity  is  also  to  be  used  for 
the  chlorine  test  the  titration  must  be  made  with  fifth-normal  nitric 
acid. 

The  presence  of  chlorides  is  an  indication  of  glucose,  as  pure  fruit 
products  do  not  contain  appreciable  amounts  of  chlorine  compounds. 

Determination  of  Insoluble  Solids.* — Modified  Kremla  Method. — 
Thoroughly  macerate  50  grams  of  the  sample  in  a  mortar  with  warm  water, 
then  transfer  to  a  muslin  filter  and  wash  thoroughly  with  warm  water, 
stirring  well  after  each  addition.  Wash  up  to  500  cc,  or  in  extreme 
cases  up  to  1000  cc,  remove  the  insoluble  solids  to  a  dish,  dry  in  a  boiling 
water-oven,  and  weigh. 

Reserve  the  filtrate  for  determinations  of  soluble  constituents. 

German  Official  Method. — Transfer  a  weighed  portion  of  the  sample 
to  a  graduated  flask,  add  water,  shake  thoroughly  and  make  up  to  volume. 
Allow  to  settle  and  either  filter  or  decant  off  the  supernatant  liquid.  Deter- 
mine the  soluble  solids  by  evaporating  and  drying  an  aliquot.  The  insoluble 
solids  are  obtained  by  subtracting  the  soluble  from  the  total  solids. 

Determination  of  Acidity. — Dilute  an  aliquot  of  the  solution  from 
the  insoluble  solids  of  a  jam  or  of  the  20%  solution  of  a  jelly  and  titrate 
with  standard  alkali.  Use  phenolphthalein  as  indicator  if  the  color  of  the 
solution  will  permit,  otherwise  use  litmus  paper.  Calculate  the  result 
as  sulphuric  acid  or  as  the  organic  acid  known  to  predominate  (see  page 

949)- 

Detennination  of  Protein. — Determine  nitrogen   in    5    grams  of  the 

material  by  the  Kjeldahl  or  Gunning  method  and  calculate  protein,  using 

the  factor  6.25. 

*  A.  O.  A.  C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107,  rev.,  p.  78. 


938  FOOD   INSPECTION   AND  ANALYSIS.  ' 

Determination  of  Sugars. — In  products  of  the  highest  grade,  wherein 
only  cane  sugar  is  employed,  a  large  portion  of  the  cane  sugar 
is  invened  in  the  process  of  boiling  the  jam  or  jelly,  so  that  when  the 
analyst  examines  it,  he  finds,  as  a  rule,  only  a  small  amount  of  sucrose, 
and  considerable  invert  sugar.  It  is  possible,  however,  to  calculate  the 
amount  of  cane  sugar  originally  employed,  if  such  information  is  desir- 
able. It  is  further  of  interest  to  calculate,  at  least  approximately,  the 
percentage  of  commercial  glucose,  when  present,  especially  in  cases  where 
the  package  contains  a  formula  setting  forth  the  amount  of  the  various 
ingredients  used.  In  such  cases  the  analyst  is  naturally  called  upon  to 
verify  the  formula,  since  a  wide  variation  in  percentage  composition  from 
the  statement  on  the  label  would  constitute  an  offense  under  some  state 
laws. 

Polarization. — Use  half  the  normal  weight  of  the  preserve  or  jelly  for 
the  Schmidt  and  Haensch  instrument,  viz.,  13.024  grams  in  100  cc.  If 
fresh  fruit  or  fruit  juice  is  to  be  examined,  use  the  full  normal  weight, 
26.048  grams.  Clarify,  before  making  up  to  the  mark,  with  subacetate  of 
lead  and  alumina  cream  (using  2  to  3  cc.  of  each  clarifier),  filter,  and 
obtain  the  direct  reading;  then  invert  in  the  usual  manner,  and  obtain 
the  invert  readings  at  20°  C,  and  in  the  water-jacketed  tube  at  87°  C, 
Drocecding  in  detail  as  directed  under  honey,  p.   641. 

Calculation  of  Sugars. — Sucrose  is  determined  by  using  Clerget's 
formula : 

5='''-''"7, (I) 

142.66 

2 

This  represents  the  sucrose  actually  present  as  such  in  the  preserve 
or  jelly,  and  not  the  amount  originally  used.  If  the  latter  is  desired,  it 
may  be  calculated  from  the  formula, 

S'  =  ^^\, W 

42.66  — 

2 

where  S'  is  the  per  cent  of  cane  sugar  originally  used,  and  h  is  the  invert 
reading  at  /°  of  the  normal  solution. 

If,  af.er  inversion,  the  correct  reading  at  20°  is  found  to  be  12  or  more 
to  the  left  of  the  zero,  it  can  be  safely  inferred  that  no  appreciable  amount 
■of  commercial  glucose  is  present,  and  i:  is  unnecessary  to  make  a  third 


yEGETABLE  AND   FRUIT  PRODUCTS.  939 

leading  at  87°,  unless  to  confirm  the  fact.     In  such  a  case,  with  cane  sugar 
alone  present,  the  reading  at  87°  will  not.  of  course,  vary  much  from  o. 

Invert  Sugar. — In  the  absence  of  commercial  glucose,  the  invert  sugar 
is  calculated  as  follows: 

(Sucrose  — direct  reading)  105.3  >.  v 

Invert  sugar  = ,    ...     (3) 

42.66  —  — 
2 

or  it  may  be  determined  directly  from  the  copper  reducing  power. 

Any  decided  reading  above  zero  at  87°  is  due  to  the  presence  of  com- 
mercial glucose,  and  when  the  latter  is  present,  it  is  impossible  to  deter- 
mine the  invert  sugar  from  the  copper  reduction  or  by  formula  No.  3. 
The  following  formula  is  proposed  for  calculating  approximately  the 
invert  sugar  from  the  polarization,  in  the  presence  of  commercial  glucose. 
While  theoretically  correct,  the  method  is  subject  to  practical  limitations, 
which  admit  of  only  roughly  approximate  results  in  such  mixtures  as 
jelly  or  jam.  It  is  perfectly  accurate  only  in  mixtures  of  sucrose,  glu- 
cose, and  invert  sugar. 

/Reading  due  to  glucose  and\      /Invert  readingN 

_  \      inverted  sucrose  zX  f      /      \  at  /°  / 

Invert  sugar  = -, -r ^ '-  105.3     (4) 

±42.66--' 


These  formulas,  (3)  and  (4),  serve  at  best  to  indicate  the  approximate 
amount  of  invert  sugar  present  in  the  sample,  resulting  from  the  inver- 
sion of  a  portion  of  the  original  sucrose  in  the  natural  process  of  manu- 
facture of  the  jam  or  jelly,  and  not  the  total  invert  sugar  resulting  from 
the  inversion  by  the  analyst  of  all  the  sucrose. 

The  factor  105.3  i^  used,  since,  in  the  natural  process  of  inversion,  100 
parts  of  sucrose  become  105.3  parts  of  invert  sugar. 

Example. — The  invert  sugar  in  the  sample  of  apple  jelly  first  on  tbe 
list  in  the  table  on  page  936  is  calculated  as  follows: 

Invert  reaaing  at  t°  (20°)  =  28.0. 

Reading  due  to  glucose  at  2o°  =  .22iX  175  =  38.68. 

"          "    "  inverted  sucrose  at  20°  =  .268X  —34=  — 9.11. 
(38.68 -o.ii)- 28 
Invert  sugar  =  • '~:^^^ ^°5-3 

=  5.76%.  ' 


940  FOOD  INSPECTION  AND  ANALYSIS 

Determination  of  Reducing  Sugar. — Proceed  as  described  on  page 
021. 

Commercial  Glucose. — ^ While  it  is  impossible  to  determine  the  exact 
jierceniagc  of  this  substance  in  preserves  and  jellies,  by  reason  of  the 
varying  composition  of  its  component  parts,  it  is  quite  feasible  to  approx- 
imate very  closely  to  the  amount  present.  Indeed,  this  approximate 
method  of  calculation,  wherein  glucose  is  treated  as  a  chemical  entity, 
has  been  found  in  practice  to  be  much  more  close  to  the  actual  truth 
than  results  gainetl  by  methods  wherein  the  copper  reducing  power  enters 
as  a  factor,  or  methods  for  determining  separately  dextrin,  maltose,  and 
dextrose.  Calculate  the  commercial  glucose  in  jellies  and  jams  exactly 
as  in  the  case  of  honey,  p,  641. 

Dextrin.* — If  alcohol  be  added  to  a  somewhat  thick  solution  of  the 
fruit  product,  a  white  turbidity  is  at  once  apparent,  followed  by  the  forma- 
tion of  a  thick  gummy  precipitate,  if  dextrin  is  present.  In  the  absence 
of  dextrin  there  is  no  turbidity,  but  a  light  flocculcnt  precipitate. 

To  determine  the  dextrin,  dissolve  f  10  grams  of  the  sample  in  a  loo-cc. 
flask;  add  23  mg.  of  potassium  fluoride,  and  then  about  one-quarter 
of  a  cake  of  compressed  yeast.  Allow  the  fermentation  to  proceed  below 
25°  C.  for  two  or  three  hours  to  prevent  excessive  foaming,  and  then 
place  in  an  incubator  at  a  temperature  of  from  27°  to  30°  C.  for  five  days. 
At  the  end  of  that  time  clarify  with  lead  subacetate  and  alumina  cream  j 
make  up  to  100  cc.  and  polarize  in  a  200-mm.  tube.  A  pure  fruit  jelly 
will  show  a  rotation  of  not  more  than  a  few  tenths  of  a  degree  either  to 
the  right  or  to  the  left.  If  a  Schmidt  and  Haensch  polariscope  be  used, 
and  a  lo''^^  solution  be  polarized  in  a  200-mm.  tube,  the  number  of  degrees 
read  on  the  sugar  scale  of  the  instrument,  multiplied  by  0.8755,  will  give 
the  percentage  of  dextrin,  or  the  following  formula  may  be  used: 

Percentage  of  dextrin  = 


in  which 


ig^XLxW  * 

C  =  degrees  of  circular  rotation, 

V  =  volume  in  cubic  centimeters  of  solution  polarized, 

L  =  length  of  tube  in  centimeters, 

Vr  =  weight  of  sample  in  solution  in  grams. 

•  Bur.  of  Chem.,  Bui.  65,  p.  78;  Bui.  107  rev.,  p.  80. 

+  Bigclow  and  McElroy,  Jour.  ."^m.  Chem.  Soc.  1893,  15,  668. 


yEGETABLE  AND   FRUIT  PRODUCTS.  94I 

Determination  of  Alcohol  Precipitate.* — Evaporate  100  cc.  of  a  20% 
solution  of  jelly,  or  of  the  washings  from  the  determination  of  insoluble 
solids  of  a  jam,  to  20  cc. ;  add  slowly  and  with  constant  stirring  200  cc 
of  95%  alcohol  and  allow  the  mixture  to  stand  over  night.  Filter  and  wash 
with  80%  alcohol  by  volume.  Wash  this  precipitate  off  the  filter  paper 
with  hot  water  into  a  platinum  dish;  evaporate  to  dryness;  dry  at  100° 
C.  for  several  hours  and  weigh;  then  bum  off  the  organic  matter  and 
weigh  the  residue  as  ash.  The  loss  in  weight  upon  ignition  is  called  alcohol 
precipitate. 

The  ash  should  be  largely  lime  and  not  more  than  5%  of  the  total 
weight  of  the  alcohol  precipitate.  If  it  is  larger  than  this  some  of  the 
salts  of  the  organic  acids  have  been  brought  down.  Titrate  the  water- 
soluble  portion  of  this  ash  with  tenth-normal  acid,  as  any  potassium 
bitartrate  precipitated  by  the  alcohol  can  thus  be  estimated. 

The  general  appearance  of  the  alcohol  precipitate  is  one  of  the  best 
indications  as  to  the  presence  of  glucose  and  dextrin.  Upon  the  addition 
of  alcohol  to  a  pure  fruit  product  a  flocculent  precipitate  is  formed  with 
no  turbidity  while  in  the  presence  of  glucose  a  white  turbidity  appears 
at  once  upon  adding  the  alcohol,  and  a  thick,  gummy  precipitate 
forms. 

Determination  of  Tartaric,  Citric,  and  Malic  Acids. — Modified  Schmidt- 
Hiepe  Method  * — Use  the  filtrate  from  the  alcohol  precipitate  in  this 
determination.  After  evaporating  the  alcohol  and  taking  up  the  acids 
with  water  add  lead  subacetate  until  the  solution  is  alkaline,  then  filter 
and  wash  the  precipitate  until  only  a  slight  amount  of  lead  remains  in  the 
washings.  Wash  the  precipitate  off  the  filter-paper  into  a  beaker  with 
hot  water,  precipitate  the  lead  by  hydrogen  sulphide,  and  filter  off  the 
lead  sulphide  while  hot,  washing  with  hot  water.  Evaporate  the  filtrate 
which  contains  the  free  organic  acids  to  about  50  cc,  neutralize  with 
potassium  hydroxide,  add  an  excess  of  strong  solution  of  neutral  calcium 
acetate  with  constant  stirring,  and  allow  to  stand  from  six  to  twelve  hours. 
Throw  the  precipitate  of  calcium  tartrate  on  a  filter-paper  and  wash 
until  filtrate  and  washings  make  exactly  100  cc;  ignite  the  filter-paper 
and  precipitate,  and  determine  the  lime  by  titration.  A  correction  of 
0.0286  gram  of  tartaric  acid,  which  is  held  in  solution  in  the  100  cc  of 
washings  as  calcium  tartrate,  must  be  added.  Evaporate  the  filtrate 
down  to  about  20  cc  and  if  a  precipitate  of  calcium  citrate  is  formed  col- 
lect it  on  a  filter  while  hot,  wash  with  hot  water,  ignite,  and  titrate.     From 

*  A.  O.  A.[C.  Method,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  107,  rev.,  p.  80. 


q^i  FOOD  INSPECTION  /iND  ANALYSIS. 

this  result  calculate  the  citric  acid.  Evaporate  the  filtrate  and  washings 
from  the  calcium  citrate  to  about  20  cc.  and  add  three  volumes  of  95% 
alcohol,  which  will  throw  down  the  calcium  salt  of  tartaric  acid  held  in 
solution,  the  remaining  citrate,  and  the  malate  and  succinate.  Filter, 
i<ynite  the  precipitate,  titrate,  and  calculate  as  malic  acid  after  subtracting 
the  tartaric  acid  present.     (The  amount  of  citric  and  succinic  acid  present 

is  very  small.) 

Determination  of  Citric  Acid.* — Fifty  cubic  centimeters  of  the  fruit 
solution  is  evaporated  on  the  water-bath  to  a  syrupy  condition.  To 
the  residue  add,  ver}'  slowly  at  first,  stirring  constantly,  95%  alcohol 
until  no  further  precipitate  is  formed;  70  to  80  cc.  are  generally  enough. 
Filter,  and  wash  the  residue  wi.h  95%  alcohol.  Evaporate  the  filtrate 
to  eliminate  the  alcohol,  take  up  the  residue  with  a  little  water,  and 
transfer  to  a  graduated  cylinder,  making  up  to  10  cc.  To  5  cc.  of  this 
solution,  add  half  a  cubic  centimeter  of  glacial  acetic  acid,  and  to  this 
add,  drop  by  drop,  a  saturated  solution  of  lead  acetate.  The  presence 
of  citric  acid  is  shown  by  the  appearance  of  a  precipitate,  which  possesses 
the  property  of  disappearing  on  being  heated,  and  reappearing  on  cooling. 
In  order  to  separate  the  citric  acid  from  other  acids,  heat  to  boiling,  filter, 
and  wash  with  boiling  water;  then  allow  to  cool,  and  the  precipitate  of 
lead  citrate  will  re-form.  This  lead  precipitate  may  be  filtered  off, 
washed  with  weak  alcohol,  dried,  weighed,  and  the  citric  acid  calculated. 
It  is  necessary  that  there  shall  be  no  tartaric  acid  present.  If  the  tartaric 
acid  has  been  estimated,  any  error  on  this  account  may  be  avoided  by 
adding  enough  decinormal  potash  to  neutralize  the  tartaric  acid  before 
the  alcohol  is  added. 

Detection  of  Coloring  Matter. — Boil  white  woolen  cloth  or  worsted 
in  a  solution  of  the  jelly  or  jam,  acidified  with  hydrochloric  acid,  or  with 
acid  sulphate  of  potassium,  according  to  Arata's  method  and  test  for 
the  color  on  the  dyed  fabric  by  methods  given  in  detail  in  Chapter  XVII. 

Detection  of  Preservatives  and  Concentrated  Sweeteners. — Extract  an 
acid  aqueous  solution  (jf  the  fruit  product  with  ether  or  chloroform  in 
a  separator/  funnel,  anrl  test  for  benzoic  and  salicylic  acids  and  for  sac- 
charin in  the  ether*  extract.  If  dulcin  is  suspected,  extract  with  acetic 
ether. 

*  Moslinf^cr,  Zeils.  Unter.  Xahr.  Genussm..  2,  1899,  p.  93;  U.  S,  Dept.  of  Agric,  Bun 
of  Chcm.,  Bui.  65,  p.  80. 


VEGETABLE  AND   FRUIT  PRODUCTS.  943 

Detection  of  Starch.* — Heat  an  aqueous  solution  of  the  preserve 
or  jelly  nearly  to  the  boiling  point,  and  decolorize  by  the  addition  of  several 
cubic  centimeters  of  dilute  sulphuric  acid  and  afterwards  permanganate 
of  potassium.  This  treatment  does  not  affect  the  starch,  which  is  tested 
for  with  iodine  in  the  ordinary  manner  in  the  solution  after  cooling.  In 
the  clear  filtrate  from  a  boiled  apple  pulp  solution,  free  from  added  starch, 
little  or  no  darkening  should  occur  on  the  addition  of  the  iodine  reagent. 
If,  however,  the  reagent  is  added  to  the  residue  of  the  previously  boiled 
pulp,  the  presence  of  starch  inherent  in  the  apple  is  usually  recognized 
by  the  blue  color  produced  thereon. 

The  presence  of  any  considerable  added  starch  paste  in  a  fruil  prepa- 
ration is  thus  readily  indicated  by  an  intense  blue  color  obtained  by  adding 
the  iodine  reagent  to  the  filtrate  (free  from  fruit  pulp). 

Detection  of  Gelatin. — Robin's  Method.^ — Add  to  a  thick  aqueous 
solution  of  the  preserve  or  jelly  sufficient  strong  alcohol  to  precipitate 
the  gelatin.  Decant  the  supernatant  liquid  after  settling,  set  aside  part 
of  the  precipitate,  and  dissolve  the  remainder  in  water.  Divide  the  latter 
solution  in  two  parts,  to  one  of  which  add,  drop  by  drop,  a  fresh  solution 
of  tannin,  which  precipitates  gelatin  if  present.  To  the  remainder  add 
picric  acid  solution,  which  in  presence  of  gelatin  forms  a  yellow  precip- 
itate. The  portion  of  the  yellow  precipitate  set  aside  is  transferred  to 
a  test  tube,  and  heated  over  the  flame  with  a  little  quicklime.  If  gelatin 
is  present,  ammonia  will  be  given  ofif,  apparent  by  the  odor,  and  by  fumes 
of  ammonium  chloride  when  a  drop  of  hydrochloric  acid  on  a  glass  rod 
is  held  at  the  mouth  of  the  bottle. 

Leffmann  and  Beam's  Method. X — Boil  the  sample  with  water,  filter, 
and  boil  the  filtrate  with  an  excess  of  potassium  bichromate.  Cool,  and 
add  a  few  drops  of  sulphuric  acid.     A  fiocculent  precipitate  indicates  gelatin. 

Detection  of  Agar  Agar.§ — The  jelly  is  heated  with  5%  sulphuric 
acid,  a  little  potassium  permanganate  is  added,  and,  after  settling,  the 
sediment  is  examined  by  the  microscope  for  diatoms,  which  will  be  found 
in  large  numbers  if  agar  agar  has  been  used. 

Detection  of  Apple  Pulp. — A  distinct  clue  to  the  presence  of  apple 
pulp  in  fruit  preparations   is  often   furnished  by  the  characteristic  apple 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chein.,  Bui.  65,  p.  81. 
t  Girard,  Analyse  des  Matieres  Alimentaires,  p.  676. 
t  Select  Methods  of  Food  Analysis,  p.  324. 

§  Marpmann,  Zeit.  f.  angew.  Mikrosk,  1896,  p.  260;  U.  S.  Dept.  of  Agric,  Bur.  of  Chem. 
Bui.  65,  p.  81. 


944  FOOD   INSPECTION   AND  ANALYSIS. 

odor  given  off  when  a  small  amount  of  the  sample  is  heated  to  boiling- 
with  water  in  a  test  tube.  Under  such  conditions,  the  apple  odor  is  quite 
apparent,  as  distinguished  from  that  of  other  fruits,  especially  if  the 
apple  is  the  chief  fruit  present,  or  predominates  in  the  mixture.   • 

Apple  pulp  in  fniit  preserves,  free  from  added  starch,  may  usually 
be  recognized  by  a  microscopical  examination,  using  iodine  reagent. 
The  cell  contents  of  the  pulp  will  show  the  characteristic  blue  color, 
undoubtedly  due  to  portions  of  unconverted  starch  still  remaining  in 
them. 

Detection  of  Fruit  Tissues  under  the  Microscope.  Ccrtaii-  of  the 
common  fruits  are  readily  identiiied  in  jams  by  their  microscopic  char- 
acters. This  is  especially  true  of  most  of  the  small  fruits,  the  skins, 
styles  and  seeds  being  more  or  less  characteristic  in  structure. 

The  apple  differs  from  the  quince  and  pear  in  that  stone  cells  are  lack- 
ing; the  starch  of  the  green  fruit  is  noteworthy.  Peaches,  plums  and 
apricots,  while  possessing  skins  and  stone  peculiar  to  each,  when  pared 
and  freed  from  stones  are  much  alike  in  structure.  Pineapples  have 
peculiar  needle-shaped  crystals.  Figs  are  identified  by  the  "  seeds " 
and  hairs.  Citrus  fruits  are  remarkable  because  of  the  oil  cavities  and 
spongy  parenchyma.  Fragments  of  elements  of  the  skins  and  cores  of 
fruits,  although  pared  and  cored  before  preparation,  find  their  way  into 
the  finished  products,  furnishing  evidence  to  the  microscopist.  The  seeds 
of  berries  are  highly  characteristic. 

DRIED    FRUITS. 

Desiccation  is  the  oldest  and  in  some  respects  the  most  satisfactory 
method  of  preserving  fruits.  It  is  an  economical  method,  as  the  apparatus 
and  the  process  arc  simple,  especially  if  the  sun's  heat  is  utilized  for  the 
evaporation;  furthermore,  the  cost  of  the  containers  is  small  and  the 
compact  form  of  the  product  reduces  the  cost  for  transportation  and  storage 
to  the  minimum.  From  the  sanitary  standpoint  dried  fruit  has  certain 
advantages,  notably  the  freedom  from  metallic  impurities  from  the  con- 
tainers; on  the  other  hand,  great  care  is  refjuired  to  protect  the  m^^terial 
during  drying  and  handling  from  surface  contamination. 

Xanti  currants  as  well  as  ra'.sins  are  dried  grapes  of  certain  Euiopean 
varieties.  These,  together  with  figs  and  dates,  although  produced  in 
California  and  the  Southern  States,  are  imported  into  the  United  States 
in  enormous  quantities  from  the  regions  adjoining  the  Mediterranean. 
Apples,  prunes,  apricots,  peaches,  and  cherries,  on  the  other  hand,  are 


I 


yEGETABLF   AND  FRUIT  PRODUCTS.  945 

produced  in  the  United  States  in  quantities  not  only  sufficient  for  domestic 
needs  but  also  for  export. 

California  fruits,  such  as  raisins,  prunes,  apricots,  peaches,  and  pears 
are  sun-dried,  as  are  also  raisins,  figs,  dates  and  other  fruits  produced 
about  the  Mediterranean.  Apples  are  commonly  dried  in  the  United 
States  by  artificial  heat,  although  the  old  process  of  sun  drying  is  still 
practiced  on  a  small  scale  in  certain  regions. 

Treatment  with  Lye.— Preliminary  to  drying  certain  fruits,  such  as 
raisins  and  prunes,  are  often  dipped  in  a  hot  but  weak  solution  of  potash, 
which  removes  the  bloom  and  otherwise  acts  on  the  skin,  thus  facilitating 
drying.  Oil  is  also  used  with  the  lye  in  preparing  "  oil-dipped  "  Smyrna 
raisins.  These  methods  of  treatment  are  cjuite  distinct  from  the  lye- 
peeling  process  employed  in  preparing  peaches,  apricots,  and  some  other 
fruits  for  canning. 

Sulphuring  of  Fruit. — The  treatment  of  fruits  with  the  fumes  of  burning 
sulphur  is  practiced  not  only  to  bleach  and  prevent  discoloration,  but  also 
to  ward  off  the  attacks  of  insects,  fungi,  and  bacteria.  It  is  allowed  with 
restrictions  in  most  European  countries  and  also,  pending  further  inves- 
tigation, in  the  United  States,  provided  the  amount  of  sulphur  dioxide 
remaining  in  the  fruit  does  not  exceed  350  mg.  per  kilo,  of  which  not  more 
than  70  mg.  is  free  sulphurous  acid.* 

There  is  reason  to  believe  that  the  sulphur  dioxide  exists  in  dried 
fruits  in  combination  largely,  if  not  wholly,  with  sugar,  although  possibly 
to  some  extent,  as  in  wines,  with  acetaldehyde,  or  even  with  protein  and 
cellulose. 

Sulphuring  when  used  for  purposes  of  deception,  as  for  example  in 
rejuvenating  old  or  damaged  stock  or  when  used  in  excessive  amount,  is 
obviously  improper.  Analyses  by  government  chemists  show  that  when 
no  restrictions  were  placed  on  sulphuring  as  high  as  3072  mg.  per  kilo 
were  present  in  dried  peaches,  2842  mg.  in  California  apricots  and  1738  mg. 
in  evaporated  apples. 

Moisture  Content  of  Dried  Fruits. — An  excessive  amount  of  moisture 
in  dried  fruit  is  not  only  a  worthless  make-weight,  but  also  facilitates  the 
growth  of  molds  and  bacteria,  causing  rapid  deterioration.  In  1904  a  law 
was  passed  in  New  York  State  recjuiring  that  dried  apples  contain  not 
above  27%  of  moisture,  determined  by  drying  4  hours  at  the  temperature 
of  boiling  water. 

Wormy  and  Decomposed  Dried  Fruits. — Figs,  dates,  and  currants 
from  Europe,  also  dried  apples,  cherries,  and  other  fruits  of  domestic 
*  U.  S.  Dept.  of  Agric,  Off.  of  Sec,  Food  Inspection  Decision  76. 


946  FOOD  INSPECTION   /1ND  /IN /i LYSIS. 

production  often  arc  infected  with  worms  or  are  in  a  moldy  or  fermented 
condition  due  to  careless  drying  or  packing.  Under  the  federal  law  such 
"  tilthy.  decomposed  or  ])utrid  "  fruit  is  adulterated. 

Zinc  in  Evaporated  Fruit.— Apples  dried  in  contact  with  galvanized 
iron  trays  may  contain  a  small  amount  of  this  metal  combined  as  malate, 
which  usually  amounts  to  only  o.oi  to  0.02%,  but  reaches  in  extreme  cases, 
according  to  Loock,  o.og'vf.  This  contamination  can  be  entirely  avoided 
by  greasing  the  galvani/ced  iron  trays  or  covering  them  with  greased  cloth 
or  else  by  the  use  of  wooden  trays. 

METHODS  OF  ANALYSIS. 

Preparation  of  the  Sample. — If  stones  are  present,  separate  and  weigh. 
Reduce  the  edible  portion  to  a  uniform  mass  by  grinding  in  a  food  chopper 
and  thorough  mixing. 

Determine  Ash,  Nitrogen,  Sugars,  and  Acids  as  described  under  Jams 
and  Jellies,  pp.  937  to  942.  and  Zinc  as  described  on  p.  915. 

Determination  of  Moisture. — Dry  5  grams  of  the  ground  sample  for 
24  hours  in  a  llat-bottomcd  dish  at  the  temperature  of  boiling  water,  and 
weigh. 

The  New  York  State  law  with  reference  to  dri^d  apples  makes  no 
provision  for  grinding  the  sample,  but  does  specify  that  the  drying  must 
be  for  4  hours.  Naturally  this  method  yields  lower  results  than  that  given 
above. 

Sulphurous  Acid. — Determine  by  the  distillation  method  as  described 
in  Chapter  X\I1I. 

FRUIT  JUICES. 

Sweet  cider,  orange  juice,  lime  juice,  grape  juice,  raspberry  shrub, 
and  the  juices  of  various  other  fruits  and  berries,  may  be  so  prepared 
and  sterilized  as  to  keep  without  fermentation  when  bottled,  and  are 
so  put  up  in  considerable  variety,  either  with  or  without  the  addition  of 
sugar. 

Such  preparations,  if  of  the  highest  purity,  should  consist  of  the 
undiluted  juices  of  these  fruits,  separated  by  pressure  and  carefully  ster- 
ilized and  bottled.  They  should  contain  no  othCr  fruit  juice  than  that 
Sfjecified  on  their  labels,  and  should  be  free  from  alcohol,  added  antisep- 
tics, or  coloring  matter,  unless  the  label  specifies  the  presence  of  the  added 
foreign  materials.  The  addition  of  pure  cane  sugar  to  such  prepara- 
tions as  grape  juice  is  allowable  if  declared,  as  well  as  charging  with 
carlx^n  dioxide  to  form  so-called  carbonated  drinks. 

The   following  analyses  of  pure   fruit  juices   are   taken   from   tables 


VEGET/IBLE  /IND   FRUIT   PRODUCTS. 


947 


prepared  by  Win  ton,  Ogden,  and  Mitchell,  showing  results  on  samples 
purchased  in  the  Connecticut  market,  as  well  as  on  some  samples  made 
in  the  laboratory.* 


COMMERCIAL  FRUIT 
JUICES. 

Blackberr)' 

Cherry 

Black  currant 

Red  currant 

Grape 

Lime  fruit 

Orange 

Pineapple 

Plum 

Quince 

Black  raspberry 

Strawberry 

MADE     IN     LABORA- 
TORY. 

Peach 

Red  raspberry 

Blackberry 

Huckleberry 

Pineapple 


Solids. 


5-32 
14-33 
10.00 

7-58 
15-29 

7.78 
12.72 

8.07 
10.81 
10.41 

8-47 

5-69 


12.70 
9-41 
8.94 

II  .40 

13.90 


Acids 
Other 
than 
COoas 
Citric. 

Cane 
Stigar. 

0.6^ 
0.80 

0.0 
0.0 

2.41 

0.0 

2.09 
0.91 

0.0 
0.0 

6.50 

0.0 

2.44 
0.81 

0.0 
1-5 

1. 00 

0.0 

0.99 

r.36 
0.99 

0.0 
0.0 
0.0 

0.95 
1. 19 

5-4 
0.8 

1.22 
O.^I 
0.68 

0.0 
0.6 
7-4 

Invert 
Sugar. 


4-6 
6-5 
9-2 
7-2 

0.0 

7-1 
5-1 
o-J 

7-8 

5-1 


2. 1 
8.6 
8-7 

9.1 


Polarization. 


Direct. 


-1-3 
-1-9 
-2.7 

—  2.1 

-6.5 
0.0 

—  2.1 
0.0   I    — 

—  0.1 
-5-0 
-2.3 
-1-5 


4.8 
-1.6 

-2-4 
-4.0 

4-7 


After 
Inver- 
sion. 

Temper- 
ature 
C. 

-1-3 

29.0 

-1-9 

26.0 

-2.7 

26.0 

—  2.1 

27.0 

-6.5 

25.0 

0.0 

-2.1 

26.0 

—  2.0 

26.0 

—  O.I 

26.0 

—  5-0 
-2-3 

25.0 
26.0 

-1-5 

26.0 

—  2.2 

28.0 

-2.8 

26.0 

-2.4 

30.0 

-4-8 
-4.8 

30.0 
28.0 

Invert 
Reading 
at  80°  C. 


0.0 

0.0 

0.0 

- 1 .0 


Preservatives. — Formerly  sahcylic  and  boric  acids  were  frequent 
additions,  now  sulphurous  acid  and  sodium  benzoate  are  the  common 
preser\'atives.  Beta-naphthol,  formaldehyde,  formic  acid  and  fluorides 
have  also  been  used. 

Unfermented  Grape  Juice  has  the  followmg  average  composition  if 


Austria, 
Per  Cent. 

California, 
Per  Cent. 

Solid    contents    by   spindle 
(Balling) 

21.62 
None 
■78 
.01 
19.62 
.61 
-03 
-37 
.02 

20.60 
None 
-53 
-03 
19-15 
-59 
.07 
.19 
.04 

Alcohol 

Total  acid  (as  tartaric) 

Grape  sugar 

Cream  of  tartar 

Free  tartaric  acid 

Ash 

Phosphoric  acid 

An.  Rep.  Conn.  Exp.  Sta.,  1899,  p.  136. 


t  California  Exp.  Sta.,  Bui.  130. 


04S 


FOOD  INSPECTION   AND  ANALYSIS. 


Grape  juice  is  prepared  by  sterilizing  at  a  temperature  of  80°  the 
juice  expressed  from  the  crushed  grapes,  filtering  by  means  of  a  press 
or  otherwise,  and  sealing  in  carefully  sterilized  bottles.  After  bottling, 
a  fmal  sterilization  is  conducted  at  a  temperature  5°  below  the  first. 
Bottled  grape  juices  are  rarely  carbonated. 

Bottled  Sweet  Cider. — The  composition  of  pure,  freshly  expressed 
apple  juice  is  shown  by  the  following  table  of  analyses  by  Browne:* 


Left- 

Total 

Unde- 

handed 

Specific 

Invert 

Su- 

Total 

SuKar 

Free 

ter- 

Rotation 

Gravitv. 

Solids. 

Sugar,  arose. 

after 

Malic 

Ash. 

mined 

Degrees 

Inver- 

.A.cid. 

(Pectin, 

Ventzke 

sion. 

etc.;. 

400  mm. 
Tube. 

Red  astrachan 

1-0532 

12.78 

6.87 

3-63 

10.50 

10.69 

1.14 

0-37 

0.77 

23.72 

Earlv  hancst 

1.0552 

13.29 

7-49 

3-97 

11.46 

11.67 

0.90 

0.28 

0.65 

24.32 

■^  fllow  transparent. 

1.0502 

11.71 

8.03 

2.10 

10. 14 

10.24 

0.86 

0.27 

0.44 

Swfft  lx)ugh 

Baldwin,  green.  . . . 

I . 0498 

11.87 

7.61 
6.96 

3.08 
1.63 

10.69 
8.59 

10.85 
8.68 

0. 10 

39-40 
36.16 

1.0488 

1 1 .  36 

1.24 

0.31 

1.22 

' '          ripe 

1.0736 

16.82 

7-97 

7-05 

15.02 

15-39 

0.67 

0.26 

0.87 

Ben  Davis 

1-0539 

12.77 

7. II 

3-«5 

10.96 

II. 16 

0.46 

0.28 

1.07 

49.00 

Bottled  sweet  cider,  properly  sterilized,  should  not  differ  materially 
from  the  fresh  juice,  and  should  contain  no  alcohol. 

Salicylic  acid,  sodium  benzoatc  and  sodium  or  calcium  bisulphite 
have  been  extensively  used  as  preservatives.     Benzoate  is  still  much  used. 

Lime  or  Lemon  Juice. — This,  according  to  the  U.  S.  Pharmacopoeia, 
should  consist  of  the  freshly  expressed  juice  of  the  ripe  fruit  of  Citrus 
limonum  (Risso),  natural  order  of  Rutaceae.  Our  supply  of  both  lemons 
and  limes  comes  chiefly  from  the  West  Indies  and  the  Mediterranean. 
Both  varieties  of  the  genus  Citrus  are  used  indiscriminately  for  furnish- 
ing commercial  lime  juice,  though  strictly  speaking,  only  that  of  the 
lemon  is  recognized  in  the  Pharmacopoeia.  The  juice  is  sharply  acid, 
and  is  largely  composed  of  citric  acid  (about  7%),  gum,  sugar  (3  to 
4  [x;r  cent),  and  inorganic  salts  from  2  to  2^-  per  cent.  It  also  usually 
contains  a  little  lemon  oil  from  the  rind.  According  to  the  pharmacopoeia, 
lemon  juice  (Limonis  succus)  should  conform  to  the  following  require- 
ments : 

"Specific  gravity:    not  less  than  1.030  at  15°  C. 

"  It  has  an  acid  reaction  upon  litmus  paper,  due  to  the  presence  of 
about  7%  of  citric  acid. 


*  Pcnn.  Dcpt.  Agric,  Bui.  58,  p.  29. 


yEGET/!BLE  AND    FRUIT  PRODUCTS.  949 

"On  evaporating  100  grams  of  the  juice  to  dryness,  and  igniting  the 
residue,  not   more  than  0.5   gram  of  ash  should  remain." 

Of  thirty  samples  of  commercial  lime  juice  examined  in  the  Massa- 
chusetts StaiC  Board  of  Health  laboratory,  representing  fifteen  brands, 
all  were  deficient  in  citric  acid,  containing  from  1.92  to  4.15  per  cent, 
thus  showing  that  these  preparations  are  frequently  watered.  Fifteen 
were  found  to  contain  salicylic  acid,  seven  had  sulphurous  acid,  while 
two  contained  both  these  preservatives.  Several  were  found  colored 
with  coal-tar  dyes. 

One  sample  examined  by  the  author,  purporting  to  be  a  "pure  West 
Indian  Lime  Juice,  triple  reiined,"  proved  to  be  a  mixture  of  hydrochloric 
and  salicylic  acids,  colored  with  a  coal-tar  dye,  and  contained  no  lime 
juice  whatever. 

METHODS   OF    ANALYSIS. 

Total  Solids,  Total  Nitrogen,  Ash,  and  Sugars  are  determined  Ijy  the 
methods  employed  for  jams  and  jelhes  (pp.  936  to  940),  Solubility  and 
Alkalinity  of  the  Ash  and  Phosphoric  Acid  as  described  in  the  chapter 
on  vinegar  (p.  764). 

Colors  and  Preservatives  are  detected  and  determined  as  described 
in  Chapters  XVII  and  XVIII. 

Total  Acidity. ^ — ^Titrate  10  grams  of  the  juice,  diluted  to  250  cc.  with 
freshly  boiled  water,  with  tenth-normal  alkali.  Use  phenolphthalein  as 
indicator  if  the  color  of  the  juice  will  permit,  otherwise  delicate  litmus  paper. 
Calculate  either  as  sulphuric  acid  or  as  the  organic  acid  known  to 
predominate. 

One  cc.  of  tenth-normal  alkali  is  equivalent  to  0.0075  gram  tartaric 
acid,  0.0067  gram  malic  acid  and  0.0064  gram  citric  acid. 

Determination  of  Tartaric  Acid — Proceed  as  directed  for  total  tartaric 
acid  in  wine,  p.  701,  except  that  20  cc.  instead  of  15  cc.  of  alcohol  are 
used  for  precipitation. 

Determination  of  Malic  Acid. — Dunbar  and  Bacon  Method.* — Dilute 
a  weighed  or  measured  amount  of  the  fruit  juice,  usually  10  grams,  with 
quite  a  large  volume  of  water,  add  phenolphthalein,  and  titrate  with 
standard  alkali  to  a  decided  pink  color.  Weigh  or  measure  another 
portion  of  the  hquid  (75  grams  orcc.  is  a  convenient  amount)  into  a  100- 
cc.  graduated  flask,  and  add  enough  standard  alkali,  calculated  from  the 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  76.   Jour.  Ind.  Eng.  Chem.,  3,  191 1,  p.  826. 


95©  FOOD   INSPECTION  AND  ANALYSIS. 

above  titration,  to  neutralize  the  acidity.  A  slight  excess  of  alkali  is  not 
objectionable.  If  the  solution  is  dark  colored,  add  5  or  10  cc.  of  alumina 
cream.  Dilute  to  the  mark,  mix  thoroughly,  and  filter  if  necessary  through 
a  folded  filter. 

Treat  about  25  cc.  of  the  filtrate  with  enough  powdered  uranyl  acetate 
so  that  a  small  amount  remains  undissolved  after  two  hours,  2.5  grams 
usually  being  sulhcient,  except  in  the  presence  of  large  amounts  of  malic 
acid.  In  case  all  the  uranium  salt  dissolves  more  should  be  added.  Allow 
to  stand  for  two  hours,  shaking  frequently,  filter  through  a  folded  filter 
until  clear  and  polarize  if  possible  in  a  200  mm.  tube  or,  if  too  dark,  in 
a  100  or  50  mm.  tube.     Designate  this  solution  and  reading  as  A. 

Treat  the  remainder  of  the  original  filtrate  with  powdered  normal 
lead  acetate  until  the  precipitation  is  just  complete,  avoiding  a  large  excess 
and  consequent  solution  of  lead  malate.  Cool  in  an  ice  bath  and  filter 
through  a  folded  filter  until  clear.  Warm  the  filtrate  to  room  temperature 
and  add  a  small  crystal  of  lead  acetate.  If  no  precipitate  forms,  remove 
the  excess  of  lead  with  anhydrous  sodium  sulphate,  filter  until  clear,  and 
polarize.  Designate  this  solution  and  its  polarization  reading  as  B. 
Solutions  which  are  sufficiently  clear  and  contain  less  than  10%  of  sugar 
may  be  polarized  directly  without  treatment  with  lead  acetate. 

If  reading  B  is  negative  treat  a  portion  of  solution  B  with  uranyl  acetate 
in  the  manner  already  described  and  polarize.  Designate  this  as  C. 
If  reading  B  is  positive,  reading  C  need  not  be  made. 

Polarize  all  solutions  at  a  uniform  room  temperature  with  white  light, 
using  the  average  of  at  least  six  readings  and  calculating  to  the  basis  of  a 
200  mm.  tube.  If  reading  C  is  numerically  less  than  reading  B,  the  latter 
should  be  discarded;  otherwise  use  reading  B  in  the  subsequent  calcula- 
tion. Multiply  the  algebraic  difference  between  this  reading  and  reading 
A  by  0.0,36,  the  product  being  the  percentage  of  malic  acid  (C4H6O5) 
in  the  solution  as  polarized. 

PratCs  Modification/^ — Place  a  weighed  amount  of  juice,  generally 
100  grams,  in  a  500  cc.  beaker  and  add,  with  vigorous  stirring,  two  or 
three  times  its  volume  of  c)$%  alcohol.  The  pectin  bodies  are  precipitated 
and  usually  in  such  a  form  that  after  standing  a  few  minutes  they  may  be 
gathered  into  a  coherent  mass.  Decant  the  liquid  through  a  filter  and  wash 
the  precipitate  twice  with  95'^  alcohol.  Evaporate  the  filtrate  in  a  cur- 
rent of  air  on  the  water-bath  to  about  75  cc.  After  cooling  make  up  to 
100  cc.  in  a  measured  flask,  using  lo  to  15  cc.  of  95%  alcohol  and  dis- 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  87. 


yEGET/iBLE  AND  FRUIT  PRODUCTS.  951 

tilled  water.  The  temperature  when  the  volume  is  finally  made  up  ta 
die  mark  should  be  close  to  that  at  which  the  polariscope  readings  are  to 
be  taken.  Treat  this  solution  exactly  as  in  the  original  method,  except 
that  no  clarification  is  necessary. 

Determination  of  Citric  Acid.— Pm//'5  Method.*— This  method  is 
applicable  in  the  presence  of  malic  and  tartaric  acids. 

1.  Apparatus. — This  consists  of  a  500  cc.  distilling  flask  provided 
with  a  small  dropping  funnel  drawn  down  to  a  small  opening  and  pro- 
truding one-half  inch  below  the  stopper.  In  the  flask  is  placed  a  glass 
rod  with  a  piece  of  small  tubing  one-half  inch  long,  sealed  on  the  lower 
end  to  insure  steady  ebullition.  This  small  tube  should  be  filled  with 
air  when  the  heating  begins.  A  condenser  preferably  of  the  spiral  type 
is  connected  with  the  flask. 

2.  Deniges  Reagent. — Add  about  500  cc.  of  water  to  50  grams  of  mercuric 
oxide;  then  add  200  cc.  of  concentrated  sulphuric  acid  with  constant 
stirring,  and  heat  the  mixture,  if  necessary,  on  a  steam  bath  until  the 
solution  is  complete.     After  cooling  make  up  to  a  liter  and  filter. 

3.  Determination. — Weigh  50  grams  of  the  fruit  juice  into  a  beaker 
and  add  no  cc.  of  95%  alcohol  to  throw  out  the  pectin  bodies.  After 
standing  fifteen  minutes  filter  and  wash  with  95%  alcohol.  Dilute  the 
filtrate  with  water  to  approximately  50%  alcohol  content  and  add  enough 
20%  barium  acetate  solution  to  precipitate  the  citric  acid.  Stir,  let 
stand  until  the  barium  citrate  partially  settles,  and  filter.  Wash  twice 
with  50%  alcohol  to  remove  the  greater  part  of  the  sugar  present.  Remove 
all  alcohol  from  the  precipitate  and  filter  either  by  drying  in  the  beaker 
used  for  precipitation  or  else  by  washing  with  ether  before  removing  from 
the  funnel.  Add  50  cc.  of  water  and  3  to  5  cc.  of  sirupy  phosphoric  acid 
to  the  beaker  containing  the  filter-paper  and  precipitate  and  warm,  thus 
dissolving  the  barium  citrate  completely.  Filter  into  a  100  cc.  measuring 
flask  and  wash  up  to  the  mark. 

Measure  an  aliquot  containing  from  0.05  to  0.15  gram  of  citric  acid, 
into  the  distilling  flask,  add  5  to  10  cc.  of  sirupy  phosphoric  acid  and 
400  cc.  of  hot  water.  Connect  with  the  condenser,  heat  and  when  briskly 
boiling,  add  potassium  permanganate  solution  (0.5  gram  per  liter),  i 
to  2  drops  per  second,  until  a  pink  color  persists  throughout  the  solution. 
Distill  off  the  acetone  formed  by  the  oxidation  into  a  liter  Erlenmeyer 
flask  containing  30  to  40  cc.  of  Deniges  reagent,  continuing  the  distilla- 
tion until  50  to  100  cc.  remain  in  the  flask.     Boil  the  distillate  gently 

*  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Circ.  88. 


952  FOOD  INSPECTION  /iND  ANALYSIS. 

under  a  reflux  condenser  for  forty-five  minutes  after  it  turns  milky. 
Filter  hot  through  a  Gooch  crucible,  wash  the  precipitate  with  water, 
alcohol,  and  linally  with  ether,  and  dry  in  a  water-oven  for  half  an  hour. 
The  weight  of  the  precipitate  multiplied  by  0.22  gives  the  weight  of  citric 
acid. 

FRUIT  SYRUPS. 

Two  classes  of  these  preparations  are  on  the  market,  one  for  use  in 
soda-fountains,  and  one  for  ''  family  trade,"  intended  as  a  basis  for 
sweetened  drinks  to  be  diluted  with  water  and  sugar.  Some  are  made 
exclusively  from  pure  fruit  pulp  and  sugar,  sterilized  by  heating  and  put 
up  in  tightly  sealed  bottles,  while  others  of  the  cheaper  variety  are  more 
apt  to  be  entirely  artificial  both  in  color  and  in  flavor,  deriving  the  latter 
principally  from  the  wide  variety  of  artificial  fruit  essences  now  available. 
Commercial  glucose  is  a  frequent  ingredient.  The  same  classes  of  coal- 
tar  dyes  and  antispetics  are  found  in  these  preparations  as  in  the  other 
fruit  products.  Citric  or  tartaric  acid  is  frequently  added  to  genuine 
fruit  syrups  to  bring  out  the  flavor  and  to  imitation  fruit  syrups  to  better 
simulate  the  characters  of  the  genuine  product. 

For  purposes  of  comparison  with  such  fruit-pulp  preparations  as 
may  come  to  the  analyst  for  examination,  he  is  referred  to  the  analysis 
of  fruits  found  on  page  274. 

NON-ALCOHOLIC    CARBONATED   BEVERAGES. 

Soda  Water. — Originally  the  beverage  known  as  soda  water  was 
prepared  ijy  the  action  of  an  acid  on  sodium  bicarbonate  in  solution  and 
corresponded  to  what  is  now  obtained  by  dissolving  Seidlitz  powders 
in  water.  Later  it  was  found  that  water  charged  with  carbon  dioxide 
was  not  only  more  practicable  commercially  Ijut  also  more  acceptable 
to  the  palate  and  this  product  was  substituted  for  true  soda  water  without 
change  of  name. 

As  dispensed  by  the  pharmacist  and  confectioner  in  the  United  States, 
soda  water  consists  of  a  syrup,  variously  flavored,  mixed  at  the  "  fountain  " 
with  carbonated  water.  The  syrup  is  first  placed  in  the  glass,  then  the 
carbonated  water  is  drawn  into  it  in  a  large  stream  and  finally  more  added 
in  a  fine  stream  to  mix  and  froth  the  liquid.  Ice  cream  or  liquid  "  cream  " 
is  used  with  certain  flavors,  eggs  and  milk  in  "  egg  chocolate,"  "  egg  shake  " 
and  other  nutritious  mixtures,  a  solution  of  calcium  acid  phosphate  in 
*'  orange  phosphate  "  and  other  phosphates — in  fact  there  appears  to  be 


yHGETABI.E   AND   FRUIT   PRODUCTS,  953 

no  end  to  the  preparations  and  comliinations  introduced  by  ingenious 
venders  to  quench  the  thirst,  gratify  the  palate,  and  furnish  nourishment 
in  an  easily  digestible  form. 

Carbonated  Water,  the  basis  of  all  efferv-escent  drinks,  is  prepared  by 
charging  ordinary  water  with  carbon  dioxide  in  a  steel  drum,  known  as 
the  fountain.  P'ormerly  the  gas  was  generated  on  the  premises  by  the 
action  of  mineral  acid  on  marble,  but  now  it  is  obtained  in  liquid  form  in 
steel  cylinders  from  mineral  springs  and  the  fermentation  industries  where 
it  formerly  went  to  waste. 

The  process  of  carbonating  consists  in  allowing  the  gas  to  discharge 
into  the  water,  rocking  the  fountain  continually  to  aid  absorption.  A 
gauge  indicates  the  pressure  in  the  fountain,  which  should  be  about  170 
pounds  per  square  inch  for  soda  water  and  somewhat  less  for  ginger  ale 
and  root  beer.  The  steel  drum  or  fountain  proper  is  kept  in  the  cellar 
or  other  convenient  place  and  the  carbonated  water  is  piped  to  the  so-called 
fountain  where  the  drinks  are  served,  or,  in  the  case  of  bottled  beverages, 
to  the  machine  for  filling  the  bottles. 

Needless  to  say  both  the  water  and  the  gas  should  be  free  from  con- 
tamination, and  the  introduction  of  metallic  salts  from  the  lead  pipes  and 
other  sources  should  be  guarded  against. 

Soda  Water  Syrups. — ^Sugar  and  flavors  are  added  to  carbonated 
beverages  in  the  form  of  syrups.  At  the  soda  fountain  these  are  drawn 
into  the  glass  from  small  reservoirs  or  poured  from  bottles,  while  in  the 
bottling  works  measured  quantities  both  of  syrup  and  carbonated  water 
are  introduced  into  each  bottle  by  an  automatic  machine. 

Fruit  Syrups  are  prepared  either  by  the  manufacturer  of  soda  water 
supplies  or  else  by  the  pharmacist  or  confectioner  who  serves  the  beverages. 
More  commonly  the  manufacturer  supplies  the  fruit  juice  or  fruit  pulp 
in  bottles  or  jars,  spoilage  being  avoided  either  by  sterilization  or  the  use 
of  sodium  benzoate.  The  vender  mixes  the  juice  or  pulp  with  sugar 
syrup  as  needed.  Orange,  lemon,  and  lime  syrups  are  commonly  made 
from  the  oils  rather  than  from  the  fresh  fruit,  the  necessary  acidity  being 
supplied  by  citric  acid.  This  acid  as  well  as  tartaric  acid  is  also  used  in 
strawberry,  raspberry  and  other  true  fruit  syrups  to  bring  out  the  flavor. 

Imitation  Fruit  Syrups  flavored  with  mixtures  of  ethers  such  as  are 
described  on  pp.  895  to  897,  are  frequently  substituted  for  genuine  fruit 
syrups  at  soda  fountains  and  quite  universally  in  the  preparation  of  cheap 
bottled  soda  water.  Aside  from  the  deception  to  the  consumer  these  mix- 
tures are  highly  objectionable  because  of  their  nauseating  and  unwhole- 
some properties. 


954 


FOOD   INSPECTION   AND   ANALYSIS. 


Viirious  Syrups  not  belonging  under  the  head  of  fruit  syrups  are  drawn 
from  fountains  and  used  in  bottled  beverages.  Among  these  are  vanilla, 
cotTee.  chocolate  (really  cocoa),  ginger,  sarsaparilla,  and  mixtures  sold 
under  distinctive  names. 

Bottled  Carbonated  Beverages.  —To  this  class  belong  various  non- 
alcoholic beverages  known  as  "  soda  "  "  soft-drinks  "  and  "  temperance 
drinks."  Some  of  these  are  high-grade  articles  of  national  or  even  inter- 
n;Uional  reputation,  so  prepared  as  to  keep  indelinitely,  while  others  are 
cheap  preparations  of  local  manufacture  sold  for  immediate  consumption 
in  pleasure  resorts. 

Ginger  Ale,  by  far  the  best-known  bottled  carbonated  beverage,  is  made 
from  ginger  (or  ginger  extract)  with  the  addition  of  lemon  juice  (or  lemon 
oil  and  citric  acid)  and  carbonated  water.  Capsicum  extract,  known  in 
solid  form  as  capsicin,  is  frecjucntly  substituted  in  part  for  the  ginger 
because  of  its  greater  pungency. 

Root  Beer  was  formerly  brewed  from  a  sweetened  infusion  of  various 
roots  and  herbs,  the  gas  being  formed  by  a  true  fermentation  process. 
A  similar  beverage  is  now  made  in  the  household,  using  so-called  "  root- 
beer  extract,"  but  the  commercial  product  is  commonly  charged,  like  soda 
water,  with  carbon  dioxide  gas. 

Birch  Beer,  formerly  made  by  fermentation,  is  now  merely  soda  water 
flavored  with  oil  of  birch  or  synthetic  methyl  salicylate. 

Sarsaparilla,  so  called,  is  flavored  with  a  mixture  of  oil  of  birch, 
natural  or  synthetic,  and  oil  of  sassafras.  The  dark  color  is  due  to  caramel 
or  other  artificial  colors. 

Lemon  Soda  and  Orange  Soda  are  flavored  respectively  with  terpene- 
less  lemon  and  orange  extract,  the  acidity  being  contri])uted  by  citric  acid. 
Orangeade  belongs  in  the  same  class.  So-called  Ijlood-orange  soda  is 
probably  never  made  from  blood  oranges,  the  color  being  artificial. 

Vanilla  Soda  is  more  correctly  vanillin  soda  or  vanillin  and.coumarin 
soda.  The  term  cream  soda  applied  to  this  colorless  beverage  is  equally 
misleading. 

Straivberry  Soda,  Raspberry  Soda  and  other  bottled  beverages  purport- 
ing to  be  made  from  fruits  are  commonly  imitations  flavored  with  ethers 
and  colored  with  coal-tar  dyes.  So-called  Cherry  Soda  is  flavored  with 
an  e.xtraf  t  of  cherry  bark  or  benzaldahyde. 

Sweeteners  in  Beverages. — Sugar  is  the  only  jjroper  sweetener  for 
syrups  or  bottled  beverages.  Glucose  because  of  its  lower  sweetening 
power  is  unsuited  for  the  jjuryjose,  while  saccharin  and  other  chemical 
sweeteners  are  objectionable  both  because  of  their  lack  of  nutritive  prop- 


yEGHTABl.R  .4ND  FRUIT  PRODUCTS.  955 

ertics  and  their  possible  injury  to  health.  The  use  of  saccharin,  which 
has  hitherto  been  extensive,  is  now  prohibited  in  beverages  entering  into 
interstate  commerce. 

Acids  in  Beverages.— Citric  and  tartaric  acids  are  used  not  only  in 
imitation  but  also  in  true  fruit  syrups  to  bring  out  the  flavor.  Lemon 
juice  serves  the  same  purpose,  but  is  more  expensive  and  does  not  keep  so 
well.  Calcium  acid  phosphate  is  a  characteristic  constituent  of  orange 
and  other  fruit  phosphates. 

Preservatives. — Sodium  benzoate  is  the  common  preservative  of  bev- 
erages, although  its  use  is  by  no  means  universal.  Formerly  salicylic, 
boric  and  sulphurous  acids  and  even  fluorides  were  employed. 

Artificial  Colors. — Cochineal,  cudbear,  caramel  and  the  seven  colors 
allowed  by  U.  S.  decisions  are  most  commonly  met  with.  The  use  of 
fuchsin,  acid  fuchsin,  rhodamine,  tartrazine  and  other  coal-tar  colors 
has  been  largely  discontinued. 

Foam  Producers. — Froth  on  soda  water  is  cheaper  to  produce  than  the 
same  bulk  of  liquid,  furthermore  it  is  sanctioned  by  custom. 

Soap-bark,  the  bark  of  Quillaja  Saponaria,  a  common  foam  producer, 
contains  two  saponins,  sapotoxin  and  quillaiac  acid,  both  of  which  are 
poisonous.  In  addition  these  principles  combine  with  the  cholesterin  of 
the  blood  and  if  in  excess  dissolve  the  corpuscles. 

Commercial  saponin,  prepared  from  Saponaria  officinalis,  and  consist- 
ing largely  of  sapotoxin,  is  also  extensively  used. 

Foam  producers  are  also  used  in  malt  liquors. 

Glycerrhizin,  the  characteristic  principle  of  licorice,  also  serves  as  a 
foam  producer. 

Habit-forming  Drugs  in  Beverages. — ^Caffein,  extract  of  cola  leaves, 
and  cocaine  are  ingredients  of  certain  proprietary  syrups  and  beverages, 
contributing  their  well-known  stimulating  properties.  The  use  of  cafifein 
is  defended  on  the  ground  that  it  is  the  active  principle  of  tea  and  coffee. 
Opponents  of  this  drug  have  pointed  out  that  tea  and  coffee  are  recognized 
as  improper  articles  of  diet  for  children  and  invalids,  furthermore,  the 
presence  of  other  consituents  tends  to  prevent  the  excessive  use  of  these 
beverages.  Again  the  presence  of  caffein  in  carbonated  beverages  is  not 
usually  known  to  the  consumer,  and  he  forms  the  habit  without  proper 
warning. 

It  would  be  difficult  to  find  an  argument  in  favor  of  the  use  of  a  drug 
so  potent  as  cocaine  or  products  containing  cocaine. 


956  '  FOOD  INSPECTION  /iND  AN/iLYSlS. 


METHODS    OF   ANALYSIS. 


Transfer  the  sample  to  a  flask  and  shake  at  intervals  for  an  hour  or 
two,  at  room  temperature,  thus  removing  most  of  the  carbon  dioxide. 
Use  the  liquid  thus  obtained  for  the  several  determinations,  measuring 
out  the  portions,  if  desired,  and  calculating  the  weight  from  the  specific 
gravity. 

Total  Solids,  Ash,  Acidity,  Sugars,  and  Organic  Acids  are  determined 
as  directed  for  jams  and  jellies  (pp.  936  to  942)  using  25  grams  of  the 
licjuid  except  for  the  polarizations,  which  may  be  made  on  normal  quantities. 

Vanillin,  Coumarin,  Citral,  and  Methyl  Salicylate  are  detected  and 
determined  by  the  methods  described  under  the  head  of  Flavoring  Extracts, 
with  such  modilications  as  are  necessitated  by  the  absence  of  alcohol  on 
tlie  one  hand  and  the  greater  dilution  on  the  other.  Methods  for  the 
detection  of  Ginger  and  Capsicum  are  given  on  page  894, 
h^  Detection  of  Colors,  Preservatives,  and  Sweeteners. — See  Chapters 
XV IF,  XVI Hand  XIX. 

Detennination  of  Phosphoric  Acid. — This  determination  is  made 
in  so-called  "'  orange  phosphate,"  "  raspberry  phosphate "  and  other 
beverages  containing  calcium  acid  phosphate. 

Treat  25  grams  of  the  liquid  according  to  the  method  described  on 
p.  346,  except  that  the  entire  residue,  after  ignition  wdth  magnesium 
nitrate,  is  used  for  the  determination,  without  aliquoting. 

Detennination  of  Alcohol. — Follow  the  method  prescribed  for  wines 
(p.  658J.  The  amount  of  volatile  oil  present  is  seldom  sufficient  to  appre- 
ciably affect  the  result. 

Detection  of  Saponin.— Of  the  various  color  tests  that  have  been 
proposed  none  has  been  found  absolutely  characteristic,  especially  if 
glycerrhizin  is  present,  although  the  reactions  with  sulphuric  acid  and 
Frohde  reagent  are  of  considerable  value.  The  haemolysis  test  is  believed 
to  be  reliable  even  in  the  presence  of  glycerrhizin.  Whichever  test  is 
applied  the  saponin  should  be  separated  from  interfering  substances  as 
follows : 

I.  Extraction  of  Saponin  by  the  Riihle-Brummer  Method.^ — In  the 
case  of  sfxla  water  and  other  products  containing  organic  or  mineral 
acids  foWier  than  carbonic),  to  100  cc.  of  the  liquid  add  an  excess  of  pre- 
cipitated magnesium  carbonate  and  filter.  If  dextrin  is  present,  as  in 
the  case  of  malt   liquors,  evaporate   100  cc.  of  the  liquid  to  20  cc,    pre- 


*  Ztits.  Unters.  Nahr.  Genussm.,  5,  1902,  p.  iig?;   16,  1908,   p.  165;  23,  1912,  p.  566. 

• 


WECETABLE  AND  FRUIT   PRODUCTS.  957- 

cipitate  with  150  cc.  of  95%  alcohol,  let  stand  30  minutes  then  heat  to 
boiling,  filter,  dilute  the  filtrate  with  water  and  dealcoholize,  finally  making 
up  the  solution  to  100  cc. 

To  100  cc.  of  the  neutral,  dextrin-free  solution  in  a  scparatory  funnel, 
add  20  grams  of  ammonium  sulphate,  9  cc.  of  phenol  and  shake  thoroughly. 
Draw  off  the  watery  layer  and  shake  the  phenol  solution  with  a  mixture 
of  50  cc.  of  water,  100  cc.  of  ether,  and  (if  necessary  to  avoid  an  emulsion) 
4  cc.  of  alcohol.  Allow  to  stand  until  the  liquids  separate,  which  usually 
requires  12  to  24  hours.  Draw  off  the  aqueous  solution  and  evaporate 
nearly  to  dryness,  finishing  the  drying  either  at  100  °  C.  or  in  a  desiccator, 
the  latter  being  preferable  if  the  residue  is  to  be  purified  by  treatment 
with  acetone,  which  is  usually  desirable.  Employ  this  extract,  consisting 
of  saponin  and  impurities,  in  the  following  tests: 

II.  Tests  for  Saponin. — i.  Sulphuric  Acid  Test. — Rub  up  a  portion 
of  the  extract  with  a  few  drops  of  sulphuric  acid.  Saponin  is  indicated 
by  the  appearance  in  a  few  minutes  of  a  reddish  color  changing  in  half 
an  hour  to  red-violet  and  finally  to  gray. 

2.  Frohde  Test. — Treat  another  portion  in  like  manner  with  a  few 
drops  of  a  mixture  of  100  cc.  of  concentrated  sulphuric  acid  and  i  gram 
of  ammonium  molybdate.  In  the  presence  of  saponin  the  drops  in  15 
minutes  become  violet,  changing  later  to  green  and  finally  to  gray. 

3.  Foam  Test. — Shake  another  portion  of  the  extract  with  water  and 
note  its  foam-producing  properties. 

In  the  presence  of  glycerrhizin  none  of  the  last  three  tests  is  reliable. 

4.  Haemolysis  Test. — This  process  is  recommended  by  Rusconi,* 
Sormali,t  and  Rhiile.J  The  following  details  are  given  by  Rhiile  and  are 
based  on  the  method  as  described  by  Gadamer :  § 

{a)  Reagents. — (i)  Physiological  Salt  Solution. — Dissolve  8  grams  of 
sodium  chloride  in  water  and  make  up  to  one  liter. 

(2)  One  per  cent  Defibrinated  Blood. — Shake  vigorously  fresh  ox 
blood  in  a  sterilized,  salt-mouth,  500-cc.  bottle  with  20  glass  beads  5-7 
mm.  in  diameter.  Separate  from  the  clot  of  fibrin  and  store  in  a  sterilized 
container  in  a  refrigerator.  Properly  cared  for  it  should  keep  for  several 
days. 

Dilute  with  100  volumes  of  physiological  salt  solution  for  use. 

(3)  One  per  cent  Blood  Corpuscles. — Centrifuge  100  cc.  of  the  1% 

*  Bol.  Soc.  Med.-Chi.      Pavia,  iqio. 

t  Zeits.  Unters.  Nahr.  Genussm.  2$,  191 2,  p.  562. 

X  Ibid.  p.  566.  V 

§  Lehrbuch  der  chemischen  Toxicologic.     Gottingen,  1909,  p.  443. 


958  FOOD   INSPECTION   AND_/iNALYSIS. 

defibrinated  blood  in  physiological  salt  solution,  pour  off  the  clear  solu- 
tion containing  the  cholesterol  and  make  up  again  to  loo  cc.  with  the  salt 
solution.     This  preparation  is  more  sensitive  than  solution  (2). 

(i)  Process. — Dissolve  about  o.i  gram  of  the  extract  in  25  cc,  of 
physiological  salt  solution,  filter,  and  shake  i,  2,  and  3  cc.  of  this  solution 
in  small  test-tubes  with  i  cc.  portions  of  1%  defribinated  blood.  If 
saponin  is  present  the  liquid  becomes  clear  in  from  a  minute  to  an  hour 
or  two,  depending  on  the  amount  of  saponin  in  the  beverage  and  the  num- 
ber of  cc.  of  the  solution  used. 

As  a  confirmatory  test  dissolve  i  mg.  of  cholesterol  in  a  sm.all  amount 
of  ether,  shake  with  10  cc.  of  the  solution  of  the  extract  in  salt  solution, 
heat  at  36°  C,  for  a  few  hours  to  remove  ether,  avoiding  concentration, 
and  treat  portions  of  this  solution  with  1%  defibrinated  blood  as  above 
described.  Cholesterol  destroys  the  haemolytic  action  of  the  saponin, 
hence  the  liquids  should  not  become  clear  in  these  tests.  In  order  to 
exert  this  influence  cholesterol  should  be  present  to  the  extent  of  i  part 
to  5  parts  of  saponin. 

If  only  a  small  amount  of  saponin  is  present  the  haemolytic  action  can 
best  be  noted  under  a  microscope  magnifying  to  300  diameters.  Mount 
a  drop  of  the  solution  of  the  extract  in  salt  solution  and  place  a  drop  of 
either  solution  (2)  or  (3)  in  contact  with  it.  The  saponin  causes  the 
corpuscles  in  contact  with  it  to  swell,  then  become  strongly  refractive, 
and  finally  dissolve. 

Determination  of  Caffein. — Fuller  Method.'^' — Weigh  50  grams  or 
measure  an  equivalent  volume  into  a  small  beaker,  add  5  cc.  of  concentrated 
ammonium  hydroxide,  allow  to  digest  over  night;  then  add  2  cc.  more 
of  ammonium  hydroxide,  heat  for  two  hours,  transfer  to  a  large  separatory 
funnel,  dilute  with  3  volumes  of  acid,  add  5  cc.  of  ammonium  hydroxide 
and  shake  out  with  four  successive,  portions  of  chloroform,  each  of  50  cc. 
In  case  any  dyestuff  is  removed  by  the  chloroform,  shake  out  with  a  satu- 
rated solution  of  sodium  bisulphite,  which  will  remove  some  of  the  color. 

Distil  off  the  bulk  of  the  chloroform  and  evaporate  the  remainder  in  a 
[X)rcelain  dish.  Dissolve  the  residue  in  25  cc.  of  2%  sulphuric  acid, 
shake  out  with  five  portions  of  15  cc.  each  of  chloroform,  filter  the  combined 
chloroform  solutions  into  a  flask,  distil  off  the  bulk  of  the  chloroform  and 
evaporate  in  a  tared  dish;  dry  at  100  °  C.  and  weigh. 

If  the  caffein  is  not  pure,  dissolve  in  15  cc.  of  10%  hydrochloric  acid, 
arid  an  excess  of  a  solution  of  10  grams  of  iodine  and  20  grams  of  potas- 

*  A.  O.A.C.  Proc.  1910,  U.  S.  Dept,  of  Agric,  Bur.  of  Chem.,  Bui.  137,  p.  191. 


FFGHT^BLH   AND  FRUIT  PRODUCTS.  959 

^sium  iodide  in  loo  cc.  of  water,  allow  to  stand  over  night,  filter,  and  wash 
twice  with  lo  cc.  of  the  iodine  solution.  Transfer  filter  and  precipitate 
to  the  original  precipitation  flask,  add  sufficient  sulphurous  acid  to  dissolve 
the  precipitate,  heating  gently,  filter  into  a  separatory  funnel,  wash  three 
times  with  water,  and  add  ammonium  hydroxide  in  excess,  shake  out 
four  times  with  15  cc.  portions  of  chloroform,  and  filter  the  chloroform 
extracts  into  a  flask,  using  a  7  cm.  filter  and  keeping  the  funnel  covered 
with  a  watch  glass.  Wash  the  filter  with  5  portions  of  5  cc.  of  chloroform. 
If  the  chloroform  extract  is  colored,  concentrate,  add  a  small  amount  of 
animal  charcoal,  rotate  several  times  and  filter.  Distil  off  part  of  the  solvent 
and  evaporate  the  remainder  in  a  tared   dish,  dry  at  100°  C,  and  weigh. 

Detection  and  Determination  of  Cocaine. — Fuller  Method:^ — To 
200  cc.  of  the  sample  in  a  large  separatory  funnel,  add  concentrated  am- 
monium hydroxide  to  alkahne  reaction,  and  shake  out  with  three  portions 
of  50  cc.  each  of  Prolius  mixture  (4  parts  ether,  i  part  chloroform,  i  part 
alcohol),  collecting  the  solvent  in  another  separatory  funnel.  If  desired 
the  aqueous  solution  may  be  reserved  for  the  detection  of  salicylic  and 
benzoic  acids  and  saccharine.  Filter  the  combined  Prolius  extracts 
into  an  evaporating  dish,  and  evaporate  on  a  steam  bath,  removing  the  dish 
as  the  last  traces  of  solvent  disappear.  Dissolve  the  residue  in  normal 
sulphuric  acid,  transfer  to  a  separatory  funnel  and  shake  out  four  times 
with  15  cc.  portions  of  chloroform;  wash  the  combined  chloroform  solu- 
tions once  with  water,  reject  the  chloroform,  and  add  the  water  extract  to 
the  original  acid  solution.  Add  10  cc.  of  petroleum  ether  boiling  at  40° 
to  50°  C,  and  shake;  draw  off  the  acid  layer,  rejecting  the  petroleum  ether, 
add  concentrated  ammonium  hydroxide  in  excess  and  shake  out  three 
times  with  15  cc.  portions  of  petroleum  ether,  collecting  the  ethereal  solu- 
tions in  another  separatory  funnel.  To  the  latter  add  10  cc.  of  water  and 
shake  thoroughly;  reject  the  water  extract  and  filter  the  petroleum  ether 
into  a  beaker,  washing  twice  with  10  cc.  portions  of  the  solvent.  Evaporate 
over  a  steam  bath,  using  a  fan.  By  this  method,  if  coca  alkaloids  are 
present,  a  nearly  colorless  residue  will  be  obtained,  which  will  finally 
crystallize  on  standing. 

Dissolve  the  residue  in  petroleum  ether  and  divide  into  four  portions, 
one  of  which  may  be  small.  Evaporate  the  solvent  and  to  the  small 
portion  add  a  few  drops  of  normal  sulphuric  acid,  warm  gently,  filter  into 
a  test-tube,  and  add  a  drop  of  potassium  mercuric  iodide  test  solution 
(Meyer's   reagent).     A   precipitate   indicates   an   alkaloid   but  does   not 

*A.O.A.C.  Proc.  1910,  U.  S.  Dept.  of  .^gric,  Bur.  of  Chem.,  Bui.  137,  p.  192. 


960  FOOD   INSPECTION  AND  ANALYSIS. 

identify  it  as  cocaine;   if  no  precipitate  forms,  cocaine  is  not  present  and 
further  test  is  unnecessary. 

To  another  portion  add  a  few  drops  of  concentrated  nitric  acid,  and 
evaporate  on  a  steam  bath  until  the  acid  is  all  driven  ofT,  then  add  a  few 
drops  of  half  normal  alcoholic  potash  and  note  the  first  odor  that  comes 
olT.  which,  if  cocaine  is  present,  is  that  of  ethyl  benzoate. 

The  residue  of  tlie  third  portion  should  be  applied  to  the  end  of  the 
tongue  by  rubbing  witli  the  linger.  Cocaine  will  cause  a  numbness  which 
is  not  apparent  immediately,  but  develops  gradually,  and  persists  for  a 
longer  or  shorter  time  according  to  the  amount  present. 

Remove  a  portion  of  the  fourth  residue  to  a  microscopic  slide,  add  a 
drop  or  two  of  gold  chloride  test  solution,  and  stir  vigorously,  noting  the 
character  of  the  crystals  under  the  microscope. 

All  the  above  tests  should  be  checked  by  controls  on  pure  cocaine. 
If  a  quantitative  determination  of  coca  alkaloids  is  desired  the  residue 
after  evaporating  the  petroleum  ether  should  be  weighed,  then,  as  a  check 
on  the  gravimetric  determination,  warmed  in  50  cc.  of  fiftieth-normal 
sulphuric  acid  until  dissolved,  cooled,  and  titrated  with  fiftieth-normal 
potassium  or  sodium  hydroxide,  using  cochineal  as  indicator.  The  fac- 
tor for  cocaine  is  0.006018. 

Determination  of  Caffein  and  Detection  of  Cocaine  and  Glycerine. — 
Fuller  Method :^—\\<i\g\\  50  grams  of  the  sample  into  an  evaporating  dish, 
add  5  cc.  of  concentrated  ammonium  hydroxide,  cover  with  a  watch-glass 
and  allow  to  stand  12  hours.  Add  2  cc.  more  of  ammonium  hydroxide 
and  evaporate  on  the  steam  bath.  Warm  the  residue  with  25  cc.  of  95% 
alcohol,  on  the  steam  bath,  cool,  and  pour  off  the  alcohol  into  another 
evaporating  dish,  repeating  the  treatment  four  times.  Evaporate  the 
combined  alcoholic  extract,  dissolve  the  residue  in  25  cc.  of  2%  sulphuric 
acid,  transfer  to  a  separatory  funnel  and  shake  out  5  times  with  15  cc. 
portions  of  chloroform. 

Reserve  the  acid  liquid  for  subsequent  tests  for  cocaine  and  glycerine. 
Distil  off  most  of  the  chloroform,  evaporate  in  a  dish  on  a  steam  bath, 
dissolve  the  residue  in  10%  hydrochloric  acid  and  transfer  to  a  small 
flask.  Add  to  the  acid  solution  an  excess  of  iodine  solution  (10  grams 
iodine  and  20  grams  potassium  iodide  in  100  cc.  of  water),  rotate  flask, 
allow  to  settle  over  night,  filter,  and  wash  flask  and  precipitate  twice  with 
the  iodine  solution,  then  transfer  filter  and  precipitate  to  the  flask.  Heat 
gently  with  sufficient  sulphurous  acid  solution  to  dissolve  the  precipitate, 

...  u.  \.  C.  Proc.  1910,  U.  S.  Dept.  of  Agric,  Bur.  of  Chem.,  Bui.  137,  p,  192. 


VEGETABLE  AND    FRUIT   PRODUCTS.  961 

filler  into  a  separatory  funnel,  cool,  add  excess  of  concentrated  ammonium 
hydroxide,  and  shake  out  four  times  with  15  cc.  portions  of  chloroform. 
Filter  the  chloroform  extract  into  a  tiask,  using  a  7  cm.  filter  in  a  small 
funnel  covered  with  a  \vatch-glass,  or  filter  through  cotton  plugged  in 
the  stem  of  the  separatory  funnel.  Decolorize  the  chloroform,  if  neces- 
sary, with  animal  charcoal,  distil  off  most  of  the  chloroform,  then  evapo- 
rate in  a  tared  dish  over  steam,  dry  at  100°  C.  and  weigh. 

Add  an  excess  of  concentrated  ammonium  hydroxide  to  the  sokititm 
from  which  the  caffein  was  extracted,  shake  out  three  times  with  [petroleum 
ether,  boiling  at  40°  to  60°  C,  filter  ether  solution,  divide  into  four  parts, 
evaporate,  and  test  for  cocaine  as  described  in  the  preceding  method. 

Evaporate  the  aqueous  solution  from  the  cocaine  extraction  with 
milk  of  lime  and  proceed  as  in  the  determination  of  glycerine  in  wines 
(p.  703).  The  glycerine  thus  obtained  will  be  only  an  approximation  to 
the  true  amount. 


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964  FOOD  INSPECTION  /1ND  ANALYSIS 

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Carolina.     North  Car.  Exp.  Sta.,  Bui.  165. 


APPENDIX. 


THE  FOOD  AND  DRUGS  ACT,  JUNE  30,  190G,  AS  AMENDED  AUGUST  23,  1912. 

AN  ACT  FOR  PREVENTING  THE  MANUFACTURE,  SALE,  OR  TRANSPORTATION  OF  ADULTERATED 
OR  MISBRANDED  OR  POISONOUS  OR  DELETERIOUS  FOODS,  DRUGS,  MEDICINES,  AND  LIQUORS, 
AND  FOR  REGULATING  TRAFFIC  THEREIN,  AND  FOR  OTHER  PURPOSES. 

Be  it  enacted  by  the  Senate  and  House  of  Representatives  of  the  United  Stales  of  America 
in  Congress  assembled,  That  it  shall  be  unlawful  for  any  person  to  manufacture  within 
any  Territory  or  the  District  of  Columbia  any  article  of  food  or  drug  which  is  adulterated 
or  misbranded,  within  the  meaning  of  this  Act;  and  any  person  who  shall  violate  any 
of  the  provisions  of  this  section  shall  be  guilty  of  a  misdemeanor,  and  for  each  offense  shall, 
upon  conviction  thereof,  be  fined  not  to  exceed  five  hundred  dollars  or  shall  be  sentenced 
to  one  year's  imprisonment,  or  both  such  fine  and  imprisonment,  in  the  discretion  of  the 
court,  and  for  each  subsequent  ofifense  and  conviction  thereof  shall  be  fined  not  less  than 
one  thousand  dollars  or  sentenced  to  one  year's  imprisonment,  or  both  such  fine  and  imprison- 
ment, in  the  discretion  of  the  Court. 

Sec.  2.  That  the  introduction  into  any  State  or  Territory  or  the  District  of  Colum- 
bia from  any  other  State  or  Territory  or  the  District  of  Columbia,  or  from  any  foreign  coun- 
try, or  shipment  to  any  foreign  country  of  any  article  of  food  or  drugs  which  is  adulterated 
or  misbranded,  within  the  meaning  of  this  Act,  is  hereby  prohibited;  and  any  person  who 
shall  ship  or  deliver  for  shipment  from  any  State  or  Territory  or  the  District  of  Columbia 
to  any  other  State  or  Territory  or  the  District  of  Columbia,  or  to  a  foreign  country,  or 
who  shall  receive  in  any  State  or  Territory  or  the  District  of  Columbia  from  any  other 
State  or  Territory  or  the  District  of  Columbia,  or  foreign  country,  and  having  so  received, 
shal'  deliver,  in  original  unbroken  packages,  for  pay  or  otherwise,  or  offer  to  deliver  to 
any  other  person,  any  such  article  so  adulterated  or  misbranded  within  the  meaning  of  this 
Act,  or  any  person  who  shall  sell  or  offer  for  sale  in  the  District  of  Columbia  or  the  Ter- 
ritories of  the  United  States  any  such  adulterated  or  misbranded  foods  or  drugs,  or  export 
or  offer  to  export  the  same  to  any  foreign  country,  shall  be  guilty  of  a  misdemeanor,  and 
for  such  offense  be  fined  not  exceeding  two  hundred  dollars  for  the  first  offense,  and  upon 
conviction  for  each  subsequent  offense  not  exceeding  three  hundred  dollars  or  be  imprisoned 
not  exceeding  one  year,  or  both,  in  the  discretion  of  the  court:  Provided,  That  no  article 
shall  be  deemed  misbranded  or  adulterated  within  the  provisions  of  this  Act  when  intended 
for  export  to  any  foreign  country  and  prepared  or  packed  according  to  the  specifications 
or  directions  of  the  foreign  purchaser  when  no  substance  is  used  in  the  preparation  or  pack- 
ing thereof  in  conflict  with  the  laws  of  the  foreign  country  to  which  said  article  is  intended 
to  be  shipped;  but  if  said  article  shall  be  in  fact  sold  or  offered  for  sale  for  domestic  use 
or  consumption,  then  this  proviso  shall  not  exempt  said  article  from  the  operation  of  any 
of  the  other  provisions  of  this  Act. 

965 


o66  FOOD  INSPECTION  AND   ANALYSIS. 

Sec.  3.  That  the  Secretary  of  the  Treasury,  the  Secretary  of  Af^riculture,  and  the 
Secretary  of  Commerce  and  Labor  shall  make  uniform  rules  and  regulations  for  carrying 
out  the  provisions  of  this  Act,  including  the  collection  and  examination  of  specimens  of 
foods  and  drugs  manufactured  or  offered  for  sale  in  the  District  of  Columbia,  or  in  any 
Territory'  of  the  United  States,  or  which  shall  be  offered  for  sale  in  unbroken  packages  in 
any  State  other  than  that  in  which  they  shall  have  been  respectively  manufactured  or  pro- 
duced, or  which  shall  be  received  from  any  foreign  country, or  intended  for  shipment  to  any 
foreign  country,  or  which  may  be  submitted  for  examination  by  the  chief  health,  food,  or 
drug  officer  of  any  State,  Territory,  or  the  District  of  Columbia,  or  at  any  domestic  or  foreign 
port  through  which  such  product  is  offered  for  interstate  commerce,  or  for  export  or  import 
between  the  United  States  and  any  foreign  port  or  country. 

Sec.  4.  That  the  examinations  of  specimens  of  foods  and  drugs  shall  be  made  in  the 
Bureau  of  Chemistry  of  the  Department  of  Agriculture,  or  under  the  direction  and  super- 
vision of  such  Bureau,  for  the  purpose  of  determining  from  such  examinations  whether 
such  articles  are  adulterated  or  misbranded  within  the  meaning  of  this  Act;  and  if  it  shall 
appear  from  any  such  examination  that  any  of  such  specimens  is  adulterated  or  misbranded 
within  the  meaning  of  this  Act,  the  Secretary  of  Agriculture  shall  cause  notice  thereof  to 
be  given  to  the  party  from  whom  such  sample  was  obtained.  Any  party  so  notified  shall 
be  given  an  opportunity  to  be  heard,  under  such  rules  and  regulations  as  may  be  prescribed 
as  aforesaid,  and  if  it  appears  that  any  of  the  provisions  of  this  Act  have  been  violated 
by  such  party,  then  the  Secretary  of  Agriculture  shall  at  once  certify  the  facts  to  the 
proper  United  States  district  attorney,  with  a  copy  of  the  results  of  the  analysis  or  the 
examination  of  such  article  duly  authenticated  by  the  analyst  or  officer  making  such 
examination,  under  the  oath  of  such  officer.  After  judgment  of  the  court,  notice  shall  be 
given  by  publication  in  such  manner  as  may  be  prescribed  by  the  rules  and  regulations 
aforesaid. 

Sec.  5.  That  it  shall  be  the  duty  of  each  district  attorney  to  whom  the  Secretary  of 
Agriculture  shall  report  any  violation  of  this  Act,  or  to  whom  any  health  or  food  or  drug 
officer  or  agent  of  any  State,  Territory,  or  the  District  of  Columbia  shall  present  satisfactory 
evidence  of  any  such  violation,  to  cause  appropriate  proceedings  to  be  commenced  and 
prosecuted  in  the  proper  courts  of  the  United  States,  without  delay,  for  the  enforcement 
of  the  penalties  as  in  such  case  herein  provided. 

Sec.  6.  That  the  term  "  drug,"  as  used  in  this  Act,  shall  include  all  medicines  and 
preparations  recognized  in  the  United  States  Pharmacopa-ia  or  National  Formulary  for 
internal  or  external  use,  and  any  substance  or  mixture  of  substances  intended  to  be  used 
for  the  cure,  mitigation,  or  prevention  of  disease  of  either  man  or  other  animals.  The 
term  "  fmxl,"  as  used  herein,  shall  include  all  articles  used  for  food,  drink,  confectionery, 
or  condiment  by  man  or  other  animals,  whether  simple,  mixed,  or  comi)ound. 

Sec.  7.  That  for  the  purposes  of  this  Act  an  article  shall  be  deemed  to  be  adulterated: 

In  case  of  drugs: 

First.  If,  when  a  drug  is  sold  under  or  by  a  name  recognized  in  the  United  States  Phar- 
macopccia  or  National  Formulary,  it  differs  from  the  standard  of  strength,  quality,  or 
purity,  as  determined  by  the  test  laid  down  in  the  United  States  Pharmacopoeia  or  National 
Formulary  official  at  the  time  of  investigation:  Provided,  That  no  drug  defined  in  the  United 
States  Pharmacopa-ia  or  National  T'ormulary  shall  be  deemed  to  be  adulterated  under  this 
provision  if  the  standard  of  strength,  quality,  or  purity  be  plainly  stated  upon  the  bottle, 
box,  or  other  container  thereof  although  the  standard  may  differ  from  that  determined  by 
the  test  laid  down  in  the  United  States  Pharmacopoeia  or  National  Formulary. 

Second.  If  its  strength  or  purity  fall  below  the  professed  standard  or  quality  under 
which  it  is  sold. 


APPENDIX.  967 

In  the  case  of  confectionery: 

If  it  contain  terra  alba,  barj'tes,  talc,  chrome  yellow,  or  other  mineral  substance  or 
poisonous  color  or  flavor,  or  other  ingredient  deleterious  or^detrimental  to  health,  or  any 
vinous,  malt,  or  spirituous  liquor  or  compound  or  narcotic  drug. 

In  the  case  of  food: 

First.  If  any  substance  has  been  mixed  and  packed  with  it  so  as  to  reduce  or  lower  or 
injuriously  aflect  its  quality  or  strength. 

Second.  If  any  substance  has  been  substituted  wholly  or  in  part  for  the  article. 

Third.  If  any  valuable  constituent  of  the  article  has  been  wholly  or  in  part  abstracted. 

Fourth.  If  it  be  mixed,  colored,  powdered,  coated,  or  stained  in  a  manner  whereby 
damage  or  inferiority  is  concealed. 

Fifth.  If  it  contain  any  added  posionous  or  other  added  deleterious  ingredient  which 
may  render  such  article  injurious  to  health:  Provided,  That  when  in  the  preparation  of  food 
products  for  shipment  they  are  preserved  by  any  external  application  applied  in  such  manner 
that  the  preservative  is  necessarily  removed  mechanically,  or  by  maceration  in  water,  or 
otherwise,  and  directions  for  the  removal  of  said  preservative  shall  be  printed  on  the  cov- 
ering or  the  package,  the  provisions  of  this  ,\ct  shall  be  construed  as  applying  only  when  said 
products  are  ready  for  consumption. 

Sixth.  If  it  consists  in  whole  or  in  part  of  a  filthy,  decomposed,  or  putrid  animal  or 
vegetable  substance,  or  any  portion  of  an  animal  unfit  for  food,  whether  manufactured  or 
not,  or  if  it  is  the  product  of  a  diseased  animal,  or  one  that  has  died  otherwise  than  by 
slaughter. 

Sec.  8.  That  the  term  "  misbranded,"  as  used  herein,  shall  apply  to  all  drugs,  or  articles 
of  food,  or  articles  which  enter  into  the  composition  of  food,  the  package  or  label  of  which 
shall  bear  any  statement,  design,  or  device  regarding  such  article,  or  the  ingredients  or 
substances  contained  therein  which  shall  be  false  or  misleading  in  any  particular,  and  to 
any  food  or  drug  product  which  is  falsely  branded  as  to  the  State,  Territor}-,  or  country  in 
which  it  is  manufactured  or  produced. 

That  for  the  purposes  of  this  Act  an  article  shall  also  be  deemed  to  be  misbranded: 

In  case  of  drugs: 

First.  If  it  be  an  imitation  of  or  oflered  for  sale  under  the  name  of  another  article. 

Second.  If  the  contents  of  the  package  as  originally  put  up  shall  have  been  removed, 
in  whole  or  in  part,  and  other  contents  shall  have  been  placed  in  such  package,  or  if  the 
package  fail  to  bear  a  statement  on  the  label  of  the  quantity  or  proportion  of  any  alcohol, 
morphine,  opium,  cocaine,  heroin,  alpha  or  beta  eucaine,  chloroform,  cannabis  indica, 
chloral  hydrate,  or  acetanilide,  or  any  derivative  or  preparation  of  any  such  substances 
contained  therein. 

Third.*  If  its  package  or  label  shall  bear  or  contain  any  statement,  design,  or  device 
regarding  the  curative  or  theraupetic  effect  of  such  article  or  any  of  the  ingredients  or  sub- 
stances contained  therein,  which  is  false  and  fraudulent. 

In  the  case  of  food: 

First.  If  it  be  an  imitation  of  or  offered  for  sale  under  the  distinctive  name  of  another 
article. 

Second.  If  it  be  labeled  or  branded  so  as  to  deceive  or  mislead  the  purchaser,  or  pur- 
port to  be  a  foreign  product  when  not  so,  or  if  the  contents  of  the  package  as  originally 
put  up  shall  have  been  removed  in  whole  or  in  part  and  other  contents  shall  have  been 
placed  in  such  package,  or  if  it  fail  to  bear  a  statement  on  the  label  of  the  quantity  or  propor- 
tion of  any  morphine,  opium,  cocaine,  heroin,  alpha  or  beta  eucaine,  chloroform,  cannabis 

*  This  paragraph  constitutes  the  amendment. 


968  FOOD   INSPECTION  AND   ANALYSIS. 

indica.  chloral  hydrate,  or  aoctanilitio,  or  any  derivative  or  preparation  of  any  of  such  sub- 
stances contained  therein. 

Third.  If  in  package  form,  and  the  contents  arc  stated  in  terms  of  weight  or  measure, 
they  are  not  plainly  and  correctly  stated  on  the  outside  of  the  package. 

Fourth.  If  the  package  containing  it  or  its  label  shall  bear  any  .statement,  design,  or 
device  regarding  the  ingredients  or  the  substances  contained  therein,  which  statement, 
design,  or  device  shall  be  false  or  misleading  in  any  particular:  Provided,  That  an  article 
of  food  which  does  not  contain  any  added  poisonous  or  deleterious  ingredients  shall  not 
be  deemed  to  be  adulterated  or  misbrandcd  in  the  following  cases: 

First.  In  the  case  of  mixtures  or  compounds  which  may  be  now  or  from  time  to  time 
hereafter  known  as  articles  of  food,  under  their  own  distinctive  names,  and  not  an  imitation 
of  or  offered  for  sale  under  the  distinctive  name  of  another  article,  if  the  name  be  accom- 
panied on  the  same  label  or  brand  with  a  statement  of  the  place  where  said  article  has  been 
manufactured  or  produced. 

Second.  In  the  case  of  articles  labeled,  branded,  or  tagged  so  as  to  plainly  indicate 
that  they  are  compounds,  imitations,  or  blends,  and  the  word  "  compound,"  "  imitation," 
or  "  blend,"  as  the  case  may  be,  is  plainly  stated  on  the  package  in  which  it  is  offered  for 
sale:  Provided,  That  the  term  blend  as  used  herein  shall  be  construed  to  mean  a  mixture 
of  like  substances,  not  excluding  harmless  coloring  or  flavoring  ingredients  used  for  the  pur- 
pose of  coloring  and  flavoring  only:  And  provided  further.  That  nothing  in  this  Act  shall 
be  construed  as  requiring  or  compelling  proprietors  or  manufacturers  of  proprietary  foods 
which  contain  no  unwholesome  added  ingredient  to  disclose  their  trade  formulas,  except 
in  so  far  as  the  provisions  of  this  Act  may  require  to  secure  freedom  from  adulteration  or 
misbranding. 

Sec.  9.  That  no  dealer  shall  be  prosecuted  under  the  provisions  of  this  Act  when  he 
can  establish  a  guaranty  signed  by  the  wholesaler,  jobber,  manufacturer,  or  other  party 
residing  in  the  United  States,  from  whom  he  purchases  such  articles,  to  the  effect  that 
the  same  is  not  adulterated  or  misbranded  within  the  meaning  of  this  Act,  designating  it. 
Said  guaranty,  to  afford  protection,  shall  contain  the  name  and  address  of  the  party  or 
parties  making  the  sale  of  such  articles  to  such  dealer,  and  in  such  case  said  party  or  parties 
shall  be  amenable  to  the  prosecutions,  fmes,  and  other  penalties  which  would  attach,  in 
due  course,  to  the  dealer  under  the  provisions  of  this  Act. 

Sec.  10.  That  any  article  of  food,  drug,  or  liquor  that  is  adulterated  or  misbranded 
within  the  meaning  of  this  Act.  and  is  being  transported  from  one  State,  Territory.  District, 
or  insular  possession  to  another  for  sale,  or,  having  been  transported,  remains  unloaded, 
unsold,  or  in  original  unbroken  packages,  or  if  it  be  sold  or  offered  for  sale  in  the  District 
of  Columbia  or  the  Territories,  or  insular  possessions  of  the  United  States,  or  if  it  be  imported 
from  a  foreign  country  for  sale,  or  if  it  is  intended  for  ex])ort  to  a  foreign  country,  shall  be 
liable  to  be  proceeded  against  in  any  district  court  of  the  United  States  within  the  district 
where  the  same  is  found,  and  seized  for  confiscation  by  a  process  of  libel  for  condemnation. 
And  if  such  article  is  condemned  as  being  adulterated  or  misbranded,  or  of  a  poisonous  or 
deleterious  character,  within  the  meaning  of  this  Act,  the  same  shall  be  disposed  of  by  destruc- 
tion or  sale,  as  the  said  court  may  direct,  and  the  proceeds  thereof,  if  sold,  less  the  legal 
costs  and  charges,  shall  be  paid  into  the  Treasury  of  the  United  States,  but  such  goods 
shall  not  be  sold  in  any  jurisdiction  contrary  to  the  provisions  of  this  Act  or  the  laws  of 
that  jurisdiction:  Provided  however,  That  upon  the  payment  of  the  costs  of  such  libel  pro- 
ceedings and  the  execution  and  delivery  of  a  good  and  sufficient  bond  to  the  effect  that  such 
articles  shall  not  be  srjid  or  otherwise  disposed  of  contrary  to  the  provisions  of  this  Act, 
or  the  laws  of  any  State,  Territory,  District,  or  insular  po.ssession,  the  court  may  by  order 
direct  that  such  articles  be  delivered  to  the  owner  thereof.     The  proceedings  of  such  libel 


APPENDIX.  969 

cases  shall  conform,  as  near  as  may  he,  to  the  proceedings  in  admiralty,  except  that  either 
party  may  demand  trial  by  jury  of  any  issue  of  fact  joined  in  any  such  case,  and  all  such 
proceedings  shall  be  at  the  suit  of  and  in  the  name  of  the  United  States. 

Sec.  II.  The  Secretary  of  the  Treasury  shall  deliver  to  the  Secretary  of  Agriculture, 
upon  his  request  from  time  to  time,  samples  of  foods  and  drugs  which  are  being  imported 
into  the  United  States  or  ofTered  for  import,  giving  notice  thereof  to  the  owner  or  consignee, 
who  may  appear  before  the  Secretary  of  Agriculture,  and  have  the  right  to  introduce 
testimony,  and  if  it  appear  from  the  examination  of  such  samples  that  any  article  of  food 
or  drug  ofTcred  to  be  imported  into  the  United  States  is  adulterated  or  misbranded  within 
the  meaning  of  this  Act,  or  is  otherwise  dangerous  to  the  health  of  the  people  of  the  United 
States,  or  is  of  a  kind  forbidden  entry  into,  or  forbidden  to  be  sold  or  restricted  in  sale 
in  the  country  in  which  it  is  made  or  from  which  it  is  exported,  or  is  otherwise  falsely  labeled 
in  any  respect,  the  said  article  shall  be  refused  admission,  and  the  Secretary  of  the  Treasury 
shall  refuse  delivery  to  the  consignee  and  shall  cause  the  destruction  of  any  goods  refused 
delivery  which  shall  not  be  exported  by  the  consignee  within  three  months  from  the  date 
of  notice  of  such  refusal  under  such  regulations  as  the  Secretary  of  the  Treasury  may  pre- 
scribe: Provided,  That  the  Secretary  of  the  Treasurv  may  deliver  to  the  consignee  such 
goods  pending  examination  and  decision  in  the  matter  on  execution  of  a  penal  bond  for  the 
amount  of  the  full  invoice  value  of  such  goods,  together  with  the  duty  thereon,  and  on  refusal 
to  return  such  goods  for  any  cause  to  the  custody  of  the  Secretary  of  the  Treasury,  when 
demanded,  for  the  purpose  of  excluding  them  from  the  country,  or  for  any  other  purpose, 
said  consignee  shall  forfeit  the  full  amount  of  the  bond:  And  provided  further,  That  all 
charges  for  storage,  cartage,  and  labor  on  goods  which  are  refused  admission  or  delivery 
shall  be  paid  by  the  owner  or  consignee,  and  in  default  of  such  payment  shall  constitute  a 
lien  against  any  future  importation  made  by  such  owner  or  consignee. 

Sec.  12.  That  the  term  "  Territory  "  as  used  in  this  Act  shall  include  the  insular  pos- 
sessions of  the  United  States.  The  word  "  person  "  as  used  in  this  Act  shall  be  construed 
to  import  both  the  plural  and  the  singular,  as  the  case  demands,  and  shall  include  corpora- 
tions, companies,  societies  and  associations.  When  construing  and  enforcing  the  [)rovisions 
of  this  Act,  the  act,  omission,  or  failure  of  any  officer,  agent,  or  other  person  acting  for  or 
employed  by  any  corporation,  company,  society,  or  association,  within  the  scope  of  his 
employment  or  office,  shall  in  every  case  be  also  deemed  to  be  the  act,  omission,  or  failure 
of  such  corporation,  company,  society,  or  association  as  well  as  that  of  the  person. 

Sec.  13.  That  this  Act  shall  be  in  force  and  effect  from  and  after  the  first  day  of  January, 
nineteen  hundred  and  seven. 


THE  MEAT-INSPECTION  LAW. 

Extract  from  an  act  of  Congress  entitled  "  An  act  making  appropriations  for  the 
Department  of  Agriculture  for  the  fiscal  year  ending  June  thirtieth,  nine- 
teen HUNDRED  AND  SEVEN,"  APPROVED  JUNE  30,  1906. 

That  for  the  purpose  of  preventing  the  use  in  interstate  or  foreign  commerce,  as  herein- 
after provided,  of  meat  and  meat  food  products  which  are  unsound,  unhealthful.  unwhole- 
some, or  otherwise  unfit  for  human  food,  the  Secretary  of  .Agriculture,  at  his  discretion, 
may  cause  to  be  made,  by  inspectors  appointed  for  that  purpose,  an  examination  and 
inspection  of  all  cattle,  sheep,  swine,  and  goats  before  they  shall  be  allowed  to  enter  into 
any  slaughtering,  packing,  meat-canning,  rendering,  or  similar  establishment,  in  which  they 
are  to  be  slaughtered  and  the  meat  and  meat  food  products  thereof  are  to  be  used  in  inter- 
state or  foreign  commerce;  and  all  cattle,  swine,  sheep,  and  goats  found  on  such  inspection  to 


970  FOOD  INSPECTION  AND  /IN A  LYSIS. 

show  svTnptoms  of  disease  shall  be  set  apart  and  slaughtered  separately  from  all  other  cattle, 
sheep,  swine,  or  goats,  and  when  so  slaughtered  the  carcasses  of  said  cattle,  sheep,  swine, 
or  goats  shall  be  subject  to  a  careful  examination  and  inspection,  all  as  provided  by  the 
rules  and  regulations  to  be  prescribed  by  the  Secretary  of  .Agriculture  as  herein  provided  for. 

That  for  the  purposes  hereinbefore  set  forth  the  Secretary  of  Agriculture  shall  cause 
to  be  made  by  insp>ectors  appointed  for  that  purpose,  as  hereinafter  provided,  a  post-mortem 
examination  and  inspection  of  the  carcasses  and  parts  thereof  of  all  cattle,  sheep,  swine, 
and  goats  to  be  prepared  for  human  consumption  at  any  slaughtering,  meat-canning,  salt- 
ing, packing,  rendering,  or  similar  establishment  in  any  State,  Territory,  or  the  District 
of  Columbia  for  transportation  or  sale  as  articles  of  interstate  or  foreign  commerce,  and 
the  carcasses  and  parts  thereof  of  all  such  animals  found  to  be  sound,  healthful,  wholesome, 
and  fit  for  human  food  shall  be  marked,  stamped,  tagged,  or  labeled  as  "  Inspected  and 
Passed;"  and  said  inspectors  shall  label,  mark,  stamp,  or  tag  as  "  Inspected  and  Con- 
demned," all  carcasses  and  parts  thereof  of  animals  found  to  be  unsound,  unhealthful, 
im wholesome,  or  otherwise  unfit  for  human  food;  and  all  carcasses  and  parts  thereof  thus 
inspected  and  condemned  shall  be  destroyed  for  food  purposes  by  the  said  establishment 
in  the  presence  of  an  inspector,  and  the  Secretary  of  Agriculture  may  remove  inspectors 
from  any  such  establishment  which  fails  to  so  destroy  anj'  such  condemned  carcass  or  part 
thereof,  and  said  inspectors,  after  said  first  inspection  shall,  when  thej^  deem  it  necessary, 
reinsf>ect  said  carcasses  or  parts  thereof  to  determine  whether  since  the  first  inspection  the 
same  have  become  unsound,  unhealthful,  unwholesome,  or  in  anj'  way  unfit  for  human 
food,  and  if  any  carcass  or  any  part  thereof  shall,  upon  examination  and  inspection  subse- 
quent to  the  first  examination  and  inspection,  be  found  to  be  unsound,  unhealthful,  unwhole- 
some, or  otherwise  ujifit  for  human  food,  it  shall  be  destroyed  for  food  purposes  by  the 
said  establishment  in  the  presence  of  an  inspector,  and  the  Secretary  of  Agriculture  may 
remove  inspectors  fr'^m  any  establishment  which  fails  to  so  destroy  any  such  condemned 
carcass  or  part  thereof. 

The  foregoing  provisions  shall  apply  to  all  carcasses  or  parts  of  carcasses  of  cattle, 
sheep,  swine,  and  goats,  or  the  meat  or  meat  products  thereof  which  may  be  brought  into 
any  slaughtering,  meat-canning,  salting,  packing,  rendering,  or  similar  establishment,  and 
such  examination  and  inspection  shall  be  had  before  the  said  carcasses  or  parts  thereof 
shall  be  allowed  to  enter  into  any  department  wherein  the  same  are  to  be  treated  and  pre- 
pared for  meat  food  products;  and  the  foregoing  provisions  shall  also  apply  to  all  such 
products  which,  after  having  been  issued  from  any  slaughtering,  meat-canning,  salting, 
[jacking,  rendering,  or  similar  establishment,  shall  be  returned  to  the  same  or  to  any  similar 
establishment  where  such  inspection  is  maintained. 

That  for  the  purposes  hereinbefore  set  forth  the  Secretar>'  of  Agriculture  shall  cause 
to  be  made  by  inspectors  appointed  for  that  purpose  an  examination  and  inspection  of 
all  meat  food  products  prepared  for  interstate  or  foreign  commerce  in  any  slaughtering, 
meat-canning,  salting,  packing,  rendering,  or  similar  establishment,  and  for  the  purjjoses 
of  any  examination  and  inspection  said  inspectors  shall  have  access  at  all  times,  by  day 
or  night,  whether  the  establishment  be  operated  or  not,  to  every  part  of  said  establishment; 
and  said  inspectors  shall  mark,  stamp,  tag,  or  label  as  "  Inspected  and  Passed  "  all  such 
prfxiucts  found  to  be  sound,  healthful,  and  wholesome,  and  which  contain  no  dyes,  chemicals, 
preservatives,  or  ingredients  which  render  such  meat  or  meat  food  products  unsound, 
unhealthful.  unwholesome,  or  unfit  for  human  food;  and  said  inspectors  shall  label,  mark, 
stamp,  or  tag  as  "  Inspected  and  Condemned  "  all  such  products  found  unsound,  unhealth- 
ful. and  unwholesome,  or  which  contain  dyes,  chemicals,  preservatives,  or  ingredients  which 
render  such  meat  or  meat  fr>od  products  unsound,  unhealthful,  unwholesome,  or  unfit  for 
human  food,  and  all  such  condemned  meat  food  products  shall  be  destroyed  for  food  pur- 


yIPPENDlX.  971 

poses,  as  hereinbefore  provirlcd,  and  the  Secretary  of  Ap;riculture  may  remove  inspectors 
from  any  establishment  which  fails  to  so  destroy  such  condemned  meat  food  products: 
Provided,  That,  subject  to  the  rules  and  regulations  of  the  Secretary  of  Agriculture,  the  pro- 
visions hereof  in  regard  to  preservatives  shall  not  apply  to  meat  food  products  for  export 
to  any  foreign  country  and  which  are  prepared  or  packed  according  to  the  specifications  or 
directions  of  the  foreign  purchaser,  when  no  substance  is  used  in  the  preparation  or  packing 
thereof  in  conflict  with  the  laws  of  the  foreign  country  to  which  said  article  is  to  be  exported; 
but  if  said  article  siiail  be  in  fact  sold  or  offered  for  sale  for  domestic  use  or  consumption, 
then  this  proviso  shall  not  exempt  said  arlit  le  from  the  o{)eralion  of  all  the  other  provisions 
of  this  act. 

That  when  any  meat  or  meat  food  product  prepared  for  interstate  or  foreign  com- 
mjrcj  which  has  boen  inspsctcd  as  hereinbefore  provided  and  marked  "  Inspected  and 
Parsed  "  shall  be  placed  or  packed  in  any  can,  pot,  tin,  canvas,  or  other  receptacle  or  cover- 
ing in  any  e.jtablishm2nt  where  inspection  under  the  provisions  of  this  act  is  maintained, 
the  person,  firm,  or  corporation  preparing  said  product  shall  cause  a  label  to  be  attached 
to  said  can,  pot,  tin,  canvas,  or  other  receptacle  or  covering,  under  the  supervision  of  an 
inspector,  which  labd  shall  state  that  the  contents  thereof  have  been  "Inspected  and 
Passed  "  under  the  provisions  of  this  act;  and  no  inspection  and  examination  of  meat  or 
meat  food  products  deposited  or  inclosed  in  cans,  tins,  pots,  canvas,  or  other  receptacle  or 
covering  in  any  establishment  where  inspection  under  the  provisions  of  this  act  is  maintained 
shall  be  deemed  to  be  complete  until  such  meat  or  meat  food  products  have  been  sealed  or 
inclosed  in  said  can,  tin,  pot,  canvas,  or  other  receptacle  or  covering  under  the  supervision  of 
an  inspector,  and  no  such  meat  or  meat  food  products  shall  be  sold  or  offered  for  sale  by 
any  person,  firm,  or  corporation  in  interstate  or  foreign  commerce  under  any  false  or  deceptive 
name;  but  established  trade  name  or  names  which  are  usual  to  such  products  and  which 
are  not  false  and  deceptive  and  which  shall  be  approved  by  the  Secretary  of  Agriculture  are 
permitted. 

The  Secretary  of  .Vgriculture  shall  cause  to  be  made,  b}'  experts  in  sanitation  or  by  other 
competent  inspectors,  such  inspection  of  all  slaughtering,  meat-canning,  salting,  packing, 
rendering,  or  similar  establishments  in  which  cattle,  sheej),  swine,  and  goats  are  slaughtered 
and  the  meat  and  meat  food  products  thereof  are  prepared  for  interstate  or  foreign  commerce 
as  may  be  necessary  to  inform  himself  concerning  the  sanitarj'  conditions  of  the  same,  and  to 
prescribe  the  rules  and  regulations  of  sanitation  under  which  such  establishments  shall  be 
maintained;  and  where  the  sanitary  conditions  of  any  such  establishment  are  such  that 
the  meat  or  meat  food  products  are  rendered  unclean,  unsound,  unhealthful,  unwholesome, 
or  otherwise  unfit  for  human  food,  he  shall  refuse  to  allow  said  meat  or  meat  food  pioducts 
to  be  labeled,  marked,  stamped,  or  tagged  as  "  Inspected  and  Passed." 

That  the  Secretary  of  .Agriculture  shall  cause  an  examination  and  inspection  of  all  cattle, 
sheep,  swine,  and  goats,  and  the  food  products  thereof,  slaughtered  and  prepared  in  the 
establishments  hereinbefore  described  for  the  purposes  of  interstate  or  foreign  commerce 
to  be  made  during  the  nighttime  as  well  as  during  the  daytime  when  the  slaughtering  of  said 
cattle,  sheep,  swine,  and  goats,  or  the  preparation  of  said  food  products  is  conducted  during 
the  nighttime. 

That  on  and  after  October  first,  nineteen  hundred  and  six,  no  person,  firm,  or  corpora- 
tion shall  transport  or  offer  for  transportation,  and  no  carrier  of  interstate  or  foreign  commerce 
shall  transport  or  receive  for  transportation  from  one  State  or  Territory  or  the  District  of 
Columbia  to  anj-  other  State  or  Territory-  or  the  District  of  Columbia,  or  to  any  place  under 
the  jurisdiction  of  the  United  States,  or  to  any  foreign  country,  any  carcasses  or  parts  thereof, 
meat,  or  meat  food  products  thereof  which  have  not  been  inspected,  e.xamined,  and  marked 
as  "  Inspected  and  Passed,"  in  accordance  with  the  terms  of  this  act  and  with  the  rules  and 


972  FOOD  INSPECTION  AND   ANALYSIS. 

regulations  prescribed  by  the  Secretary  of  Agriculture:  Provided,  That  all  meat  and  meat 
food  products  on  hand  on  October  first,  nineteen  hundred  and  six,  at  establishments  where 
inspection  has  not  been  maintained,  or  which  have  been  inspected  under  existing  law,  shall 
be  examined  and  labeled  under  such  rules  and  regulations  as  the  Secretary  of  Agriculture 
shall  prescribe,  and  then  shall  be  allowed  to  be  sold  in  interstate  or  foreign  commerce. 

That  no  person,  firm,  or  corporation,  or  officer,  agent,  or  employee  thereof,  shall  forge, 
counterfeit,  simulate,  or  falsely  represent,  or  shall  without  proper  authority  use,  fail  to  use, 
or  detach,  or  shall  knowingly  or  wrongfully  alter,  deface,  or  destroy,  or  fail  to  deface  or 
destroy,  any  of  the  marks,  stamps,  tags,  labels,  or  other  identification  devices  provided  for 
in  this  act.  or  in  and  as  directed  by  the  rules  and  regulations  prescribed  hereunder  by  the 
SccretaPt'  of  Agriculture,  on  any  carcasses,  parts  of  carcasses,  or  the  food  product,  or  containers 
thereof,  subject  to  the  provisions  of  this  act,  or  any  certificate  in  relation  thereto,  authorized 
or  recjuired  by  this  act  or  by  the  said  rules  and  regulations  of  the  Secretary  of  Agriculture. 

That  the  Secretary  of  Agriculture  shall  cause  to  be  made  a  careful  inspection  of  all 
cattle,  sheep,  swine,  and  goats  intended  and  offered  for  export  to  foreign  countries  at 
such  times  and  places,  and  in  such  manner  as  he  may  deem  proper,  to  ascertain  whether 
such  cattle,  sheep,  swine,  and  goats  are  free  from  disease. 

And  for  this  purpose  he  may  appoint  inspectors  who  shall  be  authorized  to  give  an 
official  certificate  clearly  stating  the  condition  in  which  such  cattle,  sheep,  swine,  and  goats 
are  found. 

And  no  clearance  shall  be  given  to  any  vessel  having  on  board  cattle,  sheep,  swine,  or 
goats  for  export  to  a  foreign  country  until  the  owner  or  shipper  of  such  cattle,  sheep,  swine, 
or  goats  has  a  certificate  from  the  inspector  herein  authorized  to  be  appointed,  stating  that 
the  said  cattle,  sheep,  swine,  or  goats  are  sound  and  healthy,  or  unless  the  Secretary  of 
Agriculture  shall  have  waived  the  requirement  of  such  certificate  for  export  to  the  particular 
country  to  which  such  cattle,  sheep,  swine,  or  goats  are  to  be  exported. 

That  the  Secretary  of  Agriculture  shall  also  cause  to  be  made  a  careful  inspection  of  the 
carca.sses  and  parts  thereof  of  all  cattle,  sheep,  swine,  and  goats,  the  meat  of  which,  fresh, 
salted,  canned,  corned,  packed,  cured,  or  otherwise  prepared,  is  intended  and  offered  for 
export  to  any  foreign  countrj^  at  such  times  and  places  and  in  such  manner  as  he  may  deem 
proper. 

.\nd  for  this  purpose  he  may  appoint  inspectors  who  shall  be  authorized  to  give  an  official 
certificate  stating  the  condition  in  which  said  cattle,  sheep,  swine,  or  goats,  and  the  meat 
thereof,  are  found. 

And  no  clearance  shall  be  given  to  any  vessel  having  on  board  any  fresh,  salted,  canned, 
corned,  or  packed  beef,  mutton,  pork,  or  goat  meat,  being  the  meat  of  animals  killed  after 
the  pa.ssage  of  this  act,  or  except  as  hereinbefore  provided  for  export  to  and  sale  in  a  foreign 
rountry  from  any  port  in  the  United  States,  until  the  owner  or  shii)pcr  thereof  shall  obtain 
from  an  inspector  appointed  under  the  provisions  oi  this  act  a  certificate  that  the  said  cattle, 
sheep,  swine,  and  goats  were  sound  and  healthy  at  the  time  of  inspection,  and  that  their 
meat  is  sound  and  wholesome,  unless  the  Secretary  of  .\griculture  shall  have  waived  the 
requirements  of  such  certificate  for  the  country  to  which  said  cattle,  sheep,  swine  and  goats  or 
meals  are  to  be  exported. 

That  the  inspectors  provided  for  herein  shall  be  authorized  to  give  official  certificates 
of  the  s^jund  and  wholesf>me  condition  of  the  cattle,  sheep,  swine,  and  goats,  their  carcasses 
and  products  as  herein  described,  and  one  copy  of  every  certificate  granted  under  the  pro- 
visions of  this  act  shall  be  filed  in  the  Department  of  Agriculture,  another  copy  shall  be 
delivered  to  the  owner  or  shipper,  and  when  the  cattle,  sheep,  swine,  and  goats  or  their 
carcasses  and  products  are  sent  abroad,  a  third  copy  shall  be  delivered  to  the  chief  ofl&cer 
of  the  vessel  on  which  the  shipment  shall    be  made. 


APPENDIX.  97J 

That  no  person,  firm,  or  corporation  engaged  in  the  interstate  commerce  of  meat  or  meat 
food  products  shall  transport  or  offer  for  transportation,  sell  or  offer  to  sell  any  such  meat 
or  meat  food  products  in  any  State  or  Territory  or  in  the  District  of  Columbia  or  any  place 
under  the  jurisdiction  of  the  United  States,  other  than  in  the  State  or  Territory  or  in  the 
District  of  Columbia  or  any  place  under  the  jurisdiction  of  the  United  States  in  which  the 
slaughtering,  packing,  canning,  rendering,  or  other  similar  establishment  owned,  leased, 
operated  by  said  firm,  person,  or  corporation  is  located  unless  and  until  said  person,  firm> 
or  corporation  shall  have  complied  with  all  of  the  provisions  of  this  act. 

That  any  person,  firm,  or  corporation,  or  any  officer  or  agent  of  any  such  person,  firm, 
or  corporation,  who  shall  violate  any  of  the  provisions  of  this  act  shall  be  deemed  guilty 
of  a  misdemeanor,  and  shall  be  punished  on  conviction  thereof  by  a  fine  of  not  exceeding 
ten  thousand  dollars  or  imprisonment  for  a  period  not  more  than  two  years,  or  by  both 
such  fine  and  imprisonment,  in  the  discretion  of  the  court. 

That  the  Secretary  of  Agriculture  shall  appoint  from  time  to  time  inspectors  to  make 
examination  and  inspection  of  all  cattle,  sheep,  swine,  and  goats,  the  inspection  of  which  is 
hereby  provided  for.  and  of  all  carcasses  and  parts  thereof,  and  of  all  meats  and  meat  food 
products  thereof,  and  of  the  sanitary  conditions  of  all  establishments  in  which  such  meat 
and  meat  food  products  hereinbefore  described  are  prepared;  and  said  inspectors  shall 
refuse  to  stamp,  mark,  tag,  or  label  any  carcass  or  any  part  thereof,  or  meat  food  product 
therefrom,  prepared  in  any  establishment  hereinbefore  mentioned,  until  the  same  shall 
have  actually  been  inspected  and  found  to  be  sound,  healthful,  wholesome,  and  fit  for  human 
food,  and  to  contain  no  dyes,  chemicals,  preservatives,  or  ingredients  which  render  such 
meat  food  product  unsound,  unhealthful,  unwholesome,  or  unfit  for  human  food;  and  to 
have  been  prepared  under  proper  sanitary  conditions,  hereinbefore  provided  for;  and  shall 
perform  such  other  duties  as  are  provided  by  this  act  and  by  the  rules  and  regulations  to  be 
prescribed  by  said  Secretary  of  Agriculture;  and  said  Secretary  of  Agriculture  shall,  from 
time  to  time,  make  such  rules  and  regulations  as  are  necessary  for  the  efficient  execution  of 
the  provisions  of  this  act,  and  all  inspections  and  examinations  made  under  this  act  shall 
be  such  and  made  in  such  manner  as  described  in  the  rules  and  regulations  prescribed  by 
said  Secretary  of  Agriculture  not  inconsistent  with  the  provisions  of  this  act. 

That  any  person,  firm,  or  corporation,  or  anj'  agent  or  ernployee  of  any  person,  firm, 
or  corporation,  who  shall  give,  pay,  or  offer,  directly  or  indirectly,  to  any  inspector,  deputy 
inspector,  chief  inspector,  or  any  other  officer  or  employee  of  the  United  States  authorized 
to  perform  any  of  the  duties  prescribed  by  this  act  or  by  the  rules  and  regulations  of  the 
Secretary  of  Agriculture  any  money  or  other  thing  of  value,  with  intent  to  influence  said 
inspector,  deputy  inspector,  chief  inspector,  or  other  officer  or  employee  of  the  United  States 
in  the  discharge  of  any  duty  herein  provided  for,  shall  be  deemed  guilty  of  a  felony  and,  upon 
con\action  thereof,  shall  be  punished  by  a  fine  not  less  than  five  thousand  dollars  nor  more 
than  ten  thousand  dollars  and  by  imprisonment  not  less  than  one  year  nor  more  than  three 
years;  and  any  inspector,  deputy  inspector,  chief  inspector,  or  other  ofiicer  or  employee  of 
the  United  States  authorized  to  perform  anj-  of  the  duties  prescribed  by  this  act  who  shall 
accept  any  money,  gift,  or  other  thing  of  value  from  any  person,  firm,  or  corporation,  or 
officers,  agents,  or  employees  thereof,  given  with  intent  to  influence  his  oflicial  action,  or  who 
shall  receive  or  accept  from  any  person,  firm,  or  corporation  engaged  in  interstate  or  foreign 
commerce  any  gift,  monej',  or  other  thing  of  value  given  with  any  purpose  or  intent  what- 
soever, shall  be  deemed  guilty  of  a  felony  and  shall,  upon  conviction  thereof,  be  summarily 
discharged  from  office  and  shall  be  punished  by  a  fine  not  less  than  one  thousand  dollars  nor 
more  than  ten  thousand  dollars  and  by  imprisonment  not  less  than  one  year  nor  more  than 
three  years. 

That  the  provisions  of  this  act  requiring  inspection  to  be  made  by  the  Secretary  of 


974  FOOD  IXSPECnON  ^ND    ANALYSIS. 

Agriculture  shall  not  apply  to  animals  slaughtered  by  any  farmer  on  the  farm  and  sold  and 
transported  as  interstate  or  foreign  commerce,  nor  to  retail  butchers  and  retail  dealers  in 
meat  and  meat  food  proilucts,  supplying  their  customers:  Provided,  That  if  any  person  shall 
sell  or  offer  for  side  or  transportation  for  interstate  or  foreign  commerce  any  meat  or  meat 
food  products  which  are  diseased,  unsound,  unhealthful,  unwholesome,  or  otherwise  unfit 
for  human  food,  knowing  that  such  meat  food  products  are  intended  for  human  consump- 
tion, he  shall  be  guilty  of  a  misdemeanor,  and  on  conviction  thereof  shall  be  punished  by  a 
fine  not  exceeding  one  thousand  dollars  or  by  imprisonment  for  a  period  of  not  exceeding 
one  year,  or  by  both  such  tine  and  imprisonment:  Provided  also,  That  the  Secretary  of  Agri- 
culture is  authorized  to  maintain  the  inspection  in  this  act  provided  for  at  any  slaughtering, 
meat  canning,  salting,  packing,  rendering,  or  similar  establishment  notwithstanding  this 
exception,  and  that  the  persons  operating  the  same  may  be  retail  butchers  and  retail  dealers 
or  farmers;  and  where  the  Secretary  of  Agriculture  shall  establish  such  inspection  then 
the  provisions  of  this  act  shall  apply  notwithstanding  this  exception. 

That  there  is  permanently  appropriated,  out  of  any  money  in  the  Treasury  not  other- 
wise appropriated,  the  sum  of  three  million  dollars,  for  the  expenses  of  the  inspection  of 
cattle,  sheep,  swine,  and  goats  and  the  meat  and  meat  food  products  thereof  which  enter 
into  interstate  or  foreign  commerce  and  for  all  expenses  necessary  to  carry  into  effect  the 
provisions  of  this  act  relating  to  meat  inspection,  including  rent  and  the  emploj^ment  of  labor 
in  Washington  and  elsewhere,  for  each  year.  And  the  Secretary  of  Agriculture  shall,  in  his 
annual  estimates  made  to  Congress,  submit  a  statement  in  detail,  showing  the  number  of 
persons  employed  in  such  inspections  and  the  salary  or  per  diem  paid  to  each,  together  with 
the  contingent  expenses  of  such  inspectors  and  where  they  have  been  and  are  employed. 


INDEX 


Abb^  refractometer,  loo,  io8 
construction,  log 
influence  of  temperature,  no 
manipulation,  109 
Abrastol,  837 
Absinthe,  754 
Acetanilide  in  vanilla  extract,  858 

tests  for,  859 
Acetyl  value,  497 
Achroodextrine,  575 
Acid  fuchsin,  799 
brown,  810 
green,  794 
magenta,  816,  817 
yellow,  794,  818 
Acids,  fatty,  481,  484,  499,  500 
of  acetic  series,  471 
of  linoleic  series,  472 
of  oleic  series,  472 
mineral,  in  vinegar,  767 
organic,  47,  941,  949 
Ackermann     and     Steinmann's     table     for 

alcohol  from  refraction,  715 
Ackermann's  table  for  extract  from  refrac- 
tion, 721 
Adams'  fat  methM,  134 
"  Aerated  "  butter,  540 
Agar  agar,  in  jelly,  934,  943 
Aging  of  liquors,  731,  732 
Albumin,  acid,  44 
alkali,  44 

determination  in  milk,  146 
of  muscle,  211 
preparation  of,  263 
Albuminoids,.  42 
Albumins,  41,  297 
Albumose,  44,  45 
Alcohol,  detection,  657 

determination,  658 

by  distillation,  658 

by  ebulioscope,  675 

by  evaporation,  660 

from  refraction,  715 

from  specific  gravity,  658,  659 


Alcohol,  extract  of  spices,  470 
in  malt  liquors,  715 
methyl-,  749,  878 
preparation  of,  730 
stills,  659 
tables,  661-674 
Alcoholic  beverages,  653,   654.     See  also 
Liquors, 
references  on,  756 
state  control  of,  654 
toxic  effect  of,  655 
fermentation,  653 
Aldehydes,  determination,  745 
Ale,  709,  712.     See  also  Beer. 

ginger,  954 
Aleurone,  90 
Alizarin,  804 

Alkaloidal  nitrogen,  40,  46 
Alkaloids,  proof  of  absence  of,  726 
Alkanna  tincture,  92 
Allantoin,  299 

Allen-Marquardt  method  for  fusel  oil,  747 
Allihn's  sugar  method,  608 

tables,  609 
Allspice,  420 

adulteration,  424 
composition  of,  420 
microscopical  structure,  422 
standard,  424 
tannin  in,  421 
Almond  extract,  884 

adulteration  of,  886 
alcohol  in,  888 
benzaldehyde  in.  886,  888 
hydrocyanic   acid   in,   888, 

889 
nitro  benzol  in,  887,  888 
standards,  885 
meal,  358 
Almonds,  bitter,  oil  of,  884,  885 
Alum  in  baking  powder,  2^^,  344 
in  bread,  326 
in  flour,  315 
in  pickles,  926 

Q75 


976 


INDEX. 


Alumina,  determination  of.  344 
Aluminum  salts  in  baking  powder.  344 

in  cream  of  tartar,  344 
Amagat  and  Jean's  rcfractometer,  loo 
Amaranth.  704.  806,  815.  816,  817 
Amides.  45 

in  milk.  147 
Aniido  nitrogen  determination,  74,  147 

in  wheat.  209 
Amino  acids,  40,  45 
Ammonia,  determination.  74 

in  baking  powder,  346 
in  foods.  40.  4O 
in  milk.  147 
Ammonium  fluoride.  835 
Amthor  test  for  caramel,  752 
Amylodexlrin,  575 
.Amyloid,  qi.  92 
Analyst,  functions  of,  3,  4 
Angostura.  754 
Anilin  orange,  808 

in  milk,  177 
Animal  diastase,  284 
Anise  extract,  standards,  892 

oil.  standards,  892 
Annatto  in  butter,  536,  537 
in  milk,  175,  177 
tests  for,  791,  810 
Antiseptics,  see  Preservatives. 
Apparatus,  20 
Apple  butter,  927 

essence,  imitation,  896,  897 
juice,  680 

pulp,  detection,  943 
Apples,  composition  of,  274,  275 
Araban,  285,  288 
Arabinose.  285.  288 
Arata's  color  test,  796 
Army  rations,  257 

Arsenic  detection  and  determination,  74 
compounds  in  colors,  785 
in  baking  chemicals,  346 
in  beer,  713,  728 
in  confectionery,  649 
in  glucose,  633 
in  vinegar.  780 

Johnson-Chittendcn-Gauticr     meth- 
od, 74 
Marsh  apparatus,  75 
.Sanger-BIack-Gutzcit  test  for,  76 
Arli6cial  colors,  782 

fruit  essences,  895,  897 
sweeteners.  850 

references  on,  855 
Asaprol,  845 
Asbestos  fiber,  preparation  of,  594,  598 


Ash  analysis,  scheme  for,  301 

determination  of,  62 

of  food,  47 
Asparagin,  45,  299 
Auramin,  784,  803 
Aurantia,  801 
Aurin,  804 

Azo  blue,  801,  812,  816 
Azoacidrubine,  794 

Babcock  asbestos  milk  fat  method,  135 

milk  solids  method,  134 
centrifugal  fat  method,  136 
milk  formuhe,  153 
test  bottles.  138 
Bacon  formic  acid  method.  841,  843 
Bacon  and  Dunbar  citric  acid  method,  923 
lactic  acid  method,  923 
Baier  and  Neuman's  test  for  sucrose  in  milk. 

197 
Baker  tin  method,  917 
Baking  powders,  t,j,2 

adulteration  of,  334 
alum,  m,  334 
methods  of  analysis,  336 
phosphate,  334 
tartrate,  332 
Balances,  20 

Bamihl  test  for  gluten.  322 
Banana  essence,  artificial,  896,  897 
Barium  compounds  in  colors,  784 
Bark  as  an  adulterant,  428 
Barley,  271,  272 
ash,  302 

microscopy  of,  309 
proteins,  300 
starch,  281 
Barwood,  808 
Basic  colors,  795,  798 
I^audouin's  sesame  oil  test,  519 
Beading  oil,  738 
Beans,  272,  388 
Bechi's  cottonseed  oil  test,  517 
Beckman's  test  for  glucose  in  honey,  641 
Beef,  composition  of,  213 
cuts  of,  213 

stearin,  microscopical  structure,  558 
tallow,  529 
Beer,  707 

acids  in,  724 
adulteration  of,  711 
alcohol  in,  715 
aloes  in,  727 
arsenic  in,  713,  728 
ash  of,  714 
birch,  954 


INDEX. 


977 


Beer,  bitter  principles  of,  726 
bock-,  yog 
brewing  of,  708 
carbon  dioxide  in,  726 
chiretta  in,  711,  727 
com[)osition  of,  70Q 
degree  of  fermentation  of,  724 
dextrin  in,  724 
extract  gravity  of,  722 
extract  in,  715 

specific  gravity  method,  722 
refractometcr  method,  722 
gentian  bitter  in,  711,  727 
glucose  in.  710 
glycerin  in,  724 
lager-,  708 

methods  of  analysis,  714 
phosphoric  acid  in,  725 
preservatives  in,  713,  729 
proteins  of,  725 
quassiin  in,  711,  727 
references  on,  756 
root,  954 
schenk-,  708 
standards,  711 
temperance-,  714 
varieties  of,  708 
uno-,  714 
weiss-,  709 
wort,  708 

gravity  of,  722 
Beesvv^ax,  643 

refractometer  reading  of,  645 
Beet  (color),  790 

sugar,  569 
Bellier's  peanut  oil  test,  524 
Benches,  15 
Benedictine,  754 
Benzaldehyde,  885.  886,  929 
artificial,  885 
in  almond  extract,  886 
in   maraschino   cherries,   929 
Benzoic  acid,  833 

detection  of,  834 
determination,  835 
in  milk,  180 
toxicity  of,  834 
Betaine,  45,  299 
Beta-naphthol,  845 
Beverages,     carbonated.     See     Carbonated 

beverages. 
Biebrich  scarlet.  806 
Bigelow  and  McElroy's  cane-sugar  method, 

192 
Bilberry  (color),  790 
Birch  beer,  954 


Birotation,  584,  639 
Biscuit,  gluten,  358 

soja  bean,  358 
Bishop  arsenic  apparatus,   76 
Bismarck  brown.  801,  810 
Bisul[)hites  as  preservatives,  839 
Bitter  almonds,  oil  of,  884,  885 
Biuret  reaction.  41 
Blackberry  (color),  790 
Blarez  test  for  fluorides,  843 
Blast  pump.  19 

Blue  colors,  785,  786,  788,  794,  812 
"  Blown  "  cans,  902 
Bock-beer.  709 
"  Boiled  "  butter,  540 
Bombay  mace,  467 
Bomb  calorimeter,  47 
Bomer's  phytosterol  acetate  test,  507 
Borax,  827 
Bordeaux  B,  801,  806 

S,  704 
Boric  acid,  827 

detection,  182,  184,  828 
determination,  827,  829 
in  butter,  538 
in  meat,  220,  i32 
in  milk,  182,  184 
Bourbon  whiskey,  732,  734,  737 
Brandy,  739 

adulteration  of,  741 
composition  of,  739 
"  drops,"  649 
methods  of  analysis,  745 
new,  740 
potable,  740 
standards,  740 
Brazil  wood,  790,  808 
Bread,  317,  323 

acidity  of,  325 
adulteration  of,  2,2(> 
alum  in,  326 
baking  of.  ^ij, 
composition  of,  324,  325 
fat  in,  326 
Breakfast  cereals,  352 
Brewing  beer,  708 
Brie  cheese.  202 
Brilliant  red.  806 

yellow.  816 
Bromination  oil  test.  494 
Bromine  absorption  of  oils,  492 
Brown  and  Duvel's  method  for  moisture  in 

grain,  278 
Brown  colors,  786,  788,  810 

sugar,  568 
Browne's  method  for  dextrin  in  honey,  640 


978 


INDEX. 


Bro\me's  test  for  invert  sugar  in  honey,  642 
Brucke's  glycogen  method,  230 

reagent,  jjO 
Buckwheat,  271 

ash  of,  302 

composition  of,  271,  272 
tlour,  313 

microscopy  of.  3 1 1 
Burgundy  wine,  artificial,  Oq2 
Butter,  201,  520 

adulteration  of.  535 

annatto  in,  53O 

apple,  927 

ash  in,  534 

azo  colors  in,  536,  537 

boric  acid  in,  538 

carrotin  in,  530 

casein  in,  534.  551 

coloring  in,  535 

composition  of,  530 

distinction  from  oleomargarine  and 
process  butter,  546 

effects  of  feeding,  531 

fat,  composition  of,  530 
standard,  535 

fat  in,  533,  534 

filled,  540 

foam  test,  549 

formaldehyde  in,  539 

fruit,  927 

glucose  in,  539 

methods  of  analysis,  531 

microscopical  examination  of,  552 

milk  test,  550 

preservatives  in,  538 

references  on,  562 

renovated,  540 

salicylic  acid  in,  539 

salt  in,  534 

standard,  535 

sulphurous  acid  in,  539 

turmeric  in,  536 

water  in,  531 

Waterhouse  test,  550 
Butterine,  541 
Buttcrine  oil,  522 
Butyro-refractometer,  100,  loi 

critical  line  of,  106 

limits  of  butter  readings.  547 

manipulation,  102 

oil  readings  on.  478,  479 

olive  and  cottonseed  oil  readings,  514 

sliding  scale  for,  107 

special  thermometer  for,  549 

table  of  equivalent  refractive  indices, 
104.  105 


Butyro-refractometer,  temperature  variation 
of  reading,  107 
testing  scale,  104 

Cafifeine,  372,  955 

determination  of,  373,  384,  958,  960 

in  carbonated  beverages,  955 

in  cocoa,  400 
Cafifeol,  379 

Caffetannic  acid,  379,  382 
Cake,  327 
Calcium  carbonate  crystals,  90 

oxalate  crystals,  90 

sucrate,  196 
California  wines,  688 
Calorie,  47,  48 
Calorimeter,  bomb,  47 

oil,  495 
respiration,  2 
Camembert  cheese,  202 
Camera,  96 
Canada  balsam,  86 
Candy,  see  Confectionery. 

standard,  645 
Cane  sugar,  566 

ash  of,  567 
composition  of,  568 
detection  of,  585 

in  milk,  197 
determination  of: 

by  copper  reduction,   590, 

612 
by  polarimetry,  586,  614 
in  cereals,  295 
inversion  of,  588,  589 
manufacture  of,  567 
methods  of  analysis,  585 
moisture  in,  586 
quotient  of  purity,  586 
refining,  570 
test  for,  585 
Canned  food,  900 

composition  of,  902 
decomjiosition  of,  902 
metallic  impurities  in,  904 
method  of  canning,  90x3 
methods  of  analysis,  913 
preservatives  in,  912 
references  on,  961 
Canned  fruits,  900,  902 
meats,  22 

vegetables,  900,  902 
Cans,  detection  of  s[)oiled,  902 

gases  from  sjjoilcd,  903 
Capers,  926 
Capsicin,  440 


liWEX, 


979 


Capsicums,  439 
Caramel,  792 

in  distilled  liquors,  752 
in  milk,  176,  177 
in  vanilki  extract,  869 
in  vinegar,  779 
Carbohydrates,  46,  47,  74,  279 

of  cereals,  279,  295 
of  eggs,  263 
Carbon  dioxide  in  baking  chemicals,  336 
in  beer,  726 
in  yeast,  330 
Carbonated  beverages  952 

acids  in,  955 
bottled,  954 
calTein  in,  958 
cocaine  in,  959 
colors  in,  955 
foam    producers    in, 

955 
habit-forming    drugs 

in,  955 
methods  of  analysis, 

956 
preservatives  in,  955 
saponin  in,  956 
sweeteners  in,  954 
syrups  for,  955 
water,  953 
Carmosin,  806 
Carnin,  211 
Carrot  (color),  791 
Casein,  43    125,  126 

determination  in  milk,  145 
Caseose,  44 

in  cheese,  203 
in  milk,  146 
Casoid  flour,  358 
Cassia,  424 

adulteration  of,  428 
buds,  425 

composition  of,  422 
extract,  standards,  892 
microscopical  structure,  426 
oil,  425,  892 

standards,  892 
standard,  428 
Catsup,  see  Ketchup. 
Cayenne,  439 

adulteration  of,  443 
coal-tar  colors  in,  444 
colors  in,  444 
composition  of,  441 
microscopical  structure,  441 
mineral  adulterants  in,  444 
oil  of,  440 


Cayenne,  redwood  'n,  444 

Mandard,  443 
Cazeneuvc's  color  scheme,  705,  706 
Celery  seed  extract,  standards,  892 

oil,  standards,  892 
Cellulose,  47,  285 
Centrifuge,  milk-fat,  136,  137 
Centrifuge,  universal,  25 
Cereal  products,  microscopy  of,  305 
Cereals,  271 

ash  of,  302 

breakfast  foods,  352 

cane  sugar  in,  295 

carbohydrates  of,  279 

separation  of,  295 

composition  of,  271 

crude  fiber  in,  277,  296 

dextrin  in,  295 

hcmicclluloses  in,  296 

methods  of  proximate  analysis,  276 

pentosans  in,  285,  296 

proteins  of,  296 

references  on,  361 

starch  determination  in,  283,  296 
Chace  total  aldehj'de  method,  875 
Champagne,  687 
Chaptalizing,  693 
Charlock,  459 

detection,  460 
Chartreuse,  745 
Cheddar  cheese,  202 
Cheese,  202 

adulteration  of,  203 

amides  in,  206 

ammonia  in,  206 

ash  in,  205 

composition  of,  202,  203 

cream,  203 

fat  in,  205,  207 

filled,  204 

lactic  acid  in.  207 

methods  of  analysis,  204 

milk  sugar  in,  207 

nitrogen  compounds  of,  206 

paranuclein  in,  206 

peptones  in,  206 

proteins  in,  205 

sampling,  204 

skimmed  milk,  203,  204 

standards,  203 

varieties  of,  202 

water  in,  204 

whole  milk,  203 
Cherries,  maraschino,  928 
Cherry  soda,  954 
Chicory,  386,  388,  389 


9^0 


INDEX. 


Chili  sauce,  gio 
Chiretta.  727 
Chlor  iodide  of  zinc,  91 
Chloral  hydrate,  93 

test  for  charlock,  460 
Chlorine  in  vegetable  substances.  305 
Chocolate,  see  Cocoa, 
milk.  397 

composition  of.  307 
sucrose  and  lactose  in,  3,59 
Cholesterol,  50:; 

crystallizations  of.  504 
determination  of,  503 
distinction  from  phylosterol,  503 
separation  of,  503 
Cholin,  45.  209 
Chromate  of  lead,  647 
Chrome  yellow.  810 
Chromogenic  bacteria,  130 
Chrysamin,  801,  810 
Chr>soidin  yellow,  808 
Chr>sophenin,  816 
Cider.  678 

adulteration  of,  682 
ash  of.  O82 
composition  of,  679 
fermented,  680 
malic  acid  in,  683 
manufacture  of,  678 
methods  of,  analysis,  696 
references  on,  757 
sweet,  948 
vinegar,  760,  773 
watering  of,  682 
yeast  in,  678 
Cinnamon,  424 

composition  of,  425,  426 
extract.  892 

microscopical  structure  of,  426 
oil.  standards,  892 
standard,  428 
Citral,  881 

determination,  877 
in  carbonated  beverages,  955 
in  fruit  juices,  951 
Citric  acid  in  fruit  products,  920,  923,  941 
942,  948,  951 
in  ketchup,  920,  923 
in  milk,  126,  127 
Citronellal,  881 
Citronclla  oil,  880,  881 
Citronin,  794 
Clams.  256 
Claret  wine.  687 
Clarifying  reagents  in  microscopy,  92 

in  sugar  analysis,  586, 614 


Clerget's  formula,  5SS 
Clove  extract.  892 

oil,  892 
Cloves,  412 

adulteration  of,  418 
cocoanut  shells  in,  419 
composition  of,  414 
exhausted,  418 
microscopical  structure,  416 
oil  of,  892 
standard,  418 
stems,  417 
tannin  in,  415 
Clupein,  43 
Coal-tar  colors,  793 

acid,  798 

Mathewson  method  of 
determination.  814 
allowed,  704 

Price     method    of 
identification,  814 
Arata's  test,  796 
basic,  795 

classification,  793,  800 
detection  of,  795 
double  dyeing  method,  796 
dyeing  wool  by,  795 
extraction  by  amyl  alcohol, 

797 
identification   of,    795,    799, 

801,  805 
in  milk.  177 
in  sausages,  239 
Rota's  scheme  for,  799 
separation  with  ether,  798 
Soslcgni    and    Carpentieri's 
color  test,  796 
Cocaine,  detection  of,  959,  960 

in  carbonated  beverages,  955 
Cochineal,  792,  808 

in  sausages,  238 
red,  806 
Cocoa,  392,  393 

adulteration  of,  402 
alkali  in,  403 
ash  of,  396 
butter,  393,  529 
cafTcine  in,  400 
composition  of,  393 
foreign  fat  in,  402 
manufacture  of,  393 
methtKls  of,  analysis,  398 
mi(  roscopical  structure,  403 
nibs,  394,  402 
nitr(jgeneous  bodies  in,  396 
pentosans  in,  396 


INDEX. 


Cocoa,  references  on,  406 

shells,  394,  395,  405 

standards,  402 

starch  in,  394,  395,  399,  405 

sugar  in,  399,  405 

theobromine  in,  396,  400 
Cocoanut  oil,  528 
pulp,  528 
shells,  419 
Coffee,  379 

adulteration  of,  384 

ash  of,  380,  382 

cafTeine  in,  380,  384 

caffeol  in,  379 

caffetannic  acid  in,  379,  382 

chicory  in,  388,  389 

coloring  of,  384 

composition  of,  379,  380,  381 

essential  oil  of,  379 

fat  in,  379 

glazing  of,  385 

hygienic,  390 

methods  of  analysis,  382 

microscopical  structure,  386 

"  pellets,"  384 

references  on,  406 

standards  for,  384 

starch  in,  386 

substitutes,  392 
Cognac,  739.     See  also  Brandy. 

oil,  741 
Collagen,  42,  211 
Collodion  silk,  705 
Colorimeter,  Schreiner's,  77 
Colorometric  analysis,  77 
Colors,  acid  fuchsin,  799 

artificial,  782 

allowed,  794 

animal,  792 

arsenic  compounds,  785 

barium  compounds,  784 

basic,  795 

blue,  785,  786,  788,  794,  812 

brown,  786,  788,  810 

caramel,  792 

coal  tar,  793,  794,  795 

cochineal,  792 

copper  compounds,  784 

cudbear,  791 

extraction    of,    by    immiscible    sol- 
vents, 797 

fuchsin,  800,  806 

green,  785,  786,  787,  794,  812 

harmless,  784,  786 

identification  of,  795,  799,  805 
^         in  butter,  535 


Colors,  in  carbonated  beverages,  955 
in  cayenne,  444 
in  confectionery,  649,  784,  788 
indigo,  792,  812 
in  jams  and  jellies,  942 
injurious,  784,  785 
in  ketchup,  921 
in  milk,  174-177 
in  mustard,  460 
in  sugar,  590 

lead  chromate,  647,  784,  793 
lead  compounds,  784 
logwood,  791 
mercury  compounds,  785 
mineral,  792 
non-injurious,  784,  786 
orange,  785,  794,  808 
orchil,  791 

Prussian  blue,  375,  792,  812 
reagents  for  identifying,  814 
red,  785,  786,  790,  806 
references  on,  819 
Rota's  scheme  for,  799 
separation  by  solvents,  797,  814 
toxic  effect  of,  783 
turmeric,  791 

ultramarine  blue,  793,  812 
vegetable,  789,  791,  797 
violet,  786,  789,  812 
wool  dyeing,  795,  796 
yellow,  785,  787,  790,  794,  808 
Colostrum,  129 

Commercial  glucose,  see  Glucose. 
Compressed  yeast,  328 
Conalbumin,  262 
Concentrated  foods,  257 
Condensed  milk,  186 

as  a  milk  adulterant,  186 
ash  of,  189 

cane  sugar  in,  191,  192 
composition  of,  187 
fat  in,  189,  191,  192 
foreign  fats  in,  191 
milk  sugar  in,  190 
methods  in  analysis,  188 
proteins  in,  190,  192 
solids  of,  188 
standards  for,  188 
Confectionery,  645 

adulteration  of,  645 
alcohol  in,  649 
arsenic  in,  649 
cane  sugar  in,  648 
colors  in.  645,  647 
dextrin  in,  648 
glucose  in,  648 


982 


INDEX. 


Confections n',  invert  sugar  in.  64S 
lead  chromato  in.  647 
methods  of  analysis,  646 
mineral  adulterants,  646 
paralVui  in.  047 
starch  in,  O48 
Congo  red,  801.  806,  816 
Connecti\c  tissue,  211 
Copper  salts,  ooq 

determination  of,  914,918 
in  vinegar,  780 
Copra  oil,  528 
Cordials,  754 

analysis  of,  755 
composition  of,  755 
Corky  tissue,  89 
Com,  271,  272 

ash  of,  302 

bleaching  of  canned,  912 
composition  of,  271,  272 
microscopical  structure,  309 
oil,  521 

sitosterol  in,  522 
proteins  of,  300 
starch,  281 
syrup,  575 
Comclison's  butter  color  test,  537 
Coming  of  meat,  219 
Cotton  scarlet  3  B,  816 
Cottonseed,  516 

oil,  516 

standards  for,  517 
tests  for,  517 
stearin.  517 
Cotton's  cane  sugar  method,  185 
Coumarin,  862 

determination,  865 
microscopical  structure,  867 
Crampton  and  Simon's  caramel  test,  752 

palm  oil  tests,  542 
Cream,  193 

adulteration  of,  194 
cheese,  202 
evaporated,  194 
fat  in,  195 

foreitin  fats  in,  194,  196 
gelatin  in,  195,  196 
methods  of  analysis,  195 
standards  for,  194 
sucratc  of  lime  in,  195,  197 
test  scale,  194 
viscogcn  in,  195,  197 
Cream  of  tartar,  336 

in  wine,  702 

mcthfxls  of  analysis,  T,2,(y 
Creatin,  46,  211 


Crcatinin,  46,  211 
Creme  de  menthe,  755 
Crdme  dc  Noyau,  754 
Crocein  orange,  810,  816 

scarlet,  8o() 
Crude  fiber,  277 

in  cereals,  296 
Crustaceans,  256 
Crystals,  plant,  90 
Cucumber  pickles,  925 
Cudbear,  791,  808 
Cumidin  red,  794,  806 
ponceau,  794 
Cuprammonia,  93 
Curagoa,  754 
Curcuma,  450 
Curcumin,  451 

Curd  tests  in  butter,  551,  552,  553 
Curing  meat,  219 
Currant  (color),  790 

black  (color),  790 
Curry  powder,  450 
Custard  powders,  270 

Dakota  mustard,  460 

Date  stones,  390 

Decker-Kunze  method  for  theobromine  and 

caffeine,  400 
Defren-O'Sullivan  sugar  method,  150,  594 
Defren's  sugar  tables,  595 
Denis  and  Dunbar  bcnzaldehyde  method,  886 
Desiccated  egg,  268 
Deutyro-albumosc,  44,  45 
Dextrin,  575 

determination  of,  in  cereals,  295 
in  glucose,  602 
in  honey,  640 
in  jams  and  jel- 
lies, 940 
in  molasses,  624 
Dextrose,  573 

determination  of,  591,  593,594,  598 
Diabetic  foods,  357 

analyses,  358 
Diamond  yellow,  801 
Diastase,  animal,  284 

in  malt  extract,  729 
starch  methods,  283 
Dietetics,  references  on,  49 
Dinitrocresol,  808 
Dioxin,  801 
Distilled  li(|uors,  730 

aldehydes  in,  745 
analytical  methods,  745 
caramel  in,  752 
color  tests,  752,  753 


INDEX. 


983 


Distilled  liquors,  esters  in,  745 
extract  in,  745 
furfural  in,  746 
fusel  oil  in,  746 
methyl  alcohol  in,  749 
opalescence  test,  753 
references  on,  758 
Doolittle  and  Woodruff  theine  method,  373 
Doolittle  butter  color  test,  537 
Double  dilution  sugar  method,  149 
Dough,  expansion  of,  317 
Drains,  17 
Dried  fruits,  944 

decomposed,  945 
lye  treatment  of,  945 
methods  of  analysis,  946 
moisture  content  of,  945 
sulphuring  of,  945 
wormy,  945 
zinc  in,  946 
Drugs,  haiMt-forming,  955 
Dry  wines,  690 
Dry  yeast,  328 
Dubois  salicylic  acid  method,  832 

sugar  method,  399 
Dubosc's  saccharimeter,  583 
Dulcin,  853 

determination,  854 
Dunbar  and  Bacon  malic  acid  method,  949 
Dupre's  color  method,  705 
Dvorkovitsch  theine  method,  373 

Ebulioscope,  675 
Edam  cheese,  202 
Edestan,  44 
Edestin,  299,  300 
Eggs,  261 

ash  of,  264 

carbohydrates  of,  263 

cold  storage,  267 

composition  of,  264,  265 

desiccated,  268 

fat  of,  264 

frozen,  268 

lecithin  determination,  265 

methods  of  analysis,  265 

opened,  268 

physical  examination  of,  267 

preservation  of,  266 

proteins  of,  262 

references  on,  270 

substitutes  for,  269 

waterglass  as  a  preservative,  266 

weights  of,  264 

white  of,  262 

yolk  of,  263 


Elaidin  oil  test,  499 

Elastin,  211 

Elderberry  (color),  790 

Electrolytic  apparatus,  608 

Elm  bark,  428 

Emergency  rations,  257 

Eosin,  794,  804,  806 

Ergot,  313 

Erythrodextrin,  575 

Erythrosin,  794,  806,  815,  816,  817 

Esters,  in  distilled  liquors,  745 
in  imitation  flavors,  898 

Ether,  ethyl,  preparation  of  absolute,  66 

petroleum,  preparation  of,  for  a  sol- 
vent, 66 

Eucasin,  158 

Eugenol,  412 

Ewe's  milk,  127 

Exhausted  cloves,  418 
ginger,  450 
tea  leaves,  375 
vanilla  beans,  859 

Exhaust  pump,  20 

Extraction  with  immiscible  solvents,  68 
volatile  solvents,  63 

Extractor,  Johnson,  55 
Soxhlet,  63 

"  Faints,"  732 

Farinaceous  infants'  foods,  356 

Fast  red,  794, 806, 816 

Fat  globules,  90 

Fat  of  food,  39 

of  meat,  226,  227 
Fats,  edible,  471.     See  also  Oils, 
filtering,  473 
measuring,  473 
melting-point  of,  480 
methods  of  analysis,  473 
microscopical  examination  of,  510 
parafTm  in,  510 
references  on,  561 
weighing,  473 
Fatty  acids,  499 

constants  of,  500 
insoluble,  485 
solidifj-ing  point  of,  500 
soluble,  484 
volatile,  841 
Fehling  processes,  590 

gravimetric,  150,  593 
volumetric,  150,  591 
Fehling's  solution,  591 

equivalents  of,  592 
Fermentation,  acetic,  759 

alcoholic,  653 


9S4 


INDEX. 


Fermentation,  lactic.  129 

proteolytic.  15S,  202 
Fermented  liquors,  678 
Feser's  lactoscope,  1O3 
Fibrin.  125 

Fibro  vascular  tissue,  88 
Fibroin,  42 
Filled  cheese,  204 
Fincke  formic  acid  method,  S42 
Fish,  analyses  of,  255 

preservatives  in,  257 
colors  in.  257 
Flavoring  extracts,  857 

references  on,  898 
Flesh  foods.  211 

references  on,  258 
Fletcher  and  Allen's  tannin  method,  371 
Floor.  15 
Flour,  3 1 1 

absorption  test  of,  317 
acidity  in,  320 
adulteration  of,  314 
alcohol  soluble  protein  in,  320 
alum  in,  315 
baking  tests  of,  318 
bleaching  of,  315 

detection,  321 
cold  water  extract  of,  320 
color  test  of,  317 
composition  of,  312 
damaged,  313 
dough  test  of,  317 
fineness  of,  316 
gluten  in,  320,  322 
inspection,  316 
iodine  number  of  fat  of,  321 
methods  of  analysis,  316 
nitrites  in,  321 

proximate  constituents  of,  319 
salt  soluble  protein  in,  320 
Fluoborates,  843,  844 
Fluorides,  843 

detection  of,  843 
Fluosilicates,  843,  844 
Foam  producers,  955 
"Foam"  lest  for  butter,  549 
Folin  methcxl  for  ammonia  in  meat,  226 
FcKxl  adulteration,  5 

analysis,  commercial,  3 

from  dietetic  standpoint,  2 
general  methods,  4 
references  on,  79 
and  drugs  act,  965 
concentrated,  257 
economy,  references  on,  49 
insjjection,  3,  6 


Food  inspection,  references  on,  ir 
misbranding,  6 

nature  and  composition  of,  39 
ofl'icial  control  of,  i 

references  on,  1 1 
standards,  4 
Fore  milk,  12S 
Foreshots,  732 
Formaldehyde,  824 

detection  of,  180,  824 
determination  of,    181,   825, 

827 
in  eggs,  268 
in  milk.  178 
Formic  acid,  841 

detection  of,  841 
determination  of,  842 
Fortified  wine,  685,  6qo 
Freas  drying  oven,  22 
Fresenius'  method  for  colors  in  pastes,  350 
Frozen  milk,  test  for,  129 

meat,  239 
Fructose,  d-,  574 

/-3-.  574 
Fruit,  274 

butter,  927 

candied,  646 

composition  of,  274 

essences,  artificial,  895,  896,  897 

juices,  946,  947 

methods  of  analysis,  949 

methods  of  proximate  analysis,  276 

organic  acids  in,  949 

products,  900 

references  on,  961 
references  on,  361 
sugar,  sec  Levulose. 
sugar-coated,  646 
sugar  in,  566 
syrups,  952,  953 

tissues  under  the  microscope,  944 
Fruits,  dried,  see  Dried  fruits. 
Fuchsin,  798,  803,  806 
Fuel  value,  47 

Fuller  catTcin  method,  958,  960 
cocaine  method,  959,  960 
Funnel,  jacketed,  474 

separatory,  67,  68 
Furfural,  285 

determination,  746 
in  distilled  liquors,  746 
in  vinegar,  779 
Furnace,  electric,  62,  24 

gas,  24 
Fusel  oil,  731 

detection,  746 


INDEX. 


9SS 


Fusel  oil,  determination,  747 
Fustic,  790,  810 

Game,  composition  of,  216 
Gases,  in  sjioiled  cans,  903 
Geerlig's  table  for  dry  substances  in  sugar 

products,  615 
Geissler's  carbon  dioxide  apparatus,  337 
Gelatin,  42.  211 

in  cream.  los 
in  jams  and  jellies,  943 
in  meat,  231 
Gerber's  milk  centrifuge,  136 
Gill  and  Hatch's  oil  calorimeter,  495 
Gin,  744 
Ginger,  445 

adulteration  of,  450 

ale,  054 

black,  446 

cold  water  extract  of,  448 

composition  of,  446,  447 

exhausted,  447 

extract,  methods  of  analysis,  894 

standards,  892 
liming  of,  446 

microscopical  structure  of,  449 
oil  of,  <?.46 
root,  445 
standard,  450 
white,  446 
Gliadin,  42,  298,  299 
Globulins,  42,  297 
Globulose,  44 
Glucin,  855 
Glucose,  575 

arsenic  in,  632 
composition  of,  576 

d-,  573 

determination  of,  in  honey,  637,  641 
in  jams  and  jellies,  940 
in  molasses,  621 
dextrin  in,  632 
healthfulness  of,  576 
in  beer,  710,  712 
in  butter,  539 
methods  of  analysis,  630 
standards  for,  576 
test  for,  632,  641 
Glucoses,  565 
Glutelins,  42 
Gluten,  298,  299 

Bamihl's  test  for,  322 
biscuit,  358 
determination  of,  319 
flour,  357,  358 
Glutenin,  42,  298,  300 


Glycerin  in  carbonated  beverages,  960 

in  vanilla  extract,  869 

in  wine,  703 

jelly,  86 
Glyccrrhizin,  955 
Glycogen,  212 

detection,  235 
determination,  236 
Glycoproteins,  43 
Goat's  milk,  127 
(iooch's  boric  acid  method,  830 
Gorter  caiTeine  method,  384 
Graham  flour,  311 
Grain,  moisture  in,  278 
Grape  juice,  947 
Grape  sugar,  standard,  574 
Gray's  method  tor  water  in  buticr,  532 
Green  colors,  785,  786,  787,  794,  812 
Groats,  312 
Gruyere  cheese,  202 
Guinea  green,  816 
Gums,  89 

Gunning-Arnold  nitrogen  method,  432 
Gunning  nitrogen  methods,  69,  71 
Gutzeit  arsenic  test,  76 

Habit-forming  drugs,  955 

Haemoglobins,  43 

Haemolysis  test  for  saponin,  957 

Halphen  cottonseed  oil  test,  518 

Hansen  and  Johnson  tin  method,  917 

Hanus'  iodine  absorption  method,  491 

Hefelmann's  Bombay  mace  test,  467 

Hehner  and  Richmond's  milk  formula,  151 

Hehner's  method  for  insoluble    fatty    acids, 

486 
Heidenhain's  tartaric  acid  method,  340 
Hemicellulose,  285,  296 
Hess  and   Prescott   vanillin   and   coumaria 

method,  865 
Hetero-albumose,  44,  45 
Hiltner's  citral  method,  877 
Hilyer's  benzoic  acid  method,  838 
Histones,  43 
Hock  wine,  689 
Hoffmeister's  schiilchen,  64 
Holstein  cows,  milk  from,  162 
Homogenized  fats,  191,  194,  199 
Honey,  633 

.adulteration  of,  636 

American,  634 

analysis  of,  639 

Canadian,  634 

composition  of,  633,  635,  636 

dextro-rotatory,  635,  636 

European,  633 


986 


INDEX. 


Honey,  gelatin  in,  639 

glucose  in,  637,  641,  642 
Hawaiian,  034 
invert  sugar  in,  03S,  642 
methods  of  analysis,  039 
Honeydew,  63b,  642 
Hoods,  It).  21 
Hops,  70S 

substitute,  710 
Hordein.  42 

Horseflesh,  characteristics  of,  234 
composition  of,  222 
detection  of,  235,  237 
glycogen  in,  235 
Horseradish,  920,  927 
Hortvet  method  for  acids  in  wine,  701 

number,  of  maple  products,  628 

of  \'ineg:ir,  768 
and  West's  benza'.dehyde  method, 
887 
rose  oi;  method,  895 
spice  oil  method,  893 
wintergreen   oil   method, 
890 
Hoskins'  electric  furnace,  63 
Howard  microscopic  ketchup  method,  924 
test  for  gums  in  ice  cream,  201 
volatile  oil  method,  874 
Hiibl's  iodine  absorption  method,  487 
Human  milk,  127 

Hungarian  red  pepper,  439,  441,  442 
Hunt's  iodine  reagent,  492 
Hydrocyanic  acid,  888,  889 
Hydrometer.  55 
Hypo.xanthin,  211 

Ice  cream,  198 

analytical  methods,  199 
colors  in,  201 
cones,  199 

detection  of  thickeners,  200 
fat  in,  199 
gelatine  in,  201 
homogeni/x-d,  199 
preservatives  in,  201 
standards,  198 
starch  in,  201 
Imitation  cofTce,  384 
J.nmcrsion  refractomcter,  100,  iii 
adjustment  of  scale,  113 
distilled  water  readings  on,  113 
investigation   of   small   quantities   of 
solutions  by,  115 
of  solutions    excluded    from    air 

by.  115 

milk  examination  by,  166 


Immersion     refractomcter,    scale     readings 
compared  with  «/>,  116 
solutions  standardized  by,  120 
references  on,  122 
temperature  corrections  for,  121 
Incinerator,  173 
Indicators,  38 

Indices  of  refraction,  105,  n6 
Indigo,  792,  812 

carmine,    794,  802,   812,    815,    816, 

817  _ 

disulphosacid,  794,  812 
Indigotine,  794,  802 
Indol,  92 
Indophenol,  802 
Indulin,  802,  812 
Infants'  foods,  354 

classification  of,  355 
cold  water  extract  of.  360 
composition  of,  356 
methods  of  analysis,  359 
microscopical  examination  of, 

360 
preparation  of,  355 
Inosite,  276 

Inspection  of  foods,  3,  5,  6,  9 
flour,  316 
liquors,  655 
milk,  159 
Inulin,  276 
Invalids'    foods,    354.     See    also    Infants' 

Foods. 
Inversion,  588 
Invert  sugar,  589 

detection  of,  589,  625,  642 
determination  of,  589,  598 
in  honey, 638, 642 
lodeosin,  794 

Iodine  absorption  of  oils,  487,  491,  492 
Iodine  in  potassium  iodide,  91 
Irish  whiskey,  732,  734,  735 

Jams,  930 

acids  in,  941,  942 
adulteration  of,  931,  934 
agar  agar  in,  943 
apple  stock  in,  943 
coagulator  in,  034 
coloring  matter  in,  942 
composition  of,  932,  933,  936 
compound,  934 
dextrin  in,  940 
fruit  tissues  in,  944 
gelatin  in,  943 
glucose  in,  940 
methods  of  analysis,  936 


INDEX. 


987 


Jams,  organic  acids  in,  941 

polarization  of,  938 

preservatives  in,  942 

starch  in,  943 

sugars  in,  938 
Jellies,  see  Jams. 
Johnson  extractor,  65 
Johnson-Chittcnden-Gautier  arsenic  method, 

74 
Juckenack's  lecithin  phosphoric  acid  method, 

349 

Kenrick's  tartaric  acid  method,  340 
Kephir,  159 
Keratins,  42 
Ketchup,  919 

citric  acid  in,  920,  923 

colors  in,  921 

decayed  material  in,  920 

foreign  pulp  in,  921 

lactic  acid  in,  920,  923 

manufacture,  919 

methods  of  analysis,  921 

microscopy  of,  924,  925 

organisms  in,  924 

preservatives  in,  921 

refuse  in,  920 

standards,  919 
Kjeldahl  nitrogen  method,  72 
Knorr's  carbon  dioxide  apparatus,  338 
Koelner's  baking  test,  318 
Koettstorfer's  saponification  method,  486 
Konig  and  Karach's  method  for  distinguish- 
ing honeydew  and  glucose,  642 
Koumis,  158 

Krober's  table  for  pentosans  and  pentoses, 
288 

Laboratory  benches,  15 

stain  for,  16 

drains,  17 

equipment,  14,  15 

references  on,  38 

floor,  15 

hoods,  16 

lighting,  15 

location,  14 

sinks,  17 

ventilation,  15 
Lactalbumin,  125 
Lactated  infants'  foods,  356 
Lactic  acid  in  ketchup,  923 

in  tomatoes,  920 
Lactoglobulin,  125 
Lactometer,  131 
Lactoscope,  163 


Lactose,  125,  577 

Defren's  table  for,  595 

detection  of,  625 

determination  of,  593,  594,  598,  626 

in  milk,  126,  127,  147 
Munson  ami  Walker's  table  for,  599 
Soxhlet's  table  for,  152 
Lager  beer,  708 
Lamb,  composition  of,  215 

cuts  of,  215 
Landwehr's  glycogen  method,  236 
Lard,  554 

adulteration  of,  556 

back,  554 

composition  of,  554 

composition  of  as  affected  by  feeding, 

560 
"compound,"  556 
constants  of,  555 
iodine  number,  559 
kettle-rendered,  554 
leaf,  554 

microscopical  examination  of,  557 
neutral,  554 
oil,  555 

references  on,  563 
standards,  556 
stearin,  555 
substitutes,  559 
Laurent's  saccharimeter,  583 
Law,  food  and  drugs,  965 
meat  inspection,  969 
La  Wall  and  Bradshaw  benzoic  acid  method, 

835 
Leach  and  Lythgoe  method  for  malic  value 
in  maple  products,  627 
methyl  alcohol  method,  749 
Lead  chromate,  647,  784,  793 

number,  maple  products,  628 

vinegar,  768 
salts,  of,  904,  908 

determination  of,  913,  914,  918 
Leavening  materials,  327,  t,t,2 

references  on,  364 
Lecitalbumin,  43 
Lecithin,  46 

determination  of,  265,  349 
nucleovitellin,  43 
Lecithoproteins,  43 

Leffmann  and  Beam's  method  for  volatile 
fatty  acids,  482 
fat  method,  49 
Legumelin,  41 
Legumes,  272 

ash  of,  302 
Legumin,  42,  300 


988 


INDEX. 


Lemon  extract,  S70 

adulteration  of.  871 
alcohol  in,  875 
aldehydes  in,  875 
cilral  in,  877 
citric  acid  in,  879 
colors  in,  878 
composition  of,  870 
lemon  oil  in,  871,  872 
methiKis  of  analysis,  872 
methyl  alcohol  in,  878 
standard  for,  870 
tartaric  acid  in,  879 
terpeneless.  871 
oil,  terpeneless,  871 
Lemongrass  oil,  872,  880,  881 
Lemon  juice,  948 
Lemon  oil,  8 70,  871,  880 
alcohol  in,  883 
aldehydes  in,  883 
citral  in,  882 

determination  of,  872,  873 
examination  of,  882 
pinene  in,  883 
soda,  954 
Lentils,  272 
Leucosin,  41,  299,  300 
Levallois'  bromine  absorption  method,  493 
Levulose,  574 

determination  of,  626,  640 
Liebig's  meat  extract,  242 
Li^ht  green  S.  F.,  794,  812,  815,  816,  817 
Lighting,  15 
Lignin,  94 

Lime,  determination  of,  303 
in  baking  powder,  345 
in  spices,  410 
juice,  947.  948 
sucrale  of,  196 

water,  in  vinegar  analysis,  765 
Liming  of  ginger,  446 
Limoncnc,  881 
Liqueurs,  754 

analysis  of,  755 
Liquor  ins{K;clion,  655 
Liquors,  alcohol  in,  658,  715 
ash  of,  677 
distilled,  730 

methods  of  analysis,  745 
extract  of,  677 
fermented,  678 
malt.  707 

methods  of  analysis,  714 
mailed  and  non-malted,  712 
mcthtxls  of  analysis,  657 
preservatives  in,  677 


Liquors,  specific  gravity  of,  657 
Lobster,  composition  of,  256 
Logwood,  790,  791 
Long  fermentation  baking  test,  319 

pei)i)L'r,  438 
Lovibond  tintometer,  77 
Lowenthal's  tannin  method,  370 
Low  wines,  732 
Lye  treatment  of  fruit,  045 
L_\'thgoc's  sucrose  test  for  milk,  197 

Macaroni,  347.     See  also  Pastes, 
Macassar  mace,  468 
Mace,  462,  465 

adulteration  of,  466 
Bombay,  467 
composition  of,  465 
Macassar,  468 

microscojjical  structure  of,  466 
standard,  4O6 
Madeira  wine.  687 
Magenta,  806,  816 
Maize,  see  Corn. 
Malachite  green,  812 
Malaga  wine,  artificial,  692 
Malic  acid  in  cider,  702 

in  fruit  juices,  949 
in  vinegar,  767 
in  wine,  702 

value  in  maple  products,  627 
Malt,  707 

extracts,  284,  729 
liquors,  707.     See  also  Beer, 
substitutes,  710 
vinegar,  762 
Malting,  707 
IMaltose,  574 

detection  of,  625 
determination  of,  594,  598,  626 
Manganese  brown,  810 
Maple  sap,  570 

sugar,  570.     Sec  also  Maple  syrup, 
syrup,  570 

adulteration  of,  572 
ash  of,  571,  572 
composition  of,  571,  572 
Horlvet  number  of,  628 
lead  number  of,  628 
malic  acid  value,  627 
methods  of  analysis,  627 
moisture  in,  627 
standards,  572 
Maraschino,  754 

cherries,  928 

bcnzaldehyde  in,  929 
Mare's  milk,  127 


INDEX. 


989 


Marigold,  791 

Marpmann's  color  method,  239 
Marsh  arsenic  test,  75,  728 
test  for  caramel,  753 
Martin's  color  scheme,  535 
"  Matcrna  "  milk  modifier,  157 
Mathewson  color  method,  814 
Maumenc  thermal  test,  494 
Mayrhofer's  {^lyco^en  method,  237 
McCiill's  drying  oven,  586 
Meat,  211 

ammoniacal  nitrogen  in,  226 

antiseptics  in,  220 

ash  in,  225 

bases,  211,  222,  228,  231 

boric  acid  in,  232 

canned,  221 

canning  of,  221 

colors  in,  238 

composition  of,  221 

cooking,  eilect  of,  220 

corning  of,  219 

curing  of,  219 

extracts,  240 

acidity  of,  253 

albumoses  in,  250 

ash  in,  249 

composition  of,  242,  243,  247 

creatinin,  244,  252 

creatinin  in,  244,  252 

fat  in,  249 

fluid,  241,  243,  244 

gelatin  in,  253 

glycerol  in,  254 

meat  bases  in,  252 

methods  of  analysis,  246 

nitrogen  compounds  of,  249, 

250 
peptones  in,  251 
preservatives  in,  254 
proteoses  in,  250 
solid,  241,  242,  244 
standards,  241 
xanthin  bases  in,  253 
fat,  acidity  of,  226 

composition  of,  226 
determination,  226 
gelatin  determination,  231 
glycogen  in,  236 
inspection,  217 

law,  969 
juices,  241,  24s,  247,  248 
manufactured,  218 
methods  of  analysis,  225 
mince,  927 
nitrates  in,  232 


Meat,  nitrogen  determination,  226 

nitrogenous  bodies,  separation  of,  228 
])ei)tones  in,  251 
[)ickled,  218 
])owders,  247,  248 
preservation  of,  218 
l)rescrvatives  in,  232 
proteins,  coagulable,  231 
proteoses  in,  231 
ptomaines  in,  218 
refrigeration  of,  219 
salicylic  acid  in,  233 
salted,  219 
smoked,  219 
standards  of,  218 
sulphurous  acid  in,  231 
unwholesome,  218 
water  in,  225 
Melting  point,  480 
Mercury  compounds  in  colors,  785 
Metallic  salts  in  canned  goods,  toxic  effects 
of,  911 
determination,  914 
Metanil  yellow,  810,  816 
Metaproteins,  44 

Methyl  alcohol,  detection  of,  749,  878 
Methylene  blue,  802,  812 
orange,  808 
violet,  812 
Micro-chemical  reactions,  94 
Micro-polariscope,  84 
Microscope  in  food  analysis,  81 
references  on,  98 
reagents  for,  90 
stand,  82 
Microscopical  accessories,  84 
analysis,  81 
apparatus,  82 
diagnosis,,  86 
reagents,  90 

analytical,  91 
clarifying,  92 
^licroscopy  of  agar  agar,  943 
allspice,  422 
arowroot,  282 
barley,  309 

starch,  281 
bean,  388 

starch,  282 
buckwheat,  311,  437 

starch,  281 
butter,  552 
cassia,  426 
cayenne,  441 
cereal  products,  305 
charlock,  460 


990 


INDEX. 


Microscopy  of  chicory.  386 

cinnamon,  426 
cloves,  410 
cocoa,  403 
cocoanut  shells,  419 
coffee.  386 
corn,  309 

starch,  281 
date  stones,  390 
fats,  510 

flour,  306,    7,22 

fruit  tissues,  944 
ginger,  449 
honey,  633 
jams,  944 
jellies,  944 
ketchup,  724,  725 
lard,  557 
mace,  466 
milk,  124 
mustard,  458 
nutmeg,  464 
oats,  309 
oat  starch,  282 
oils,  510 

oleomargarine,  552 
olive  stones,  436 
paprika,  441 
pea,  388 

starch,  282 
pepper,  black,  433 
long,  439 
red,  441 
white,  433 
potato  starch,  282 
rice,  310 

starch,  282 
rye,  308 

starch,  281 
sago,  283 
sawdust,  444 
starches,  280 
tapioca  starch,  282 
tea,  378 
turmeric,  451 
wheat,  306 

starch,  281 
Micro-technique,  82 
Milk,  124 

acidity  of,  124,  153 
adulteration  of,  159 
alkalinity  of  ash,  198 
anilin  orange  in,  175,  177 
annatto  in,  175,  176 
ash  of,  127,  134 
ashing  of,  134 


Milk,  ass's,  127 

boiled  milk,  detection,  155 

borii'  acid  in,  182 

calcium  oxide  in,  189 

calculation  of  proteins,  153 

caramel  in,  176,  177 

carbonate  in,  180,  182 

chocolate,  397 

citric  aci<l  in,  127 

coloring  matter  in,  174-177 

composition  of,  124-126 

constants,  169 

ewe's,  127 

fat  of,  127,  134 

fermentations  of,  129 

foods,  prepared,  157 

fore  milk,  128 

formaldehyde  in,  178,  181 

goat's,  127 

human,  127 

inspection,  159 

known  purity,  169 

mare's,  127 

methods  of  analysis,  130,  163,  168 

microscopical  appearance,  124 

modified,  155 

nitrogen  compounds  in,  125,  145 

powder,  157 

preservatives  in,  177 

proteins  of,  125,  145,  153 

records  of  analysis  of,  172 

references  on,  208 

ropy, 130 

sampler,  131 

serum,  refraction  of,  166,  167 

specific  gravity  of,  166,  167 
skimmed,  161 
sour,  analysis  of,  186 
souring  of,  1 29 
standards,  160 
strippings,  128 
sucratc  of  lime  in,  196 

detection,  197,  198 
sugar,  125,  577 

determination  of,  593,  594,  598 
determination  of,  in  milk,  147^ 

149-  151 
systematic  examination  of,  130,  168 
total  solids  in,  133,  134 

calculation  of,  151,  153,  154 
watering  of,  161 
Milliau's  cottonseed  oil  test,  518 
Millon's  reaction,  41,  92 

reagent,  92 
Mill's  bromine  absorption  method,  493 
Mince  meat,  927 


INDEX. 


99] 


Mince  meat,  adulteration  of,  927 
condensed,  928 
standards,  927 
Mineral  colors,  792 

content  of  food,  47 
Mirbane,  oil  of,  886,  888 
Mitchell  and  Smith  fusel  oil  method,  748 
Modified  milk,  155 
Mohler's  test  for  benzoic  acid,  835 
Moisture,  determination  of,  6i 
Molasses,  567 

adulteration  of,  621 

ashing  of,  614,  624 

clarifying,  614 

composition  of,  568 

glucose  in,  621 

invert  polarization  at  87°  C,  623 

methods  of  analysis,  613 

standard  for,  621 

sucrose  in,  614 

tin  in,  625 

total  solids  in,  613 

vinegar,  763 
Mollusks,  256 
Mucoid  protein,  127 
Munson  method  for  metallic  salts,  914 
Munson  and  Walker  sugar  method,  151,  598 

table,  599 
Muscle  albumin,  211 

fibers  in  meat,  211 
sugar,  212,  238 
Muscovado,  567,  568 
Mushroom  ketchup,  919 
Mustard,  453 

adulteration  of,  459 

ash  of,  457 

black,  453 

cake,  455 

charlock  in,  459,  460 

coloring  matter  in,  460 

composition  of,  455,  456 

Dakota,  459 

flour,  454 

methods  of  analysis,  457 

microscopical  structure  of,  458 

oil,  fixed,  454,  525 
volatile,  453,  457 

pickles,  926 

prepared,  460 

adulteration  of,  460 
composition  of,  460,  461 
methods  of  analysis,  461 

sinalbin  in,  454 

mustard  oil,  453 

sinapin  sulphocyanate,  457 

standard,  459 


Mustard,  starch  in,  459 

turmeric  in,  460 
volatile  oil  of,  453 
wheat  in,  459 
white,  453 
Mutton,  composition  of   215 
cuts  of,  215 
tallow,  529 
Myosin,  42 

insoluble,  44 

Naphthion  red,  808 
Naphlhol  green,  801,  812 
orange,  794 
yellow,  794,  8or,  808 

S.,  794,  808,  816,  817 
Natural  wine,  685 
Neufchatel  cheese,  202 
New  coccin,  816 
green,  812 
Nickel  salts,  911 

determination  of,  918 
Niebel's  glycogen  method,  236 
Nigrosin,  802 
Nile  blue,  802 
Nitrates  in  food,  40,  46 

in  watered  milk,  168 
Nitrobenzol,  886,  888 
Nitrogen  apparatus,  72,  73 

compounds  in  milk,  145 

determination  of,  69,  73 

free  extract,  54 
Nitrogenous  bodies,  40 

classification  of,  40 

separation  of,  in  cheese,  205 
in  meat,  228 
in  milk,  125,  126, 145 
Noodles,  347 
Notification,  10 
Noyau,  754 
Nuclein,  43 
Nucleoproteins,  43 
Nutmeg,  462,  463 

adulteration  of,  464 

composition  of,  462,  463 

extract,  standards,  881 

Macassar,  465 

microscopical  structure  of,  464 

oil  of,  463 

standard,  892 

standard,  464 
Nutrose,  158 
Nuts,  composition  of,  275 


Oats,  271 

analysis  of,  271, 


272 


992 


INDEX. 


Oats,  ash  of,  302 

microscopic  structure,  30Q 
starch  in,  2S2 
Oil  cakes,  effects  on  butter  of  feeding,  531 
lard  of  feeding,  560 

anise,  S92 

basil,  Sq3 

bitter  almond,  884.  885,  886 

calorimeter,  495 

cassia,  425,  892 

celery  seed,  892 

cinnamon,  892 

cloves,  892 

cocoanut,  528 

com,  521 

cottonseed,  516 

ginger.  446 

lard,  555 

lemon,  870,  871,  880 
terpcneless,  871 

lemongrass,  872,  880,  38 1 

majoram,  893 

mustard,  fixed.  454,  525 

volatile,  453,  457 

nutmeg,  892 

oleo,  541 

olive,  511 

orange,  884 

peanut,  522 

peppermint,  890 

poppysced,  526 

rape,  520 

rose,  895 

rosin,  527 

savorj',  892 

sesame,  519 

spearmint,  891 

staranisc,  893 

sunflower,  526 

thyme,  893 

wintcrgreen,  889 
Oils,  edible,  471.     See  also  Fats, 
acetyl  value,  497 
bromine  absorjilion  of,  492 
bromination  test,  494 
cholesterol  in,  502,  503,  507 
composition  of,  471,  472 
constants  of,  508,  509 
claidin  test,  499 
fatty  acids  in,  484,  499 
iodine  absorption  of,  487.  492 
judgment  as  to  purity  of,  473 
Maumen6  test,  494 
melting  point,  480 
methfxJs  of  analysis,  473 
microscopical  examination,  510 


Oils,  edible,  phytostcrol  in,  502.  503,  507 
Polenske  number  of,  483 
rancidity  of,  473,  530 
references  on,  561 
refractive  index  of,  477 
Rcichcri-Meissl  number,  481 
saponification  of,  472,  484,  486 
sitosterol  in,  522 
specific  gravity  of,  474 

factors,  475 
thermal  tests.  493 
titer  test.  500 

unsaponifiable  matter  in,  501 
Valcnta  test,  499 
viscosit}'  of,  477 
Oleomargarine,  541 

adulteration  of,  543 
coloring  of,  542 
constants  of,  544 
distinction  from  butter,  544,  546 
healthfulness  of,  543 
manufacture  of,  541 
microscopical  examination,  552 
odor  and  taste,  545 
palm  oil  in,  542 
Zega's  test  for,  553 
Oleo  oil,  541 
Olive,  composition,  511 
oil,  512 

adulteration  of,  512,  515 
examination  of,  515 
refraction  of,  514 
standard,  513 
Olives,  pickled,  920,  926 
Olive  stones,  436 

Orange  colors,  787,  794,  808,810,  815,816,817 
extract,  884 
oil,  884 
soda,  054 
standards,  884 
Icrpeneless,  884 
Orchil,  791,  808 

substitute,  808 
O'Sullivan-lJefrcn  sugar  method,  150 
Ovalbumin,  262 
Oven,  drying,  22 

Mc(;iirs,  586 
Ovomucin,  262 
Ovomucoid,  263 
Oxygen  absorbed,  415 

equivalent,  415 
Oxyha;moglobin,  43 
Oysters,  257 

Palas  rapeseed  oil  test,  521 
Paprika,  439 


INDEX. 


993 


Paprika,  added  oil  in,  445 

adulteration  of,  444,  445 
comijosition  of,  442 
methods  of  analysis,  445 
microscopical  structure  of,  441 
Paraffin  in  beeswax,  643 

in  confectionery,  647 
in  fats,  510 
in  oleomargarine,  543 
Paranuclein,  206 
Parenchyma,  87 
Pastes,  adulteration  of,  349 

artificial  colors  in,  349 
edible,  347 
Italian,  347 

lecithin  phosphoric  acid  in,  349 
methods  of  analysis,  349 
noodles,  347 
Patrick's  method  for  water  in  butter,  531 
test  for  thickeners  in  ice  cream,  200 
Paul  method  for  foreign  fats,  191 
Pea,  composition,  272 
proteins  of,  300 
starch  of,  282 
Peanut  oil,  522 

adulteration  of,  523 
standards  for,  522 
tests  for,  523,  525 
Pear  cider,  683 

essence,  imitation,  896,  897 
Pectose.  93,  276 
Pekar's  color  test  of  flour,  317 
Pentosans,  285,  296 

determination  of,  285,  296 
in  cocoa  products,  396 
table  for,  288 
Pentose,  285,  296 
Pepper,  428 

adulteration  of,  435 

black,  429 

buckwheat  in,  437 

composition  of,  430,  432 

dust,  436 

ether  extract  in,  410 

long,  438 

microscopical  structure  of,  433 

nitrogen  in,  432 

in  ether  extract,  433 

olive  stones  in,  436 

piperin  in,  429 

determination  of,  433 
red,  see  Cayenne  and  Paprika, 
shells,  435 
standard,  435 
varieties  of,  429 
white,  429 


Peppermint  extract,  890 

composition  of,  891 
standards,  891 
oil,  891 
Peptides,  45 
Peptones,  44 

in  cheese,  202 
in  meat,  211,  231 
in  milk,  146 
Peter's  test  for  benzoic  acid,  835 
Perry.  683 

Persian  berries,  790,  810 
Petroleum  ether,  66 
Phloroglucidc,  286 
Phloroglucinol,  287 
Phloxin,  806 

Phosphate  baking  powders,  333 
Phosphin,  803 
Phosphoproteins,  43 
Phosphoric  acid  in    baking    chemicals,    346 

in  beer,  725 
Phosphotungstic  acid  reaction,  45 
Photomicrography,  93 

camera  for,  96 
Phytolacca,  700 
Phytosterol,  502 

acetate  test,  507 
crystallization  of,  503 
determination  of,  503 
distinction  from  cholesterol,  503 
separation  of,  503 
Piccalilli,  926 
Pickled  meats,  218 
Pickles,  925 

adulteration  of,  926 
Pickling  pump,  219 
Picric  acid,  350,  808 
Pie  filling.  928 
Pimiento,  439,  442 
Pineapple  essence,  imitation,  896,  897 
Pioscope,  164 
Piperin,  429 

determination  of,  433 
Piutti  an:".  Bentivoglio's  method  for  colors 

in  pastes,  351 
Plant  crystals,  90 
Plasmon.  158 
Plastering,  of  wine,  629 
Platinum  dishes,  61, 133,  134,  170 

counterweights  for,  170 
Poisoned  foods,  74 
Poivrette.  436 
Polariscope,  578.     See  also  Saccharimeter. 

micro.  84 
Polariscope  tube  jacketed,  639 

short,  for  oils,  880 


994 


INDEX. 


Polarization  at  high  temperature.  639 
of  essential  oils,  880 
honey,  039 
jams  and  jellies,  938 
lemon  extract,  S73 
molasses,  614 
orange  extract,  884 
sugar,  578 
vinegar,  769 
wine.  604.  703 

Polenske  number,  483 

Ponceau,  794,  80b,  810,  815,  816,  817 

Poppyseed,  5^6 

oil,  526 

Pork,  composition  of,  216 
cuts  of,  216 

Porter,  709,  712.     See  also  Beer. 

Port  wine,  689 

Potash  determination.  304,  345 

Potassium  myronate,  453,  457 

Potatoes,  composition  of,  273 
proteins  of,  301 
starch  of,  282 

Poultry-,  composition  of,  216 

Pratt  citric  acid  method,  951 

Preparation  of  sample,  55 

Preservatives,  821 

commercial  food,  823 

in  butter,  538 

in  canned  goods,  912 

in  carbonated  beverages,  955 

in  fish,  ^57 

in  fruit  juices,  947 

in  jams  and  jellies,  942 

in  ketchup,  921 

in  meats,  220,  232 

in  milk,  177,  183 

in  preserves,  928 

of  eggs,  266,  268 

references  on,  846 

regulation  of,  822 

Preserves,  927 

Pressure  pump,  20 

Price  color  method,  814 

Primulin,  803 

orange,  810 

Process  butter,  540 

Prolamins,  42 

Prfxjf  spirit,  677 

Prr*sccution,  10 

Protamins,  43 

Protcans,  44  /   - 

Protein  grains,  90 

Proteins,  40 

coagulated,  44 
conjugated,  43 


Proteins,  derived,  44 

factor  for.  40 

of  barley,  277,  300 

of  beer,  725 

of  cereals,  296 

of  condensed  milk,  190 

of  eggs,  262 

of  milk,  125 

calculation  of,  153 
determination  of,  145 

of  peas,  300 

of  potatoes,  301 

of  rye,  277,  300 

of  wheat,  277,  298 

secondary  derivatives,  44 

simple,  41 

tests  for,  41 
Proteolytic  fermentation,  158,  202 
Proteoses,  44,  297 
Proto-albumose,  44,  45 
Proximate  analysis,  extent  of,  53 

expression  of  results  of, 

53 
Prussian  blue,  792,  812 

in  tea,  375 
Ptomaines,  218 

Publication  of  adulterated  foods,  10 
Pulfrich  rcfractomcter,  100 
Pycnometer,  57 
Pyroligneous  acid,  764 

in  meats,  219 
Pyronin,  803 
Pyrosin,  794 

Quassiin,  727 
Quercetin,  804 
Quercitannic  acid,  415 
Quercitron  bark,  790,  810 
Quevcnne's  lactometer,  132 
Quince  essence,  imitation,  896,  897 
Quinolin  yellow,  803 
Quotient  of  purity  of  sugar,  586 

Raffinose,  270,  577 

determination  of,  620 
Rancidity,  473,  530 
Rape  oil,  520 

test  for,  521 
seed,  520 
R aphides,  go 
Raspberry  (color),  790 

soda,  954 
Reagents,  35,  90 

references  on,  38 

table  of,  26-34 
Red  colors,  785,  78C,  790,  794,  806 


INDEX. 


995 


Red  ochre  in  sausages,  238 
Red  pepper,  see  Cayenne  and  Paprika. 
Red  wines,  684,  689 
Red  wood,  444 
References  on  beer,  756 
butter,  562 
canned  goods,  961 
cereals,  361 
cocoa,  406 
coffee,  406 
colors,  819 
dietetics,  49 
distilled  liquors,  758 
eggs,  270 

flavoring  extracts,  898 
flesh  foods,  258 
food  economy,  49 
inspection,  11 
fruit  products,  961 
fruits,  361 

general  analytical  methods,  79 
laboratory  equipment,  38 
leavening  materials,  364 
liquors,  756 
microscope,  98 
mi'W,  208 
oils,  561 

preservatives,  846 
reagents,  38 
refractometer,  122 
spices,  468 
sugars,  650 
sweeteners,  855 
tea,  406 

vegetable  products,  961 
vinegar,  780 
wine,  757 
Refractometer,  100 

Abbe,  100 

Amagat  and  Jean,  100 

butyro,  100,  loi 

heater  for,  102 

immersion,  iii 

in  oil  analysis,  477 

Pulfrich,  100 

sliding  scale  for,  107 

tables  for,  104,  105, 113,  116, 

120,  121 
Wollny,  100,  139 
Reichert-Meissl  method,  481 
Reichert  number  of  butter,  549 
Reinsch's  test  for  arsenic,  728 
Relishes,  920,  926 
Renard's  test  for  peanut  oil,  523 

for  rosin  oil,  527 
Renovated  butter,  540 


Renovated  butter,  distinction    from'  butter 
and  oleomargarine,  546 
Resins,  89 

Resorcin  brown,  816 
green,  81  ^ 
yellow,  816 
Respiration  calorimeter,  2 
Rhodamin,  803 
Rice,  c()m()osition  of,  272 

microscopical  structure  of,  310 
polished,  272 
starch,  282 
Riche  and  Bardy  methyl  alcohol  method  751 
Richmond's  cane  sugar  method,  185 

sliding  milk  scale,  153 
Ritsert's  tests  for  acetanilide,  869 
Ritthausen's  method  for  milk  proteins,  145 
Roese-Gottlieb  fat  method,  190,  199 
Roeser's  mustard  oil  method,  457 
Rohrig  tube,  199 
Root  beer,  954 
Ropy  milk,  130 
Roquefort  cheese,  202 
Rose,  attar  of,  895 
Bengal,  806 
extract,  895 

standards,  895 
rose  oil  in,  895 
Rosin  oil,  527 
Rota's  color  scheme,  799 
Rubner's  fuel  value  factors,  48 
Riihle-Brummer  saponin  method,  956 
Rum,  742 

composition  of,  742 
essence,  743 

methods  of  analysis,  745 
new,  743 
standards,  742 
Rye,  composition  of,  271 

microscopical  structure  of,  308 
proteins  of,  300 
starch,  281 

Saccharimeter,  578 

double  wedge,  581 
forms  of,  583 
normal  weights  for,  583 
scales  compared,  583 
single  wedge,  579 
Soleil-Ventzke,  578 
triple  field,  581 

Saccharimetry,  578 

Saccharin,  850 

detection  of,  851 
determination  of,  852 

Saccharine  products,  565 


996 


INDEX. 


Saccharoses,  565 
Saftlowcr,  701.  808 
SalTron,  7gi 
Safranin,  S02.  Sob 
Sago,  2S3 
Saleratus,  33  J 
Salicylic  acid,  831 

detection  of,  831 
determination  of,  $^2 
in  meat.  2^^,$ 
in  milk,  180 
Salmin.  43 
Salted  meats,  218 
Sample,  preparation,  55 
Sanatogen,  158 
Sanger  arsenic  method,  75 

Black-Gutzeit  method.  76 
Sanose,  158 

Saponification,  472,  484,  486 
Saponin,  955 

detection,  956 
tests  for.  957 
Sarcolemma,  21 1 
Sarsaparilla,  954 
Sausages,  223 

mh  of,  225 
color  of,  224 
composition  of,  223 
fat  in,  226 
glycogen  in,  234 
horseflesh  in,  234 
methtd;  of  analysis,  225 
starch  in,  223 
water  in,  225 
Sauterne  wine,  C85,  688 
Savor>'  extract,  standards,  892 

oil,  standards,  892 
Sawdust,  450 
Scarlet  OR,  816 
Schiedam  schnapps,  744 
Schcnk  beer,  708 

Schlegel's  method  for  colors  in  pastes,  350 
Schreiner's  colorimeter,  77 
Schultzc's  reagent,  93 
Sclerenchyma,  87 
Scovell  sampling  tube,  131 
Scaled  samples,  6,  1 59 
Semolina,  347 

Separator>'  funnel  support,  68 
Scricin,  42 
Sesame  oil,  518 

adulteration  of,  519 
tests  for,  519 
seeds,  518 
Shannon  formic  acid  method,  842 
Sherry  wine,  687 


Short's  method  for  fat  in  cheese,  205 

Shredded  wheat,  352 

Sic\'e  tubes,  8q 

Silent  sjiirit,  731 

Sinahaldi's  asai)r()l  method  846 

Sinalbin,  545 

mustard  oil,  454 
Sinigrin,  453 
Sinks,  17 
Sitosterol,  522 

Smith  and  Bartlctl  tin  method,  916 
Smoked  meats,  218 
"  Soaked  "  goods,  912 
Soap-bark,  055 
Soda,  cherry,  054 

determination  of,  304,  345 
lemon.  054 
orange,  954 
raspberry,  954 
strawberry,  954 
vanilla,  954 
water,  952 

syrups,  953 
Sodium  benzoate,  833 

bicarbonate,  332 
bisulphite,  839 
carbonate,  in  milk,  180,  182 
hydroxide,  tenth-normal  solution,  35 
salicylate,  831 
Soja  bean  meal,  357 
Solcil-Ventzkc  saccharimeter,  578 
Solid  yellow,  801 
Sorghum,  573 

Sostegni  and  Carpentieri's  test,  796 
Souring  of  milk,  129 
Sour  milk,  139 
Soxhlet,  extractor,  64 
Soxhlet's  milk  sugar  method,  150,  152 
Spaghetti,  347.     See  aleo  Pastes. 
Sparkling  wine,  685,  691 
Spearmint,  extract,  891 

standards,  891 
oil,  891 
Specific  gravity  bottle,  57 

of  beeswax,  643 
of  liquids,  55 
of  li(|Uors,  657 
of  milk,  131 
of  milk  serum.  166 

temperature    correc- 
tion for,  133 
of  oils,  474 
of  vinegar,  764 
rotary  power,  584 
Spent  tea  leaves,  375 
Spices,  408 


INDEX. 


997 


Spices,  adulterants  of,  413 

Standards  for  meat  extracts,  241 

alcohol  extract  of,  410 

milk,  160,  162 

ash  of,  40Q 

mince  meat,  927 

crude  fiber  of,  411 

molasses,  621 

ether  extract  of,  410 

mustard,  459 

lime  in,  410 

nutmeg,  464 

methods  of  analysis,  408 

extract,  892 

microscopical  examination  of,  41 2 

oil,  892 

nitrogen  in,  410 

olive  oil,  513 

references  on,  468 

pepper,  435 

starch  in,  411 

renovated  butter,  541 

volatile  oil  of,  411 

rum,  742 

Spiral  ducts,  89 

savory  extract,  892 

Spirits,  cologne,  731 

oil,  892 

distilled,  730 

staranise  extract,  893 

neutral,  731 

oil,  893 

silent,  731 

starch  sugar,  574 

standards,  730 

sugars,  566,  574,  772 

velvet,  731 

sweet  basil  extract,  893 

Spirit  vinegar,  760,  763 

oil,  893 

Spoon  test  for  butter,  549 

marjoram  extract,  893 

Sprengel  tube,  60 

oil,  893 

Stahlschmidt's  caffeine  method,  374 

thyme  extract,  893 

Standards  for  allspice,  424 

oil,  893 

anise  extract,  892 

vanilla  extract,  862 

oil,  982 

vinegar,  772 

beer,  711      , 

wine,  689 

brandy,  74o\ 

whiskey,  733 

butter,  535     \ 

Standard  solutions,  equivalents  of,  36 

cassia,  428         \ 

refractometric     readings 

extract,  892 

of,  120 

oil,  892 

Staranise  extract,  standards,  893 

cayenne,  443 

oil,  standards,  893 

celery  seed  extract,  892 

Starch,  47,  89,  279 

oil,  892 

arrowroot,  282 

cheese,  203 

barley,  281 

cinnamon,  428 

bean,  282 

extract,  892 

buckwheat,  281 

oil,  892 

classification  of,  280 

clove  extract,  892 

corn,  281 

oil,  892 

detection  of,  279,  943 

cloves,  418 

determination  of,  283 

cocoa,  402 

by  acid  conversion,  283 

cream,  195 

by  diastase  method,  283 

foods,  4 

in  baking  powder,  343 

fruit  butter,  927 

in  cereals,  283,  296 

ginger,  450 

in  jams  and  jellies,  943 

extract,  892 

in  milk,  185 

ice  cream,  198 

in  sausages,  2^2, 

ketchups,  919 

in  spices,  411 

lard,  556 

oat,  282 

lemon  extract,  870 

pea,  282 

oil,  871 

potato,  282 

mace,  460 

rice,  282 

maple  products,  572 

rye,  281 

meats,  218 

sago,  283 

998 


INDEX. 


Starch,  syrup,  575 
tapioca,  2S2 

under  polarized  light,  283 
wheat,  281 
Stearin,  beef,  541 

cottonseed,  517 
lard,  555 
Sterilized  butter,  540 
Still,  alcohol,  65Q 

fractionating,  67 
nitrogen,  73 
water,  22 
wine,  685 
Stilton  cheese,  202 
Stokes'  milk  centrifuge,  136 
Stone's  method  of  carbohydrate  separation, 

Storch's  method  for  boiled  milk,  155 

mucoid  protein,  127 
Stout.  7oq,  712.     See  also  Beer. 
Strawberry'  soda,  954 
Strippings,  128 
StuLzer's  gelatin  method,  231 
Suberin.  8q 

Sucrate  of  lime,  195,  197 
Sucrose,  see  Cane  sugar. 
Suction  pump,  19 
Sudan  i,  801 
Suet,  529 
Sugar,  561 

beet,  569 

brown,  composition  of  ash,  567 

cane,  566,  567 

classification  of,  565 

composition  of,  568 

grape,  see  Dextrose. 

in  fruits,  566 

in  jams,  938 

maple,  see  Maple  syrup. 

methods  of  analysis,  585 

muscovado,  567 

organic  non-sugars  in,  586 

quotient  of  purity,  586 

raw,  568,  569 

references  on,  650 

refining,  570 

standards,  566,  572,  574 

ultramarine  in,  570,  590 
Sulphur,  dete  mination  of,  305 
Sulphuric  acid  in  baking  chemicals,  346 

in  vinegar,  767 
Sulphuring,  839 

of.fruits,  945 
Sulphurous  acid,  839 

detection  of,  840 
determination  of,  840 


Sulphurous  acid,  in  meat,  220,  232 
Sunflowc"  oil,  526 

seeds,  527 
Sweet  b    ;il  extract,  standards,  893 

oil,  standards,  893 
Sweeteners,  artificial,  850 
Sweet  marjoram  extract,  standards,  893 

oil,  standards,  893 
Sweet  ^•■ine,  685,  690 
Syrup,    .lalysis  of,  613 

:    '   ng  of,  614 

n.aplc,  see  Maple  syrup. 

mixing.  57b 

starch,  576 

total  solids  in,  613 
Syrups,  fruit,  952 

soda  water,  953 
Sy's  lead  method,  630 

Table  sauces,  919.  920 

preservatives  in,  921 
Tallow,  529 
Tannin  in  cloves,  415 
in  tea,  370 
in  wine,  704 
Tapoica,  282 

Tartaric  acid  in  baking  powder,  339,  340 
in  fruit  products,  941,  949 
Tartrate  baking  powders,  332 
Tartrazin,  816 
Tea,  365 

adulteration  of,  374  % 

ash  of,  368,  369 

astringents  in,  377 

calTeine  in,  372,  373 

composition  of,  366,  367 

exhaustive  leaves  in,  375 

extract  of,  370 

facing  of,  374 

foreign  leaves  in,  376 

leaf,  characetristics  of,  376 

methods  of  analysis,  368 

microscopical  examination  of,  378 

references  on,  406 

spent  leaves  in,  375 

stems  in,  376 

tablets,  377 

tannin  in,  370 

theine  in,  372,  373 
Tcchnif|ue,  82 

Teller's   method   of   separating   wheat   pro- 
teins, 298 
Theine,  372 
Theobromine,  396,  400 
Thompson's  boric  acid  method,  829 
Thyme  extract,  standards,  893 


INDEX. 


999 


Thyme  oil,  standards,  8q3 
Tin,  action  of  fruits  and  vegetabicp  on,  904, 
905, 906 
determination  of,  914,  916       jg, 
salts  in  molasses,  625 
Tintometer,  Lovibond,  78 
Titer  test,  500 
Tocher's  sesame  oil  test.  519 
Tomato  ketchup,  see  Ketchup.         ,- 
Tonka  bean,  8O0  ■,£ 

tincture,  862 
Trillat  methyl  alcohol  test,  750 
Tropaeolin,  794,  808,  810 
Turmeric,  450,  790,  810 

as  an  adulterant,  452 
microscopical  structure  of,  451 
tests  for,  453,  791 

Ultramarine  blue,  793,  812 

in  sugar,  570,  590 
in  tea,  375 

Uno  beer,  714 

Unsaponifiable  matter,  501 

Vacuoles  in  yeast  cells,  330 
Vanilla  bean,  857,  858 

exhausted,  859 
extract,  857 

acetanilide  in,  868 
adulteration  of,  862 
alcohol  in,  869 
alkali  in,  860 
artificial,  863 
caramel  in,  869 
color  value  of,  870 
composition  of,  859 
coumarin  in,  863,  865 
glucose  in,  869 
glycerin  in,  869 
lead  number  of,  867 
methods  of  analysis,  864 
prune  juice  in,  863 
resins  in,  864 
standards,  862 
tannin  in,  865 
tonka  in,  863 
vanillin  in,  863,  865,  870 
soda,  954 
Vanillin,  859 

determination,  865 
microscopical  structure,  867 
Van  Slyke's  protein  formula,  153 

method  of  nitrogen   separation 
in  cheese.  205,  206 
in  milk,  146 
Vaporimeter,  675 


Veal,  composition  of,  214 

cuts  of,  214 
Vegetable  colors,  789 
\'cgetable  colors  in  sausages,  239 
Vegetables,  273 

ash  of,  302 
composition  of,  273 
methods    of    proximate    analy- 
sis of,  276 
references  on,  361 
Ventilation,  15 

Vermicelli,  347.     See  also   Pastes. 
Vessels,  89 
Vesuvine,  809 

Victoria  yellow,  352,  801,  808,  810 
Villi vecchia  and  Fabris'  sesame  oil  test,  520 
Vinegar,  759 

acidity  of,  765 

acids  of,  766 

adulterated.  778 

adulteration  of,  772 

alcohol  in,  766 

apple,  773 

arsenic  in,  780 

artificial,  774 

ash  of,  761,  764,  775 

solubility  and  alkalinity  of,  764 

beer,  762 

caramel  in,  779 

cider,  760,  773 

artificial,  774 

composition  of,  760 

copper  in,  780 

distilled,  763,  773 

extract  of,  764 

furfural  in,  779 

glucose,  763,  773 

glj'cerine  in,  770 

grain,  773 

Hortvet  number  of,  768 

hydrochloric  acid  in,  767 

lead  in,  779 

acetate,  test  for,  768,  779 
number  of,  768 

malic  acid  in,  767 

malt,  762,  773 

manufacture  of.  760 

metallic  im[)uritics  in,   779 

methods  of  analysis,  764 

mineral  acids  in,  766,  767 

molasses.  763 

nitrogen  in.  765 

pentosans  in,  770 

phosphoric  acid  in.  764 

polarization  of,  769,  776 

reducing  sugars  in.  770 


lOCO 


INDEX 


Vinegar,  references  on,  7S0 

residue  of,  774 

specific  gravity  of,  764 

spices  in,  779 

spirit,  773 

standards,  772 

sugar,  773 

sugars  in,  769,  776 

sulphuric  acid  in,  767 

tartrate  in,  769 

tests  on,  779 

varieties  of,  759 

volatile  acids  of,  766 

wine,  761,  773 

wood,  764,  779 

/.inc  in.  779 
Vinous  fermentation,  654 
Vioiamin,  803 
Viscogen,  196 
Viscosity  of  cream,  195 

of  oils,  477 
Vitellin,  43 

Waage's  Bombay  mace  test,  468 
Walnut  ketchup,  919 
Water-bath,  21 
Water  glass,  266 
Waterhouse  butter  test,  550 
Weiss  beer,  709 
Weld,  810 

Werner-Schmidt  method  for  fat  in  cheese, 

205 
in  milk,  139 

Westphal  balance,  56 

West's  benzoic  acid  method,  838 

Wheat,  271,  272 

ash  of,  302 

composition  of,  271,  272 
microscopic  structure  of,  306 
proteins  of,  277,  298 
shredded,  352 
starch,  281 
Whiskey,  731.     See  also  Distilled  lifjuors. 

adulteration  of,  738 

aging  of,  732 

American,  735 

Bourbon,  732,  734,  736,  737 

British.  735 

composition  of,  734 

imitation,  738 

Irish.  732,  734,  735 

manufacture  of,  731 

methods  of  analysis,  745 

rye,  732,  734,  737 

Scotch.  732,  734,  73S 


Whiskey,  standards,  733,  734 

Wijs's  iodine  absorption  method,  492 

Wild's  saccharimetcr.  583 

\\'iley's  bromine  pii)ettc.  495 

Wiley    and    Ewell's    double    dilution    sugar 

method,  149 
Wine,  6S4 

acidity  of,  696 

added  alcohol  in,  695 

adulteration  of,  691 

ameliorated,  691 

Burgundy,  artificial,  ,692 

California,  688 

cane  sugar  in.  693 

Cazeneuve's  co'or  method,  705 

chaptalizing,  693 

claret,  687 

artificial,  692 

classification  of,  685 

coloring  matter  in,  704,  705 

composition  of,  686 

corrected,  691 

cream  of  tartar  in,  702 

"dr>',"  690 

Dupre's  color  method,  705 

extract  in,  696,  697 

fortified,  685,  690 

fruit  other  than  grape,  695 

glycerin  in,  703 

hocks,  689 

Madeira,  685,  686 

Malaga,  artificial,  692 

malic  acid  in,  702 

manufacture  of,  684 

methods  of  analysis,  696 

modified,  691 

natural.  685 

non-volaliie  acids  in,  701 

plastering,  692 

polarization  of,  703 

port,  689 

potassium  sulphate  in,  704 

raisin,  691 

red,  684,  689 

reducing  sugar  in,  703 

references  on,  757 

sherry,  687 

artificial,  692 

sparkling,  685,  691 

standards,  689 

still,  68s 

sweet,  690 

tannin  in,  704 

tartaric  acid  in,  701 

varieties  of,  687 

vinegar,  761,  773 


INDEX. 


lOOI 


"Wine,  volatile  acids  in.  696 
watering  of,  694 
white,  684,  689 
yeast  of,  684 
Wintergreen  extract,  88g 

adulteration  of,  890 
wintergreen  oil  in,  890 
oil  of,  889 
Winton  lead  number,  628,  768 
moisture  aj)paratus,  62 
Wollny  milk  fat  rcfractometer,  100,  139 
tables  for  using,  141 
table  for  converting  Wnllny  de- 
grees into  «£),  143 
Woodman  and  Davis  benzaldehyde  r.:elhod, 
929 
and    Taylor's    caffetannic     acid 
method,  383 
Wood  vinegar,  764,  777 
Wool,  double  dyeing  method  with,  796 
dyeing  of,  795 
for  color  tests,  795 
vegetable  colors  on,  797 
Wormy  fruit,  945 


Xanthin,  46,  211 
Xantho-proteic  reaction,  41 
Xylan,  285,  288,  296 
Xylose,  285,  288,  296 

Yeast,  327 

adulteration  of,  331 

composition  of,  329 

compressed,  328 

dr>',  328 

in  cider,  678 

in  wine,  684 

microscopical  examination  of,  329 

starch  in,  331 

testing,  330 

vacuoles  in,  330 
Yeast  extracts,  246 
Yellow  colors,  785,  787,  790,  794,  808 

Zega's  test  for  oleomargine,  553 
Zein,  42,  300 
Zinc  salts,  909 

determination  of,  914 


PLATE  I. 


CEREALS. 


Fig.  121. — Barley,  Xiio. 

Transverse  section,   showing  in  order,   pericarp, 

seed  coats,  aleurone  layer,  and  starch  cells. 


Fig.  122. — Barley,  X>,5- 
Surface  \ie\v  of  epidermis  with  hairs. 


Fig.  123.- — Barley,  X12S. 
Surface  view  of  upper  chaff  layer. 


Fig.  124. — Barley  Starch,  X220. 


PLATE  II. 


CEREALS. 


■■';;*  V 


'■;>;;?• 


Fig    13:;. — Buckwheat,  X  1 10. 

Traiisxcrsc  stction  through  ])art  of  pericarp,  seed 

coat,  and  part  of  eiiflosperm. 


Fig.  126. — Buckwheat,  Xiio. 
Surface  view  of  scutellum. 


.ijL**., 


Fig.  127. — Buckwheat,  Xiio. 
Surface  section.     Aleurone  or  proteid  layer. 


^.. 


'.CCJ 


<^c^^^^^^-^o  %-2-o 


(5 


Fig.  1 28. — Buci 


Starch  granules  separated. 


.h,   X220.^ 


PLATE  III. 


CERFALS. 


"U 


Fig.  129. — Buckwheat  Starch,  Xiio. 
Starch  grains  in  masses. 


Fig.  130. — Com,  Xuo. 
Transverse   section   through   pericarp,  seed  coat, 
proteid  layer,  and  part  of  endosperm,  sho\\'ing 
starch  cells. 


Fig.  131. — Com,  Xno- 
Svirface  view  showing  two  layers  of  the  mesocarp. 


Fig.  132. — Corn,  Xiio. 
Surface  section.     Proteid  laver. 


CEREALS. 


PLATE  IV 


tic.  133. — Cornstarch,  X220. 


Fig.  h4. — Corn  Siarch,  X22C 
With  polarized  light. 


Fig.  135. — Oat,  Xiio. 
Transverse  section  through  chaffo 


Fig.  136. — Oat,  X  1 10. 
Surface  section.     Proteid  layer  with  fragments  of 
epidermis  and  hairs. 


PLATJ-:  V. 


Ci:  REALS. 


Fig.  137. — Oat,  Xuo. 
Surface  view  of  upper  chaff  layer. 


Fig.  138.— Oat,  XsS- 
Surface  view  of  epidermis  and  hairs. 


""^^^^N^^JJjtv. 


..rt'>*»vv>- 


FiG.  ijy. — Ual  Starch,  X220. 


buj.  140.— Kice,  Xiio 

Transverse  section  throue;h  seed  coat  and  part  of 

endosperm 


CKRKALS. 


I'LATi:  \'l. 


Fig.  141. — Rice,  Xno. 
Surface  section  throutrh  starch  cells. 


I'u;.  1  )2      I    -         110. 
Surface  view  of  upiier  chalT  laver 


iCO)      Act »t5*, :«-^'  ^-'^^^u^-    -,■ 


Fig.  143. — Rice  Starch,  X220. 


Flo.  144. — Ryi-,  X  lii 
Transverse  section  through  the  entire  prrain 


PLATE  VII. 


CEREALS. 


Fig.  145.— Rye,  Xiio.  ^       Fig.  146.— Rye,  X  no. 

Transverse  section   through  pericarp,   seed  coat,       Surface  view  of  epidermis  and  underlying  layers 
aleurone  layer,  and  starch  cells  of  endosperm. 


■if^^SKir 


^ 


7'^\ 


Fig.  147. — Rye,  X  no. 
Surface  view  of  epidermis  and  of  seed  ooat 


Fig.  14S. — Rye  Starch,  X220. 


PLATE  VIII. 


CEREALS, 


Fig.  149.— Wheat,  :;iio.  Fig.  150.— Wheat,  X  no. 

Transverse   section  through   pericarp,  seed  coat.       Surface  view  of  outer  and  inner  epidermis       Also 
proteid  layer,  and  starch  cells  of  endosperm.  showing  protcid  lavcr. 


/#   'h. 


'■'■m 


,.>^ 


Fig.  151. — Wheat,  Xno. 
Surface  view  of  epidermis,  with  hairs. 


Fig.  152. — Wheal  :MarLli,  .-.220. 


PLATE  IX. 


LEGUMES. 


jr^  ■  '  (  r  - 


i- 


Fig.  153. — Bean,  Xno. 
Transverse  section  through  starch  cells. 


Fio.  154. —  Bean  Starch,  X220 


\w- 


Fig.  i 
Transverse  section  through  hull,  showing  palisade 
cells  of  epidermis,  and  underlying  hypoderma. 


Fii.  ■;  no. 

Transverse  section  through  hull  and  part  of  endo- 
sperm, showing  some  of  the  starch  cells. 


PLATE  X. 


LEGUMES. 


Fig.  157 — Lentil,  Xiio. 
Surface  view  of  epidermis. 


Fig.  158.— Pea,  Xiio. 
Transverse  section   through  hull    and   seed  coal, 
showing    outer  palisade   cells    and  underhing 
hypoderma. 


Fig.  159. — Pea.  Xiio. 
Surface   section    through   base  of  palisade  layer. 


Fig.  160.— Pea,  Xiio. 
Powdered  pea  hulls. 


^ 


Fig.  i6i. — Pea,  Xiio. 
Surface  view  of  palisade  cells 


Fro.  162.— Pea,  Xuo. 
Transverse  section  through  starch  cells 


f:^ 


Fig.  1O3. — Pea,  X30. 
Transverse  section  through  starch  cells. 


Fig.  164. — Pea  Starch   X220. 


PLATK  XU. 


MISCET.LANEOUS  STARCH KS. 


r^^ 


Fig.  165. — Potato  Starch,  X220. 


Fig.  166. — I'olaU)  Starch,  X  220. 
With  polarized  light. 


/ 


'e 


w 


o. 


•<Hjg,. 


Fig.  167. — Arrowroot  Starch,  X220. 


Fig.  168. — Tapioca  Starch,  X220. 
(Cassava.) 


TURMERIC.     SAGO. 


PLATE  XIII. 


Fig.  169. — Turmeric,  X  70. 
Transverse  section  through  rhizome. 


Fig.  170. — Turmeric,  Xiio. 
Longitudinal  section.     Note  spiral  ducts  through 
the  center. 


Fig.  171. — Powdered  Turmeric,  Xiio. 

Showing  starch   grains,   fragments  of  cell  tissue, 

coloring  matter,  etc. 


f.-a 


'v^ 


> 


y 


Fig.  172. — Sago  Starch,  X220. 


PLATE  XV 


COFFEE.     CHICORY 


Fig.  177. — Adulterated  Coffee,  X  130. 
Dark  masses  of  roasted  pea   starch  are  shown, 
with    transparent    fragments    of    the     palisade 
cells  of  the  pea-hull. 


Fig.  17S. — .-Vdulterated  Colfee,  X130. 
The  vascular  ducts  of  chicory  show  most  con- 
spicuously in  this  field. 


i'lG.  179. — Chicory,  X25. 
Transverse  section  through  the  root. 


Fig.  180. — Chicory,  Xiio. 
Transverse  section. 


I'LATE  X\"I. 


CHTCORY.     COCOA. 


Fig.  i8i. — Chicon,',  Xiio.  Fig.  182. — Chicoty,  Xuo 

Tangential  section,  showing  reticulated  ducts  and       Radial   section,   showing  bark   parenchyma   and 


wood  parenchyma. 


milk  ducts. 


/f^-.*n^«r-'"'  ^ 


-tti 


«.w 


I 


,v4» 


af 


Fig.  183. — Chicon,-,  Xiio.  Fio.  1S4. — Cocoa,  Xno. 

Roasted    and    ground,    showing    fragments    of        Transverse    section    through    peripherj'   of   seed, 

ducts  and  other  tissues.  seed  coats,  and  cotyledon. 


ILATI-:  X\I1. 


COCOA 


Fig.  185. — Powdered  Cocoa,  Xiio. 


Flc.  186. — Aduluraud  Cocoa,   Xiro 

Showing  admixture  of  arrowroot  with  the  cocoa 

powder. 


Fig    187. — Cocoa  Slicll,  Xiio. 
Transverse  section  through  epidermis,  pulp,  and 
mucilaginous  layers  of  the  pericarp  and  seed 
coat. 


Fig.  ]88. — Cocoa  Shell,  Xiic. 
Longitudinal  section  through  shell 


PLATE  XVIII. 


TKA.     SPICKS. 


Fig.  189.— Tea,  X55. 
Transverse  section  through  midrib  of  leaf.     Note 
the  palisade  layer  below  the  upper  epidermis, 
the  inner  wood  vessels  above  the  center,  and 
the  parench3'ma  of  the  pulp. 


Fig.  190. — ^Tea,  Xiio, 
Surface  view  of  lower  epidermis,  %vith  stomata  and 
one  of  the  hairs. 


Fig.  191. — .Allspice,  X9. 
Transverse  section  through  the  entire  berry,  show- 
ing the  two  cells,  with  kidney  shaped  seed  in 
each. 


Fig.  192. — Allspice.  X  70. 

Transverse  section  through  pericarp,  showing  oil 

spaces  and  stone  cells. 


PLATE  XIX. 


SPICES. 


P'iG.  193. — Allspice  Seed    Xiio. 

Transverse  section  through  seed  shell  and  part  of 

embryo,  showing  starch  cells. 


Fig.  194. — Allspice  Seed,  Xno. 
Transverse  section  through  the  resinous  portion  of 
the  seed  coat,  showing  port  wine  colored  lumps 
of  gum  or  resin. 


^^> 


# 


Fig.  195. — Powdered  Allspice,  Xiio. 
Showing  stone  cells,  resinous  lumps,  and  starch. 


Fig.  196. — Adulterated  Allspice,  Xiio. 
Showing  a  large   fragment  of  the  seed   skin  of 
cayenne  at  the  left. 


SPICES. 


PLATE  XX. 


Fig.  197. — Cassia  Bark,  X45 
Trans%'erse  section  through  the  bark. 


Fig.  :9.s. — (  assia  Hark,  X45. 
Longitudinal  section. 


Fig.  lyy. — Cassia  liark,  Xiio.  Fig.  200. — Cassia  Bark,  Xiio. 

Transverse  section,  showing  cork  cells,  parenchy-       Longitudinal   section,    showing   bunches   of   bast 
ma,  and  stone  cells.  tihers  at  the  left,  starch  cells  in  the  center,  and 

stone  cells  at  the  right. 


PLATE  XXL 


SPICES. 


Fig.  20I. — Ceylon  Ciniumioii  liark,  Xiio.  Fio    202.— Ceylon  Cinnamon  Bark,  Xiio. 

Transverse  section,  showing  many  bast  fibers  and       Longitudinal  section,  showing  bast  fibers,  stone 
starch  cells.  celli,  and  parenchyma. 


V 


Fig.  203. — Powdered  Cassia,  Xno. 
Showing  stone  cells,  starch,   and  corky  tissue. 


Fig.  2C4. — Powdered  Cassia,  Xrio. 
Showing  bast  fibers  and  starch. 


I'LATE  XXII. 


SPICES. 


\ 


Fig.  205. — Powdered  Cassia,  X   no. 
Showing  large  bast  fiber  and  starch  grains. 


Yic.  206. — AduUerated  Cassia,  Xiio. 
A  mass  of  foreign  bark. 


Fir..  207. — Cayenne,  Xno. 
Transverse  section  through  pericarp. 


Fig.  20S. — Cayenne,  Xno. 
Transverse  section  through  seed  coat  and  part  of 
endosperm.     Collapsed  parenchyma  cells  sepa- 
rate endosperm  from  long  epidermal  cells. 


SPTCES. 


I'LATJ':  XX HI. 


Fig.  209. — Cayenne,  Xiio. 
Surface  view  of  fruit  epidermis. 


^ 


\ 


Fig.  210. — Cayenne,  Xno. 
Surface  view  of  two  lavers  of  seed  coat. 


Fig   211. — Powdered  Cayenne,  Xiio. 
A  large  mass  of  fruit  epidermis. 


Fig.  212. — Powdered  Cayenne,   Xiio. 
Showing  chiefly  two  of  the  seed  coat  lavers. 


PLATE  X.\  IV. 


SPICES 


1^ 


■1 


t'^^ 


■^■^  ^ 


.v<» 


Fig.  213. — Adulterated  Cayenne,  X130. 

Corn  and  wheat  starch  and  cocoanut  shells  appear 

chiefly.     A  bit  of  cayenne  is  shown  at  the  right. 


Fig.  214. — Adulterated  Cayenne,  X214. 

The  central  mass  is  ground  red  wood,  surrounded 

by  corn  starch  grains. 


4 

Fig.  215.  65. 

Transverse  section   from    the  center  outward  to 

epidermis,  showing  parenchyma. 


Fig.  216. — Clove,  Xiio. 
Transverse  section  near  epidermis,  showing  large 
oil  cavities. 


PLATE  XXV. 


SPICES. 


Pig.  217.— Clove,  X2S. 
Longitudinal  section  through  entire  clove. 


Fig.  218 — Clove,  X70. 
Centra!  longitudinal  section,  showing  duct  bundles. 


Flu    219. — Clove,  Xiio. 
Surface  view  of  epidermis. 


Fig.  220. — Powdered  Cloves,  X130. 
Dense,  spongy  tissue,  with  small  oil  drops. 


PLATE  XX\  I. 


SPICES. 


Fig.  221. — Clove  Stem,  X7C. 
Transverse   section   through  outer  part  of   stem, 
showing  bast  fibers  at  the  left,  parenchyma  in 
the  center,  and  stone  cells  near  the  epidermis. 


Fig.  222. — Clove  Stem,  X25. 
Central  longitudinal  section  through  entire  stem, 
showing  bast  fibers  in  the  center,  and  stone  cells 
at  the  right. 


Fig.  223. — Clove  Stem,  X70. 
Longitudinal  section,  showing  the  stone  cells. 


Fig.  224. — Powdered  Clove  Stems,  Xiio. 

Showing  fragments  of  tissues,  stone  cells,  and  bast 

fibers. 


PLATE  XX\  II. 


SPICES. 


Fig.  225. — Powdered  Clove  Stems,  Xiio. 
Showing  bundle  of  bast  fibers. 


Fig.  226.— Adiilicratcd  Doves,  X  i  ^o. 
Showing  chiefly  stone  cells  of  cocoanut  shells. 


W 


Fig.  227.^A(lulterale(l  C"lo\-cs,  X130. 
ith    large    admixture    of    cocoanut    shells. 


Fig.  228.— Cringcr,  X  no. 

Transverse   section,   showing   starch  cells    with 

contents. 


'i&w--4^'' 


SPICES. 


PLATE  XXVlll. 


i 


Fig.  229. — 'iingt-r,  ,\iio.  Fk;.  J30.     Uitiger,  ,-,110. 

Transverse  section,  showing   parenchyma,  starch       Longitudinal   section,   showing  spiral   ducts   and 
grains,  and  duct  vessels.  pigment  cells. 


^%^-- 


fy' 


-t. 


■Ix^. 


-o^'xvi 


Fic;.  231. — Ginger  M.n\h,  >,  220. 


Fig.  232. — .\duileralfd  Ginger,  X  130. 
.\  mass  of  wheat  bran  tissue  is  most  conspicuous. 


SPICES. 


FLATK  XXIX. 


*o 


o    ^^ 


Fig.  233. — AdullcratL<l  (.iiif^cr,  X130. 


•o 

.  0 


^«r>« 


■0> 


Fig.  234. — .\dultcralcd  Ginger,  X130. 


The  central  dark  mass  is  a  yellow  fragment  of       Containing  a  large  admixture  of  corn  and  wheat 
turmeric.  starches 


Fig.  j;^.-   1       i    4  M  ilc,  Xiio.  Fig.  236. — Bombay  or  Wild  Mace,  Xiio 

Transverse  section  through  epidermis  and  oil  cells,  Transverse  section  through  outer  lovers,  showing 
showing    also    parenchyma    with    contents    of  yellow  and  red  resinous  lumps 

amylodextrin. 


PLATE  XXX. 


SPICES. 


Fig.  237. — Nutmeg,  Xiio. 
Transverse  section  through  the  exterior  and  in- 
terior teguments  of  the  seed   and   part   of   the 
endosperm,  showing  starch  cells. 


Fig.  238. — Nutmeg,  X25. 
Transverse  section  near  exterior  of  seed. 


Fig   239. — Nutmeg,  Xiio. 

Surface  view  of  seed  coat,  showing  also  portions  o[ 

underlying  tissues. 


Fig.  240. — Powdered  Nutmeg,  Xiio. 


PLATE  XXXI. 


SPICES. 


\ 


/ 


Fig.  241. — White  Mustard,  Xiio 
Transverse  section  through  mucilaginous  epider- 
mis,  sub-epidermal  parenchyma  layer  (sciuare 
cells"),  palisade  cells,  and   broken  parenchyma 
laver  of  the  hull. 


242. — White  Mustard,  Xiio. 
Transverse    section    through    the    tissue    of    the 
radicle. 


Fig.  243. — White  Mustard    Xiio 
Surface  view  of  two  layers  of  the  hull  or  seed  coat- 


Fig.  244. — White  Mustard.  Xiic. 
Surface  section  through  palisade  cells  and  under- 
lying layer  of  the  seed  coat. 


PLATE  XXXII. 


SPICES. 


Flu.  24s.      I.lni  k  a1  ...oMid,  Xiio. 
Transverse  section,  showing  fragments  of  the  epi- 
dermis and  dark  colored  paUsade  cells  of  the 
seed  coat. 


Fl(..  .'4(;. — likick  -Mu.'^iarn,  ,■'.  no. 
Surface  view  of  two  of  the  seed  coat  lavers. 


'% 


Fig.  247. — Ground  Mustard,  X130. 
Ground  without  removal  of  the  oil. 


Fig.  24S. — Groutnl  .Mu>iard  Hulls,  Xiio. 


PLAir.  XXXIII. 


SPICES. 


'-%.' 


>?  : 


Fig.  249. — Dakota  Mustard  Flour,  Xiio. 

Dark  spots  show  starch    grains  of    foreign  weed 

seed,  stained  with  iodine. 


Fig.  250. — .Vduiiiratrd  Mustard  Flour,  X  130. 
Showing  masses  of  wheat  starch. 


F'iG.  25i.^Pepper,  Xno. 
Transverse  section  through  inner  part  of  pericarp 
(including  parenchyma  and  seed  coat  layers)  and 
portion  of  pc-risperm,   showing  starch   and   oil 
cells. 


Fig.  252. — Pepper,  Xiio. 
Surface  view  of  hypodermal  layer. 


SPICES. 


PLATK  XXX IV 


Fig.  253. — Pepper,  Xiio. 
Triins\erse  section  through  outer  part  of  pericarp, 
showing  epidermis,  underlying  stone  cell  layers, 
parenchyma,  and  seed  coat. 


Fig.  254. — Pepper,  :<iio. 
Surface  section  through  stone  cell  layer. 


i  9 


t 

l^t 


1 


Fig.  255. — Pepper  Starch,  X220. 
Starch  granules  separated. 


Fig.  256. — Pepper  Starch,  Xiio. 
Starch  grains  in  masses. 


SPICKS. 


J'LATF.  XXXV 


Fig.  257. — Grouiul  I'epper  Sht-lls,  Xno. 
Mainly  showing  stone  cells. 


i 


X 


Fig.  258. — Adulterated  Pepper,  X 130. 
Showing  wheat  and  buckwheat  starches. 


.j*^ 


•t>. 


•    v 
'•'•- 


00 


m 


Fig.  259. — Adulterated  Pepper,  X  130. 
Showing  wheat,  corn,  and  rice  starches. 


Fig.  260. — Adulterated  Pepper,  X  130. 
The  large,  lower  mass  shows  buckwheat  starch, 
while  the  finer-grained  mass  near  the  top  is  of 
pepper. 


PLATE  XXX\'I. 


SPICES.     SPICE  ADUI/IFR AXTS. 


Fig.  261. — Adulterated  I'qjpcr,  Xiio.  Fig.  262. — Adulterated  Pepper,  X130. 

The  central  mass  shows  the  sclerenchyma  cells  of       Cayenne  and  wheat  starch  are  the  adulterants, 
olive  stones. 


<*-''^ 


I  -J 


'K 


\;  V, 


V* 


i 


j^ 


Fig.  263. — Powdcren  ^  *iivc  Moncs,   X  no.  FiG.  264. — Powdered  Cocoanul  Shells,   Xiro 


SPICK  ADri^TKRAXTS. 


I'l.A'U-:  XX.WII. 


Fig.  265. — Powdered  Kim  Bark,   Xiio. 


.■^ 


\ 


k 


Fig.  2C6. — Pine  Sawdust,  Xiio. 
Finely  ground. 


•  ••« 


-  «i»  «'• 


Fig.  267. — I'ine  Wood,   Xiio. 
Transverse  section. 


Fig.  26S. — Pine  Wood,   y  no 
Radial  and  tangential  sections. 


PLATE  XXXVIII. 


EDIBLE  FATS. 


Fig.  269. — Pure  Butter,  X25. 
With  polarized  light  and  selenite  plate. 


Fig.  270. — Process  or  Renovated  Butter,  X2,. 
Witl^  t)(il.iii/c(l  liofht  and  selenite  plate 


Fig.  37T. — Oloomarorarine,  ^25. 
\\ith  polarized  light  and  seleniie  plate. 


I'l.ATi:  XXXIX. 


F.DTTU.F.  FATS. 


Fic;.  272. — Lard  Stearin,  Xiio. 
I.caf  lard,  crystallized  from  ether. 


Fig.  273. — l.ani  Mcariii,  ;■.  220. 
Leaf  lard,  crystallized  from  ether. 


^ 


!»■ 


Fig.  274. — Lard  Stearin,  X220. 
"Back"  lard,  crvstallizcd  from  ether. 


Fig.  275. — Lard  .Stearin,  X4S0. 
"Back"  lard,  cr>-stallizcd  from  ether. 


PLATJ-:  XL. 


EDIBLE  FATS. 


Fig.  276.— Beef  Stearin,  X35. 
Crystallized  from  ether. 


^' 


Fig.  277. — Beef  .Stearin,  X  no. 
Crvstallized  from  ether. 


Fig.  27S. — Bet-l  Mearin,  ;;220. 
Crystallized  from  ether. 


Tliis  book  is  DUE  on  the  last  date  stamped  below 


APR  7      1958 


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TX 

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AA    000  492165 


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